An image processing system processes images such that a proportion of area of regions of interest within the image can be increased at the expense of regions of lesser interest. First, regions of interest, such as portions of the image including participants, are determined. Then compressible background regions are determined and compressed. This results in the proportion of the area of the regions of interest to increase. After the image is stored or transmitted, the regions of interest can be seen more clearly both because they are larger and because any loss of detail caused by down-sampling or lossy image compression needed to limit the amount of image information is reduced due to the smaller image size. The process also preserves more of the relative spatial relationship between various regions of interest than prior methods.

Clarity of an image presented to a videoconferencing participant is an important aspect of videoconferencing and video-telephony systems. Attainment of sufficient clarity is particularly challenging in group videoconferencing applications, in which more than one participant is present at one or both ends of the videoconferencing session. In such cases, a camera that is used to capture the participants is typically zoomed out so that the camera can capture all the participants of the group. However, zooming out diminishes the sizes of the participants as they appear in the captured image. In other words, the number of pixels dedicated to each of the most interesting parts—the participants or other regions of interest (ROI)—are reduced. As a result, when the image is sent to the far end, the images of participants within the image are less clearly seen by the far end participants.
For example, FIG. 1 shows a captured image 101 of a conference room. An image captured by a typical camera has only a finite number of pixels, and therefore finite resolution. The camera capturing the image 101 has been zoomed out in order to include the entire area of the conference room where conference participants are likely to sit, although the three actual participants 102-104 occupy only the center region of the captured image. Most of the area in the image 101 is occupied by objects that are not interesting or necessary as far as a specific videoconference with participants 102-104 is concerned. The interesting portions of the image 101 are the faces and torsos of conference participants, e.g., 102, 103, and 104. Thus, the number of pixels capturing the ROI—the conference participants—is considerably less than the pixels capturing non-interesting regions of the image 101. When image 101 is shown to the far end participants in a typical videoconference according to prior art, the far end participants can see the images of participants 102-104 with limited clarity, because (a) the number of pixels in the image 101 is finite, (b) the videoconferencing system will typically reduce the number of pixels by down-sampling prior to transmission in order to reduce the bandwidth and computational resources required by the system, (c) the video encoding algorithms typically used are lossy, and will produce a decoded picture with less detail than the originally transmitted picture, and (d) the image displayed to the far-end participants is of finite size—therefore the image of each person may be so small that human visual acuity is able to resolve only a portion of the displayed details.
To elaborate, transmitting the image 101 to the far end can have further adverse impact on clarity. For example, compression, down-sampling, etc. may be carried out on an image to be transmitted to the far end in order to meet transmission bandwidth limits. FIG. 2 shows FIG. 1 down-sampled to QCIF resolution (176×144 pixels) for transmission to the far end. Down-sampling reduces the number of pixels for each participant to an even lower number than captured in the original image.
One traditional solution is to use multiple cameras, where each camera captures only the face/torso of one participant, and to combine the individual captured images in a so-called "Hollywood Squares" fashion to form a composite image, as shown in FIG. 3. Thus, majority of pixels of image 106 are dedicated to the images of the participants. The regions of image 101 that contained less interesting objects and features are desirably absent from image 106. Yet, while the faces of individual participants are clear, the actual spatial relationship between the participants is lost by the arrangement in image 102. For example, when participants 102 and 103 turn their heads to make eye contact with each other, the resultant motion in image 106 will appear with participant 102 turning to his left and participant 103 turning to his right. Because the image of participant 104 is to the left of the image of participant 102, it will seem as if participant 102 is turning to converse with participant 104, instead of participant 103. This can be very disorienting to the far end participants who are unaware of the relative positions of the near end participants.
Thus, it is desirable to have a technique that not only provides clearer images of the interesting regions of a captured image, but also maintains relative spatial arrangements of local participants in the captured image.

Background compression and resolution enhancement technique for video telephony and video conferencing


A dual electrode arrangement, is provided, wherein two, preferably unidirectional, electrode configurations flank a nerve junction from which a preselected nerve branch issues, proximally and distally to the junction, with respect to the brain. The arrangement is conducive to the following: generating efferent action-potential propagations, substantially restricted to the preselected nerve branch, inhibiting afferent action-potential propagations, from the preselected nerve branch, selectively generating action-potential propagations, in a subset of nerve fibers of a predetermined diameter range, substantially restricted to the preselected nerve branch, and selectively inhibiting action-potential propagations, in a subset of nerve fibers of a predetermined diameter range, substantially restricted to the preselected nerve branch. The dual electrode arrangement is further conducive to monitoring naturally-occurring, efferent action-potential propagations, heading towards the preselected nerve branch, and monitoring naturally-occurring, afferent action-potential propagations, from the preselected nerve branch. The unidirectional electrode configurations may be monopolar, bipolar, tripolar, or multipolar. Communication with extracorporeal stations, and closed loop operations are also provided.

