A process for the recovery and production of meso-lactide from a crude lactide containing stream may include subjecting a starting crude lactide stream to a first distillation step to obtain: a top stream mainly containing meso-lactide; a bottom stream; and a side stream mainly containing L-lactide and meso-lactide. The process may include recovering the side stream and subjecting the side stream to a melt crystallization step to obtain: a first purified stream mainly containing L-lactide; and a drain stream mainly containing meso-lactide and L-lactide. The process may include recovering the top stream and drain stream, and subjecting the top stream and drain stream to a second distillation step to obtain a second purified stream containing L-lactide and meso-lactide.

As concern for the environment grow, biodegradable polymers are becoming of increasing commercial interest as a substitute for conventional and less degradable synthetic polymers such as polyolefins and polyurethanes. The use of biodegradable polymers in areas of packaging and textiles is therefore steadily growing. Consequently, much research is directed to the synthesis of these biodegradable materials. Among the various biodegradable polymers, polylactide (PLA) is one of the most commonly used and studied.
PLA is an aliphatic polyester based on lactic acid, the latter being obtained by fermentation of sugars and/or starch. PLA is therefore derived from renewable vegetables and is biodegradable by composting.
PLA is prepared from lactide by ring-opening polymerization. Lactide, which is a dimeric cyclic ester of lactic acid is in turn formed by dehydrating aqueous lactic acid to form a mixture of oligomers, which mixture is then depolymerized to form lactide. In order to prepare PLA of a high quality, it is very important to use lactide of a high purity. The lactide needs therefore to be purified to a high extent before ring-opening polymerization may take place to prepare PLA of a high quality.
A variety of lactide purification processes are known, that usually comprise one or more integrated distillation, condensation and melt crystallization steps, like in U.S. Pat. Nos. 5,521,278, 5,357,034, 5,214,159.
However, none of them suggest improving the production of meso-lactide while producing L-lactide in high yield from the crude lactide stream to be purified.
It is also well known that with the increasing demand in PLA polymers, it appears that a range of PLA polymers with various concentrations in enantiomers L- and D- is more and more interesting; but there is a need for easy means to obtain such type of polymers, and mainly to avoid the implementation of a second polymerization unit for D-Lactide or meso-lactide.
Presently, for the usual applications involving L-Lactide, it is requested to have such L-Lactide with a high optical purity; a usual process to get such a purity often needs a step to separate meso-lactide. One has to do with controlling the proportion of D-enantiomers in the lactide stream that is taken for the polymerization step.
It is also important to control the ratio of L- and D-enantiomers in the lactide stream. It is known that removing meso-lactide from the lactide stream has the effect of reducing the proportion of D-enantiomers, which leads to the production of a more crystalline grade of polylactide. In new applications it is more and more interesting to obtain copolymers having a low content of D-enantiomers, so broadening the range of grades of PLA which are needed to cover the different applications where PLA may be used; those grades of PLA may contain various amounts of D-enantiomers ranging from about 1% by weight to more than 10% by weight, depending of the final use desired.
In usual process to prepare PLA, mostly on the basis of the L-lactide enantiomer, these processes comprise a purification step of the crude lactide to selectively separate the L-lactide enantiomer from the crude lactide stream.
Concerning the meso-lactide, it is also separated from the crude lactide stream, but the separated stream will also comprise certain impurities such as water, lactic acid as well as dimers and trimers of lactic acid.
With the usual methods of separation, like distillation and/or melt crystallization, there occurs a concentration of the impurities in the meso-lactide stream. Although it is of common practice to blend impurities containing meso-lactide stream with the pure L-lactide stream in proportion not higher than about 15% by weight, this leads to production of less crystalline polylactide, and this is the reason why much or all the meso-lactide recovered in such processes, is simply discarded, and therefore, this drastically reduces the overall yield in lactide. Solutions have already been envisioned in the art, but they are not satisfactory.
It is therefore an object of the present invention to provide a process to recover a purified meso-lactide either alone or in the presence of L-lactide, from a crude lactide stream, said purified meso-lactide having a limited amount of acid impurities, the content of which is expressed in the form of mEq/kg and is not exceeding 50 mEq/kg, preferably less than 30 mEq/kg and most preferably less than 15 mEq/kg, in order to blend such meso-lactide with purified L-lactide stream to prepare suitable PLA polymers useful for the different applications where the presence of D-enantiomers are needed.
Another object of the invention is to provide such a process where the polymer obtained with the recovered meso-lactide does not present the drawbacks of the prior art.
It is a further object of the present invention to provide a process enabling to use recovered meso-lactide for blending with L-lactide.
It is still a further object of the present invention to increase the overall yield in lactides (polymerizable lactides/crude lactides fed) up to high values equal to or higher than 90% and most preferably higher than 95%. By lactides, it is meant the L-lactide, the D-lactide and the meso-lactide.
Finally it is an object of the present invention to provide an apparatus to operate the process of the invention.
At least one of the objects is fullfilled by the present invention.
Applicants have now found that meso-lactide from which certain impurities have been substantially removed like water, lactic acid, lactic acid oligomers, catalysts derivatives, light and heavy colour impurities as for instance sugars, nutrients, proteins and amino acids, is a source of D-enantiomers to prepare suitable PLA grades containing L- and D-enantiomers.
The process of the invention for the recovery and production of meso-lactide from a crude lactide containing stream comprises the steps of:                a. Subjecting a starting crude lactide stream (A) to a first distillation step to obtain:                    a top stream (B) mainly containing meso-lactide,            a bottom stream (C) and            a side stream (D) mainly containing L-lactide and meso-lactide;                        b. Recovering the side stream (D) and subjecting said stream to a melt crystallization step to obtain:                    a first purified stream (E) mainly containing L-lactide and            a drain stream (F) mainly containing meso-lactide and L-lactide;                        c. Recovering top stream (B) and drain stream (F);        d. Subjecting top stream (B) and drain stream (F) to a second distillation step to obtain a second purified stream (G) containing L-lactide and meso-lactide.

Process for recovering and improving production of meso-lactide from a crude lactide containing stream


An ink refilling adapter to be used for refilling a used ink cartridge with ink from a separate ink container. The ink refilling adapter includes a main plate having a conduit and an ink absorbing sheet attached to the under surface of the adapter, and it further includes an overflow indicator which is a through hole opened in the main plate. Any overflowing ink is absorbed by the ink absorbing sheet and such ink is observed through the overflow indicator, thus giving a sign of the beginning of the overflow of the ink and allowing the ink refilling operation to be stopped immediately.

1. Field of the Invention
The present invention relates to an ink refilling assembly or ink refilling adapter for refilling ink into an ink cartridge installed in ink jet printers.
2. Prior Art
A variety of ink cartridges have been developed for printers which use liquid ink for printing, such as ink jet printers. Some ink cartridges are disposed once ink contained in the cartridges has been depleted, and other ink cartridges may be refilled with ink when ink contained in the cartridges has been depleted.
Typically, a refillable ink cartridge has an inlet which is closed by a plug. A syringe with a needle-like injector may be used to transport ink from a separate ink container into the refillable ink cartridge through the inlet after the plug has been removed. A separate ink container may include an injection nozzle which is attached to the container so that ink can be directly supplied from the container to the refillable ink cartridge.
These prior art ink refilling injectors suffer from some problems. For instance, if the cartridge is transparent, the amount of the ink refilled therein can be observed and, therefore, the ink refilling can be stopped when the cartridge is filled with a proper amount of ink. However, such observation is impossible with a non-transparent ink cartridge. In addition, even though the cartridge is transparent, if the cartridge includes inside thereof an ink absorption material such as cotton or sponge, it is not easy to know the amount of ink refilled. Furthermore, depending upon the condition of the ink absorption material after the ink inside the cartridge has been completely depleted, the amount of ink to be absorbed by the ink absorption material varies. As a result, ink occasionally overflows out of the cartridge and sometimes the ink is not refilled completely.

Mitsubishi Pencil Corporation of America


The anchoring device, for anchoring at least two reinforcements for prestressing a civil engineering works structure, has a block through which there pass at least two pairs of anchoring orifices arranged symmetrically on each side of a mid-plane of the block. The two orifices of each pair have axes substantially parallel to the mid-plane and are directed toward two opposite sides of the block to take, respectively, two ends of a taut reinforcement surrounding the structure. The block has a bearing zone pressed against the structure in response to the tension in the reinforcements.

