A communications system employing the Discrete Multitone (DMT) line code divides the used frequency band W into a large number of subchannels, each with a bandwidth .DELTA.f=W/N. The signal in each subchannel is independently modulated at the symbol rate 1/.DELTA.f. Because of noise and the non-ideal characteristics of the transmission channel, the signal-to-noise ratio (SNR) varies for different subchannels across the frequency band. Each subchannel is used to transmit an integer number of bits in a two-dimensional signal constellation, the susceptibility to noise increasing with the size of the constellation assuming that the same signal energy is used. In order to use the transmission channel optimally, subchannels are assigned different numbers of bits depending on their specific SNR values, i.e., a subchannel with a high SNR value is assigned a large number of bits and vice versa. An optimal bit allocation is determined that ensures a certain bit error rate (BER) is obtained for all subchannels. In order to simplify numerical computations, thresholding is employed to make initial bit assignments. Further simplification of the bit loading procedures is obtained by ending bit allocation optimization efforts after a targeted BER is achieved.

The general principle of transmitting data by dividing it into several interleaved bit streams, and using these bit streams to modulate several carriers is well known. Modems using this principle employ what is referred to as Discrete Multitone (DMT) modulation and demodulation. These types of modems are being used or considered for use in such applications as cellular radio and High rate Digital Subscriber Lines (HDSL).
In a Discrete Multitone system, the input bit stream is first serial-to-parallel converted. The parallel output is then grouped into N groups of bits corresponding to the number of bits per symbol. Portions of bits are allocated to each DMT carrier or subchannel. The power transmitted over each subchannel corresponds to the number of bits transmitted over each DMT subchannel.
Like a single carrier system, a multicarrier data transmission system tries to maximize a data transmission or bit rate for a particular Bit Error Rate (BER) and a particular Signal to Noise Ratio (SNR). In theory, the total bit rate (transmitted over all of the sub-channels) is maximized if the bit error rates for all the subchannels are equal. The concern is how best to allocate bits to each subchannel to attain the same BER over all of the subchannels.
FIG. 1 shows an example Discrete Multitone (DMT) communication system in which the present invention may be advantageously employed. Transmitter 10 includes a serial-to-parallel converter 14, a multicarrier modulator 16, and a pretransmit processor 18. Receiver 12 includes a post channel processor 20, a multicarrier demodulator 22, and a parallel-to-serial converter 24. The transmitter and receiver are linked in this example by a digital subscriber line (DSL) or other form of communication channel 26. Serial input data at a rate of b.sub.total /T bits per second are grouped by converter 14 into blocks of b.sub.total bits for each multicarrier symbol, with a symbol period of T. The b.sub.total bits in each multicarrier symbol are used to modulate N separate carriers in modulator 16 with b.sub.i bits modulating the i.sup.-th carrier.
A preferred example embodiment uses an Inverse Discrete Fourier Transform (IDFT) during modulation to generate N.sub.s time-domain samples of a transmit signal for each block of b.sub.total bits, where N.sub.s is preferably equal to 2N. The corresponding multicarrier demodulator performs a Discrete Fourier Transform (DFT), where b.sub.i bits are recovered from the i.sup.-th carrier. As depicted in FIG. 2, the carriers or subchannels in a DMT system are spaced 1/T Hz apart across N/T Hz of the frequency band. More detailed discussion of the principles of multicarrier transmission and reception in general is given by J. A. C. Bingham in "Multicarrier Modulation for Data Transmission: An Idea Whose Time Has Come", IEEE Communications Magazine, Volume 28, Number 5, pp. 5-14, May 1990.
The general structure of a Discrete Multitone Modulation DMT system is illustrated in FIG. 3, where {X.sub.0,X.sub.1, . . . , X.sub.N-1 } are the original, complex, input data symbols, {x.sub.k } is the modulated data sequence (before cyclic prefix), {h.sub.k } is the discrete-time channel response, {n.sub.k } is the additive noise sequence, {y.sub.k } is the received sequence (after the removal of cyclic prefix), and {x.sub.0, x.sub.1, . . . ,x.sub.N-1 } are the decoded, complex data symbols. The p.sub.i 's and p.sub.i *'s in FIG. 3 are known as the modulating and the demodulating vectors, and preferably they are chosen to be orthonormal.
Adding the cyclic prefix is a discrete-time technique used to eliminate interblock interference (IBI) in the DMT system. The independent modulating and demodulating vectors in FIG. 3 are the IDFT and the DFT vectors, given by the following pair of relationships: ##EQU1##
A DMT system with N complex subchannels in the frequency domain requires a DFT size of 2N, and the forced conjugate symmetry in the frequency domain results in the desired real-valued time domain samples. In the preferred embodiment, IDFT and DFT are implemented with the well known IFFT and FFT algorithms using the approach disclosed in commonly-assigned "Method and Apparatus for Efficient Computation of Discrete Fourier Transform and Inverse Discrete Fourier Transform," U.S. patent application Ser. No. 08/887,467, (attorney docket 1410-340), filed on Jul. 2, 1997.
FIG. 4 is a more detailed block diagram showing the principal operative components of a basic DMT transmitter 30 and a basic DMT receiver 32 connected through a channel 34. Serial input data are grouped into blocks, converted to a parallel form, and appropriately encoded by an encoder 36. Each one of the N active subchannels contains a number of b.sub.k bits allocated to that subchannel. The total number of bits in a DMT symbol is therefore: ##EQU2##
Each of the N bit groups is mapped by the symbol into a two-dimensional signal constellation. The relation between the number of bits in each block of bits b.sub.k and the necessary number of signal points in a constellation M is given by: EQU M.sub.k =2.sup.b.sbsp.k (4)
The signal points in a constellation are typically arranged in a rectangular pattern for even values of b.sub.k and a cross for odd values of b.sub.k. Provided that the same signal energy is used for all constellations, the distance between neighboring signal points is reduced with increasing constellation size resulting in increased BER with the same signal-to-noise ration (SNR).
The output from the encoder is N complex numbers, one for each group of bits, which are then fed to a device that calculates the Inverse Discrete Fourier Transform (IDFT). The output is a real sequence that can be considered the superposing of N modulated orthogonal carriers spaced .DELTA.f apart.
The parallel IFFT output is converted back to a serial data stream by a converter 40. The digital modulated data stream is cyclically prefixed, converted to analog form by a digital-to-analog converter (DAC) 42, low-pass filtered at 44, and passed through a D.C. isolating transformer 46 during pre-transmit processing to produce an analog signal transmitted over a transmission channel 34.
At the receiver end, the received analog signal is passed through a D.C. isolating transformer and low-pass filter 48, converted to digital form by an analog-to-digital converter (ADC) 50, time domain pre-equalized by a finite impulse response (FIR) filter 52 to limit the effective memory of the channel, and stripped of the cyclic prefix during post-receive processing in converter 54. The resulting digital signals are demodulated by 2N FFT operation 56 and converted to parallel frequency domain signals. Since the amplitude vs. frequency and the delay vs. frequency responses of the channel are not necessarily constant across the entire used frequency band, the received signal will differ from the transmitted signal, and the parallel inputs to the decoder 58 will differ from those parallel outputs from the encoder 36. One form of equalization used to compensate these differences is a frequency domain equalizer (FEQ) which individually adjusts for the attenuation and delay of each of the carriers immediately before the parallel frequency domain signals are passed to the decoder. The frequency domain equalized signals are appropriately decoded and converted back to a serial form by the decoder 58. Ideally, the detected output serial data from the decoder 58 is the same as the input serial data to the encoder 36.
In a conventional single-carrier digital transmission system, such as a Quadrature Amplitude Modulation (QAM) system implemented with an equalizer or a encoder, the transmission bandwidth is determined by the symbol rate and the carrier frequency of the system. Unfortunately, variable symbol rate, single-carrier systems are still impractical to implement from a complexity standpoint with today's technology, and even if they are implemented, the granularity of possible symbol rates are typically very coarse. This is a direct consequence of the fact that for a fixed data rate, the symbol rate can only change in discrete multiples of b.sub.symbol /(b.sub.symbol .+-.1), where b.sub.symbol is the number of bits transmitted by each data symbol, provided that only signal constellations with integer numbers of bits are used.
Multicarrier modulation, however, offers much more flexibility in granularity because it acts on block symbols that consist of a much larger number of bits per symbol over a large number of carriers. Since different numbers of bits can be transmitted through the different carriers (subchannels), the multicarrier transceiver can control the transmission bandwidth. As a result, more data bits are transmitted through the better carriers, i.e., having a greater Signal to Noise Ratio (SNR), and less data bits are transmitted through the worse carriers, i.e., having a lower SNR as shown in FIG. 5. In this manner, optimal performance can be achieved, in terms of either maximizing total data throughput for a fixed system performance margin or maximizing overall system performance margin for a fixed target data rate under a fixed, total input power constraint and target bit-error-rate.
Various bandwidth/bit allocation optimization techniques for multicarrier modulation have been proposed for different applications. The theoretical optimal energy allocation is the well known water-pouring energy distribution as described for example in J. G. Proakis, (1995), Digital Communications 3.sup.rd edition, McGraw-Hill, New York. Conceptually, the water pouring energy distribution model is obtained by first inverting the channel SNR curve shown in FIG. 5 in the frequency domain and then pouring the available energy into the resulting curve. The final "water level" at each particular frequency/carrier/subchannel is the optimal amount of energy to use at that particular frequency/carrier/subchannel. The number of bits transmitted by each carrier is determined by the maximum number of bits that can be supported by each carrier, given the water-pouring energy distribution and the desired bit-error-rate of each carrier. While the water-pouring technique yields the optimal bit and energy allocations, and therefore the optimal transmission bandwidth, it is typically complex and impractical to implement.
Another multicarrier bandwidth optimization technique designed for voice-band modem applications, where only constellations with an integer number of bits are used, was proposed by D. Hughes-Hartogs and described in "Ensemble Modem Structure for Imperfect Transmission Media", European Patent Number 0 224 556 B1 (published October 1991). The basic idea behind Hughes-Hartogs' algorithm is to incrementally add, one bit at a time, the amount of data to be transmitted in each multicarrier symbol until a desired data rate or power constraint is satisfied. Furthermore, this algorithm always chooses the subchannel that requires the least amount of incremental power to support an additional bit at the given desired bit-error-rate. Hughes Hartogs' algorithm, however, is typically too slow in convergence, making it especially unsuitable for applications where there are large numbers of carriers and bits to be supported by each multicarrier symbol as pointed out in P. S. Chow, J. M. Cioffi, J. A. C. Bingham, "A Practical Discrete Multitone Transceiver Loading Algorithm for Data Transmission Over Spectrally Shaped Channels," IEEE Transactions on Communications, Vol. 43, No. 2/3/4, pp. 773 775, 1995. Also, the channel response is assumed to be fixed, i.e., time-invariant after training, which is not a good assumption for many applications, e.g., mobile radio communications.
In order to achieve faster convergence at the expense of a slight performance degradation, Chow et al. proposed a three-step bit loading algorithm. First, an optimal system performance margin is found; second, convergence is guaranteed with a suboptimal loop; and third, the energy distribution is adjusted for each subchannel if the transmission system is constrained by the total transmit power.
However, Chow's bitloading algorithm requires computationally complex steps best run on a microprocessor and a number of iterative elements that may be excluded. Both requirements increase the system cost and reduce speed. The bit loading procedure in accordance with the present invention minimizes computational complexity and permits execution by specific hardware which is faster than programmed microprocessor driver solutions. Also those parts of the algorithm that are best run on a microprocessor are of such basic character that only a rudimentary, inexpensive device is necessary.
It is an object of this invention therefore to provide optimal bitloading using less computational power and at a fast rate.