The present invention relates to nerve stimuli, and more particularly, to apparatus and methods for nerve-branch-specific action-potential activation, inhibition, and monitoring.
The nervous system is a network of billions of interconnected nerve cells, or neurons, that receive various types of stimuli and cause the body to respond appropriately. The neurons link the central nervous system (CNS) consisting of the brain and the spinal cord, with the body. A neuron usually has a cell body, dendrites that receive inputs, and an axon, an elongated nerve fiber that transmits electrical potentials as action potential. Efferent neurons send impulses peripherally to activate muscles or secretory cells, while afferent neurons convey sensory information centrally from the periphery.
The axon, the fiber-like, elongated portion of the nerve cell, conducts impulses in two directions, to and from the body of the nerve cell and transmits the information along the nervous system. Its function is somewhat analogous to a wire in an electric circuit. However, whereas in an electrical circuit, a wire allows the passage of a current, generally along its core, the axon, on the other hand, operates by the propagation of a potential difference along its plasma-membrane external surface, formed as a molecular lipid bilayer.
The propagating potential difference is referred to as action potential. It is an "all-or-nothing" phenomenon, described below:
1. Rest Condition: When at rest, sodium-potassium pumps in the plasma membrane keep a higher concentration of sodium ions outside the cell and a higher concentration of potassium ions inside, and create a voltage difference, of about 60-100 mV, generally referred to as the resting potential. Since the external surface is positive and the internal surface is negative, the membrane is polarized.
2. Depolarization: When the neuron is stimulated, a small region of the cell's membrane is depolarized to a threshold potential. When this happens, voltage-gated Na channels along the membrane open, and Na+ ions rapidly diffuse into the cell, causing the electrical potential across the cell membrane to be reduced. As Na+ ions continue to diffuse into the cell, an excess of positive ions accumulates inside, and the membrane becomes positively charged inside and negatively charged outside, at that small region. The action potential that is formed is typically about 20 mV. The voltage-gated Na channels then spontaneously close.
4. Propagation: The negatively charged membrane at the small region of the action potential stimulates the adjacent region to become depolarized. Thus the action potential propagates as a wave.
5. Repolarization: By the time the action potential has moved from one small region along the membrane to the adjacent region, the first region has repolarized and returned to its resting potential. Repolarization occurs as the Na+ channels close and K+ channels open, allowing K+ ions to diffuse out of the cell more rapidly, restoring the positive charge to the external surface of the membrane, and the negative charge to the internal surface.
6. The Refractory Period: The refractory period is defined as the time period when an excitable membrane cannot be stimulated. It prevents the action potential from stimulating the region from which it came. In other words, it prevents reverberation between two adjacent regions. Thus, propagation must continue forward. During the refractory period, Na+ ions are actively transported out of and K+ into the cell by the Na—K pumps. The refractory period can be divided into two distinct portions:                i. The absolute refractory period is the time during which no stimulus can initiate a new action potential.        ii. The relative refractory period is the time during which a hyper-threshold stimulus can initiate an action potential.
The phase propagation process is very rapid, about 3 msec to a region, in myelinated fibers. Neurons typically fire at rates of 100 action potentials per second.
Because of the 'all-or-nothing characteristic of action potential, conduction is non-decremental, that is, it does not diminish, or 'die out' with distance from the initial site of stimulation. This is in marked contrast to conduction in a wire of an electrical circuit.
Neurons may be classified by conduction speed, diameter and the presence or absence of specialized lipoprotein insulation called myelin. The main nerve fibers, of about 2-20 microns in diameter, are myelinated, while the lower branches, down to about 0.2 microns in diameter, are unmyelinated. In myelinated fibers, conduction is saltatory, or by jumps, along the unmeylinated nodes of Ranvier. In unmyelinated nerve fibers, conduction is smooth.
Type A fibers are myelinated and can conduct impulses at 12-120 m/sec. Type B are also myelinated fibers but they only transmit impulses at 3-5 m/sec. Type C fibers are unmyelinated, small in diameter, and their conduction is very slow, at a rate of about 0.2-2.0 m/sec. An example of a Type A fiber is a motor efferent neuron innervating the gastrocnemius. An example of a Type B fiber is an autonomic preganglionic efferent neuron. An example of a Type C fiber is a sensory afferent neuron carrying information about diffused pain.
The refractory period of action-potential propagation makes nerve blocking possible. A number of blocking techniques are presently known for blocking or stimulating motor nerves controlling muscular or glandular activities. These include: (1) collision block; (2) high frequency block; and (3) anodal block.
In high frequency block, high frequency (e.g., 600 Hz) stimulations are used to block the transmission of the action potentials through the nerve fibers.
In anodal block, nerve fibers are locally hyperpolarized by a DC anodal current. If sufficiently hyperpolarized, action potentials are not able to propagate through the hyperpolarized zone and will be blocked. Anodal block is described, for example, in N. J. M. Rijkhof et al., "Acute Animal Studies on the Use of Anodal Block to Reduce Urethral Resistance in Sacral Root Stimulation" IEEE Transactions on Rehabilitation Engineering, Vol. 2, No. 2, pp. 92, 1994, whose disclosure is incorporated herein by reference.
In collision block, artificially induced action potentials are generated by a unidirectional electrode (an electrode adapted for generating an action-potential propagation substantially in one direction) and collide with, and thereby block, the naturally induced action potentials, coming towards them. In essence, the artificially induced action potential at a region along the axon membrane is timed and shaped so that when a naturally induced action potential arrives at that region, the region is in a refractory period, and the naturally induced action potential cannot propagate through it.
Collision block has been described, for example, in C. van den Honert, J. T. Mortimer "A Technique for Collision Blocks of Peripheral Nerve: Single Stimulus Analysis", IEEE Transactions on Biomedical Engineering, Vol. 28, No. 5, pp 373, 1981, whose disclosure is incorporated herein by reference.
The unidirectional electrode is an important component in collision blocking. Designs of unidirectional electrodes may be found, for example, in the following articles, Ungar I J et al., "Generation of unidirectionally propagating action potentials using a monopolar electrode cuff," Annals of Biomedical Engineering, 14:437-450 (1986), Sweeney J D et al., "An asymmetric two electrode cuff for generation of unidirectionally propagated action potentials," IEEE Transactions on Biomedical Engineering, vol. BME-33(6) (1986), and van den Honert C et al., "Generation of unidirectionally propagated action potentials in a peripheral nerve by brief stimuli," Science, 206(4424):1311-1312 (1979), whose disclosures are incorporated herein by reference.
Additionally, U.S. Pat. No. 4,649,936, to Ungar, et al., dated Mar. 17, 1987, and entitled, "Asymmetric single electrode cuff for generation of unidirectionally propagating action potentials for collision blocking," whose disclosure is incorporated herein by reference, describes a single electrode, having an asymmetric electrode cuff, which is disposed around a nerve trunk. A signal generator is connected between a cathode disposed asymmetrically in the electrode cuff and an anode disposed in an electrically conductive relationship within the body tissue. The signal generator applies a stimulus signal, which generates unidirectionally propagating action potentials on the nerve trunk. The electrode cuff includes a dielectric sleeve in which the cathode is positioned a first distance from an escape end and a second distance from an arrest end. The first distance is at least 1.7, and preferably about 7, times the second distance. This asymmetry causes a primary or forward stimulus signal current to be correspondingly greater than a secondary or reverse current.
Further work by the same group includes U.S. Pat. No. 4,628,942, to Sweeney, et al., dated, Dec. 16, 1986, and entitled, "Asymmetric shielded two electrode cuff," whose disclosure is incorporated herein by reference, and which describes an annular electrode cuff positioned around a nerve trunk, for imposing electrical signals on to the nerve trunk for the purpose of generating unidirectionally propagated action potentials. The electrode cuff includes an annular cathode having a circular passage therethrough of a first diameter. An annular anode has a larger circular passage therethrough of a second diameter, which second diameter is about 1.2 to 3.0 times the first diameter. A non-conductive sheath extends around the anode, cathode, and nerve trunk. The anode and cathode are placed asymmetrically to one side of the non-conductive sheath. Specifically, a first length along the electrode sheath between a first end and the cathode is at least twice a second length between the anode and cathode. A third length between the anode and a second end of the conductive sheath is smaller than the first or second lengths. With this geometry, the majority of the current applied to the anode electrode flows to the cathode along desired path segments with lesser amounts of current flowing in the less desired path segments.
Selective blocking relies on some combination of these techniques, for example, using a tripolar electrode formed as a cathode and primary and secondary anodes. In general, nerve stimulation is performed with the cathode. As the current is increased, fibers of lower diameters are "recruited," or stimulated. At a low current, only A fibers are activated, while at a higher current, both A and B fibers are activated. However, when it is desired to activate, for example, only B fibers, the current is divided between the primary and secondary anodes, such that while the cathode operates at a current that activate both A and B fibers, the primary anode inhibits A fibers, by hyper-polarization tuned specifically for these larger-diameter fibers. Thus an overall activation of B fibers is achieved, with the action potential propagation in the B fibers being towards the secondary anode. In this manner it is possible to predefine a range of nerve-fiber diameters and activate them specifically.