The present invention relates to anchoring devices for anchoring the ends of reinforcements intended to stress a civil engineering works structure (reservoir, silo, pipe, etc)
It is commonplace for a civil engineering works structure to be reinforced by hoop reinforcements which may in particular consist of prestressing strands. These reinforcements are kept taut in a configuration in which they surround the structure. Their tensioning therefore generates compressive stresses in the structure, and these can improve its behavior under load, particularly in the case of concrete structures.
A known anchoring device consists of a block intended to press at its base on a civil engineering works structure and provided with orifices in which the ends of a reinforcement surrounding the structure are immobilized, for example using wedge-effect jaws arranged in opposition.
The orifices of such a block have to lie approximately in the continuation of the path of the reinforcement along the structure. If they do not, the taut reinforcement has a zone of steep curvature at the mouth of the orifice where it carries the risk of being weakened. This arrangement also prevents undesirable moments from being exerted on the block as the reinforcement is tensioned.
However, the two orifices of the block which are intended to receive the opposite ends of the reinforcement cannot be coincident. For space reasons, the orifices and the immobilizing means (jaws or the like) have to be mutually offset.
In order to meet these two requirements, the orifices of the block are given curved shapes: on the two opposite sides of the block, the (entry) directions of the two orifices are aligned in such a way as to lie in the plane of the turn described by the reinforcement around the structure; then the orifices curve away from this plane on each side in order to leave enough space for the tensioning and immobilizing means to be installed.
One disadvantage of the anchoring blocks of this last type is that the curvature of the orifices impedes the insertion of the reinforcements. These have a certain stiffness which opposes their entry into curved orifices. In practice, recourse has to be had to ram-powered tools in order to introduce the reinforcements into the anchoring block, and this considerably complicates the fitting of the prestressing system. In addition, such anchoring cannot be used when it is desirable for the reinforcement to describe more than one turn between its two anchored ends.
It is a particular object of the present invention to alleviate these disadvantages by proposing an anchoring device which adequately meets the above requirements and is easier to mount on the civil engineering works structure.

Device for anchoring prestressing reinforcements


A hybrid distortion compensation method and apparatus that greatly improves the capability to compensate for non-linear distortion due to a high frequency power amplifier over a wideband in strict conditions of smaller size and reduced power consumption. An adaptive pre-distortion section (14) and a feed forward distortion compensation circuit (30) are connected via a D/A converter (20), an A/D converter (28) and the like, and signals of parts of the feed forward distortion compensation circuit (30) are taken out using a switch circuit (SW), fed back to a digital signal processing system, and processed using highly accurate digital signal processing in a control-monitoring section (60). After an adjustment section (51) makes characteristics of two input signals of the feed forward distortion compensation circuit (30) coincide, feed forward distortion compensation is performed. A sequencer (80) controls the components sequentially.

In mobile communications of a CDMA scheme and digital terrestrial television broadcast scheduled to be implemented in the immediate future in Japan, a so-called multicarrier communication scheme is used wherein information is transmitted using a plurality of carriers distributed over a wideband.
Providing the same number of high frequency power amplifiers as the number of carriers in multicarrier transmission would be a great burden in terms of the size and cost of the apparatus.
Therefore, a multicarrier signal needs to be collectively amplified by one high frequency power amplifier.
When a high frequency signal of a wide band is amplified by one high frequency power amplifier, various distortions due to the non-linearity of the high frequency power amplifier (non-linear distortions: for example, a mutual modulation distortion) easily appear.
Methods for reducing non-linear distortions are mainly classified into a pre-distortion scheme and a feed forward scheme.
The pre-distortion scheme is a scheme in which a pseudo-distortion for canceling out distortion expected to occur in a power amplifier is preliminarily given to a signal to be input into the power amplifier.
The feed forward scheme is a scheme that extracts a distortion component contained in the output signal of a power amplifier, inverts the phase of the distortion component, and feeds back the inverted signal to the output signal of the power amplifier to cancel out the distortion component.
In recent years, a scheme has been proposed that combines these typical distortion compensation techniques. An analog distortion compensation circuit having an adaptive pre-distortion circuit and a feed forward power amplifier combined is disclosed in U.S. Pat. No. 5,760,646.
As can be seen from the circuit diagram of FIG. 1 of the above publication, the distortion compensation circuit disclosed in this U.S. Pat. No. 5,760,646 is configured such that a distortion component signal (an error signal fed back to a main path after inverted in phase) that appears in the feed forward loop of a typical feed forward power amplifier is also input into a pre-distortion function generator (a circuit generating a control signal for a pre-distortion characteristic) to control an analog pre-distortion circuit to perform adaptive pre-distortion processing.
The distortion compensation circuit disclosed in the above U.S. Pat. No. 5,760,646 detects distortion contained in the output signal of the power amplifier when being a high frequency analog signal (a RF analog signal), and performs RF pre-distortion processing (pre-distortion processing on the high frequency analog signal) based on the distortion component signal.
However, there is a limit to accuracy in detecting the distortion component signal (RF error signal) from the high frequency analog signal (limit due to processing of detecting the analog signal).
Also there is a limit to accuracy in pre-distortion processing using an analog circuit due to analog signal processing.
Therefore, the capability of this distortion compensation circuit to compensate for non-linear distortions is not so high.
Meanwhile, with respect to multicarrier transmission in mobile communications of the CDMA scheme and digital terrestrial television broadcast scheduled to be implemented in the immediate future in Japan, it is required to satisfy unprecedented strict standards in order to maintain high communication quality.
That is, it is required to compensate for distortion of the transmit signal having an extremely wide band with high accuracy and stably adapting to the environment.
The prior art technology cannot meet such strict requirements.
Moreover, in the mobile communications field, much smaller transceivers with reduced power consumption and cost to an extreme extent are required. This makes it further difficult to realize a great improvement of the capability to reduce non-linear distortions of a wideband.

Hybrid distortion compensation method and hybrid distortion compensation device

Matsushita Electric Industrial Co., Ltd.


A flat folding writing instrument includes a generally planar elongated support, the support including a lengthwise direction, and at least two spaced apart living hinges extending in a generally lengthwise direction of the support, so as to divide the support into at least three lengthwise extending sections. A further hinge extends in a generally widthwise direction of the support so as to divide the support into two widthwise extending sections. The support also has two opposite lengthwise edges and a bottom edge. A writing member is secured to one of the lengthwise extending sections in one of the widthwise extending sections, and has a writing point thereof extending below the bottom edge of the support. A locking assembly is provided for securing the two lengthwise extending edges together when the support is folded along the hinges. The support can be folded along the lengthwise extending hinges such that the two opposite lengthwise edges are adjacent to each other and locked in position relative to each other by the locking assembly, so that the writing instrument can be used for writing. A pen cover is provided on the other widthwise extending section for engaging or covering the writing point of the writing member when the support is folded along the further widthwise extending hinge.

The present invention relates generally to writing instruments, and more particularly, is directed to a writing instrument that can be folded and stored in a substantially flat configuration.
Conventionally, writing instruments, such as pens, pencils and the like, are formed in an elongated cylindrical configuration. However, in many instances, it is not convenient to carry such writing instrument, because of the configuration thereof.
It would therefore be desirable to have a pen that can be carried flat in a wallet or the like and then converted into the general configuration of a conventional writing instrument.


An anti-leakage apparatus for a toilet tank, consisting of a device for detecting leakage, a device for restraining water from entering the toilet tank in response to the leakage detecting device and a device for mounting the anti-leakage apparatus on the toilet tank.

1. Field of Invention
The present invention relates to an anti-leakage apparatus for toilet tanks.
2. Related Prior Art
Toilet tanks are automatically refilled with water after water is released therefrom. Each toilet tank has an input valve and an output valve. The level of water contained in the toilet is initially retained at a highest point. At this instant, the input and output valves are both shut. Once the output valve is opened for releasing water out of the toilet tank for flushing, the input valve is automatically opened for refilling the toilet tank with water. Although water is filled into and released out of the toilet tank synchronously, water decreases in the toilet tank as the rate of flow passing through the input valve is much slower than the rate of flow passing through the output valve. That is, the level of water contained in the toilet tank gets lower. The output valve is shut again when the level of water contained in the toilet tank reaches a lowest position. At this instant, the input valve is still open for refilling the toilet tank with water so that the level of water contained in the toilet tank gets higher. The input valve is shut when the level of water contained in the toilet reaches the highest point again. Normally, those functions should take place automatically, except for opening the output valve. That is, the toilet tank is no longer manually monitored after the output valve is opened. However, the input valve will always be opened for inducing water into the toilet tank when the output valve cannot be properly shut again. Such a leakage might cause a serious waste of water. Therefore, the present invention is intended to solve the above-mentioned problem by providing an anti-leakage apparatus.

Anti-leakage apparatus for containers for liquid


Methods and apparatus for processing of GNSS signals are presented. These include GNSS processing with predicted precise clocks, GNSS processing with mixed-quality data, GNSS processing with time-sequence maintenance, GNSS processing with reduction of position jumps in low-latency solutions, GNSS processing with position blending to bridge reference station changes, and GNSS processing with delta-phase correction for incorrect starting position.