Reduced complexity bit allocation to subchannels in a multi-carrier, high speed data transmission system


To provide a magnetic transfer system capable of smoothly delivering a carrier between chambers by providing a independently-rotating carrier-feed driving shaft for each chamber without using a synchronous control mechanism and used for a semiconductor fabrication equipment or the like provided with a plurality of chambers. The magnetic transfer system is provided with a rotational driving member which is divided into two portions serving as a fixed driving shaft and a movable driving shaft in the axial direction and in which the fixed driving shaft is secured to a shaft core member and the movable driving shaft is set to the shaft core member so as to be limited in the rotational direction but so as to be freely movable in the axial direction at a certain width, and spiral magnetic coupling sections are formed on the surface of each driving shaft at the same pitch. The carrier can be freely moved against the surface of the rotational driving member in its axial direction, and is provided with magnetic coupling sections at an interval equal to a pitch in the spiral magnetic coupling sections. By rotating the rotational driving member, the carrier linearly moves.

1. Field of the Invention
The present invention relates to a magnetic transfer system for transmitting a driving force to a movable body by a non-contact system, suitable for a driving mechanism for transferring an object in a vacuum environment isolated from the atmosphere, and capable of performing smooth transfer generating less dust, a power transmission mechanism of the magnetic transfer system, and a rotational driving member preferably used for the magnetic transfer system.
2. Description of the Related Art
To transfer an object in a vacuum environment, a rack and pinion mechanism, roller-type driving mechanism, and chain driving mechanism have been frequently used. These driving mechanisms comprise a system for directly transmitting a driving force by a contact action and are referred to as a contact transmission system. This type of driving mechanism has the poor characteristics that friction coefficient increases and lubricating oil cannot be used in the vacuum environment. Therefore, there are problems that abrasion loss extremely increases and much dust is generated (this state is referred to as "dust generation"). Moreover, because the friction coefficient increases, the clearance of a contact portion must be increased and thereby an accurate movement is interrupted.
Furthermore, recently as represented by a semiconductor, it has been requested to extremely limit an amount of dust to be attached to an electronic part or the like. A driving mechanism capable of completely preventing dust from being generated is ideally desired.
To decrease the amount of dust, a transfer system of the non-contact transmission type is clearly preferable. Various systems have been proposed so far as the transfer system of the non-contact transmission type. Among the proposed systems, a system using the action of electromagnetic coupling (hereafter referred to as "a magnetic transfer system") has a relatively simple structure. A linear transfer mechanism constituted by combining a spiral magnetic circuit with an magnetic electrode has been recently proposed as the magnetic transfer system (official gazette of U.S. Pat. No. 5,377,816). Moreover, a magnetic screw used as a feeder is proposed as an art indirectly related to the magnetic transfer system in the field of machining tools or the like (official gazette of Japanese Patent Application Laid-Open No. 7-280060).
The above official gazette of U.S. Pat. No. 5,377,816 discloses a mechanism for generating a linear motion by using a spiral magnet. That is, the mechanism comprises a cylindrical body to be rotated by a motor, on which many magnet pieces of N and S poles are alternately arranged so as to form a spiral layout and a base member movably arranged closely to the cylindrical body in its axial direction and provided with a magnet segment, and which is constituted so that the base member linearly moves by magnetic attraction the magnet pieces and the magnet segment when the cylindrical body rotates.
Moreover, the above official gazette of Japanese patent Laid-Open No. 7-280060 discloses a magnetic screw. The magnetic screw comprises a screw shaft which is made of a magnetic material and on whose surface a thread is spirally formed and a cylindrical nut body arranged on the outer periphery of the screw shaft at an interval and provided with a spirally-polarized magnetic pole on the inner periphery correspondingly to the thread. When the screw shaft rotates, the cylindrical nut body moves in the axial direction of the screw shaft.
According to the above-described general magnetic transfer system, a contact portion related to a transfer mechanism in a vacuum device is usually only a roller section for supporting a movable body (a carrier or tray; hereafter referred to as "carrier") and a contact portion is absent at the driving-force transmission section for moving the carrier. Therefore, it is possible to eliminate the contact portion causing dust to be generated. Therefore, the magnetic transfer system is able to moderate the problems of abrasion and dust generation compared to the contact transmission system and has an ideal structure as the internal transfer mechanism of the vacuum device.
Because the above-described magnetic transfer system generally has only a small thrust which is obtained from the magnetic coupling action of a magnetic coupling section, it is requested to form many magnetic coupling sections. In this case, the "magnetic coupling section" denotes a section in which magnetic poles are coupled with each other because a magnetic force works a driving section and a driven section. Therefore, in the case of a magnetic transfer system comprising a columnar rotational driving section with a spiral magnet portion formed on its surface (hereafter referred to as "driving shaft") and a movable body provided with magnets arranged at an interval of the same distance as the pitch of the spiral magnet portion, the number of magnetic coupling sections is increased by increasing the length of the driving shaft in the transfer direction (axial direction) and increasing the number of turns of the spiral magnet portion and the number of magnets of the movable body.
For example, a case is considered in which the above magnetic transfer system is applied to a semiconductor fabrication equipment including a plurality of vacuum process chambers connected in series. The chambers are separated from each other by a gate valve. Therefore, when using the magnetic transfer system as a system for transferring the carrier for mounting a substrate, it is a matter of course that the above driving shaft is provided for each chamber so as to move the carrier by rotating each driving shaft. The carrier is transferred through each chamber in order in accordance with a predetermined substrate processing procedure. In this case, the carrier is constituted so that it is delivered the driving shafts of the chambers while it is moved the adjacent chambers.
The conventional magnetic transfer system having the above structure has the following problems.
Because the chambers are separated from each other by the gate valve, a gap is present the driving shafts and therefore, a crossing portion is formed for the carrier to be transferred. Therefore, to smoothly move the carrier, it is necessary to match magnetic circuits driving shafts at the crossing portion. Unless properly performing the matching, the carrier cannot be smoothly moved. Moreover, if repulsion occurs in carrier delivery at the crossing portion, not only a purposed thrust is not produced but also transfer may stop.
Therefore, to smoothly move the carrier driving shafts, it is desired to synchronize the rotations of the driving shafts. As a simple structure for realizing the synchronization, it is considered to rotate all the driving shafts of each chamber by a motor. However, because this structure has a large problem that the load excessively increases, it cannot be practically used. Then, it is considered to perform the control for synchronization the driving shafts by providing motors which rotate the driving shafts for each chamber and synchronously controlling the operation of each motor. In the case of this synchronous control, however, it is practically very difficult to align the positions of a plurality of magnetic poles arranged on the carrier with the position of the spiral magnet portion of the driving shaft when delivering the carrier the chambers because the stop position of the object to be processed is independently set for each chamber and dimensional errors of the chambers or errors in assembling the semiconductor fabrication equipment are present.
As described above, in the case of the conventional semiconductor fabrication equipment provided with a plurality of vaccum process chambers connected in series and providing a driving shaft for each chamber so that it rotates in an independent driving system, it is difficult to perform the control for aligning the position of the magnetic pole arranged to the carrier with the position of the next driving shaft when delivering the carrier from the driving shaft of each chamber to the driving shaft of adjacent other chamber.
The above problems are not included in the above-described documents of prior art. Therefore, the problems cannot be solved by the magnetic feed mechanism or magnetic screw shown in these documents.