Techniques for selective blocking, have been described, for example, in D. M. Fitzpatrick et al., "A Nerve Cuff Design for the Selective Activation and Blocking of Myelinated Nerve Fibers", Ann. Conf. of the IEEE Eng. in Medicine and Biology Soc., Vol. 13, No. 2, pp. 906, 1991, describing a tripolar electrode device useful for this purpose. Also see N. J. M. Rijkhoff et al., "Orderly Recruitment of Motoneurons in an Acute Rabbit Model" Ann. Conf. of the IEEE Eng., Medicine and Biology Soc., Vol. 20, No. 5, pp. 2564, 1998; and R. Bratta et al., "Orderly Stimulation of Skeletal Muscle Motor Units with Tripolar Nerve Cuff Electrode", IEEE Transactions on Biomedical Engineering, Vol. 36, No. 8, pp. 836, 1989. The contents of the foregoing publications are incorporated herein by reference.
As taught by Fitzpatrick et al., the tripolar electrode used for muscle control includes a central cathode flanked on its opposite sides by two anodes. The central cathode generates action potentials in the motor nerve fiber by cathodic stimulation; one anode produces a complete anodal block in one direction so that the action potential produced by the cathode is unidirectional; and the other anode produces a selective anodal block to permit passage of the action potential in the opposite direction through selected motor nerve fibers to produce the desired muscle stimulation or suppression. Further details concerning the construction and operation of such tripolar electrodes are set forth in the above-cited publications incorporated herein by reference.
Additionally, J. F. X. Jones, Y. Wang, and D. Jordan (1995): Heart Rate Response to Selective Stimulation of Cardiac Vagal C-Fibers in Anesthetized Cats, Rats, and Rabbits," J. Physiol., 489, 203-214, incorporated herein by reference, describes the use of two bipolar electrodes to stimulate only a certain group of fibers (for example, only C-fibers), based on their diameters.
Additionally, commonly owned U.S. Pat. No. 6,600,954 to Cohen et al., dated Jul. 29, 2003, and entitled, "Method and Apparatus for Selective Control of Nerve Fibers," whose disclosure is incorporated herein by reference, describes a method and apparatus particularly useful for pain control by selectively blocking the propagation of body-generated action potentials traveling through a nerve bundle by using a tripolar electrode device to generate unidirectional action potentials to serve as collision blocks with the body-generated action potentials representing pain sensations in the small-diameter sensory fibers. In the described preferred embodiments there are a plurality of electrode devices spaced along the length of the nerve bundle which are sequentially actuated with delays corresponding to the velocity of propagation of the body-generated action potentials through the large-diameter fibers to produce a "green wave" effect which minimizes undesired anodal blocking of the large-diameter fibers while maximizing the collision blocking of the small-diameter fibers.
Furthermore, commonly owned US Patent Application US20030045914, to Cohen et a., published on Mar. 6, 2003 and entitled, "Treatment of Disorders by Unidirectional Nerve Stimulation," whose disclosure is incorporated herein by reference, describes an apparatus for treating a condition of a subject. An electrode device is adapted to be coupled to longitudinal nervous tissue of the subject, and a control unit is adapted to drive the electrode device to apply to the nervous tissue a current, which is capable of inducing action potentials that propagate in the nervous tissue in a first direction, so as to treat the condition. The control unit is further adapted to suppress action potentials from propagating in the nervous tissue in a second direction opposite to the first direction.
A problem with nerve activation is a "virtual cathode effect," or a "virtual anode effect," which causes some interference, as follows:
As defined by Rattay, in the article, "Analysis of models for extracellular fiber stimulation," IEEE Transactions on Biomedical Engineering, Vol. 36, no. 2, p. 676, 1989, which is incorporated herein by reference, the activation function (AF) is the second spatial derivative of the electric potential along an axon. In the region where the activation function is positive, the axon depolarizes, and in the region where the activation function is negative, the axon hyperpolarizes. If the activation function is sufficiently positive, then the depolarization will cause the axon to generate an action potential; similarly, if the activation function is sufficiently negative, then local blocking of action potentials transmission occurs. The activation function depends on the current applied, as well as the geometry of the electrodes and of the axon.
For a given electrode geometry, the equation governing the electrical potential is:∇(σ∇U)=4πj
where U is the potential, σ is the conductance tensor specifying the conductance of the various materials (electrode housing, axon, intracellular fluid, etc.), and j is a scalar function representing the current source density specifying the locations of current injection. The activation function is found by solving this partial differential equation for U. If the axon is defined to lie in the z direction, then the activation function is:
  AF  =                    ∂        2                  U              ∂              z        2
In a simple, illustrative example of a point electrode located a distance d from the axis of an axon in a uniformly-conducting medium with conductance σ, the two equations above are solvable analytically, to yield:
  AF  =                    I        el                    4                πρ                                          2                                z            2                          -                  ⅆ          2                                      (                                    z              2                        +                          ⅆ              2                                )                2.5
where Ie1 is the electrode current. It is seen that when σ and d are held constant, and for a constant positive Ie1 (to correspond to anodal current), the minimum value of the activation function is negative, and is attained at z=0, i.e., at the point on the nerve closest to the source of the anodal current. Thus, the most negative point on the activation function corresponds to the place on a nerve where hyperpolarization is maximized, namely at the point on the nerve closest to the anode.
Additionally, this equation predicts positive "lobes" for the activation function on either side of z=0, these positive lobes peaking in their values at a distance which is dependent on each of the other parameters in the equation. The positive values of the activation function correspond to areas of depolarization, a phenomenon typically associated with cathodic current, not anodal current. However, it has been shown that excess anodal current does indeed cause the generation of action potentials adjacent to the point on a nerve corresponding to z=0, and this phenomenon is therefore called the "virtual cathode effect." (An analogous, but reverse phenomenon, the "virtual anode effect" exists responsive to excess cathodic stimulation.)
US Patent Application 20030050677, to Gross, et al., entitled, "Electrode assembly for nerve control," whose disclosure is incorporated herein by reference, describes an apparatus for applying current to a nerve, the apparatus being designed also to reduce the virtual cathode effect. A cathode is adapted to be placed in a vicinity of a cathodic longitudinal site of the nerve and to apply a cathodic current to the nerve. A primary inhibiting anode is adapted to be placed in a vicinity of a primary anodal longitudinal site of the nerve and to apply a primary anodal current to the nerve. A secondary inhibiting anode is adapted to be placed in a vicinity of a secondary anodal longitudinal site of the nerve and to apply a secondary anodal current to the nerve, the secondary anodal longitudinal site being closer to the primary anodal longitudinal site than to the cathodic longitudinal site. For most applications, the secondary anodal current is of lower magnitude than the primary anodal current. In this manner, the "virtual cathode" effect induced by the primary anodal current is minimized. As described hereinabove, the virtual cathode effect can stimulate, rather than block, the generation of action potentials in fibers in a region adjacent to the application of anodal current of a sufficiently high magnitude. In accordance with the teaching of US Patent Application 20030050677, to Gross, et al., application of the primary and secondary anodal currents in appropriate ratios is configured to generally minimize the virtual cathode effect. Typically, but not necessarily, the ratio of the primary to the secondary anodal current ranges from 5:1 to 10:1. Additionally, the apparatus of US Patent Application 20030050677 may include a housing to which the cathode and a plurality of anodes are coupled, wherein one of the anodes is positioned within the housing so as to reduce a virtual cathode effect induced by another one of the anodes.
The Vagus nerve (the tenth cranial nerve) has been the subject of considerable research in nerve stimulation. It is composed of somatic and visceral afferents and efferents, and is responsible for controlling and (or) receiving feedback from various glands, the pharynx, larynx, heart, lungs, liver, stomach, intestine, and uterus. Because of its large number of functions with respect to a range of body systems, the Vagus nerve is preferred in many applications for purposes of modulating the functions of designated organs or portions of the central nervous system.
Nerve blocking along a major nerve trunk such as the Vagus nerve may be achieved by implanting an electrode along the trunk, which is large enough, and visible. Yet, such blocking affects the large plurality of nerve branches that emerge from the trunk, and their respective organs, without discrimination. However, in general, discrimination is important, and it is generally desired to target only a specific organ. Because the nerve fibers leading to the specific organs are very fine, implanting an electrode along it is technically difficult. There is thus a need for activating, inhibiting, and monitoring action-potential propagations along a specific nerve branch, with minimum interference to other nerve branches.