Single-receiver rover position difference estimates are normally generated at say 5, 10 or 20 Hz. Typically the rover position difference estimates form a smooth trajectory Small jumps sometimes occur with changes in satellites geometry, i.e. new satellites entering the solution, or satellites being lost. As implied by the name, rover position difference estimates only provide relative changes in user location over time. The absolute position of the user is required at an epoch to be able to anchor the rover position differences. Synchronous position estimates derived from a position+ambiguity processor are normally used in conjunction with delta phase processing to produce low-latency position estimates.
Measurement errors lead to variations in the synchronous position estimates, which in turn leads to discontinuities in the reported position trajectory.
FIG. 12 illustrates a 10 Hz rover position difference trajectory 1005, from time 1.0 to 4.0 s. Just the height component is shown. Synchronous position solutions are generated at 1 Hz and are illustrated as solid black circles 1010, 1020, 1030 & 1040. The rover position difference trajectory 1005 is first adjusted to the synchronous position 1010, at 1.0 s. When the next synchronous position is available for 2.0 s, 1020, the rover position difference trajectory is shifted by 1045, to 1060. Trajectory 1060 is again shifted based on the synchronous position 1030, at 3.0 s, to form 1070. This adjustment process is repeated at 4.0 s, and so on.
A step in the rover position difference trajectory occurs for each synchronous position adjustment. Note that the magnitude of the stepping effect has been exaggerated for the purposes of this example.
FIG. 13 illustrates a 4 s rover position difference trajectory (1105). Synchronous positions are obtained at times 1,2,3 & 4 s, denoted 1110, 1120, 1130 & 1140 respectively. Comparisons can be made between the rover position difference estimates at 1 Hz epochs (1115, 1125 & 1135) with the corresponding synchronous position estimates (1120, 1130 & 1140), thus leading to the differences 1145, 1150 and 1155, respectively. Rather than introducing abrupt steps in the reported position trajectory, it is possible to blend the rover position difference trajectory with the synchronous positions.
The blending process involves the following steps:                1. Obtain a synchronous position for a given anchor epoch (time),        2. Obtain an older synchronous position and propagate it using rover position difference(s) to the anchor epoch—thus producing a propagated position for the anchor epoch,        3. A weighting factor is generated for the anchor epoch synchronous position and a weighting factor is generated for the older synchronous position, propagated to the anchor epoch.        4. A blended anchor position is generated from the anchor epoch synchronous position and the older synchronous position propagated to the anchor epoch.        5. Optionally, multiple synchronous positions, propagated to the anchor epoch can be used in the blending process. The number of synchronous positions considered in the blending process is a design parameter.
Blending Factor Adjustment
A buffer of the last n synchronous position fixes is maintained, as well as a buffer of the last n corresponding rover position difference estimates. Table 8 provides an example of the position buffering and blending process for the example given in FIG. 13. The synchronous positions are shown in column 2 as: U(1.0), U(2.0), U(3.0) & U(4.0). Delta phase processing yields rover position differences: U(1.0,2.0), U(2.0,3.0), U(3.0,4.0) as shown in column 3 Multiple estimates of the position at the anchor epochs can be obtained using the previous synchronous solutions and the buffered delta positions as shown in column 4. Blending factors η(a,b) are used to weight the synchronous solution and propagated synchronous positions at the anchor epoch.
The selection of the weighting factors [η(a,b)] determines the characteristics of the blended solution. Normally the most recent synchronous position is given the most weight, while the oldest position the least weight. A linear, exponential or other suitable, weighting scheme can be used.
The example in Table 8 shows that the last 4 seconds of propagated synchronous solutions are used in the blended anchor position. The number of solutions considered in the blending process is limited in order to minimize the computation load and buffer storage requirements. Furthermore, in practice, only 2-10 s are needed to effectively blend the solutions.
Linear Blending
The following formula can be used to compute linear blending factors:
                                          n            linear                                          (                          a              ,              b                        )                          =                  {                                                                                χ                    -                                          [                                              b                        -                        a                                            ]                                                        χ                                                                                for                                                                                [                                          b                      -                      a                                        ]                                    ≤                  χ                                                                                0                                            else                                                                        (        33        )            where:
a time of first synchronous epoch considered in blending;
b time of latest synchronous epoch considered in blending;
χ maximum time span to consider in blending;
ηlinear (a,b)) Linear blending factor for time span a to b.
Table 9 presents an example of linear blending factors where the maximum blending time-span χ=4 seconds.
TABLE 8Blending factor adjustment for Low-latency solution generation forepoch 3.0 s, based on synchronous solution at 2.0 s and 5 Hz rover position differences.SynchronousSynchronousRover PositionPropagatedBlendedEpochPositionDifferenceSynchronous PositionsAnchor Position1.0U(1.0)—U(1.0)U(1.0) *η(1, 1)2.0U(2.0)δU(1.0, 2.0)U(1.0) +[U(1.0) +δU(1.0, 2.0)δU(1.0, 2.0)] *η(1, 2) +U(2.0) *η(2, 2)3.0U(3.0)δU(2.0, 3.0)U(1.0) +[U(1.0) +δU(1.0, 2.0) +δU(1.0, 2.0) +δU(2.0, 3.0);δU(2.0, 3.0)] * η(1, 3) +U(2.0) +[U(2.0) +δU(2.0, 3.0)δU(2.0, 3.0)] * η(2, 3) +U(3.0) *η(3, 3)4.0U(4.0)δU(3.0, 4.0)U(1.0) +[U(1.0) +δU(1.0, 2.0) +δU(1.0, 2.0) +δU(2.0, 3.0) +δU(2.0, 3.0) +δU(3.0, 4.0);δU(3.0, 4.0)] * η(1, 4) +U(2.0) +[U(2.0) +δU(2.0, 3.0) +δU(2.0, 3.0) +δU(3.0, 4.0);δU(3.0, 4.0)] * η(2, 4) +U(3.0) +[U(3.0) +δU(3.0, 4.0);δU(3.0, 4.0)] * η(3, 4) +U(4.0) *η(4, 4)5.0U(5.0)δU(4.0, 5.0)U(1.0) +[U(1.0) +δU(1.0, 2.0) +δU(1.0, 2.0) +δU(2.0, 3.0) +δU(2.0, 3.0) +δU(3.0, 4.0) +δU(3.0, 4.0) +δU(4.0, 5.0);δU(4.0, 5.0)] * η(1, 5) +U(2.0) +[U(2.0) +δU(2.0, 3.0) +δU(2.0, 3.0) +δU(3.0, 4.0) +δU(3.0, 4.0) +δU(4.0, 5.0);δU(4.0, 5.0)] * η(2, 5) +U(3.0) +[U(3.0) +δU(3.0, 4.0) +δU(3.0, 4.0) +δU(4.0, 5.0);δU(4.0, 5.0)] * η(3, 5) +U(4.0) +[U(4.0) +δU(4.0, 5.0);δU(4.0, 5.0)] * η(4, 5) +U(5.0) *η(5, 5)
TABLE 9Linear blending factors for example in Table 6,based on a maximum blending time-span χ = 4 s.        Epoch      Factor Indices (a, b)      Raw Blending Factors η(a, b)Normalized Blending Factors         η                                (              a        ,        b            )                  Σ      a            η                                (              a        ,        b            )      1.01, 11.01.02.01, 20.750.42862, 21.00.57143.01, 30.50.22222, 30.750.33333, 31.00.44444.01, 40.250.10002, 40.50.20003, 40.750.30004, 41.00.40005.01, 50.00.02, 50.250.10003, 50.50.20004, 50.750.30005, 51.00.4000
Precision-Based Blending
Changes in satellite geometry result in changes to the synchronous position fix quality. Hence, the precision of each synchronous position fix will generally be different. Furthermore, the longer a synchronous position is propagated with rover position differences, the greater the uncertainty in the resultant solution. The relative precisions of each propagated position fix can be used to compute the blending factors. A precision-based blending scheme endeavors to account for the relative differences in precisions of the rover position difference propagated and synchronous solutions.
The raw precision-based blending factors are given by:ηprec(a,b)x=1/σ2(a,b)x ηprec(a,b)y=1/σ2(a,b)y nprec(a,b)z=1/σ2(a,b)z  (34)where:                σ2(a,b)x Variance of the x-coordinate for the position fix spanning time a to b.                    For example if a=b, then this is the variance of the synchronous fix. When a<b, the variance corresponds to synchronous fix at time a, that has been propagated using rover position differences, to time b.                        σ2(a,b)y Variance of the y-coordinate for the position fix spanning time a to b;        σ2(a,b)z Variance of the z-coordinate for the position fix spanning time a to b.        ηprec(a,b)x Precision-based blending factor for the x-coordinate, for the position fix spanning time a to b. With analogous definitions for the y and z coordinates.
Note that the raw blending factors need to be normalized (so that they sum to 1.0).
An illustration of the precision-based blending scheme is presented in Table 10. Just the x-coordinate is included in the example. However the approach used for the y- and z-coordinate is analogous to that used for the x-coordinate.
TABLE 10Precision-based blending factors for example in Table 6.The x-coordinate blending factors are computed basedon the precisions of the x-coordinate shown in column 3.        Epoch    Factor Indices a, b  Precision of Solution (x-coordinate) σ2(a, b)x  Raw Blending Factors ηprec(a, b)xNormalized Blending Factors               η      prec                                            (                  a          ,          b                )            x                  Σ      a                  η      prec                                            (                  a          ,          b                )            x      1.01, 10.02540.001.02.01, 20.03132.260.43632, 20.02441.670.56363.01, 30.03727.030.27352, 30.03033.330.33733, 30.02638.460.38924.01, 40.04323.260.18762, 40.03627.780.22413, 40.03231.250.25214, 40.02441.670.33615.01, 50.04920.410.13672, 50.04223.810.15953, 50.03826.310.17624, 50.03033.330.22325, 50.02245.450.30446.01, 60.05518.180.10162, 60.04820.830.11643, 60.04223.810.13314, 60.03627.780.15525, 60.02835.710.19966, 60.01952.630.2941
Bridging Reference Station Changes
Background
In a prior invention described in GNSS Position Coasting, US Patent Publication 2010/0214162 A1 {A2555}, single-difference delta phase processing is used to propagate fixed quality synchronous position results forward in time in order to bridge segments of float quality synchronous position results. The GNSS Position Coasting scheme helps to extend the amount of time that fixed quality solutions are available for high precision operation.
The use of rigorous satellite clock and orbit information for improved delta positioning is described in Vollath, Position Determination with reference data outage, U.S. Pat. No. 7,576,690. The satellite clock and orbit errors are significant component of the single-reference delta phase measurements. Once satellite clock/orbit errors are removed, the precision of the single-receiver rover position difference estimates are greatly improved.
Single-receiver delta phase processing with rigorous satellite and clock information, is termed here Precise (single-receiver) Delta Phase. When the rigorous satellite clock information is predicted in time, this is termed Predicted Precise Delta Phase.
The following events can cause interruptions to high-precision position results at the rover:                1. Switch from fixed quality to float quality synchronous position results;        2. Cycle slips occur on reference station satellite data which results in insufficient single-difference satellite tracking to perform a synchronous solution;        3. The physical reference station changes in a network data stream, which normally causes a reset in the synchronous position processor and an interruption to the position report, followed by a period of float-quality positioning.
New Approach
A new unified approach has been developed which addresses specifically issue 3 above, as well as more generally handing degraded positioning caused by issues 1, 2 & 3. In the new approach, the following methods of solution propagation are used to produce the best position result (where the best result is deemed as the one with the highest precision (smallest uncertainty)):                1. Single-difference delta phase (which yields single-difference rover position difference);        2. Precise (single-receiver) delta phase (which yields precise rover position difference);        3. Predicted precise (single-receiver) delta phase (which yields predicted-precise rover position difference);        4. Single-receiver delta phase (which yields rover position difference (broadcast orbits and clocks).
FIG. 14 provides an illustration of the relative uncertainties of various solutions types over time assuming all solution types use the same satellite geometry. The axis 1205 corresponds to fixed-quality synchronous solutions, with each position 1230, identified with solid black dots. The uncertainty of the positions is represented by error bars 1235.
The float-quality synchronous positions on axis 1210, have larger uncertainty than the fixed-quality synchronous solutions, as evidenced by the longer error bars 1245. Each float-quality synchronous position, 1240, shows larger variations about the zero axis, 1210.
The error growth of single-difference rover position differences is represented by the region between the dashed lines (1255) on axis 1215. Each single-difference rover position estimate 1250, is shown by a grey circle surrounded by a black ring.
The precise single-receiver rover position difference positions are presented on axis 1220. Each position fix is marked by a black ring (1260). The error growth of the precise rover position difference estimates is shown as the region 1265, assuming that the propagation time starts at first epoch and accumulates thereafter.
The predicted-precise single-receiver rover position differences are presented on axis 1222. Each position fix is marked by a dark grey circle surrounded by a black ring (1262). The error growth of the predicted-precise rover position difference estimates is shown as the region 1267.
The single-receiver rover position differences (broadcast orbits and clocks) is shown on axis 1225, with each position fix marked by a grey ring. The error growth of the single-receiver rover position differences is defined by the region 1275.