Magnetic transfer system, power transmission mechanism of the magnetic transfer system, and rotational driving member used for the system


A railgun having a composite insulator of laminated materials positioned between the rails. The composite insulator is comprised of a series of conducting layers oriented with the edges toward the bore, or barrel, of the railgun and their wide edges away from the bore. The laminate is layed lengthwise along the rails and is comprised of conducting layers of a high heat conductivity metal interleaved with an insulator material. The insulator material allows the composite insulator to stand off the voltages in a plasma armature even under high radiation flux conditions. Below the conducting material's ablation threshold the amount of ablation produced by the composite insulator is reduced by the reduction of insulator surface area exposed to the radiation. This allows better control of armature growth, mass acceleration by the plasma armature, secondary formation, and other factors normally found to retard projectile acceleration.

1. Field of the Invention
The present invention relates generally to electric mass launchers, and more particularly to a railgun using an ablation resistant or composite insulator within the bore of a railgun electric mass launcher.
2. Description of the Related Art
Electric mass launchers have been investigated, in various forms, for several decades. One form of an electric launcher is called a railgun. A railgun is basically a linear motor for driving a projectile along a barrel. The barrel of the railgun is generally comprised of rails and an insulator material forming a bore, an armature located within the bore and an electrical power source which supplies the electrical current for driving the armature along the bore.
The railgun electric mass launcher 10, FIG. 1, uses a set of parallel conducting rails 12a and 12b separated by insulators (not shown), and a current shunt 14, called an armature which is free to slide between the rails 12a and 12b. Current 16 from an external source (not shown), such as a capacitor bank, battery bank, homopolar generator, or other high current power supply, is driven down one rail 12a, through the armature 14 and back along the other rail 12b. The insulators must be able to hold off the voltage between the rails 12a and 12b which can range from 10-500 v, depending upon the type of armature 14. The voltage across the rails 24a and 24b for a solid metal armature 14 is in the 10-50 v range. The magnetic field produced by the current 16 in the rails 12a and 12b applies a force on the current 16 driven through the movable armature 14. Such force is perpendicular to both the magnetic field direction and the direction of the current flow in the armature 14 and has a magnitude proportional to their product. In the railgun 10 this force is applied along the axis of the rails 12a and 12b, accelerating the armature 14 from the breech 18 to the muzzle end 19 of the railgun 10. The accelerated mass may be a solid mass such as an insulating jacket, called a sabot 21, encasing a solid projectile 22, as shown in FIG. 2. For low velocity applications (<1.5 km/s) the sabot 21 is usually made of a sliding metal structure which makes good electrical contact with the conducting rails 24a and 24b. As the velocity increases into the 1-2 km/s range, the sliding metal-to-metal contact becomes resistive, due to localized arcs (not shown) which form between the contacts between the rails 24a and 24b, and the sliding metal sabot. Eventually the current 28 contact transitions into a single large area arc 26 which trails behind the solid armature. This arc 26, known as a plasma armature, is comprised of a high pressure (>100 atmospheres), partially ionized gas distribution which fills the region between the conducting rails 24a and 24b. The current 28 is conducted between the rails 24a and 24b by this plasma distribution. Plasma armatures 26 are more resistive than solid metal armatures producing higher voltages across the arc 26. These voltages can be as high as 300-500 v depending on the current driven through the plasma. The magnetic field from the rails 24a and 24b causes a force on the current through the plasma armature 26 directed toward the muzzle 29. This force compresses the gas trapped between the arc 26 and the rear of the sabot 21 and the projectile 22 is accelerated down the bore 24 by the high pressure gas. Pressures driving the sabot 21 along the bore 24 can be -1,000 atmospheres allowing high velocities to be reached in relatively short barrels. Such railguns have been able to accelerate gram-sized masses to -8 km/s and 600 g masses to -4 km/s.
The materials that comprise the bore of the railgun are very important to its operation. In most cases it is the bore materials that limit the performance of the railgun. Local pressures in the armature can reach 1000 atmospheres over the plasma armature length which is typically several bore diameters long. Thus the bore walls, including the seal between the rails and the insulators, must be able to withstand the full armature gas pressure. Under these extreme pressures the rails and insulators tend to expand outward measurably, even with a high pre-load compression provided by the surrounding support structure. Thus the bore materials must be able to flex sufficiently to recover from the high gas pressure without losing their high pressure seal, cracking, or permanently deforming. In general metals are better at both resisting the pressure and at recovering from the localized flexing associated with the moving pressure distribution. Some insulators, such as ceramics, can withstand the pressure but tend to crack or craze under localized stress. Softer materials can compress and tend not to return to their original shape and size. The expansion can also affect the sliding high pressure seal between the bore and the projectile. If the rails and the insulators expand too much they can allow gas to escape forward past the projectile. This lowers the available pressure to accelerate a projectile. The escaping gas which blows by the projectile can also break down and lead to precursor arcs forming in front of the projectile. Such arcs can divert current from the armature and further decrease the acceleration. The smoothness of the bore wall surface is also important. The smoother the surface, the better the seal. Thus cracks or pits which are left on the bore wall must be smoothed or honed periodically. The wall material must resist damage while being able to be smoothed if necessary. Soft insulator materials or materials that crack under stress have to be replaced often which can severely restrict the utility of hypervelocity plasma armature railguns.
In addition to the high pressures the plasma armature also bathes the bore walls in an extremely high particle and radiation flux. The plasma armature has a small but finite resistivity. Current driven through the armature resistively deposits a significant amount of heat energy in the plasma. Ohmic heating rates can reach -300 megawatts during the typical 1-2 millisecond accelerating pulse. This energy heats the plasma in the armature which then reradiates the energy out of the armature plasma as black body electromagnetic radiation or hot particles. This radiated energy bathes the surrounding walls in the bore. Black body radiation from the hot gas distribution, which scales with the fourth power of the gas temperature, dominates the process. A equilibrium between the ohmic heating and the radiation is usually reached when the plasma temperature is 10,000.degree.-20,000.degree. K (1-2 eV). The armature is continually moving so a particular location on the rails or insulators is exposed to this radiated energy only when the armature passes. A typical location on the bore surface will see 100 s of kW/cm.sup.2 for times .about.100 microseconds. This amount of energy is sufficient to melt and ablate most materials from a surface. The threshold for ablation of the bore walls (heat flux necessary for ablation to occur for a given duration of exposure) depends on the wall material's heat capacity, heat conductivity, melting temperature, as well as the bore geometry. Likewise, the amount of material ablated from the surface once the ablation threshold has been reached depends on the amount of energy delivered to the surface as well as the heat of fusion (metal) or heat of formation (insulator) for the material. The heat of fusion or formation represents the energy required to release individual atoms of material from the surface. In general, metals have a relatively high ablation threshold (10-100 times larger) compared to the hydrocarbon-based insulators commonly used in railguns. Plastic insulators have ablation thresholds in the order of 10.sup.4 watts/cm.sup.2 while metals have ablation thresholds in the order of 10.sup.5 W/cm.sup.2. The amount of material ablated can be significant. The ablation products coming off the walls can enter the plasma arc and be accelerated along with the armature or can be left behind in the form of hot, partially ionized gas. Such hot gas trapped by the armature increases its length and mass and forces energy to be used accelerating the gas to the armature velocity. Hot gas left behind can lead to secondary arcs forming behind the plasma armature. Such secondary arcs divert current from he armature and slow the acceleration. Both cases, and other more subtle effects resulting from ablation, lead to a decrease in projectile acceleration. Thus control of the wall ablation is critical to optimizing the acceleration. The key to minimizing wall ablation is using ablation resistant materials for the rails and insulators.
A considerable effort has been expended trying to find the ideal material for rails and insulators. Metals are able to withstand high heat fluxes, but once the threshold for ablation is reached (100 s of KW/cm.sup.2) they begin to ablate large amounts of mass due to their low heat of fusion (energy needed to separate atoms from the metal lattice). Insulators in general have a much lower ablation threshold (10 s of KW/cm.sup.2) but a higher heat of formation (energy needed to break up the molecules into their constituents). This means that insulators, in general, start to ablate at a lower threshold level than metals but once the metal ablation threshold is reached, the metals will produce more ablated material than insulators. Most existing railguns use plastic (acrylic or epoxy resin) insulators which are particularly vulnerable to ablation. This results in rapid ablation of the surfaces and a flooding of the region in and around the arc with ablated hydrocarbons. Silicon carbide insulators have been tried but found to melt under the radiation flux and crack under the pressure. Diamond insulators are the best alternative, however, they cannot be fabricated in large volumes with existing technology. Machinable ceramics have relatively low ablation thresholds but tend to be brittle. Boron nitride has a high ablation threshold but tends to fill the bore with dust under high pressures. Epoxy materials like G-9 and G-10 (a form of fiberglass laminate bonded together with epoxy) are used routinely but produce copious amounts of ablated material. Such glass-epoxy materials also tend to delaminate under the high pressure and heat conditions in the barrel.
The ideal insulator would be a material that has a high ablation threshold as well as high heat of formation such as silicone carbide, alumina, or diamond. Unfortunately these materials are very expensive to make and tend to crack under extreme pressures.

High velocity electromagnetic mass launcher having an ablation resistant insulator

The United States of America as represented by the Secretary of the Navy


A glue applicator for the installation of laminate flooring on subfloors has three laterally spaced nozzles for applying separate beads of glue onto the back of a plank of laminate flooring. Two nozzles are spaced for applying separate beads of glue along the lateral edges of a plank, the third nozzle is spaced for applying beads of glue through the center of the plank. Flanges on the sides of the glue applicator position the beads of glue on the back of a plank of laminate flooring and standoff flanges hold the nozzles above the back of the plank a sufficient distance for assuring that the glue applicator of this invention does not smear the beads.