Nerve-branch-specific action-potential activation, inhibition, and monitoring


In a method for manufacturing blown film web on a blown film line, film is heated above the takeoff device and then treated mechanically. This allows the film to be brought from initial heat to an easy-to-process temperature level with little energy. A horizontally oriented treatment roll path is provided between the takeoff and a reversing device is arranged above the takeoff. In both aspects, controlling is performed to achieve a uniform film gauge after stretching.

Blown film lines are known. The lines are fed plastics in granulated form, which are then plasticized into a viscous mass under high pressure in extruders. This mass is formed into an annular shape in a die head and exits the die head through an annular nozzle. The mass already forms a film tube from the time of leaving the annular nozzle. The film tube is taken off towards the top along a tube-forming zone, in which compressed air is injected into the interior of the film tube. This results in transverse stretching of the film tube. At a tolerable distance from the annular nozzle, cooling the melt is achieved by using an active means of cooling for the rising film tube. On its path to the top, the film tube—in a mostly semi-crystalline state—passes through a calibration cage and then a collapsing frame, which flattens the tube. The collapsing frame unit feeds the double-layer film web to a pre-nip system. The pre-nip system usually includes a pair of rolls through the gap of which—the nip—the film runs. The pre-nip system is followed by a nip system, in which the film tube is finally turned into a practically air-free double-layer film web. From this point in the process on at the latest, or rather, already from the pre-nip process on, there is a double-layer film web. The distance from the pre-nip system to the nip system has been sized such that the film can dissipate the heat from the extrusion process during the transport between the two roll pairs. Thus, in this way, the film tube is cooled additionally so that it can then be processed further. This includes, e.g., the slitting of the film tube, resulting in two separate film webs.
Many lines work without a pre-nip system; instead, they route the film directly from the collapsing frame to the nip system. In such a line design, the rising film is also already cooled off so much at the nip roll pair that strong intervention at the surface will not do any, or little, damage to the film. For the nip system normally draws the film up at a significantly higher speed than the speed with which the film is extruded at the annular nozzle. An exemplary speed ratio is from about 10:1 up to 20:1. The blown film is immediately inflated with compressed air from the inside as the tube forms above the annular nozzle, and thus stretched transversely. At the same time, the nip roll pair draws the film off upwards at high speed so that longitudinal stretching occurs below the frost line.
Thus, in total, the film tube is stretched biaxially below the frost line. Depending on the application the film end product will be used in, the share of longitudinal stretching or that of lateral stretching can prevail.
However, a blown film line will always have to grapple with the technical disadvantage that the visual film quality cannot keep up with the film quality of cast films. This results from the fact that the rising film tube shape cools off relatively slowly. The longer the cooling process of the plastic melt takes, the more opaque and less glossy the film surface will get.
However, in order to be able to exert a sufficient force onto the rising film with the nip roll pair, the film must have cooled off relatively strongly. Given the slow cooling-off speed of the extruded film, this results in great built height for blown film lines. Thus, as fast as possible above the nip system, the double-layer film web is deflected horizontally, routed next to the line and downward from there for the further treatment steps. Usually, a winder is placed next to the system on the floor of its erection location, which winder winds the double-layer film web onto a roll for further transport.
Upstream from the winder, stretching systems are sometimes provided, whereby the term "stretching" is understood as a generic term for "strong stretching in machine direction, MDO" and "extending in machine direction" in the context of the present patent application.
An "MDO stretching" system stretches the film by more than 5%, at any rate, in the longitudinal/machine direction, preferably by 50% and more, often also by up to 1,000%. Such systems are often called "MDO", which stands for "machine direction orientation"; i.e., for orienting the plastic molecules in the direction of the machine; i.e., the material's transport direction through the line.
As an alternative to an MDO, a so-called layflat package can be provided as a stretching system upstream from the winder. This package irreversibly "stretches" the film, usually by between 0.5% and 5% in the direction of the machine, which merely serves to even out differences in running lengths over the width of the double-layer film web and in the directional stability of the film web, allowing the film to be more easily wound up and processed further.
Both stretching systems—i.e., an MDO and a layflat package—are easily technologically comparable insofar as they stretch the film longitudinally. For this purpose, after an initial slower roll, or, e.g., after additional passive rolls, a roll that is driven faster follows immediately. The speed differential between the two rolls, which can also be embodied as nip roll pairs, which each transport the film by means of adhesive friction, results in a change of the film's length.
The distance between the two areas in which the film is transported at the circumferential speed of each roll is called the "stretching section", or as "stretched length", when projected onto the machine direction.
In a roughly central section of the film web's enveloping of a roll, the film web is transported by means of adhesive friction, i.e., at the circumferential speed of the roll. Static friction ends even before the film web leaves the roll surface at a lift-off point. This is of significance particularly when the subsequent roll runs at a higher circumferential speed; i.e., the film web transitions already on the roll surface from adhesive friction to the faster dynamic friction and only then lifts off from the roll surface.
The same principle can also be found in the winding process onto a roll: The film web already makes contact with the revolving roll surface from a contact point; adhesive friction, however, does not begin until beyond the contact point.
For simplicity's sake, the term "points" is used here. A film web lifts off a roll at a lift-off line and lands on a roll surface with a contact line. In a side view, the two-dimensional film web has, however, been reduced to a line by one dimension; accordingly, the lift-off and the contact line are each reduced to points by one dimension.
It should be noted that instead of a roll, as a rule, a nip roll pair can also be used just as well for transporting the film. For simplicity's sake, the present application usually speaks only of a roll, but it thereby also means a nip roll pair as a replacement means known in the art.
A nip roll pair can tend to effect more secure gripping of the film because the film surface is gripped from both sides. However, a roll impinging laterally can also exert a sufficient longitudinal force on the film, which, e.g., depends on the surface design of the roll in concert with the respective film to be processed and, e.g., from the roll's arc of contact. Usually, for a single driven roll, a contact roll will be provided at any rate in order to ensure more reliably that the film can actually be gripped securely by the driven roll, excluding any slippage.
The blown film method is suitable for the manufacture of stretch plastic films. These films are stretched monoaxially in the direction of the machine in MD stretching systems, which results in films with reduced film gauges. MD stretching improves, e.g., the following film properties: Tear strength, rigidity, transparency, barrier properties, and/or machinability. The films are used, e.g., in flexible packaging.
In the manufacture of tube films, film gauge profile control systems with segmented control zones are used. These systems allow controlling the film gauge profile in such a manner that the thickness variances over the entire tube circumference are minimized. DE 100 47 836 A1 describes such a method for controlling the film gauge profile in blown film lines, specifically based on measuring one or several individual layer thickness(es) of a multi-layer film as a reference parameter.
Systems for controlling film gauges in longitudinal/MD stretching systems for cast films or laminated films are also known. Control is significantly easier as the film will not be reversed and thus, the direct assignment of the individual measuring points in the gauge profile diameter of the longitudinally stretched film to the extrusion nozzle including actuators, or respectively, to the control zones is possible.
From DE 39 41 185 A1, a method for controlling the film gauge of tube films from blown film lines with downstream axial or biaxial stretching of the inflated tube films in an oven is known, resulting in a final film with minimized gauge variances.
In the longitudinal stretching process of an MD system, the film is stretched in the direction of the machine according to the MD stretch degree, thus reducing the film gauge. At the same time, the film shrinks in the lateral direction, reducing the film's width. This shrinkage results in the stretched film becoming slightly thicker from the center of the film towards the film edges, despite the fact that it was controlled to have the most constant gauge possible during the preceding blowing process. This increase in film gauge is especially pronounced in the film edge areas. During the subsequent winding of the film, this causes thicker edges in the film rolls. With increasing roll diameters, the film web edges will increasingly be stretched, resulting in severe disadvantages for subsequent processing such as printing or laminating.
Shrinkage and thus, thicker edges on the film roll, can be reduced by measures such as a minimized stretching gap, suitable roll coating, mechanical or electro-static holding of film edges, optimized temperature management, or suitable selection of plastic materials. However, this is not sufficient for many subsequent processing steps. Only if the film edges are trimmed will the remaining film web have a sufficiently small variance from the gauge profile that is required for the subsequent winding of the film web and its further processing. But much of the film width is lost by trimming. Regardless of film width, about 200 mm are trimmed on either side of the film.
In WO 2014/023282 A1, published later by the same Applicant as the present one, it is proposed that the film be heated above the nip and then treated mechanically. Thus, the film can be brought to an easily processable temperature level from the initial heat, using little energy. According to a second aspect, it is proposed that a tensile force bottom-out brake be provided.
EP 2 277 681 A1, which is part of the prior art, discloses a control method for achieving a film having the most even gauge possible at the winder.
EP 1 147 877 A2 discloses in its second embodiment in FIG. 5 a manufacturing line for stretch film whereby, however, the initial heat is no longer present in the stretching section between the stretch roll pairs because there, the double-layer film web is routed around the take-off roll pair to the side and is not stretched until significantly later. In particular, there is little or no rising initial heat from the blown film process.
The same applies to U.S. Pat. No. 6,413,346 B.
U.S. Pat. No. 2,976,567 shows a cast film line, not a blown film line. Thus, there is no take-off roll pair; besides there is precisely no effect of great heat collecting above the die head, and thus, above the nip roll pair.
In U.S. Pat. No. 7,396,498 B1, optional stretching of the double-layer film web is performed at the very bottom directly next to the die head; i.e., practically on the factory floor.
U.S. Pat. No. 5,458,841 performs longitudinal stretching between a pre-takeoff roll pair and a takeoff roll pair; namely, above the rising blown film. But this is precisely where no heating is provided for the film; instead, the citation calls the stretching section "cold orientation zone". Besides, above the ultimate takeoff roll pair, no more mechanical processing takes place. Instead, a reversing roll is used for immediate routing into the horizontal orientation and ultimately, further down.
In DT 1 504 461, an internal mandrel for heating the film tube is provided. The first takeoff roll pair does not close. Stretching downstream from the first takeoff roll pair is performed by means of positive pressure flowing through.
In AT 267 160, the blown film is embossed within the take-off roll pair.
AT 342 292 provides for the tube film to be routed through a number of infrared heaters that increase the tube film temperature to the temperature required for stretching. The tube film is then stretched in the transverse direction from the extrusion direction by introducing compressed air into it through a pipe, and it is simultaneously stretched in its longitudinal direction using means that are not shown, effecting an airtight sealing of the tube and taking it off at a speed that is greater than the speed with which it is being transported by the nip rolls. In the meaning of the preceding, the means for longitudinal stretching that are precisely not shown are the nip rolls, and beyond them, apparently no further treatment is to happen; not to mention that the citation extrudes from top to bottom and is thus anyway in a position where it cannot use the rising heat as well.
CH 432 815 also deals with the design of the line upstream from the takeoff roll pair; not, however, with, e.g., the design downstream from the takeoff roll pair.
The same applies to CH 475 082.
DE 21 32 259 C3 describes rather unrelated prior art.
DE 102 42 174 A1 explains a conventional blown film line, whereby the longitudinal stretch factor, or respectively, the blow-up factor is to be set by means of the ratio between the circumferential speed of the nip rolls and the internal pressure.
U.S. Pat. No. 6,447,278 B1 discloses lateral routing of the double-layer film web away, directly downstream of the takeoff roll pair.
U.S. Pat. No. 4,086,045 again shows a cast film line, which is therefore not highly relevant here because there is no processing above the rising heat from the extruder.
U.S. Pat. No. 3,768,949 shows an early embodiment of a reversing device, with the takeoff of the tube film being performed by two individual rolls that do not press against each other as a takeoff, but which, however, together represent a takeoff roll pair in the wider meaning.
U.S. Pat. No. 3,340,565 shows rotatable chill rolls for variably setting the cooling time.
U.S. Pat. No. 3,116,787 again shows a cast film line, which is therefore unrelated prior art due to a lack of processing steps above the hot extruder.
U.S. Pat. No. 4,676,728 provides for a reversing device with vertically standing reversal bars or rolls. The same applies to U.S. Pat. No. 5,727,723.
In DE 35 08 626 C1, rolls for threading the incoming film tube can be moved apart when the blown film line starts up. This is followed by a comb-like movement against each other of the reversing bars and the reversing rolls until an operating position has been reached.
In DE 692 08 002 T2 also, longitudinal stretching of the film tube is only performed upstream from a pre-takeoff roll; i.e., not downstream from the takeoff roll pair. Besides, there is no heating taking place in the cold orientation zone there.
In GB 2 201 371 A, a tube film is first unwound from a roll, then routed upwards above a blown film line, heated there, then routed vertically downward while being inflated, and finally taken off and wound up again. Heating downstream from the takeoff roll pair is not provided for, and besides, a hot die head is not provided for so that the heat generated above the latter does not exist, and thus cannot be used.
WO 2005/102666 A1 shows a blown film line in which either the clearance between the pre-takeoff roll pair and the takeoff roll pair is adjustable by means of a vertical adjustment mechanism, or in which a carousel with different rolls is provided, whereby in both cases, the double-layer film web is routed downstream from the takeoff roll pair, first laterally and then downward.
Above the treatment roll path, a reversing bar device can be provided for, in particular, within a reversing device. By means of reversing rotation of reversing bars and/or rolls, the reversing device provides for even laying of any point in the film tube having an uneven thickness, resulting in total in quite even winding on the roll. A reversing device can be seen, e.g., in EP 0 673 750 A1.
A reversing device shall, in the context of the present patent application, not be considered a "treatment roll path".
A treatment roll path in addition also preferably comprises rolls exclusively; one could imagine also reversing bars or other means for guiding or rerouting film.
In addition, a reversing device does not include an active heating device for the double-layer film web.
The task underlying this disclosure is to provide an improvement of or an alternative to the prior art.