Assuming a common satellite geometry, the time-wise error growth of single-difference rover position difference is lower than that of the precise (single-receiver) rover position difference; which is lower than the predicted-precise rover position difference; which is lower than the single-receiver rover position difference (broadcast orbits and clocks). Single-difference processing requires reference and rover receivers to be tracking common satellites. In many circumstances, the number of single-difference satellites may be less than the number of rover (single-) receiver satellites. In which case, the single-difference rover position difference error growth may be worse than that of single-receiver rover position differences.
FIG. 15 presents timeline views of positions (height component only) derived from prior art and new techniques. The upper axis 1305, refers to prior-art positioning methods, while the lower axis, 1310, to new techniques. The position trace for axis 1305 is denoted 1315; for axis 1310, the position trace is denoted 1320.
Considering the prior-art method (axis 1305), during times 1-2, the solution has fixed quality. Between epochs 2 & 3, there is a switch in the physical reference station (or loss of satellite tracking at the reference), this event, denoted 1325, causes the synchronous processor to reset. This results in a period of float quality synchronous positioning up until epoch 6. During the float period, the accuracy of the reported position is only decimeter-level. At epoch 6, the synchronous fixed quality is reestablished (segment 1350) and retained until reference station corrections are lost just after epoch 7. The float quality solutions are propagated using single-receiver delta positions through segment 1355.
In the new approach, precise single-receiver rover position difference processing is used at epoch 3 (denoted 1370) to propagate the fixed quality synchronous solution from epoch 2 to epoch 3. Single-difference rover position difference processing is then used at epochs 4-6, to produce high-quality position estimates until regular synchronous fixed quality solutions are regained at epoch 6. Precise single-receiver rover position difference processing is again used between epochs 7-9, while the reference receiver data is unavailable. Note that the use of precise-single receiver rover position difference processing and single-difference rover position differences enables fixed quality solutions to be provided (segment 1360). The rigorous clock/orbit corrections are lost at event 1335, around epoch 9, after which only single-receiver (broadcast orbits and clocks) rover position difference processing is used to deliver solutions with float quality (segment 1365).
The combination of precise single-receiver rover position difference and single-difference rover position difference processing gives the new method a clear advantage in delivering fixed quality positions, versus prior art techniques.
FIG. 16 presents a flowchart that explains the handling of data at the rover. When new data arrives at 1505, it is tested at 1510 to see if it is rover data. If so, rover data handling occurs at 1525. Predicted Precise orbit and clock information when available (see test 1512) is handled at 1527. Test 1515 checks for the presence of Precise Orbit and Clock information. When present, the Precise Orbits and Clocks are handled at 1530. The input data is tested at 1520 to see if it is from the reference and can be single-differenced. If so, the single-difference data is handled at 1535.
FIG. 17 shows an expanded view of flowchart 1500. When rover data is received, it is used to form a rover position difference solution between the current and previous epoch (1605). The rover position difference estimate is then buffered at step 1610, and optionally used to generate a low-latency position estimate at 1612.
When available, the rigorous predicted satellite clock/orbit models are updated at 1613. The rigorous predicted clock/orbit information is optionally used at 1614 to update the rover position difference for the current data epoch. At 1615, the rigorous predicted orbit information is used to update the time sequence of rover position difference estimates. The best rover position difference time sequence is generated at 1616 based on the predicted precise rover position difference time sequence and existing broadcast rover position difference time sequence. The best rover position difference from 1616 is used to replace the predicted rover position difference time sequence at 1617.
The rigorous satellite clock/orbit models are updated at 1620, as soon as rigorous orbit and clock information is received for one or more satellites. The rigorous clock models enable the rover position difference time sequence derived from broadcast clocks to be optionally refined (1625) and stored. The rigorous orbit and clock information is used to form a precise rover position difference estimate for the current and previous epochs at 1630. At step 1635, the best rover position difference time sequence is produced based on the existing precise position sequence Finally at 1640, the predicted rover position difference time sequence is replaced by the rover position difference time sequence with the smallest error.
When synchronous reference data are received, they are used to compute single-difference delta phase measurements and rover position difference estimates at 1645. The rover position difference time sequence with the smallest uncertainty is generated at step 1650, and used to replace the existing rover position difference time sequence at 1655. A synchronous position result is produced at 1660, using the latest single-difference GNSS measurements. The best (smallest uncertainty) synchronous position solution is derived from the latest synchronous position result, and the single-difference rover position difference time sequence in step 1665. If for example the synchronous position result is float quality, then often the single-difference rover position difference time sequence that was propagated from the last fixed quality solution will be the best (smallest uncertainty). At 1670, all of the single-difference rover position differences up to the reference data time tag are replaced with the new synchronous position solution Finally at step 1675, an optional report of the synchronous position is provided which will be latent with respect to the current time.
Following is a summary of some of the inventive concepts described herein:
[Part A: Predicted Precise] [TNL A-2796]                1. A positioning method, comprising:                    a. obtaining GNSS data derived from signals received at a rover antenna,            b. obtaining at least one of correction data and rigorous satellite data,            c. maintaining a time sequence of at least one rover position and at least one rover position difference with associated time tags,            d. using the time sequence to determine at least one derived rover position,            e. reporting the derived rover position, and            f. maintaining a set of GNSS satellite clock error models, comprising                            i. upon arrival of rover data associated with a new time tag, extending the time sequence, and                ii. upon arrival of rigorous satellite data, updating at least one clock error model.                                                2. The method of 1, wherein maintaining a set of GNSS satellite clock error models further comprises, upon arrival of rigorous satellite orbit and clock data, updating the time sequence.        3. The method of 1 or 2, further comprising using the updated at least one clock error model to update at least one rover position of the time sequence.        4. The method of one of 1-3, wherein the set of satellite clock error models comprises up to one clock error model per satellite.        5. The method of one of 1-4, wherein the correction data comprises at least one of: single-base-station observations [RTK], virtual reference station observations derived from reference stations of a regional network [VRS], synthetic base station observations derived from reference stations of a global network [SBS], synthetic reference station observations derived from reference stations of a global network with regional augmentation [SRS], and state space representations [RTCM SSR].        6. The method of one of 1-5, wherein rigorous satellite data comprises precise orbit and precise clock data per satellite.        7. Apparatus for performing a method according to one of 1-6.        8. A computer program comprising instructions for causing an apparatus to perform a method according to one of 1-6.        9. A computer program product comprising a tangible computer-readable medium embodying instructions for causing an apparatus to perform a method according to one of 1-6.
[Part B: Mixed Delta—Mixing Quality in One Epoch] [TNL A-2798]                1. A positioning method, comprising                    a. obtaining GNSS data derived from signals received at a rover antenna,            b. obtaining at least one of correction data and rigorous satellite data,            c. maintaining a time sequence of at least one rover position and at least one rover position difference with associated time tags, by estimating at least one position difference using rigorous satellite data from multiple satellites using at least two selected combinations of                            i. for at least one satellite, no correction data and broadcast satellite data,                ii. for at least one satellite, no correction data and rigorous predicted satellite data,                iii. for at least one satellite, no correction data rigorous satellite data for said at least one satellite,                iv. for at least one satellite, correction data and broadcast satellite data,                v. for at least one satellite, rigorous predicted satellite data and correction data,                vi. for at least one satellite, rigorous satellite data and correction data,                                    d. using the time sequence to determine at least one derived rover position, and            e. reporting the derived rover position.                        2. The method of 1, wherein estimating at least one position difference using rigorous satellite data from multiple satellites using at least two selected combinations comprises applying a filter having two clock states per satellite.        3. The method of one of 1-2, wherein the correction data comprises at least one of: single-base-station observations [RTK], virtual reference station observations derived from reference stations of a regional network [VRS], synthetic base station observations derived from reference stations of a global network [SBS], synthetic reference station observations derived from reference stations of a global network with regional augmentation [SRS], and state space representations [RTCM SSR].        4. The method of one of 1-3, wherein rigorous satellite data comprises rigorous orbit data per satellite and rigorous clock data per satellite.        5. Apparatus for performing a method according to one of 1-4.        6. A computer program comprising instructions for causing an apparatus to perform a method according to one of 1-4.        7. A computer program product comprising a tangible computer-readable medium embodying instructions for causing an apparatus to perform a method according to one of 1-4.
[Part C: Improve/Cleanup the Buffer] [TNL A-3126]                1. A positioning method, comprising                    a. obtaining GNSS data derived from signals received at a rover antenna,            b. obtaining at least one of correction data and rigorous satellite data,            c. maintaining a time sequence of at least one rover position and at least one rover position difference with associated time tags by,                            i. upon arrival of correction data, extending the time sequence with a computed synchronized position, and                ii. upon arrival of one of correction data and rigorous satellite data, modifying at least a portion of the time sequence,                                    d. using the time sequence to determine at least one derived rover position, and            e. reporting the derived rover position.
2. The method of 1, wherein the computed synchronized position comprises one of: a real-time kinematic [RTK] position, a position determined using a weighted average of integer ambiguity candidates, a position determined using a differential positioning technique [DGPS], a position determined with the aid of an inertial navigation system, and a technique using GNSS data to determine an absolute position.                3. [Mixing and Replacing] The method of one of 1-2, wherein modifying at least a portion of the time sequence comprises replacing at least one position difference by at least one improved position difference [lower variance].        4. The method of 3, wherein replacing at least one position difference by at least one improved position difference comprises replacing at least one position difference determined using broadcast satellite data with at least one position difference determined using rigorous predicted satellite data.        5. The method of one of 3-4, wherein replacing at least one position difference by at least one improved position difference comprises blending at least one position difference determined using broadcast satellite data with at least one position difference determined using rigorous predicted satellite data.        6. The method of one of 3-5, wherein replacing at least one position difference by at least one improved position difference comprises replacing at least one position difference determined using rigorous predicted satellite data with at least one position difference determined using rigorous satellite data.        7. The method of one of 3-6, wherein replacing at least one position difference by at least one improved position difference comprises blending at least one position difference determined using rigorous predicted satellite data with at least one position difference determined using rigorous satellite data.        8. The method of one of 3-7, wherein replacing at least one position difference by at least one improved position difference comprises replacing at least one position difference determined using rigorous satellite data with at least one position difference determined using corrected single-differenced data.        9. The method of one of 3-8, wherein replacing at least one position difference by at least one improved position difference comprises blending at least one position difference determined using rigorous satellite data with at least one position difference determined using corrected single-differenced data.        10. The method of one of 3-9, wherein replacing at least one position difference by at least one improved position difference comprises replacing at least one position difference determined using corrected single-differenced data with at least one position difference determined using corrections synchronous with rover data.        11. The method of one of 3-10, wherein replacing at least one position difference by at least one improved position difference comprises blending at least one position difference determined using corrected single-differenced data with at least one position difference determined using corrections synchronous with rover data.        12. The method of one of 1-11, wherein maintaining a time sequence further comprises, upon arrival of rigorous satellite data, replacing at least one position difference by at least one improved position difference.        