1. Field of the Invention
This invention relates to a glue applicator for laminate flooring.
2. Description of the Related Art
Commercially available laminate flooring generally includes a wear surface glued to a substrate. The wear surface generally is high-wear resistant decorative laminate. The substrate generally is fiber board or particle board. Each piece of laminate flooring generally has a groove along one end and one side suitable for joining with a tongue along one side or end of an adjacent piece of laminate flooring. Laminate flooring is commercially available as planks and as tile. The planks are 46.5 inches long and 7.75 inches wide. The tiles are 15.5 inches square.
Laminate flooring is commercially installed over a pad. There is a need for installing laminate flooring by gluing it to a subfloor.


Embodiments of the invention include an amplifier having an enhanced feedforward arrangement. In a typical operational amplifier output stage of this type, conventional feedforward arrangements comprise one or more active electrical components coupled between the second stage amplifying transistor and the negative output driver. The enhanced feedforward arrangement includes a resistor connected between the second stage amplifying transistor and the negative voltage source and a second resistor connected between the second stage amplifying transistor and the negative output driver. Alternatively, a capacitor is connected in parallel with the second resistor. In this manner, feedforward arrangements according to embodiments of the invention advantageously provide stable, enhanced frequency response, including high frequency response, e.g., above approximately 10 kHz, using economically advantageous passive rather than active electrical components. Furthermore, feedforward arrangements according to embodiments of the invention typically require less components than conventional feedforward arrangements, making them further advantageous from an economic standpoint.

1. Field of the Invention
The invention relates to integrated circuit devices. More particularly, the invention relates to driver output stages of integrated circuit devices.
2. Description of the Related Art
The manufacturers of integrated circuit devices have always sought improved frequency response for their circuits, especially for circuits typically operating at higher frequencies, e.g., frequencies above 10 kHz. One technique used in attempting to enhance the frequency response of, e.g., amplifier circuits including those used in operational amplifiers, is a feedforward arrangement.
Feedforward arrangements are known process control arrangements in which changes are detected near the process input and an anticipating correction signal is applied before the process output signal is affected. For example, see Widlar et al., "Operational Amplifiers And Voltage Regulators", Digest of Technical Papers, 1985 IEEE International Solid-State Circuits Conference, which discloses an operational amplifier having a feedforward arrangement incorporated therein.
In the Widlar article, the feedforward arrangement includes a current modulator, formed by a pair of transistors, that modulates current added to the input drive current to the negative driver output transistor. However, such arrangement includes active components and also includes compensation to prevent oscillation of the circuit. Still, the arrangement suffers from problems such as stability (especially at higher frequencies, i.e., above approximately 10 kHz).
Accordingly, a simple, low cost feedforward arrangement is sought that enhances high frequency response, yet does not suffer from operational instability or the other problems associated with conventional feedforward arrangements.

Amplifier feedforward arrangement and method for enhanced frequency response


A nozzle for use with a pressure washer, and the nozzle includes a body portion that defines a longitudinal axis and a head portion coupled to the body portion and in fluid communication with the body portion. The head portion includes a face substantially perpendicular to a longitudinal axis of the body portion. An elongated first slot is disposed upon the face of the head portion, and an elongated second slot is disposed upon the face of the head portion and in a nonparallel orientation with respect to the first slot. A fluid outlet aperture extends through the face and is at least partially located within at least one of the first and second slots to allow a fluid flow from within the body portion to exit the nozzle from the head portion.

Pressure washers are often used to provide a substantially constant flow of fluid at an increased pressure to a work surface or object for cleaning of that surface or object. Pressure washers often include a pump for increasing the pressure of fluid provided therefrom, a path for fluid flowing from the pump discharge, and a wand or similar output device that can be held by the user to direct the relatively high pressure flow to the object or surface to be cleaned. A nozzle is often attached to the output device that includes a wand. Some nozzles provide output flow in a single cylindrical stream, multiple parallel streams, or planar fluid flows.

Techtronic Outdoor Products Technology Limited


Systems and methods for simulating a melt pool characteristic for selective laser melting additive manufacturing. The system includes a selective laser melting apparatus and an electronic controller configured to obtain a surface geometry of a previous layer of a component being manufactured using the selective laser melting apparatus, simulate an addition of a powder layer having a desired powder layer thickness to the component based upon the surface geometry of the previous layer, determine a melt pool characteristic based upon geometric information of the simulated powder layer and the desired powder layer thickness, determine an adjustment to the simulated powder layer based upon the melt pool characteristic, and actuate the selective laser melting apparatus based upon the simulated powder layer and the determined adjustment.

Selective Laser Melting ("SLM") is a manufacturing technology that is capable of building complex components with nearly full density. The key feature of SLM is the layer-by-layer fabrication of complicated shapes that are difficult to make using traditional manufacturing methods, such as casting and machining. In the SLM process, digital information of the desired part, such as a computer-aided design ("CAD") model, is sliced into many layers. The laser beam scans a metallic powder bed layer in a way defined by the CAD model to form the layers of the part that is being fabricated. The laser beam irradiates the top surface of the power bed, locally melting the powders and creating a melting pool. With repeated heating and cooling and solidification cycles, the part is fabricated.
There are significant challenges in using the SLM fabrication process. Parts fabricated using SLM frequently encounter build defects such as local porosity and layer delamination. It is well known that melt pool characteristics and powder layer thickness have a significant influence on part quality and any defects created during the fabrication process. During a normal fabrication process, the powder layer thickness is a constant value, pre-selected before initiation of part fabrication. Adjusting the powder layer thickness can be challenging, because the powder layer thickness influences melt pool characteristics.

Simulating melt pool characteristics for selective laser melting additive manufacturing


The present invention provides an image recording apparatus which has a pack compartment to be loaded with an instant film pack containing multiple instant film sheets stacked together and records images on the instant film sheets contained in the instant film pack loaded into the pack compartment while transporting the instant film sheets. The pack compartment has receiving surfaces projecting into the pack compartment and support the instant film pack loaded into the pack compartment. The receiving surfaces support the instant film pack while keeping the instant film pack tilted by making the respective amounts of projection thereof mutually different.

1. Field of the Invention
The present invention relates to an image recording apparatus which has a pack compartment to be loaded with an instant film pack containing multiple instant film sheets stacked together, and records images on the instant film sheets contained in the instant film pack loaded into the pack compartment while transporting the instant film sheets.
2. Description of the Related Art
Printers which record images on instant film sheets are conventionally known. Such printers are equipped with: a pack compartment to be loaded with an instant film pack containing multiple instant film sheets stacked together; a film door which openably covers the pack compartment; and a display unit which displays the number of remaining instant film sheets in the instant film pack loaded into the pack compartment. An image is recorded on an instant film sheet as follows: an instant film sheets contained in an instant film pack loaded into the pack compartment is raked up by a claw and transported by a pair of transport rollers while being held between them, and irradiated cyclically with lights from light-emitting elements with red (R), green (G), and blue (B) luminescent colors to write a latent image, and then a developer pod of the instant film sheet is squeezed by a pair of developing rollers to spread a developer (e.g., Japanese Patent Application Publication No. 2002-221761).
Further, U.S. Pat. No. 4,668,062 shows a structure in which projections different in the amount of projection are provided to support an instant film pack loaded in a pack compartment. This is a shape to keep a tilted pack in a straight position.
A claw raking up an instant film sheet contained in an instant film pack loaded into the pack compartment is normally so configured as to rake up a part of the rear end of the instant film sheet, the part being closer to one corner of the sheet. If the claw rakes up one corner of the instant film sheet in this way, the instant film sheet may be discharged from the instant film pack and transported by the transport rollers while it remains tilted. As a result, a latent image is recorded on the tilted instant film sheet and a tilted image is formed on the instant film sheet, lowering its quality as a product.


A method, computer program product and system providing management and control of the disposition of personal financial resources, taking into account the effects of inflation and deflation. The method is used to project target gross income, income taxes, after-tax income, living costs and savings over a period of time. The compounding effect of inflation (deflation) is applied to actual amounts for gross income, income taxes, after-tax income, living costs and savings to project targets for these amounts through the projected period by applying to the actual amounts the estimated rate of inflation or deflation and rates that are related to these rates. Actual inflation and deflation rates are used to determine and recalculate the inflation and deflation rates, and the rates that are related to those rates, and the recalculated rates are applied to the actual amounts to recalculate the targeted amounts. Variances between targeted amounts and actual amounts, which are calculated as actual figures are determined during the projected period, are produced.