Method for manufacturing a blown film web as well as a blown film line

REIFENHÄUSER GMBH & CO. KG MASCHINENFABRIK


A base station or an associated control entity determines when base station's air interface is threshold highly loaded or is predicted to be threshold highly loaded, and the base station responsively reduces the number of transmit antennas that the base station uses. Further, the base station or associated control entity could determine when the base station's air interface is no longer actually or predicted to be threshold highly loaded, and the base station could responsively increase the number of transmit antennas that the base station uses, such as by reverting to use a default number of antennas. Reducing the number of transmit antennas that the base station uses when its air interface is threshold highly loaded may help to increase air-interface capacity by reducing resource consumption from transmission of reference signals associated with the transmit antennas.

A cellular wireless network typically includes a number of base stations that are configured to provide wireless coverage areas, such as cells and cell sectors, in which user equipment devices (UEs) such as cell phones, tablet computers, tracking devices, embedded wireless modules, and other wirelessly equipped communication devices (whether or not user operated), can operate. In turn, each base station could be coupled with network infrastructure that provides connectivity with one or more transport networks, such as the public switched telephone network (PSTN) and/or the Internet for instance. With this arrangement, a UE within coverage of the network could engage in air interface communication with a base station and could thereby communicate via the base station with various remote network entities or with other UEs served by the base station.
Such a network could operate in accordance with a particular radio access technology, with air-interface communications from the base stations to UEs defining a downlink or forward link and air-interface communications from the UEs to the base stations defining an uplink or reverse link.
Over the years, the industry has embraced various generations of radio access technologies, in a continuous effort to increase available data rate and quality of service for end users. These generations have ranged from "1G," which used simple analog frequency modulation to facilitate basic voice-call service, to "4G"—such as Long Term Evolution (LTE), which facilitates mobile broadband service using technologies such as orthogonal frequency division multiplexing (OFDM) and multiple input multiple output (MIMO). And most recently, the industry is now exploring developments in "5G" and particularly "5G NR" (5G New Radio), which may use a scalable OFDM air interface, advanced channel coding, massive-MIMO, beamforming, and/or other features, to support higher data rates and countless applications, such as mission-critical services, enhanced mobile broadband, and massive Internet of Things (IoT).
In accordance with some radio access technologies, each coverage area could operate on one or more carriers, each of which could be frequency division duplex (FDD), defining separate frequency channels (each with respective a bandwidth and center frequency) for downlink and uplink communication, or time division duplex (TDD), with a single frequency channel (having a single bandwidth and center frequency) multiplexed over time between downlink and uplink use.
Further, on the downlink and uplink, the air interface of the coverage area on each of one or more carriers could be structured to define a set of resources for carrying information between the base stations and UEs. For example, under some radio access technologies, the air interface could be divided over frequency into subcarriers and over time into frames, subframes, timeslots, and symbol time segments. As such, the air interface could define an array of resource elements each occupying a subcarrier and a symbol time segment, and the subcarrier of each resource element could be modulated to carry data. The resource elements within each timeslot on the carrier could then be grouped to define physical resource blocks (PRBs) that could be allocated for use to carry information on as as-needed basis.

Method and system for controlling air-interface resource availability through dynamic configuration of antenna structures


A CAD apparatus is used to design a three-dimensional model having at least one part made of a material which changes shape depending on assembling conditions. The CAD apparatus automatically obtains structural dimensions of the part in a deformed state after assembly, from structural dimensions of the part before the assembly, based on parameters including at least the assembling conditions. The CAD apparatus then creates the three-dimensional model using the structural dimensions of the part in the deformed state.

This application claims the benefit of a Japanese Patent Application No.2000-256339 filed Aug 25, 2000, in the Japanese Patent Office, the disclosure of which is hereby incorporated by reference.
1. Field of the Invention
The present invention generally relates to designing methods, computer-aided-design (CAD) apparatuses and storage media, and more particularly to a designing method for designing a three-dimensional model having a part which changes shape before and after assembly, a CAD apparatus which employs such a designing method, and a computer-readable storage medium which stores a program for causing a computer to design a three-dimensional model by such a designing method.
2. Description of the Related Art
Conventionally, a CAD apparatus is used to design a three-dimensional model which is made up of a plurality of parts. In a case where the three-dimensional model is a printer, for example, an interference check is carried out to detect interfering locations which are generated when various parts forming the printer are automatically arranged and assembled. The interfering location refers to a portion where at least two parts overlap and interfere with each other. When such an interfering location is detected, an operator, that is, the designer, modifies the arrangement of the parts related to this interfering location based on an interfering volume, so as not to generate the interference, and then assembles the rearranged parts. Hence, the interference check is an important element of the designing of the three-dimensional model, from the point of view of improving the design quality.
The parts which are assembled include parts which are made of materials which change shape before and after the assembly. In other words, when a soft (or deformable) part is inserted between two hard parts and a thickness of this soft part before the assembly is greater than a predetermined value and a gap between the two hard parts after the assembly is set less than or equal to the predetermined value, the soft part will undergo resilient deformation.
However, the conventional CAD apparatus treats both the soft part and the hard part in the same manner. As a result, the part which actually changes shape before and after the assembly is treated with the shape before the change occurs.
For this reason, when the parts forming the three-dimensional model are automatically arranged and assembled, an interfering location which is generated on the CAD may not occur when the parts are actually assembled due to the resilient deformation of the soft part. In this first case, the interfering location generated on the CAD actually does not need to be recognized as an interfering location. On the contrary, even when no interfering location is generated on the CAD when the parts forming the three-dimensional model are automatically arranged and assembled, an interfering location may occur when the parts are actually assembled due to the resilient deformation of the soft part which causes the soft part to expand in one or more directions. In this second case, although no interfering location is generated on the CAD, it is desirable to recognize the interfering location which will actually occur.
In the first case, the interference check is carried out with respect to the interfering location which actually does not occur.
Consequently, the designer modifies the arrangement of the parts and assembles the rearranged parts although such modification and assembly are actually unnecessary or, the designer at least confirms whether or not it is necessary to modify the arrangement of the parts or the like. Therefore, there were problems in that the load on the designer becomes large, and that the designing efficiency becomes poor.
On the other hand, in the second case, the interfering location which will actually occur cannot be detected during an initial stage of the designing. For this reason, there were problems in that the load on the designer is even larger, and that the designing efficiency likewise becomes poor.
Accordingly, it is a general object of the present invention to provide a novel and useful designing method, CAD apparatus and compute-readable storage medium, in which the problems described above are eliminated.
Another and more specific object of the present invention is to provide a designing method, CAD apparatus and computer-readable storage medium which are capable of reducing the load on the designer and designing a three-dimensional model with a high designing efficiency.
Still another object of the present invention is to provide a designing method for designing a three-dimensional model having at least one part made of a material which changes shape depending on assembling conditions, comprising the steps of (a) automatically obtaining structural dimensions of the part in a deformed state after assembly, from structural dimensions of the part before the assembly, based on parameters including at least the assembling conditions, and (b) creating the three-dimensional model using the structural dimensions of the part in the deformed state. According to the designing method of the present invention, it is possible to reduce the load on the designer, and to design a three-dimensional model with a high designing efficiency.
A further object of the present invention is to provide a CAD apparatus for designing a three-dimensional model having at least one part made of a material which changes shape depending on assembling conditions, comprising a first section which automatically obtains structural dimensions of the part in a deformed state after assembly, from structural dimensions of the part before the assembly, based on parameters including at least the assembling conditions, and a second section which creates the three-dimensional model using the structural dimensions of the part in the deformed state. According to the CAD apparatus of the present invention, it is possible to reduce the load on the designer, and to design a three-dimensional model with a high designing efficiency.
Another object of the present invention is to provide a computer-readable storage medium which stores a program for causing a computer to design a three-dimensional model having at least one part made of a material which changes shape depending on assembling conditions, where the program comprises a first procedure which causes the computer to automatically obtain structural dimensions of the part in a deformed state after assembly, from structural dimensions of the part before the assembly, based on parameters including at least the assembling conditions, and a second procedure which causes the computer to create the three-dimensional model using the structural dimensions of the part in the deformed state. According to the computer-readable storage medium of the present invention, it is possible to reduce the load on the designer, and to design a three-dimensional model with a high designing efficiency.
Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.