13. [Replacing] The method of one of 1-12, wherein modifying at least a portion of the time sequence comprises replacing a portion of the time sequence with an improved portion of the time sequence.        14. The method of 13, wherein the improved portion of the time sequence has an estimated precision which is better than an estimated precision of a portion of the time sequence which it replaces.        15. The method of one of 13-14, wherein the improved portion of the time sequence has a number of entries which is fewer than a number of entries of a portion of the time sequence which it replaces.        16. The method of one of 13-15, wherein the improved portion of the time sequence is determined by, starting from a position determined using corrections synchronous with rover data as an anchor position at a time tag, deriving a new anchor position for the time tag from the anchor position and at least one other previously estimated position at the time tag.        17. [selecting] The method of 16, wherein deriving a new anchor position for the time tag comprises selecting between the anchor position and the at least one other previously estimated position at the time tag based on comparison of an estimated precision of the anchor position with an estimated precision of the at least one other previously estimated position at the time tag.        18. The method of 17, wherein at least one estimated precision is determined from a covariance matrix.        19. The method of one of 17-18, wherein the new anchor position for the time tag is selected based on smallest estimated three-dimensional precision.        20. The method of one of 17-18, wherein the new anchor position for the time tag is selected based on smallest estimated horizontal precision.        21. The method of one of 17-18, wherein the new anchor position for the time tag is selected based on smallest vertical precision.        22. [blending] The method of 16, wherein deriving a new anchor position for the time tag comprises blending the anchor position with the at least one other previously estimated position at the time tag.        23. The method of 22, wherein blending comprises forming a weighted mean of the anchor position and at least one other previously estimated position at the time tag.        24. Apparatus for performing a method according to one of 1-23.        25. A computer program comprising instructions for causing an apparatus to perform a method according to one of 1-23.        26. A computer program product comprising a tangible computer-readable medium embodying instructions for causing an apparatus to perform a method according to one of 1-23.
[Part D: Jump Reduction] [TNL A-2638]                1. A positioning method, comprising                    a. obtaining for each epoch of a set of at least one epoch a respective synchronous position to be propagated to an anchor epoch,            b. for each epoch of the set, combining the respective synchronous position with at least one rover position difference defining a change of rover position from the epoch of the respective synchronous position to the anchor epoch, to obtain a respective propagated position for the anchor epoch,            c. obtaining a synchronous position for the anchor epoch,            d. blending at least one propagated position for the anchor epoch with the synchronous position for the anchor epoch to obtain a blended anchor position for the anchor epoch,            e. determining a propagated rover position for a current epoch by combining the blended anchor position with at least one rover position difference defining a change of rover position from the anchor epoch to the current epoch.                        2. The method of 1, wherein the blending comprises blending a selected number of propagated positions for the anchor epoch with the synchronous position for the anchor epoch.        3. The method of one of 1-2, wherein the blending is based on at least one weighting factor.        4. The method of one of 1-3, wherein at least one weighting factor is based on age of a synchronous position used to obtain a propagated position which is blended to obtain the blended anchor position for the anchor epoch.        5. The method of 4, wherein at least one weighting factor declines linearly with age of a synchronous position used to obtain a propagated position which is blended to obtain the blended anchor position for the anchor epoch.        6. The method of 4, wherein at least one weighting factor declines exponentially with age of a synchronous position used to obtain a propagated position which is blended to obtain the blended anchor position for the anchor epoch.        7. The method of one of 1-3, wherein at least one weighting factor is based on an estimated precision of a propagated position which is blended to obtain the blended anchor position for the anchor epoch.        8. The method of 8, wherein at least one weighting factor is based on an estimated precision of the synchronous position for the anchor epoch.        9. The method of one of 1-3, wherein the blending is proportional to respective estimated precisions of the at least one propagated position for the anchor epoch and of the synchronous position for the anchor epoch.        10. Apparatus for performing a method according to one of 1-9.        11. A computer program comprising instructions for causing an apparatus to perform a method according to one of 1-9.        12. A computer program product comprising a tangible computer-readable medium embodying instructions for causing an apparatus to perform a method according to one of 1-9.
[Part E: Selecting/Blending] [TNL A-2797]                1. A positioning method, comprising                    a. obtaining GNSS data derived from signals received at a rover antenna,            b. obtaining correction data,            c. maintaining a time sequence of at least one rover position and at least one rover position difference with associated time tags,            d. using the time sequence to determine at least one derived rover position by, starting from a position determined using corrections synchronous with rover data as an anchor position at a time tag, deriving a new anchor position for the time tag of the anchor position and at least one other estimated rover position at the time tag of the anchor position, and            e. at least one of                            i. reporting the new anchor position at the time tag as the rover position at a time associated with the time tag of the anchor position, and                ii. combining the new anchor position at the time tag of the anchor position with at least one rover position difference to determine a new derived rover position for a subsequent time tag, and reporting the new derived rover position as the rover position at a time associated with the subsequent time tag.                                                2. [selecting] The method of 1, wherein deriving a new anchor position for the time tag comprises selecting between the anchor position and the at least one other previously estimated position at the time tag based on comparison of an estimated precision of the anchor position with an estimated precision of the at least one other previously estimated position at the time tag.        3. The method of 2, wherein at least one estimated precision is determined from a covariance matrix.        4. The method of one of 1-3, wherein the new anchor position for the time tag is selected based on smallest estimated three-dimensional precision.        5. The method of one of 1-3, wherein the new anchor position for the time tag is selected based on smallest estimated horizontal precision.        6. The method of one of 1-3, wherein the new anchor position for the time tag is selected based on smallest vertical precision.        7. [blending] The method of 1, wherein deriving a new anchor position for the time tag comprises blending the anchor position with the at least one other previously estimated position at the time tag.        8. The method of 7, wherein blending comprises forming a weighted mean of the anchor position and at least one other previously estimated position at the time tag.        9. Apparatus for performing a method according to one of 1-8.        10. A computer program comprising instructions for causing an apparatus to perform a method according to one of 1-8.        11. A computer program product comprising a tangible computer-readable medium embodying instructions for causing an apparatus to perform a method according to one of 1-8.
[Part F: Correcting Delta-Phase for Incorrect Starting Position] [TNL A-2705]                1. A positioning method, comprising                    a. obtaining an approximate rover anchor position for a first epoch,            b. using the approximate rover anchor position to determine a rover position difference for at least one succeeding epoch,            c. obtaining an improved rover anchor position for the first epoch,            d. deriving an adjusted rover position difference for each said succeeding epoch, and            e. deriving a rover position for a current epoch from the improved rover anchor position for the first epoch and at least one adjusted rover position difference.                        2. The method of 1, wherein the approximate rover anchor position contains an initial error, wherein the rover position difference for each said succeeding epoch contains a respective partial error based on the initial error, and wherein deriving an adjusted rover position difference for each said succeeding epoch comprises correcting each rover position difference for the respective partial error.        3. Apparatus for performing a method according to one of 1-2.        4. A computer program comprising instructions for causing an apparatus to perform a method according to one of 1-2.        5. A computer program product comprising a tangible computer-readable medium embodying instructions for causing an apparatus to perform a method according to one of 1-2.
The foregoing description of embodiments is not intended as limiting the scope of but rather to provide examples of the invention as defined by the claims. Those of ordinary skill in the art will realize that the detailed description of embodiments of the present invention is illustrative only and is not intended to be in any way limiting. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of this disclosure.
In the interest of clarity, not all of the routine features of the implementations described herein are shown and described. It will be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as compliance with application- and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure.
In accordance with embodiments of the present invention, the components, process steps and/or data structures may be implemented using various types of operating systems (OS), computer platforms, firmware, computer programs, computer languages and/or general-purpose machines. Portions of the methods can be run as a programmed process running on processing circuitry. The processing circuitry can take the form of numerous combinations of processors and operating systems, or a stand-alone device. The processes can be implemented as instructions executed by such hardware, by hardware alone, or by any combination thereof. The software may be stored on a program storage device readable by a machine. Computational elements, such as filters and banks of filters, can be readily implemented using an object-oriented programming language such that each required filter is instantiated as needed.
Those of skill in the art will recognize that devices of a less general-purpose nature, such as hardwired devices, field programmable logic devices (FPLD5), including field programmable gate arrays (FPGAs) and complex programmable logic devices (CPLDs), application specific integrated circuits (ASICs), or the like, may also be used without departing from the scope and spirit of the inventive concepts disclosed herein.
In accordance with an embodiment of the present invention, the methods may be implemented in part on a data processing computer such as a personal computer, workstation computer, mainframe computer, or high-performance server running an operating system such as a version of Microsoft Windows, or various versons of the Unix operating system such as Linux available from a number of vendors. The methods may also be implemented on a multiple-processor system, or in a computing environment including various peripherals such as input devices, output devices, displays, pointing devices, memories, storage devices, media interfaces for transferring data to and from the processor(s), and the like. Such a computer system or computing environment may be networked locally, or over the Internet.
Any of the above-described methods and their embodiments may be implemented in part by means of a computer program. The computer program may be loaded on an apparatus as described above. Therefore, the invention also relates to a computer program, which, when carried out on an apparatus performs portions of any one of the above above-described methods and their embodiments.
The invention also relates to a computer-readable medium or a computer-program product including the above-mentioned computer program. The computer-readable medium or computer-program product may for instance be a magnetic tape, an optical memory disk, a magnetic disk, a magneto-optical disk, a CD ROM, a DVD, a CD, a flash memory unit or the like, wherein the computer program is permanently or temporarily stored. The invention also relates to a computer-readable medium (or to a computer-program product) having computer-executable instructions for carrying out any one of the methods of the invention.
The invention also relates to a firmware update adapted to be installed on apparatus already in the field, i.e. a computer program which is delivered to the field as a computer program product. This applies to each of the above-described methods and apparatuses.
Although the present invention has been described on the basis of detailed examples, the detailed examples only serve to provide the skilled person with a better understanding, and are not intended to limit the scope of the invention. The scope of the invention is much rather defined by the appended claims.