The present invention relates to financial control and management, and, more particularly, to a system, a method and a computer program product for managing and controlling the disposition of financial resources.
While many individuals employ techniques of one form or another to try to manage their personal finances, they often fail as a result of their ignorance of the effects of inflation on their financial situation. In particular, inflation has a compounding effect on living costs, a fact that is not widely appreciated, and that has a significant effect on personal financial planning.
The compounding process, which is a mathematical operation based on the laws of multiplication, has been referred to as the eighth wonder of the world. This is a result of its ability to greatly magnify (increase) whatever is being compounded over time.
Despite the best attempts to describe with clarity the power of compounding, it still remains a mystery to many. While most are familiar with how investment return compounds, few have come to understand that living costs as measured by inflation increase at a compound rate. The same mathematical operation that increases investment return--which is compounding--increases living costs. This effect complicates the financial planning process.
TABLE 1 ______________________________________ Compounding Inflation During 1949-1994 B C D Approximate A Inflation Conversion Index Time Year Rates Factor Value of Doubling ______________________________________ 100.00 1949 -2.10 .979 97.90 1950 5.90 1.059 103.68 1951 6.00 1.06 109.90 1952 0.80 1.008 110.78 1953 0.70 1.007 111.56 1954 -0.70 .993 110.78 1955 0.40 1.004 111.22 1956 3.00 1.03 114.56 1957 2.90 1.029 117.88 1958 1.80 1.018 120.00 1959 1.70 1.017 122.04 1960 1.40 1.014 123.75 1961 0.70 1.007 124.62 1962 1.30 1.013 126.24 1963 1.60 1.016 128.26 1964 1.00 1.01 129.54 1965 1.90 1.019 132.00 1966 3.50 1.035 136.62 1967 3.00 1.03 140.72 1968 4.70 1.047 147.33 1969 6.20 1.062 156.46 1970 5.60 1.056 165.22 1971 3.30 1.033 170.67 1972 3.40 1.034 176.47 1973 8.70 1.087 191.82 1974 12.30 1.123 215.41 First Doubling 1975 6.90 1.069 230.27 1976 4.90 1.049 241.55 1977 6.70 1.067 257.73 1978 9.00 1.09 280.93 1979 13.30 1.133 318.29 1980 12.50 1.125 358.08 1981 8.90 1.089 389.95 1982 3.80 1.038 404.77 Second Doubling 1983 3.80 1.038 420.15 1984 3.90 1.039 436.54 1985 3.80 1.038 453.13 1986 1.10 1.011 458.11 1987 4.40 1.044 478.27 1988 4.40 1.044 499.31 1989 4.60 1.046 522.28 1990 6.10 1.061 554.14 1991 3.10 1.031 571.32 1992 2.90 1.029 587.89 1993 2.70 1.027 603.76 1994 2.70 1.027 620.06 TOTAL 188.50 ______________________________________
Table 1 lists the annual rates inflation for the period 1949 through 1994. The year 1949 was chosen as the beginning year in the study, since prior to 1949, excluding the eight year period 1941 through 1948, inflation was basically non-existent in the United States on a continuing basis, and typically occurred only during war-time periods. The eight year period from 1941 through 1948 was excluded, since it contains the five year period 1941 through 1945, representing the years of World War II--an inflationary period--and the three year period following World War II, 1946 through 1948. The three years from 1946 through 1948 can be characterized as a period when pent-up demand, which accumulated during the war years, was unleashed in the form of increased consumer spending--which generated inflation. Thus the eight year period from 1941 through 1948 was atypical regarding the rates of inflation that have been experienced in the United States. As a result, 1949 will be the beginning year for measuring increases in the price level.
Column A of Table 1 lists the years of the time period that is covered by this analysis--1949 through 1994. Column B shows the annual inflation rates for the time period. These rates are the annual rates of inflation as reported by the Department of Labor using the CPI-U (consumer price index reading for all urban consumers). Column C shows conversion factors that were calculated by dividing the annual inflation rate (or deflation rate) for each year in Column B by 100 and then adding the whole number 1 to the result. The formula for calculating the conversion factor is shown in equation ##EQU1##
Changing the annual rates of inflation and deflation into conversion factors is necessary to apply the annual rates--by multiplication--to the CPI-U index value for each year that is shown in Column D. In Table 1, the CPI-U index value for each year is calculated by multiplying the CPI-U index value for the prior year by the conversion factor for the year for which the CPI-U index is being calculated. This is exactly how the price level is increased as measured by the CPI-U. That is, the price level for goods and services increases at a compound rate--by multiplication.
As is illustrated in Table 1, a first doubling took place in the average level of prices in 1974--the index value increased to 215.41--and a second doubling took place in 1982--the index value increased to 404.77 (Column D). The United States is now on its way to a third doubling when using 1949 as the base year for measuring compound increases in the average level of prices. It is important to note at this point that each time the price level doubles, the purchasing power of a dollar diminishes. Using 1949 as the point of reference, at the first doubling a 1949 dollar decreased in purchasing power to $0.50, at the second doubling it decreased to $0.25 and at the third doubling it will decrease to $0.125. It is important to note also that when the annual rates of inflation are added together each year during the period 1949 through 1994, the total is 188.50% (Column B). However the increase in the price level was not 188.50%, but rather 520.06% (comparing the ending 1994 index value of 620.06 to the beginning index value of 100--Column D). This is a result of the compounding process.
It is important to keep in mind that at the time of the first doubling, the index value increased from 100 to 200, at the time of the second doubling the index value increased from 200 to 400, at the time of the third doubling the index value will increase from 400 to 800, and at the time of the fourth doubling the index value will increase from 800 to 1600, and so on. In terms of dollars, what originally cost $1 would increase to $2, then to $4, then to $8, then to $16 and so on.
Table 2 shows the increases that take place in the average level of prices--represented by the index value--at the time of the first four doublings. Although only two doublings in the price level have occurred, when using 1949 as the beginning year, four doublings are shown. Significantly, when the sum of the annual rates of inflation total to 72 in any period, the price level (index value) doubles during that period--because the inflation rates are being applied multiplicatively as conversion factors. The number 72 is calculated by adding the inflation rates in Column B of Table 1. Each time a total of 72 is attained during a period of years in Column B, the index value in Column D doubles during that period. Note that 72 is an estimate for determining the time of each doubling. As a result the inflation rates may total slightly more than 72 before a doubling actually takes takes place in the index value (or price level).
TABLE 2 ______________________________________ Time of Doublings Inflation Total Annual Index Total Adjusted Inflation Number of Value Percentage Dollars Rates Doublings 100 Change $1 ______________________________________ 72 1 200 100% 2 72 2 400 300 4 72 3 800 700 8 72 4 1600 1500 16 ______________________________________ *Accuracy of the number 72 is somewhat diminished by the prescence of deflation.
In summary, the major problem that is affecting the personal financial plans of those residing within the United States has been identified above. It is not the effect or component of inflation that increases by addition. Rather, it is the compounding component of inflation--that is, inflation that increases multiplicatively. Compounding inflation is not only driving up average living costs for goods and services as measured by the CPI-U, it is also driving up the cost of homes and college education. Just as investment returns increase at a compound rate, living costs, home costs and college costs do likewise, each compounding at their own specific rates of inflation.
This presents a serious problem that the typical American does not realize, let alone know how to address. In summary, annual inflation rates for living costs, homes or college do not increase additively--by addition--but multiplicatively--by multiplication. This process of multiplying the index value of the prior year by the inflation rate of the current year expressed as a conversion factor--which is mechanically how the price level increases--sets the compounding process in motion (see Column D of Table 1). Note that the cost of any item also increases in the same manner--that is, the prior year's cost is multiplied by the current year's inflation rate as a conversion factor. This would include the costs of homes, college education, cars and so on.
It is the compounding process that generates a snowballing increase in the price level. At each doubling, or 100% increase, the index value does not increase additively--from 100% to 200%, 200% to 300%, 300% to 400% and so on--but rather multiplicatively--from 100% to 200%, 200% to 400%, 400% to 800%, 800% to 1600% and so on.
FIG. 10 helps to clearly illustrate the need for this invention. As indicated in FIG. 10, between 1950 and 1994 median family incomes have risen from $3,319 to $38,782. However while incomes have been increasing, the value of the dollar has been depreciating--declining in purchasing power. In fact the purchasing power of a 1994 dollar, stated in terms of the purchasing power of a 1950 dollar, has declined to approximately 18 cents (having approximately 1/6 the purchasing power).
Therefore as incomes rise, purchasing power declines. This illustrates the problem of two economic forces moving in opposite directions and at different rates--yet affecting the same medium of exchange--which is the dollar. If inflation did not exist, we could remove from FIG. 10 the declining value of the dollar, as the prices of goods and services would be the same year in and year out. Rising incomes and a declining dollar present a confusing reality. People are earning more but their dollars are worth less. How does one couple together this economic dysfunction of rising incomes and declining purchasing power in order to accurately determine if they are ahead, behind or simply keeping pace with living costs? This invention unwinds and untangles this economic dysfunction of rising incomes coupled with a declining dollar (due to inflation) in order to provide an approach for inflation adjusting family income performance, living costs and savings. Let's take a closer look at the problem.
FIG. 11 illustrates the ranges of 1994 family incomes and is being used to provide a macro perspective of family earnings in the United States. As illustrated, in 1994 9% of all family incomes were under $10,000, 22% were between $10,000 and $24,999, 32% were between $25,000 and $49,999, 20% were between $50,000 and $74,999 and 17% were over $75,000. From here we will move to the FIG. 12 which illustrates median family incomes from 1950 to 1994 for selected time periods. (Note the term median denotes midpoint which is different from the average and family is defined as two or more persons residing together related by marriage, adoption or birth).
As illustrated in FIG. 12, in 1950 median family income in the United States was $3,319. By 1994 that figure increased to $38,782--an increase of 11.7 times. However while earnings were increasing, the purchasing power of the dollar was simultaneously decreasing--this being a result of inflation increasing living costs. In other words families were earning more but their dollars were buying less--an economic dysfunction.
According to the Consumer Price Index X1 (CPI-U X1), an accepted government index for restating current dollars to constant dollars (which differs from the CPI-U), from 1950 to 1994 the price level increased 5.66 times or 466%. Therefore what cost on average $1 in 1950 increased to approximately $5.66 in 1994. Stated another way, a 1994 dollar in terms of a 1950 dollar had about one sixth the purchasing power. Therefore when comparing the 1950 median family income figure of $3,319 to the 1994 figure of $38,782, one must first adjust for the fact that inflation is driving down the dollar's purchasing power. To accurately compare the numbers across time, either the figures in the chart must be restated in terms of the purchasing power of a 1994 dollar or the figures must be restated in terms of the purchasing power of a 1950 dollar.
Restating the 1994 figure of $38,782 in terms of a 1950 dollar's purchasing power yields $6,852 ($38,782 divided by 5.66, 5.66 representing the increase in the price level from 1950-1994). Comparing the inflation adjusted income figure of $6,852 to $3,319 yields an increase--after accounting for inflation--of approximately 106% during the period 1950-1994. Approaching the situation from the current level of prices (the 1994 price level), and restating the figures in FIG. 12 to the current level of prices (stated in terms of the purchasing power of a 1994 dollar) produces FIG. 13.
FIG. 13 begins with 1950 median family income of $18,774. Keep in mind all the figures in the chart have been restated to the current level of prices. Therefore the $18,774 median family income figure represents the amount of income needed in 1994 to buy the same amount of goods and services that $3,319 purchased in 1950 (1950 median family income of $3,319 multiplied by 5.66, the increase in the price level from 1950-1994 as measured by the CPI-U X1--the accepted government index for restating current dollars to constant dollars--in this example 1994 dollars). The other figures in FIG. 13, except the most recent figure which is 1994 , are also inflation adjusted in the same manner--by taking the non inflation adjusted numbers in FIG. 12 and then increasing them by the rise in the price level--as reported by the CPI-U X1-using the comparative percentage change between each year in the chart and the year 1994 as the multiplier.
Once the figures are restated in 1994 dollars--the most recent year in FIG. 13--termed constant dollars--we can now accurately and correctly compare the numbers. As illustrated during the first 20 year period 1950-1970--median family incomes increased from $18,774 to $35,407, an increase of 89% after accounting for inflation--termed a real increase. During the next 24 year period incomes increased from $35,407 in 1970 to $38,782 in 1994, an increase of 10%. Therefore it is clear in FIG. 13 that during the first 20 years of the period 1950-1994, median family incomes increased significantly-almost doubled.
However during the next 24 year period, income performance began to slow considerably only increasing 10% over a 24 year period on an inflation adjusted basis. For the overall period 1950-1994 the increase is 106%, from $18,774 in 1950 to $38,782 in 1994. FIG. 13 is informing us that incomes have been increasing during both periods, however during the latter the increases in inflation were almost commensurate with that of family incomes. As a result families were unable to provide for improvements in their their standard of living, an increase in their savings rate or both.
It must be pointed out that inflation picked up during the last 24 years in FIG. 13, accelerating the decline in the purchasing power of the dollar (refer to FIG. 10--see decline in dollar's purchasing power). Further it is important to keep in mind that during the first 20 year period there was predominantly one wage earner while during the second period their has been an increase to two wage earners. As a result their is a definite need to understand inflation better, and to devise a method to measure its effects as it relates to personal financial planning. This has led to the development of this invention.