Designing method, CAD apparatus and storage medium


For the removal of trace quantities of iodine-containing contaminants from corrosive liquid feed streams, an alternative with distinct advantages over the prior art is provided. The treatment method involves the use of a crystalline manganese phosphate which has been cation-exchanged with an iodine-reactive metal. This inorganic adsorbent may be used in unbound form, or it can bound with a substantially insoluble porous inorganic refractory metal oxide binder. A reactivation technique for this material is also presented.

Methanol carbonylation, the reaction of methanol with carbon monoxide, is used to produce a significant share of the world's acetic acid and represents the basis for virtually all new acetic acid capacity. The fundamental process, whereby methanol and carbon monoxide are reacted in the presence of a rhodium catalyst and methyl iodide promoter, is disclosed in U.S. Pat. No. 3,769,329 and has become well-known as the "Monsanto process". Although numerous improvements have since been developed, the use of an iodine-containing promoter, either as an organic iodide or metal iodide salt, has proven necessary to obtain industrially-competitive reaction rates and production economies.
Unfortunately, the use of any suitable iodine-containing promoter invariably results in the incorporation of trace iodine and organic iodide impurities into the final acetic acid product. These contaminants result from numerous transformations (thermal cracking, recombination, isomerization, etc.) of the iodine-containing catalyst promoters which occur not only in the reactor but also in downstream equipment, such as distillation column reboilers and recycle lines. A resulting array of C.sub.1 to C.sub.10 organic alkyl iodide species is produced, which are removed from the acetic acid product with varying degrees of effectiveness via the standard distillation steps used in downstream purification. Additionally, iodine may be present in the acetic acid product in the form of hydrogen iodide or iodide salts. Ultimately, without supplemental treatment to remove trace iodine-containing contaminants, product acetic acid made using methanol carbonylation technology with even the most careful fractionation steps, will still contain a small amount, typically below 100 parts per billion (ppb) of total iodine (both organic and inorganic) by weight.
The interest in a process for essentially complete removal of iodine-containing contaminants from acetic acid stems from the large share (about 40 to 50%) of its use as a precursor for vinyl acetate monomer (VAM) synthesis. Current methods of VAM production rely on a catalyst which is intolerant to even minute levels of iodine-containing compounds in the acetic acid feedstock. Therefore, the VAM production costs associated with reduced catalyst life increase dramatically with increasing feed iodine concentration.
Several disclosures in the prior art present techniques for the selective removal of iodine-containing species from process streams such as nuclear reactor containment environment off gases as well as emissions from spent nuclear fuel reprocessing operations. For example, U.S. Pat. No. 3,658,467 addresses the removal of radioactive iodine-containing materials from the gaseous waste streams generated either during normal nuclear fuel reprocessing operations or even in the event of a fuel element cladding failure whereby radioactive methyl iodide is formed in significant amounts. The solution proposed in the '467 patent is a zeolite X molecular sieve exchanged with silver for treating the gaseous waste stream. All cited examples referring to the adsorptive ability of this formulation are based on performance in a dry air stream contaminated with trace radioactive methyl iodide. The structures of X-type zeolites are known to have aluminosilicate frameworks with maximum silica to alumina molar ratios, expressed as the ratio of SiO.sub.2 to Al.sub.2 O.sub.3 in the fundamental zeolite framework, of about 3 and pore openings typically in the range of 7 to 8 .ANG..
In U.S. Pat. No. 4,735,786, an alternate solution for filtering radioactive iodine-containing compounds from nuclear facility exhaust gases in the event of an accident is proposed. In offering an improvement over the prior art, the '786 patent recognizes the practical deficiencies of silver-exchanged zeolite X adsorbent for this service under high humidity conditions. The improvement offered is a different type of adsorbent, characterized as a high silica to alumina molar ratio pentasil zeolite. The adsorbent specified is exemplified by the well-known ZSM-5 type material, which is clearly described in U.S. Pat. No. 3,702,886 as having ten-member rings forming medium-sized pores in the range of 5.1 to 5.6 .ANG.. The teachings and specific examples of the '786 patent are restricted to pentasil zeolites having silica to alumina molar ratios in the range of 15 to 100, preferably 20 to 50.
In U.S. Pat. No. 4,913,850, another solution for methyl iodide removal from gaseous streams is presented, whereby a silver-exchanged "binderless" zeolite material, composed of 80 to 90% zeolite X and 10 to 20% zeolite A, is used. Among the possible candidates for zeolite X materials, those having the faujasite structure are of particular interest. As mentioned previously, zeolite X formulations generally have a maximum silica to alumina molar ratio of 3. In U.S. Pat. No. 5,075,084, the progress of treating radioactive iodine-containing gas streams is continued, where the problem of the proposed silver-exchanged zeolite material catalyzing the highly exothermic reaction of hydrogen and oxygen and, in the extreme case, causing catalytic ignition of hydrogen, is solved. According to the '084 patent, this undesired side reaction is suppressed when a heavy metal such as lead is added to the silver-exchanged adsorbent. The underlying zeolite compositions of the preferred materials in this patent and the previously-mentioned '850 patent are identical.
In U.S. Pat. No. 4,088,737, gaseous radioactive methyl iodide removal is further addressed in a multi-step treatment procedure where the initial gas purification is performed with a silver-exchanged zeolite exemplified by zeolite X. After iodine-compound breakthrough, regeneration and concentration steps are undertaken, which involve i) withdrawing the spent adsorbent from contact with the gaseous waste stream, ii) subjecting the adsorbent to desorption conditions with a hydrogen-rich stream to produce a hydrogen iodide containing off gas, and iii) treating this effluent gas with a lead-exchanged zeolite to re-adsorb and concentrate the desorbed hydrogen iodide. Lead-exchanged zeolite X is specifically cited as achieving the desired result for the final adsorption step. The advantage of the multi-step treatment is that the long-term storage of the contaminated material is less expensive for the lead-exchanged zeolite, compared to a silver-exchanged material.
In spite of these continuing developments and improvements in trace iodine and organic iodide removal from gaseous effluent streams, the methods employed have been found unsuitable for the more difficult problem of iodine-containing compound adsorption from corrosive liquids, such as commercial acetic acid product streams. Adsorbent carrier materials of the prior art such as zeolite X and zeolite A, which are classified as having low silica to alumina molar framework ratios (typically below 5), have experimentally been proven to be unstable in acetic acid. This means that the dissolution (or leaching) rate of framework components into the liquid is sufficiently large to render such materials ineffective for iodine-containing compound adsorption service in corrosive liquid media.
Depending on the specific silica to alumina framework molar ratio, the pentasil zeolites, exemplified in '786 patent for gas-phase iodine-containing compound removal, are significantly more stable in acetic acid than zeolite types X and A. However, the high silica to alumina framework molar ratios (20 to 50) of the preferred zeolites of the '786 patent have a significantly lower capacity for iodine-reactive metal by ion exchange than the crystalline manganese phosphate materials of the present invention. As is known in the art, increasing the silica to alumina framework molar ratio of a zeolite directionally improves its resistance to decomposition in corrosive environments, at the expense of reduced ion-exchange capacity. The reported silver loadings for the pentasil zeolite formulations in the '786 patent examples were below 10% of the total adsorbent weight. In contrast, the improved metal loadings (maximally 50% by weight) achieved by using metal-exchanged crystalline manganese phosphates result in overall greater capacity for iodine-containing compound removal, expressed in milligrams of iodine per gram of adsorbent.