GNSS signal processing with delta phase for incorrect starting position


Provided is a method for designing, managing and executing response plans. Specific plan and resources are defined and a defined plan is executed either automatically or manually according to pre-determined or “real-time” parameter definitions. An executed plan notifies, by various user-defined means, actively or pre-defined parties in a near simultaneous fashion of security communications, notifications, directives and/or information. One embodiment of the system includes a component that requires a notified party to acknowledge a particular notification event by responding with a personal identification number (PIN) or calling a specified telephone number and entering the PIN. The system enables parties to be organized into groups based upon member profiles. Individual parties can be assigned to sub-groups, enabling specifically designed communications to go to the parties of any particular sub-group. Alternative means of contact can be prioritized and utilized either simultaneously or sequentially until contact with a particular party is achieved.

As national and international events demonstrate, situations, whether man-made or natural, may be inherently chaotic. Regardless of the type of situation (e.g. hurricanes or other severe weather, terrorist attack, fires, explosions or merely operational), resources necessary for an appropriate and timely response need to be identified, notified and deployed in an efficient and timely manner. For example, as a hurricane approaches a coast, it may be necessary to close roads subject to high water, initiate evacuations of people in dangerous areas and put on standby emergency personnel such as ambulance drivers and hospital workers to deal with injuries, police to route and direct evacuation traffic and utility workers to repair damaged electrical lines or water pipes.
Although advance planning for hypothetical situations is often performed, there does not exist, until now, a system that manages the planning, organization, notification of personnel and deployment of resources both before and during a situation. Even the best plans need to be located prior to implementation in order to be effective. This location and implementation of a plan can consume valuable time and, when performed on an ad hoc basis, present a chance of serious omissions and mistakes to occur, including the loss of precious time. In addition, some actions, e.g. the notification of critical personnel, (even if their identification has been performed in advance), typically occurs in a sequential fashion. Thus, there exist many potential sources of error and time loss in current emergency response planning.

This patent is subject to a terminal disclaimer.

Management of resources in emergency and operational situations


An injection device is disclosed which comprises a housing (140, 240, 440, 740) for a plurality of cartridges (110,310,410,810) each containing a medicament to be administered to a patient. A plurality of needles (120, 220, 320, 420, 720, 820) may be provided in communication with the plurality of cartridges. A delivery mechanism is arranged to deliver medicament through the plurality of cartridges via the plurality of needles. An injection device may comprise a drive member (130) having a cam surface (136) configured to engage a surface of a carrier (150) and rotate the carrier about a pivot (152) and at least one plunger (134) arranged to engage a cylinder in the cartridge.