System, method and program product for managing and controlling the disposition of financial resources


The Medic-Cam is a wireless, highly integrated, portable, lightweight sys which provides high quality video and audio communications between highly trained specialists and remotely located field personnel. The system utilizes a head mounted display, a subminiature high resolution color CCD camera, microphone, transmitter, receiver, antenna, battery and vest. The size and integration of the head mounted components allow it to be worn under a combat kevlar helmet.

Many scenarios can be envisioned where it would be desirable for a person of limited knowledge to communicate with a person having extensive knowledge. For example, an army medic has limited knowledge regarding the treatment of wounded soldiers, while an army doctor is an expert in this type of treatment. It is impractical to train all army medics to the extent that army doctors are trained, yet it would be of great benefit to wounded soldiers if all army medics had the ability to communicate in real time with army doctors at field hospitals regarding the wounds they are treating. If army medics had the ability to transmit video images of the wounds they are treating back to army doctors, and to discuss the treatment of these wounds via two way radio, then the treatment of the wounded soldier would be greatly enhanced. However, army medics must operate in hostile environments, and cannot be encumbered by bulky equipment, no matter how desirable the equipment might be. Therefore, this type of equipment must be small, lightweight, robust, and compatible with existing army combat equipment. The medic must be able to perform his combat medical tasks unhindered by any extra equipment, while the army doctor, located miles away, must be able to view clearly what the medic is doing. Bulky cameras, transmitters, receivers, and display devices are not suitable in this type of environment. However, recent technology in the miniaturization of components now makes the integration of this type of equipment possible.

The United States of America as represented by the Secretary of the Army


A method of producing microparticles by spray drying comprises the steps of providing a spray-drying feedstock solution comprising water, a volatile divalent metal salt, weak acid, 5-15% dairy or vegetable protein (w/v) and 1-20% active agent (w/v). The feedstock solution is adjusted to have a pH at which the volatile divalent metal salt is substantially insoluble. The feedstock solution is then spray-dried at an elevated temperature to provide atomised droplets, whereby the volatile divalent metal salt disassociates at the elevated temperature to release divalent metal ions which crosslink and aggregate the protein in the atomised droplets to produce microparticles having a crosslinked aggregated protein matrix and active agent dispersed throughout the matrix.

The disintegration of liquid into small droplets have long been a significant field of research interest, due to two reasons: (1) to apply to a liquid in some unit operations (particularly drying, cooling or freezing) and 2) to produce granular/capsular materials that offer some advantages such as stability, ease of dosing/handling and specific processing surface characteristics. This disintegration of liquid into droplets is evident in the field of micro-encapsulation where a core material (i.e. bioactive) is inserted or entrapped in a matrix (for example, WO2010119041) for improved bioactive protection, product yield and also to facilitate subsequent production processes. Examples of such encapsulation methods include emulsification, fluidized-bed coating, laminar jet breakup, coacervation, liposomes, complexation, crystallization and spray-drying. Most of these methods require the disintegration of a liquid, which can be done by a large number of techniques such as pressure atomization by pressure nozzles or two-fluid gas-stream atomization usually with air or steam as the atomising fluid.
Laminar jet breakup (i.e. production of micro-particles) and spray-drying (i.e. atomization by rotating disc) both remain the most promising processing technologies for the food and feed industry since conditions are mild, there is no significant problem of blockages/plugging and the processes are continuous and commercially viable. For example, methods of producing microparticles (using laminar jet breakup) having dairy protein matrices are well known and described in, for example, WO2010119041 (Teagasc). Generally, these types of microparticles are produced by providing a suspension of denatured protein, for example whey protein, and an active agent, treating the suspension to provide microdroplets using a vibrating nozzle, and then immediately immersing the microdroplets in an acidification bath to gel and solidify the microdroplets. While this method produces spherical, homogenously-sized microdroplets that are capable of gastric transit intact, the process involves use of specialised vibrating nozzle machinery which represents an additional expense for food companies. There is therefore a desire amongst food/feed producers and especially milk producers for a method of producing such microparticles using conventional food processing machinery such as spray dryers (See FIG. 1 schematic). Furthermore, this technology also requires a pre-heating step for the preparation of denatured protein. This pre-denaturation step can indeed be incorporated into industrial operations for value-added products; however, manufacturers of commodity/lower value products continue to seek practical and direct routes for the stabilisation of lower market value materials. Furthermore, the drying of microbeads generated by the technology WO2010119041 is not easily achieved using spray drying technology since the relatively large size of the micro-beads causes a disruption of the atomisation processes. In order to avoid deposits of wet and sticky micro-beads on the drier wall (See FIG. 2), micro-beads must be completely dry before they make contact with the interior wall of the drying chamber. Hence, micro-bead trajectories must be kept away from the drying chamber wall for longest time possible to allow correct drying; however this is not practically possible for commercial spray-drying scenarios.
Spray drying is a suspended particle dryer technique consisting of three essential steps: i) atomization, where the droplets are formed; ii) drying gas and droplet contact, where the liquid feed is turned into droplets; and finally iii) powder recovery, where the dried particles are separated from the drying gas stream. The use of a spray dryer to produce microparticles for bioactive stabilisation would involve re-designing of the micro-bead production process (WO2010119041), as it is not possible or appropriate to employ an acidification bath with spray dried particles, as the particles are dehydrated and atomised in the drying chamber.
A principal objective in drying involves the assurance that the liquid comes to disc speed and to obtain a uniform drop size distribution in the atomised liquid. However, the readjustment of shear stresses within the liquid once the droplet is airborne is another factor contributing to further disintegration of the droplet/microparticle. This is again a limitation for microbead technologies using spray-drying. To date, there is almost no records or publication on the area required for the collection of cross-linked & aggregated particles from the rotating disc in good conditions. In comparison to lyophilisation, spray drying is generally more flexible, more efficient and more economical in terms of installation, investment and operation for the same evaporative capacity. For instance, the evaporative capacity of a normal sized pharmaceutical spray dryer can match the evaporative capacity of 5-7 large freeze dryers. In many cases, however, the two technologies are supplementary. For small batches of difficult-to-dry powders to be supplied in vials, lyophilisation has an advantage, whereas spray drying has an advantage if free flowing powders are required. For this reason, the stabilisation of bioactive material using spray drying is a field with huge interest.
To summarise, spray-drying of protein feedstock solutions produces very small particles, too small to be able to entrap active agents such as probiotic cells (See FIGS. 5 and 6). One possible solution to this problem is replacement of an atomiser nozzle in a spray dryer with a vibrating nozzle, however this approach resulted in large droplets that stuck to the dryer wall (FIG. 2). A further possible solution is to add a cross-linking agent to the liquid feedstock with a view to making larger spray-dried particles that consist of cross-linked protein, however this results in cross-linking of the protein in the feedstock liquid prior to atomisation, with a resultant increase in viscosity and in most cases gelation of the feedstock liquid making it impossible to atomise the feedstock solution.
US2014/348815 discloses a method of producing microparticles by spray-drying that employs sodium alginate as a polymer for making the microparticle matrix, and employs a feedstock comprising a volatile base such as ammonia hydroxide or other volatile amines such as hydrazines, methylamine, trimethylamine, or ethylamine. The use of such volatile bases would prevent the microparticles being classified as food-grade products. Moreover, as alginate is such a strong gelling agent, only very low amounts can be employed in spray-drying feedstock which means that the total solids of the resultant microparticles is quite low, resulting in less polymerisation of the matrix and consequently a weaker and less stable matrtix, reduced yield of active agent (cargo) during drying, and less control of particle size.
It is an object of the invention to overcome these problems. It is a particular object of the invention to provide a method of producing food grade active-containing microparticles by means of conventional spray-drying that have greater yields that the methods of the prior art.