Other prior-art teachings more specifically apply to iodine-compound removal from corrosive liquid media, where the principal area of concern, as described previously, is in the manufacture of carboxylic acids such as acetic acid via a process which results in a product stream contaminated with trace amounts of iodine-containing byproducts. Thus far, techniques such as adsorptive distillation, iodine scavenger addition, alkyl iodide oxidation to molecular iodine, and others have not achieved practical utility, because such methods not only fail to achieve the extremely low levels of iodine-containing compounds demanded industrially but also require additional purification steps. For this reason, far greater emphasis has been placed on the development of solid materials capable of adsorbing essentially all iodine-containing compounds from acetic acid streams.
For instance, in U.S. Pat. No. 5,457,230, the use of activated carbon fiber is contemplated for this purpose. However, the examples demonstrate the removal of molecular iodine and hydrogen iodide only and fail to specifically disclose the level of iodine-containing compounds in the treated acetic acid stream. In the case of iodine-compound removal from acetic acid, it is the ability of the invention to provide a treated product with only extremely minute levels of total iodine which primarily determines its practical utility. It is known in the art that activated carbon alone can neither remove iodine-containing compounds from commercial acetic acid streams to single parts per billion levels, nor can it effectively remove organic iodide species, such as methyl iodide and hexyl iodide which are commonly present in these product streams, without the use of an iodine-reactive metal.
Recently, considerable development efforts in acetic acid purification technology have focused on resins containing iodine-reactive metals such as silver, mercury, copper, lead, thallium, palladium or combinations of these metals known to react with iodine-containing compounds to form insoluble complexes. For example, in U.S. Pat. No. 4,615,806, the removal of these impurities is achieved with a macroreticulated strong acid cation-exchange resin which is stable in the organic medium and has at least one percent of its active sites converted to the silver or mercury form, presumably by cation-exchange. The use of macroreticulated resins is claimed as an advance over the prior art formulations, which are generally characterized as gel-type ion-exchange resins, for this service. In U.S. Pat. No. 5,139,981, other silver-exchanged resins are offered, along with a novel technique for preparing such resin compositions. In U.S. Pat. No. 5,220,058, a performance benefit is claimed, whereby the subject resin contains thiol functional groups, compared to the prior art sulfonate functional groups, which are exchanged with the iodine-reactive metal. In U.S. Pat. No. 5,227,524, the resin degree of crosslinking is decreased somewhat, resulting in improved silver utilization. In U.S. Pat. No. 5,300,685, the iodine-reactive metal is coordinated, as a salt, with a polymeric resin, rather than being ionically-bound to a cation-exchange resin. In U.S. Pat. No. 5,344,976, a resin guard bed without the iodine-reactive metal is placed upstream of the metal-exchanged resin to scavenge any metal cations in the acetic acid stream which would otherwise potentially displace the iodine-reactive metal. Finally, in U.S. Pat. No. 5,801,279, an improved method of operating the iodine-compound removal step is disclosed in order to reduce the amount of leaching of the iodine-reactive metal into the treated acetic acid effluent stream. As noted in this reference, the dissolution of the iodine-reactive metal is acknowledged as a problem for iodine-compound removal techniques of the prior art whereby metal-exchanged resins are applied.
While the invention of the U.S. Pat. No. 4,615,806 patent and other modified resin-based formulations have been used commercially with some success, resins in general suffer some disadvantages, in addition to the previously-mentioned metal loss, when used in the acetic acid environment of the present invention. More specifically, resins, even those characterized as "stable" are known to "swell" or increase in diameter by as much as 50% when exposed to an organic medium, making bed design difficult. Resins are also vulnerable to decomposition at relatively mild conditions and are furthermore susceptible to chemical attack by corrosive reagents. These factors additionally complicate the use of a resin-based material for the purification of acetic acid.
The problem therefore addressed by the present invention is to provide an adsorbent for use in removing iodine-containing compounds from commercial acetic acid feed streams where the adsorbent is free of the chemical exposure effects and swelling problems associated with the typical organic materials used in the prior art. There are significant teachings in the prior art associated with the use of non-resin adsorbents that point away from their utility in this treatment service. In particular, in the comparative example recited in U.S. Pat. No. 4,615,806 (column 6, lines 36 to 49), a silver-exchanged zeolite, characterized as 1/16 inch 5A molecular sieve pellets, was tested in acetic acid for contaminant methyl iodide removal and found to be unstable as evidenced by the continuous silver leaching from the adsorbent and the finding of a yellowish precipitate in the treated effluent. Given this discouraging result, it is remarkable that a suitable inorganic adsorbent for use in this corrosive environment has been discovered.
The adsorbent material of the present invention in fact comprises a crystalline manganese phosphate which has been cation exchanged with a metal known to react with iodine-containing compounds. The crystalline manganese phosphate composition is represented by the empirical formula: EQU (A.sup.a+).sub.v (Mn.sup.b+)(M.sup.c+).sub.x P.sub.y O.sub.z
where A is typically either an alkali or alkaline earth metal, but may also be hydronium ion, ammonium ion, organoammonium ions, silver, copper (II), zinc (II), nickel (II), mercury (II), or cadmium (II), or any combination of these species, "a" represents a weighted average valence of A and varies from about 1.0 to about 2.0, "v" is the mole ratio of A to Mn and varies from about 0.1 to about 10.0, "b" is the average valence of Mn and has a value of greater than 2 to about 4, M is (optionally) a metal selected from the group consisting of Al, Fe.sup.3+, Ga, Sn.sup.4+, Ti, Sb.sup.5+, Ag, Zn, Cu, Ni, Cd, and mixtures thereof, "x" is the mole ratio of M to Mn and varies from 0 to about 3.0, "c" is the weighted average valence of M and varies from about 1.0 to about 5.0, "y" is the mole ratio of P to Mn and varies from about 0.1 to about 8.0, and "z" is the mole ratio of O to Mn and has a value determined by the equation: EQU z=1/2(a.cndot.v+b+x.cndot.c+5.cndot.y).
Of the crystalline manganese phosphate compositions of this type, those characterized as having manganese with an average valence of greater than 3.0 but less than or equal to 4.0 are defined and described according to their unique structural details and synthesis procedures in U.S. Pat. No. 5,780,003, which is incorporated by reference. The broader range of crystalline manganese phosphate compositions applicable to the present invention include structures with manganese having an average oxidation state of greater than 2.0 but less than or equal to 4.0. All suitable materials are characterized, as described in the '003, as having an extended network. By extended network is meant that the defining Mn--P--O structural unit of the material repeats itself into at least two adjacent unit cells without termination of bonding, i.e., the material is not molecular.
The crystalline manganese phosphates of the present invention are further characterized in that they exhibit ion-exchange capacity with metals (e.g. silver) which are reactive with iodine and iodine-containing compounds. Ion-exchanged crystalline manganese phosphates alone are therefore useful as adsorbents of the present invention, but it is often desired to bind such compositions into larger particles of various shapes using an inorganic refractory metal oxide binder (e.g. silica). It is also possible to ion-exchange crystalline manganese phosphates with an effective amount of iodine-reactive metal subsequent to binding. Even after use in the iodine-containing compound adsorption service of the present invention, adsorbents comprising ion-exchanged crystalline manganese phosphate compounds can be reactivated using a relatively simple metal re-exchange procedure.

Method for treating a liquid stream contaminated with an iodine-containing compound using a cation-exchanged crystalline manganese phosphate


High accuracy is achieved by employing, in conventional DAC architectures, very accurate current sources. To create these high-accuracy current sources, the outputs of several smaller, less accurate, nominally equal current sources are summed. A procedure is taught for selecting the number of current sources to achieve an arbitrary degree of accuracy with a desired level of confidence. Assuming the current sources are taken from a population whose output currents deviate from a design value according to a normal distribution, the minimum number of constituent current sources, n, required to provide an accurate total current is given by the formula n=(Z.sigma./E).sup.2, where Z is a number which corresponds to the probability that the output will fall within an error band E (i.e., a predetermined accuracy level) with a predetermined level of confidence, .sigma. is the standard deviation of the population.