Injection devices, such as the Owen Mumford Autopen®, are commonly used by patients to self-administer injections of medicament. Such devices are typically provided in a pen-like body which contains, defines or receives a cartridge (which it will be understood may comprise a syringe) of medicament. The injection device generally comprises a delivery mechanism which is arranged to dispense the medicament via a needle in response to a user pressing a button or trigger. Depending upon the type of device and or medicament to be delivered the injection device may be arranged to deliver the entire contents of the cartridge or a selected dose therefrom. In some injection devices the delivery mechanism may also be arranged to move the needle between a retracted and delivery position and, in doing so, may automatically pierce the skin of the user prior to the dispensing of the medicament.
In some circumstances it is necessary to deliver medicaments in relatively high volumes (for example up to 10 mL of medicament in a single dose) and/or to deliver medicament which are highly viscous such that it may be necessary for the delivery to be carried out over an extended period. Such injections may normally necessitate a user remaining in a health care facility for the duration of an injection. As an alternative, it would be advantageous to provide an injector device which a user could wear against the skin during the delivery of a dose (which could for example take an hour), and such devices may be referred to as "bolus injectors". Such bolus injector devices are distinct from other wearable devices such as infusion pumps (for example for use in the treatment of diabetics) which are generally more complex and expensive devices which are arranged to deliver a regular discrete dose of medicament with a predefined time interval or with a user controlled dosage.
Embodiments of the invention are intended to provide an injection device which may be used as a wearable or bolus injector.

Spring driven injector apparatus with needle insertion


Systems and methods are provided for performing intraoperative fusion of two or more volumetric image datasets via surface-based image registration. The volumetric image datasets are separately registered with intraoperatively acquired surface data, thereby fusing the two volumetric image datasets into a common frame of reference while avoiding the need for complex and time-consuming preoperative volumetric-to-volumetric image registration and fusion. The resulting fused image data may be processed to generate one or more images for use during surgical navigation.

This disclosure relates generally to surgical systems and methods, and more particularly to systems and methods for performing surgical navigation.
Image fusion is a technique used to represent or overlay multiple images, often obtained using different imaging modalities, into a single coordinate system in order to support the visualization of different aspects of the patient's anatomy/pathology. For example, the fusion of magnetic resonance imaging (MRI) image data and computed tomography (CT) image data enables a user or operator to view image data of soft tissue from the MRI scan overlaid onto bone and/or vasculature image data from the CT scan.

Systems and methods for performing intraoperative image registration


A system for preventing unauthorized access to a firearm trigger includes a database of PIN numbers associated with a plurality of trigger locks and access tokens, each corresponding trio represented by an identification code. At purchase, a purchased firearm includes a two-piece trigger lock along with an access token. Each token includes a unique configuration of ferro-magnetic wires. If a background check of the firearm purchaser is approved, a central computer coupled to the database and to a computer network displays a personal identification number (PIN). Entry of this PIN into a keypad on a corresponding trigger lock actuates a read head therein and a token may be positioned thereby. A processor coupled to the read head is able to determine if the trigger lock and token match and, if so, to release of the trigger lock.

This invention relates generally to trigger locks and, more particularly, to an apparatus and system which releases a trigger lock only upon background check approval, subsequent entry of a personal identification number, and matching of ferro-magnetic access codes relative to the respective trigger lock.
The need for more stringent standards relative to background checks on firearm purchasers and mandatory provision of trigger locks on purchased firearms has been suggested with increasing frequency and fervor. While numerous trigger locks of a conventional type have been proposed in the art, existing devices do not provide a comprehensive system which permits release of the lock from the trigger of a firearm only upon approval of a background check as well as possession of a special magnetic access token.
Therefore, it is desirable to have an apparatus and system for releasing a trigger lock from a firearm upon entry of a personal identification code issued through a computer network following approval of a firearm purchaser background check. Further, it is desirable to have an apparatus which also requires that a token having a unique ferro-magnetic wire configuration be recognized by a read head within a corresponding trigger lock before the trigger lock is released.
A system for preventing unauthorized access to the trigger of a firearm according to a preferred embodiment of the present invention includes a plurality of trigger locks and tokens. The system further includes a database of personal identification numbers (PIN""s) associated with the trigger locks and tokens. Each trio of a corresponding PIN, trigger lock, and token are represented by a unique identification code. This code is imprinted on the corresponding trigger lock and token prior to the time of purchase and will be used later to supply a corresponding PIN to a consumer following approval of a background check. Each trigger lock includes a two-piece housing releasably coupled with a locking bolt that is pivotally coupled to one portion of the housing and rotatably activated by a solenoid.
At the time of a firearm purchase, a consumer fills out documentation that is later used to conduct a background check designed to verify the consumer""s fitness to bear a firearm, such as checking for felony convictions, pending warrants, etc. This documentation will include the identification code of the trigger lock and token sold to the consumer. Upon approval of the background check, a central computer coupled to the database and a wide area computer network such as the Internet will display the PIN associated with the identification code in response to the consumer entering that identification code. One section of each trigger lock housing includes a keypad into which the PIN may be entered. Comparator circuitry is also included within that section and coupled to the keypad for determining if the PIN matches the predetermined PIN corresponding to the trigger lock identification code. If they match, the comparator circuitry delivers a signal to enable a read head.
Each token includes a unique number or configuration of ferro-magnetic wires. These wires are specifically formed to switch magnetic states when proximately exposed to a magnetic read head disposed within each trigger lock assembly. This magnetic switching of the wire induces a short duration voltage impulse across the read head. Each read head is coupled to a processor which converts the voltage impulses into a numeric value. This actual or sensed value is then compared to a predetermined value to identify whether the token was the appropriate or expected one. If the values match, the processor delivers a signal to the solenoid of the coupling mechanism to release the trigger lock housing sections.
Therefore, a general object of this invention is to provide a system for preventing unauthorized access to the trigger of a firearm.
Another object of this invention is to provide a system, as aforesaid, having a plurality of trigger locks which cannot be released until a background check has been completed and a PIN corresponding to a respective trigger lock is input into a keypad thereon.
Still another object of this invention is to provide a system, as aforesaid, in which the PIN is displayed over a wide area network upon approval of a background check and upon a user entry of a corresponding identification code.
Yet another object of this invention is to provide a system, as aforesaid, in which a trigger lock is not released until a unique magnetically encoded token is passed proximately over a read head in a trigger lock and generates electromagnetic impulses having a value which matches a predetermined value.
A further object of this invention is to provide a system, as aforesaid, in which an unlocked trigger lock is automatically locked again if the two-part trigger lock housing is not separated within a predetermined amount of time after the trigger lock has been unlocked.
A still further object of this invention is to provide a system, as aforesaid, in which a token is small and capable of being carried on a key ring.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.

Electronic trigger lock apparatus and system


A License Sanction Enforcement System™ technology that includes at least one sensor worn by an individual to be monitored and a data storage unit. The sensor can detect directional angle and acceleration motion. The data storage unit is coupled with the sensor and stores the angle kinematic data detected by the sensor. The device determines whether the individual is operating or has operated a motor vehicle based upon analysis of the angle and acceleration data, and creates a record in the data storage unit of each occurrence that operation of a motor vehicle is detected. Alternatively, the data storage unit may be used to store the raw detection data, which can be transferred to an external data processing device for analysis.

1. Field of the Invention
The present invention is directed to systems and methods for determining when an individual is operating or has operated a motor vehicle.
2. Description of the Related Art
Upwards of 10 million individuals illegally drive in the United States after their licenses have been administratively suspended or revoked. While illegally driving, these offenders kill thousands of individuals and injure tens of thousands of innocent people each year. Although attempts have been made, at the present time, there is no effective technology to deter and facilitate the apprehension of these illegal drivers.
In 1998 the National Highway Traffic Safety Administration (NHTSA) funded the development of a technology called the Problem Driver Detection System (PDDS), which consists of wrist mounted transmitters for individuals with suspended/revoked licenses. The proposed devices transmit coded signals to roadside police cruisers as the illegal driver is going by, which will cause a picture of the offender to appear on a monitor in the cruiser. The purpose of the PDDS is to deter illegal driving by proactively apprehending individuals driving with suspended/revoked licenses. However, the PDDSs have a number of drawbacks, which have prevented their adoption.
For example, the PDDS system does not distinguish between passengers and drivers wearing the devices. This will result in unacceptable false positive indications that an individual is illegally driving the vehicle. In addition, police will not be able to visually match the picture shown in the monitor in the cruiser with the driver going by in foul weather or at night.
Another drawback of the PDDS is that it requires the installation of dedicated antennas in police cruisers to receive the signals from the wrist mounted sensors. This will require the expense of procurement and installation of the antennas.
The PDDS system also requires the frequent installation/removal of electronic images of offenders in the cruiser's computer memory.
Moreover, the PDDS may be relatively easy to defeat or circumvent by:
(1) Operating the vehicle outside the local jurisdiction where the police cars are modified to receive the signal and where the pictures of the offenders are not loaded in the memory of the computers of the police vehicles;
(2) Blocking, degrading or corrupting the signal from the wrist sensor with shielding material; and
(3) Operating the vehicle in known times and circumstances when the PDDS will not work, such as at night and in foul weather.
The PDDS will also fail when police officers in the roadside cruiser are performing other tasks such as making and receiving dispatch calls. The PDDS requires the use of a modified police cruiser and will not work with an officer on roadside patrol on a motorcycle. The PDDS requires dedicated police manpower, which frequently must compete with higher priority police manpower requirements.
Another technology called "Driver-ID," is currently in limited use in the State of Michigan. In this program, the offender wears a court ordered ankle mounted transmitter. The vehicles the offender "might" drive are outfitted with a system called an Ignition Interlock Device (IID) installed under their dashboards. When the IID receives a signal transmitted by the ankle sensor of the individual in the driver's seat, it will disable the vehicle from starting.
Driver-ID technology is in very limited use because it has a number of drawbacks. First, it motivates wearers of the sensors to obtain and drive vehicles without IIDs, which is relatively easy to do. Second, it requires an infrastructure of trained and certified technicians to install and remove the IIDs. Third, it is easy to defeat.
This technology may be defeated or circumvented by:
(1) The offender obtaining and driving vehicles without IIDs;
(2) The offender blocking or degrading the signal from the ankle transmitter with shielding material placed over or around the IID or ankle transmitter; or
(3) The offender placing his/her foot in such a manner that the IID falsely determines it is on the passenger's foot and not the driver's foot.
Thus, in view of the above-described deficiencies with the state-of-the-art, there is a need for new and improved technology to deter and facilitate the apprehension of illegal drivers.