Method of producing microparticles of the type having a crosslinked, aggregated protein matrix by spray drying


A method for detecting a polymerase chain reaction (PCR) product is provided. The method includes (a) providing at least a pair of electrodes in a PCR solution-containing vessel; (b) performing PCR; (c) producing an electric field between the electrodes; and (d) measuring a change in a dielectric property in the PCR solution. Therefore, a PCR product can be detected in real time.

This application claims the priority of Korean Patent Application No. 2002-70141, filed on Nov. 12, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to a method for detecting a polymerase chain reaction (PCR) product using an electrical signal.
2. Description of the Related Art
A representative biosensor includes an enzyme sensor and an immune sensor using an immune response of the immune system. However, as a considerable amount of DNA information is obtained by the completion of the human genome project, and thus, potential and expectation of an early discovery and treatment of human genetic diseases increase, a DNA chip is rapidly emerging as another type of biosensor. Presently, active research areas in the development of biosensors are the possibilities of obtaining a low manufacturing cost, high speed, accuracy, easy handling property, and miniaturization (portability). In this regard, a DNA sensor for detecting a human disease at an early stage by using DNA information must be also developed toward satisfaction of the above requirements to strengthen an international market competitiveness.
One of essential genetic assays is a PCR DNA assay, which has been widely used in clinical, biological, and genetic laboratories since it was invented at the end of the 1980s.
A traditional PCR shows the qualitative results of amplified DNA by a gel electrophoresis at the end-point of the PCR reaction, but has many problems such as inaccuracy of the quantitative detection of DNA. Therefore, a Real-Time PCR was developed to allow for the quantitative detection of amplified DNA by detecting the intensity of fluorescent light, which is in proportional to the concentration of the amplified DNA, using an optical detection system.
A quantitative assay of DNA is essential for studies of disease treatments and DNA expression. For example, in order to ensure a successful medicinal therapy for patients infected with hepatitis B-type virus (HBV), the drug resistance of HBV must be tested by periodically detecting the concentration of HBV in the blood plasma using a Real-Time PCR.
A conventional Real-Time PCR requires many optical devices such as a laser source, a micromirror, a microscope, and a filter, and an expensive fluorescent dye. In addition, because a conventional Real-Time PCR chip is based on the principle of detecting fluorescent light, there are many disadvantages in terms of miniaturization (on a chip) and economical efficiency.
In order to solve this problem, an effort was made to electrically detect DNA using capillary electrophoresis (CE) [Christa L. Colyer et al, Journal of Chromatography A, Volume 781, Issues 1–2, 26 Sep. 1997, pp. 271–276; F. Laugere et al, Sensors and Actuators B: Chemical, Volume 83, Issues 1–3, 15 Mar. 2002, pp. 104–108; Pumera et al., Anal. Chem., 2002, 74(9), pp. 1968–1971). This method allows for a qualitative assay, but has many problems for a quantitative assay. In addition, transfer of PCR products to a CE detection system using a micro-channel after the completion of PCR is a laborious process and a high voltage is required. Therefore, requirements of economical efficiency and miniaturization are not satisfied.
Miles et al. filed a U.S. patent application, which has been published under U.S. Patent Application Publication No. 2002/007254A1, based on the concept that as the concentration of DNA increases during PCR, impedance decreases and conductivity increases. However, the Miles' concept that impedance decreases as the concentration of DNA increases during PCR is contrary to the fact demonstrated by the present inventors. Therefore, this patent application comes from a misunderstanding of the mechanism of PCR reaction.
During PCR, dNTPs are dissociated into dNMPs and many diphosphates. At the same time, dNMPs are polymerized into DNA using a primer supplementary to a template DNA. In this case, the disclosure of Miles et al. considers only the electrical mobility of diphosphates as a byproduct. However, considering an entire electrical mobility which decreases by dNMPs, a primer, and a template, all of which have electric charges during DNA synthesis, as the concentration of DNA increases, impedance of PCR increases due to the decrease of the electrical mobility. Furthermore, the Miles' invention is concerned with a PCR chip for end-point detection not a Real-Time PCR chip. In addition, there is a problem in that an ionically-labelled probe must be used to detect an amplified PCR product.

Method for detecting PCR product using electrical signal


Provided are a shift register, a gate drive circuit and a display panel. The shift register includes a reset module, where a first control terminal of the reset module is electrically connected to a first reset-signal input terminal, a second control terminal of the reset module is electrically connected to a second reset-signal input terminal, an input terminal of the reset module is electrically connected to a second power-signal input terminal, a first output terminal of the reset module is electrically connected to a first node, and a second output terminal of the reset module is electrically connected to a scanning-signal output terminal. In the third phase, the potential of the first node P is at a second level, each of potentials of the first control terminal and the second control terminal of the reset module is at the second level.

A liquid crystal display panel generally includes an array substrate, a color filter substrate, and a liquid crystal disposed between the array substrate and the color filter substrate. The array substrate includes multiple shift registers for providing scanning signals to the liquid crystal. When a leakage current exists in a shift register, the leakage current increases the power consumption of the shift register, increasing the power consumption of the liquid crystal display panel.

Shift register, gate drive circuit and display panel

SHANGHAI AVIC OPTO ELECTRONICS CO., LTD.


A portable energy device having a housing and an energy storage device is disclosed. The housing includes electrical input terminals and electrical output terminals, the input terminals being configured to receive electrical power from a vehicle having an electrical chassis operating at DC voltage, the output terminals being configured to provide electrical power to an electrical distribution system connected to a utility power grid operating at AC voltage. The energy storage device is in electrical communication with the input and output terminals, and is configured to store electrical power received from the vehicle via the input terminals and to provide the stored electrical power to the electrical distribution system via the output terminals. The housing is so dimensioned as to be insertable through a space defined by a trunk opening of the vehicle with the trunk open, or so dimensioned as to be insertable between a doorframe of the vehicle and a seat of the vehicle.

The present disclosure relates generally to portable energy devices, and particularly to a portable energy device for use between a vehicle and a residence.
Existing supplemental energy sources include such devices as solar panels, wind turbines, auxiliary generators, fuel cells, and batteries, which may or may not be directly connectable to the electrical distribution system of a residence via an inverter and controller. Existing power generating devices include among other things automobile generators/alternators. Existing power storage devices include, for example, batteries, capacitor banks, and ultra-capacitors. Existing supplemental energy sources, however, may not fully exploit the benefits of the aforementioned power generation and storage devices.
Accordingly, there remains a need in the art for a supplemental portable energy device that provides advantages over existing art.


There is provided a system and method for dynamically transmitting a services list to a playback device. The system comprises a display device, a playback device, and a mediator server with a mediator application. The mediator application is configured to receive, from the playback device, a service request for a services list, to send a services list for presenting on a display device in response to receiving the service request, to receive an activation request for at a third-party service listed in the services list, and to activate the third-party service in response to receiving the activation request. By programming a digital video disc such as a Blu-ray disc according to an API and using such a mediator server, a dynamically adjustable list of third-party services may be supported and used by the playback device without changing the disc application code.

1. Field of the Invention
The present invention relates generally to transmitting data to a playback device. More particularly, the present invention relates to transmitting a services list to a playback device.
2. Background Art
Blu-ray players and other digital video disc playback devices allow users to connect to the Internet to access additional features and data during playback of Blu-ray Discs and other digital discs. Many digital video discs have incorporated capabilities to allow users to access their accounts on numerous third-party services, including social networking services such as Facebook, Twitter, and Google Plus (Google+).
Presently, a digital video disc, such as a Blu-ray Disc, provides capability for users to access accounts on a fixed number of third-party services. While the availability of new and existing third-party services may change over time, present digital video discs are hard-coded with a fixed set of supported third-party services that may be managed from menu options. In order to gain access to additional third-party services unavailable on a particular digital video disc, users may have to purchase or exchange for newly updated discs with updated support code, which may be costly and inconvenient.
Accordingly, there is a need to overcome the drawbacks and deficiencies in the art by providing a method that provides updated access to third-party services on digital video discs without resorting to replacement discs.

This patent is subject to a terminal disclaimer.

System and method for transmitting a services list to a playback device


An internally expanding cutting device is used for severing large cylindraceous objects in two. The device comprises a spider mechanism in which a series of radially extending arms are attached to a central hub. The spider is arranged to be mounted on a base member so that the spider mechanism is free to rotate. A series of self propelled cutting wheels are mounted on the arms of the spider to allow the cutter wheels to contact the interior wall of the cylinder to be cut. The cutting wheels are arranged to drive the spider in a rotational manner while the cutter wheels are progressively pushed outwardly to deepen the cut. Each wheel follows in the track of the previous cutter wheel until the cylinder is severed.

The operation of a traditional pipe cutter used by a plumber is well understood. As the cutter is rotated around the exterior of the pipe, the pipe is progressively grooved by the force of the cutting wheel and the groove deepens with each successive passage of the cutting wheel until the pipe breaks.
A close examination of the above "cutting" process will show that the pipe really is not "cut", but a groove is formed in the pipe by swaging the metal of the pipe at the "cut", and this metal undergoes cold flow as the cutter wheel wedges the metal at the groove apart. The cold flow of the metal in the pipe continues as the cutter forces its way inwardly until the separation force produced by the wedging action of the cutter wheel is sufficient to fracture the portion of the pipe wall remaining at the "cut". If the cutter wheel is operating correctly, there will be practically no swarf produced by the pipe cutter during the "cutting" operation.
The cutting tool of this application functions in a somewhat similar manner but its application is typically found in severing large cylindrical objects which have relatively large diameters and relatively thin walls and which must be "cut" in environments where (in this instance) the cylinder is immersed under several feet of water. The cutting operation for these objects thus progresses (underwater) from the inside surface of the cylindrical wall toward the exterior surface of the wall until the cylinder fractures. This invention may be advantageously applied to applications in the nuclear reactor art where reconfiguring and/or decommissioning of nuclear reactors must be undertaken. The invention may be specifically applied to good advantage in severing such items as pressure vessels or stainless steel shrouds in Boiling Water Reactors (BWR's) which typically have diameters in the order of 12-20 feet and which have a wall thickness from about one to eight inches. The ratio of the cylinder diameter to wall thickness gives some indication of the stability of the cylindrical wall (the higher the number, the greater the flexibility of the wall). For cylinders applicable to this invention, the diameter to thickness ratio may be in the order of 25-150; for a commercial steel pipe used in the plumbing industry the ratio may be as small as 4. It will therefore be apparent that the cylindrical objects to which this invention applies typically have walls which are quite flexible and which may be easily deformed by the application of localized radial force.
In reconfiguring and/or decommissioning BWR's, it is necessary to cut large cylindrical reactor components into pieces in order to make the removal of the component possible as well as to facilitate handling and storage of the cut pieces which may yet be radioactive.
Attempts to cut such components (successfully or otherwise) while the cutting equipment is immersed in substantial depths of water, have included plasma arc torch, Electric Discharge Machining (EDM), Laser cutting devices, water jets and metal cutting saws.
Most of the above devices produce significant amounts of swarf during a cutting operation. In some instances, the swarf is produced as a vapour and in other processes, the swarf consists mainly of small metallic particles. It is easily seen that the production of substantial amounts of radioactive swarf formed during the cutting process, can lead to a very serious and expensive cleanup and containment operation which must be carried out under a substantial height of water.
Other severing techniques, which have been tried with varying degrees of success, appear below.

Cutting appliance for large cylindraceous objects


Systems, apparatuses, and methods for uplink timing maintenance in wireless communications are provided. Certain aspects of the disclosure involve applying a timing advance command to adjust uplink transmission timing/resume uplink synchronization; and determining a metric. The metric can be used in determining whether to apply a timing advance command (TAC) to resume uplink resynchronization.

This disclosure relates to uplink timing maintenance in wireless communication systems.
Wireless communication systems can include a network of one or more base stations to communicate with one or more wireless devices such as fixed and mobile wireless communication devices, mobile phones, or laptop computers with wireless communication cards. Base stations can emit radio signals that carry data such as voice data and other data content to wireless devices. A base station can transmit a signal on a downlink (DL), to one or more wireless devices. A wireless device can transmit a signal on an uplink (UL), to one or more base stations.
The uplink signals from multiple wireless devices may go through different paths and experience different propagation delays to arrive at one base station. The base station may need to control the transmission timing of the wireless devices such that the uplink signals from multiple wireless devices are time aligned when the signals arrive at the base station. An absence of time alignment may cause significant interference to other uplink users. One of the main purposes of time alignment is to counteract different propagation delays among multiple wireless devices.

Uplink timing maintenance upon time alignment timer expiry


A multi-axis acceleration sensor comprises a frame, a central mass disposed within the frame, and a plurality of transducers mechanically coupled between the frame and the central mass. At least a first set of the transducers are arranged between the frame and the central mass in a manner configured to measure translational and rotational motion with respect to a first predefined axis.

This application relates generally to geophysical exploration, and more specifically to seismic data acquisition and sensor technologies. In particular, the application relates to sensor systems for marine seismic surveys, including, but not limited to, ocean bottom cables and autonomous seismic node applications.
Seismic survey technologies are commonly used to explore and develop resources for the petrochemical industry. Petrochemical products are ubiquitous in the modern economy, and can be found in everything from oil and gasoline to medical devices, children's toys, and a wide range of other everyday household items. To meet the continuing demand for these products, oil and gas reserves must be accurately located and surveyed, so that these important resources can be effectively managed. As a result, there is an ongoing need for new seismic sensor systems and more advanced exploration technologies.
Scientists and engineers typically utilize seismic wave-based exploration techniques to locate new oil and gas reservoirs, and to survey and manage existing reserves over time. Seismic surveys are performed by deploying an array of seismic sensors or receivers over the region of interest, and monitoring the response to controlled emission of seismic energy via seismic sources such as vibrators and air gun arrays, or explosive detonations. The response depends upon the seismic energy reflected from subsurface structures, allowing the corresponding geological features to be imaged, including mineral reservoirs and other underground structures of interest.
Marine seismic surveys may proceed by towing an array of seismic sensors or receivers behind a survey vessel, with the receivers distributed along one or more streamer cables. A set of air guns or other seismic sources is used to generate seismic energy that propagates down through the water column to the ocean floor (or other bottom surface). A portion of the seismic energy penetrates the ocean floor and is reflected from subsurface structures, then returns back through the water column to be detected in the streamer array. Seismic receivers can also be disposed along ocean-bottom cables, or provided in the form of individual, autonomous seismic nodes distributed on the seabed.
Typical seismic receivers include pressure sensors and particle motion detectors, which can be provided as individual sensor components, or combined together with both sensor types located in close proximity within a receiver module or seismic node. For example, a set of pressure sensors can be configured in a hydrophone array, and adapted to record scalar pressure measurements of the seismic wavefield propagating through the water column or other seismic medium. Particle motion sensors include accelerometers and geophones, which can be configured to provide single-axis or three-dimensional vector velocity measurements that characterize motion of the medium in response to propagating seismic waves.
Geophysical data pertaining to the subsurface structures is acquired by observing the reflected seismic energy with an array of such receiver components. The observed seismic signals are used to generate a seismic image that described the subsurface geology and composition a in and around the survey area. The overall image quality depends not only on signal sensitivity but also noise effects, contributing to the constant demand for more advanced sensor and receiver technologies.


A head mounted display (HMD) and a method for controlling the same are disclosed. Most particularly, the HMD and the method for controlling the same may detect an external device having a ticket stored therein and display augmented reality information related to the stored ticket in a location approximate to an individual carrying an external device, in order to check tickets.

1. Field of the Invention
The present disclosure relates to system related to a head mounted display (HMD) and a method for controlling the same and, more particularly, to a HMD and a method for controlling the same that can detect an external device having a ticket stored therein and display augmented reality information related to the stored ticket in a location approximate to an individual carrying an external device, in order to check tickets.
2. Discussion of the Related Art
As the digital devices are becoming more light-weight and more compact in size, the application and usage range of portable devices is increasing. Accordingly, a user may use his (or her) portable device in order to be capable of more easily performing a wanted operation whenever and wherever he (or she) wishes. For example, the user may use a ticketing service by using his (or her) portable device without any limitations in time and space. Additionally, since the purchased tickets may be issued through an application installed in the user's portable device, the user is not required to carry the actual ticket(s).
However, when a user seeks to enter a concert hall or a movie theater by using his (or her) issued ticket, the user is required to show his (or her) ticket to a ticket checking agent (or ticket agent). Accordingly, the user is required to undergo the inconvenience of having to take out his (or her) portable device from his (or her) pocket or bag and to personally show the purchased digital ticket to the ticket agent.

Head mounted display and method for controlling the same


An article comprising a folded sheet, that is able to be unfolded, the folded sheet comprising a plurality of segments defined by folds lines, with at least one stiff portion provided at one of said exposed segments of the folded sheet, wherein at least part of the stiff portion comprises a transparent material and the folded sheet is folded with two sets of concertina folds, and one of said concertina folds being transverse of the other of said concertina folds.

This invention relates to articles each comprising a sheet folded with a first set of concertina folds and so as to be transverse to these a second set of concertina folds. It also relates to improved apparatus and processes for producing such articles. Certain features or combinations of features of the apparatus and processes are thought to have independent value and the invention therefore extends to such features and combinations and to corresponding articles.
The present inventor has experimented to produce the first-mentioned articles with finishing of them, by attaching outer stiff portions to the folded sheet, being done by hand. In attempting to produce apparatus for carrying out this process and further steps of processing such articles, there have been encountered much inconsistency in production, very slow maximum speeds of production and various other snags.

Method and apparatus for laminating stiffeners with folded sheets