Device and method for detecting operation of motor vehicles by monitored individuals


A recommendation method includes generating a feature sequence based on to-be-predicted data of a user for a target object and according to a preset encoding rule, obtaining probability distribution information corresponding to each feature in the feature sequence, and obtaining, through calculation, a feature vector corresponding to each feature, obtaining a predicted score of the user for the target object based on values of N features and a feature vector corresponding to each of the N features, and recommending the target object to the user when the predicted score is greater than or equal to a preset threshold.

Artificial intelligence (AI) is a theory, a method, a technology, or an application system that simulates, extends, and expands human intelligence using a digital computer or a machine controlled by a digital computer, to sense an environment, obtain knowledge, and obtain an optimal result using the knowledge. In other words, artificial intelligence is a branch of computer science, and is intended to understand the essence of intelligence and produce a new intelligent machine that can react in a manner similar to human intelligence. Artificial intelligence is to study design principles and implementation methods of various intelligent machines, to enable the machines to have perception, inference, and decision-making functions. Researches in an artificial intelligence field include a robot, natural language processing, computer vision, decision-making and inference, human-computer interaction, recommendation and search, an AI basic theory, and the like.
Prediction performed through artificial intelligence has been widely applied in a field such as a recommendation system. For example, a predicted score of a user for an object is obtained through artificial intelligence, and then the object is recommended to the user based on the predicted score. An application store is used as an example. Statistics about a predicted score of a user for an application (for example, statistics about a predicted score of clicking the application by the user may be collected, and the predicted score may reflect a possibility of clicking the application by the user) are collected. In this way, applications that interest different users can be learned, and an application is pushed more accurately to each user, to improve user experience. An accurate predicted score of a user for an application may increase a probability of clicking the application by the user in an actual scenario, thereby increasing profits. An implementation for obtaining the predicted score of the user for the application is as follows. The predicted score of the user for the application is obtained based on historical statistics. In an embodiment, a predicted score of the user for each application is obtained by dividing clicks of the application in a historical time period by impressions, and an application with a relatively high click-through rate (CTR) is recommended to the user. However, clicking an application by the user may be affected by a plurality of factors. In the foregoing manner, the predicted score of the user for each application is determined based on only clicks and impressions of the application. Consequently, prediction is inaccurate, and an effective recommendation cannot be implemented.
Therefore, currently, a recommendation method is urgently needed to resolve a technical problem that an object cannot be effectively recommended to a user due to an inaccurate predicted score of the user for the object.


An integrated circuit device cooling structure includes a wiring substrate, an integrated circuit device, a heat sink, and heat radiation vias. The integrated circuit device is mounted on the first surface side of the wiring substrate. The heat sink is fixed to the second surface of the wiring substrate and thermally coupled to the wiring substrate. The heat radiation vias are formed in the wiring substrate to transmit heat generated by the integrated circuit device to the heat sink.

The present invention relates to an integrated circuit device cooling structure and, more particularly, to an integrated circuit device cooling structure which cools an integrated circuit device, which is packaged by flip chip bonding called an area bump method or in a ball grid array (BGA) package, with air by attaching a heat sink to it.
Conventionally, in an integrated circuit device cooling structure of this type, the integrated circuit device is mounted on a wiring substrate such that its lower surface faces the upper surface of the wiring substrate. A heat sink is attached to the upper surface of the integrated circuit device.
FIG. 6 shows a conventional integrated circuit device of this type. Referring to FIG. 6, a heat sink 26 is arranged on the upper surface of an integrated circuit device 21. The lower surface of the heat sink 26 is fixed to the upper surface of the integrated circuit device 21 so that it is thermally coupled to the integrated circuit device 21. Heat generated by the integrated circuit device 21 is transmitted to the heat sink 26 and is radiated in the air.
Solder bumps 22 used for inputting/outputting signals and connecting a power supply are formed on the lower surface of the integrated circuit device 21. The integrated circuit device 21 is not directly mounted on a wiring substrate 25 but is mounted on an interposer substrate 23 through the solder bumps 22. This is because the solder bumps 22 have a small pitch and the integrated circuit device 21 cannot be directly mounted on the wiring substrate 25.
Solder balls 24 are arranged on the lower surface of the interposer substrate 23. The solder balls 24 are arranged at such a pitch that they can be mounted on the wiring substrate 25. The interposer substrate 23 is mounted on the wiring substrate 25 through the solder balls 24.
The prior art described above cannot cope with an increase in power consumption that accompanies an increase in operation speed and integration degree of the integrated circuit device 21. To cope with an increase in power consumption of the integrated circuit device 21, the size of the heat sink 26 must be increased, but the cooling performance does not increase in proportion to an increase in size of the heat sink 26. To attach a large heat sink 26 to the integrated circuit device 21, the attaching structure must also be improved in accordance with the heat sink 26.

Integrated circuit device cooling structure


Chrysanthemum Make Time is a new cultivar, distinguished by its lavender-rose ray floret color, spreading to upright branching habit and exceptional number of flowers per break. Make Time was selected from among progeny of a cross between female parent Pink Arola and male parent Cindy. The new cultivar is distinguishable from other Chrysanthemums and from both parents in its full, robust branching habit arising from a large number of blooms per break. Make Time has an exceptionally long shelf life giving it a commercial advantage over several other Chrysanthemums.

The new Chrysanthemum cultivar was selected as one flowering plant from among the progeny of a cross made by Peter Wain between the female parent Pink Arola (U.S. Plant Pat. No. 6,129) and the male parent Chrysanthemum Cindy (U.S. Plant Pat. No. 6,838). Make Time differs from either parent in having an unusually large number of flowers per break which give the plant a full, yet compact and robust appearance. Make Time florets are lighter in color than the florets of the female parent Pink Arola. Make Time flower buds typically open cleanly, giving a healthy, full appearance unlike that of the male parent Cindy. Although Make Time is similar in color to the Chrysanthemum Charm (U.S. Plant Pat. No. 5,502), the number of flowers per break typically average 40% higher over a smaller diameter capitulum when grown under the same conditions. Make Time therefore can be grown as a CBR/Spray (central bud removal) pot throughout the year, saving time and cost of disbudding.
The cross which produced Make Time was made as part of a controlled breeding program conducted in Havant, Hampshire, England. Selection of Make Time was based on its distinctive flat form and exceptional number of flowers per break which distinguished it from other Chrysanthemum cultivars and appeared to make the plant desirable for commercial greenhouse production.
Make Time is similar in capitulum form, type and branching habit to the cultivar Charm described in U.S. Plant Pat. No. 5,502. Charm is normally grown as a disbud pot and the diameter across the capitulum when grown this way is 9.7 cm. Make Time is normally grown as a CBR (central bud removal) pot and the diameter of the capitulum when grown this way is 5.4 cm. Make Time has an average of 8.4 flowers per break which is significantly more than Charm which has 6.2 flowers per break. The larger number of flowers per break in Make Time makes it possible to grow this plant as a CBR/Spray (center bud removal) pot throughout the year which saves time and cost of disbudding. The number of flowers per pot also makes the plant very full and robust in appearance. Make Time has a similar average number of breaks per pinch to Charm. Make Time takes approximately 6 days longer than charm to flower. Make Time is very similar in color to Charm. Make Time ships well and provides the customer with an excellent plant with exceptional shelf life (blooming time) of 4-6 weeks.
The first act of asexual reproduction of Make Time was accomplished when vegetative cuttings were taken in April 1989 in a controlled environment in Havant, England by the inventor.
Horticultural examination of controlled flowerings of successive plantings has shown that the unique combination of characteristics as herein disclosed for Make Time are firmly fixed and are retained through successive generations of asexual reproduction.
Make Time has not been observed under all possible environmental conditions. The phenotype may vary significantly with variations in the environment such as temperature, light intensity and day length.
The following traits have been repeatedly observed and are determined to be basic characteristics of Make Time, which in combination distinguish this Chrysanthemum as a new and distinct cultivar.
1. Flat capitulum form;
2. Decorative capitulum type;
3. Lavender-rose ray floret color;
4. Exceptional number of flowers per break;
5. Diameter across capitulum face of 5.4 cm;
6. Spreading to upright branching pattern with an average of 5.4 breaks after a single pinch;
7. Flowering response approximately 63 days from the start of short days;
8. Relatively easy to control plant height such that the finished height ranges from 10 to 17 inches depending on pot size.