Digital-to-analog converters (DAC's) are widely used in a variety of situations in which analog signals must be produced from digital information provided as digital words. The number of bits of resolution in the digital word, the speed of conversion, the integral and differential linearity, and the accuracy of the conversion are dominant parameters which characterize a DAC. Some applications require very high speed DAC's, some require very high resolution DAC's, and many require highly linear, highly accurate DAC's. In many uses, high integral linearity and high accuracy are even more important than resolution. Thus, a DAC with five- to eight-bit resolution may be adequate where conversion to an accuracy of twelve or fourteen bits is required.
Such requirements for high accuracy place severe constraints on matching components within the DAC. A typical DAC will consist of many current sources, each of which is switched (i.e., turned on or off), depending on the value of the digital input. The currents are summed to produce the analog output current. The accuracy of the DAC output is fundamentally limited by the accuracy of these current sources. Typically, 2.sup.n -1 current sources, or fewer, are employed to provide the analog output. Lower resolution DAC's (e.g., up to about eight bits) can be made directly, by employing techniques such as R-2R ladders, binarily weighted current sources, and so forth. Conventional manufacturing process technology, however, generally allows only about 10-bit accuracy in matching components, such as current sources. Eight-bit accuracy is more typical from customary processes. A DAC accurate to twelve bits, however, typically requires more complex processing, because the simple component matching requirements can not be achieved using current process technologies. Thus, alternative approaches such as laser trimming, "zener zapping", and the like, are used. Unfortunately, these alternative approaches generally are associated with higher cost and lower manufacturing yields.

Digital-to-analog converters with improved linearity


The present invention provides a replication competent hepatitis C virus that includes a heterologous polynucleotide. The invention also includes methods for modifying a hepatitis C virus polynucleotide, selecting a replication competent hepatitis C virus polynucleotide, detecting a replication competent hepatitis C virus polynucleotide, and identifying a compound that inhibits replication of a hepatitis C virus polynucleotide.

Hepatitis C virus is the most common cause of chronic viral hepatitis within the United States, infecting approximately 4 million Americans and responsible for the deaths of 8,000-10,000 persons annually due to progressive hepatic fibrosis leading to cirrhosis and/or the development of hepatocellular carcinoma. Hepatitis C virus is a single stranded, positive-sense RNA virus with a genome length of approximately 9.6 kb. It is currently classified within a separate genus of the flavivirus family, the genus Hepacivirus. The epatitis C virus genome contains a single large open reading frame (ORF) that follows a 5′ non-translated RNA of approximately 342 bases containing an internal ribosome entry segment (IRES) directing cap-independent initiation of viral translation. The large ORF encodes a polyprotein which undergoes post-translational cleavage, under control of cellular and viral proteinases. This yields a series of structural proteins which include a core or nucleocapsid protein, two envelope glycoproteins, E1 and E2, and at least six nonstructural replicative proteins. These include NS2 (which with the adjacent NS3 sequence demonstrates cis-active metalloproteinase activity at the NS2/NS3 cleavage site), NS3 (a serine proteinase/NTPase/RNA helicase), NS4A (serine proteinase accessory factor), NS4B, NS5A, and NS5B (RNA-dependent RNA polymerase).
With the exception of the 5′ non-translated RNA, there is substantial genetic heterogeneity among different stains of hepatitis C virus. Phylogenetic analyses have led to the classification of epatitis C virus strains into a series of genetically distinct "genotypes," each of which contains a group of genetically related viruses. The genetic distance between some of these genotypes is large enough to suggest that there may be biologically significant serotypic differences as well. There is little understanding of the extent to which infection with a virus of any one genotype might confer protection against viruses of a different genotype.
Several types of human interferon have proven effective in the treatment of infection by hepatitis C virus, either alone as monotherapy, or in combination with ribavirin. However, treatment with interferon-ribavirin carries a high risk of treatment failure, either primary failure of virus elimination, or relapse of the infection upon cessation of therapy. Moreover, these therapeutic agents are relatively toxic and are associated with a high frequency of adverse reactions. The development of better (more effective and safer) antiviral agents capable of suppressing or eliminating hepatitis C virus infection has been hindered by the fact that this virus replicates with very low efficiency, or not at all, in cultured cells. The absence of a highly permissive cell culture system that is capable of supporting robust replication of the virus has prevented the development of high throughput antiviral screens for use in the development of inhibitors of viral replication, and has delayed the investigation of the virus and relevant aspects of its molecular and cellular biology. It has also stymied efforts at vaccine development and the immunologic characterization of the virus, the human response to hepatitis C virus, and the diseases associated with infection. The development of infectious molecular cDNA clones of the viral genome has done little to solve this problem, since virus can be rescued from the RNA transcribed from such clones only by its injection into the liver of a living chimpanzee or other susceptible primate.

This patent is subject to a terminal disclaimer.

Replication competent hepatitis C virus and methods of use

Board of Regents, The University of Texas System


Training a machine learning model such as a neural network, which can automatically extract a hypernym from unstructured data, is disclosed. A preliminary candidate list of hyponym-hypernym pairs can be parsed from the corpus. A preliminary super-term—sub-term glossary can be generated from the corpus, the preliminary super-term—sub-term glossary containing one or more super-term—sub-term pairs. A super-term—sub-term pair can be filtered from the preliminary super-term—sub-term glossary, responsive to detecting that the super-term—sub-term pair is not a candidate for hyponym-hypernym pair, to generate a final super-term—sub-term glossary. The preliminary candidate list of hyponym-hypernym pairs and the final super-term—sub-term glossary can be combined to generate a final list of hyponym-hypernym pairs. An artificial neural network can be trained using the final list of hyponym-hypernym pairs as a training data set, the artificial neural network trained to identify a hypernym given new text data.

The present application relates generally to computers and computer applications, and more particularly to machine learning and unsupervised hypernym induction.
In linguistics, hypernyms refer to a word with a broad meaning under which words with more specific meaning or meanings (referred to as hyponyms) can fall. For example, "color" is a hypernym of "purple", the word "purple" being a hyponym of "color". Another example of a hypernym-hyponym pair is "cutlery"-"spoon".
Given sufficient amount of training data, supervised machine learning systems can be trained to predict hypernyms. However, training data is not available equally in all domains. While manually constructed Hypernym databases may exist, building such databases manually can be a costly task. Some approaches to determining hypernyms are based on lexico-syntactic patterns. Such patterns are sparse and require exact word sequences.
A support vector machine (SVM) based supervised system to identify hypernym relations finds that frequency in the corpus is the best indicator of hypernym frequency. That system, however, does not handle phrases, and instead focuses on single words.
Recent studies have explored distributional inclusion using vectors of adjacent words, part-of-speech (POS) tags and dependency parses of contexts. A literature found that lexico-syntactic patterns capture contextual constraints not covered by distributional inclusion approaches. Yet another work uses a simple substring matching.

Unsupervised hypernym induction machine learning

International Business Machines Corporation


Systems, apparatus and methods are discussed for controlling resonance in in-the-ear headphones. Resonance effects resulting from wave reflection and superposition can occur in the cavity formed by the port tube of an earbud and the wearer's ear canal. In this invention, acoustically resistive structures are provided to create sound diffusion in the cavity. In one embodiment, a spring coil with several adjustable parameters is inserted into the port tube. In another embodiment, a pattern of grooves is carved into the inner surface of the port tube. Porous filters can also be used in conjunction with both of the embodiments described above. The result of providing the resistive structures in an earbud is a flattened cavity frequency response and improved sound quality.

This disclosure relates to headphone acoustics design, and in particular, relates to porting structures that control resonance in in-the-ear headphones.
Headphones are commonly used with a variety of electronic devices to provide mobile and/or personal access to audio content. For example, headphones can be used with music players, such as MP3, CD, and cassette players. Headphones can also be used with cellular phones, personal digital assistants, computers, and most other types of electronic devices that produce audio signals.
There are many types of headphones in existence. Some headphones are supra-aural, meaning that they sit on top of the ear. These headphones are particularly susceptible to external noise because they do not enclose the ear. Other headphones are circum-aural. These headphones surround the ear to create a sound-isolated cavity that blocks out external noise. Circum-aural headphones can perform very well, but are bulky and inconvenient for portable applications. Still another type of headphone is worn inside the ear. These headphones, also called earphones or earbuds, can sit outside the ear canal or be inserted into the ear canal. The latter type, often called canalphones or in-the-ear earbuds, can have better acoustic performance than the former types because the earbuds form an air tight seal in the ear canal to block out external noise.
Like loudspeakers, headphones convert electrical signals into audible sound via one or more transducers. One basic type of transducer comprises a coil of wire, called a voice coil, attached to the apex of a cone or dome shaped diaphragm. The voice coil is positioned in a permanent magnetic field, created, for example, by a pair of permanent magnets. Electrical current is passed through the voice coil, turning it into an electromagnet. The force generated by the fields of the electromagnet and the permanent magnet moves the voice coil back and forth, which in turn moves the diaphragm. The movement of the diaphragm creates longitudinal pressure waves in the air, which are perceived by our ears and brain as sound. In this manner, information carrying electrical current can be converted to information carrying acoustic waves.
The sound quality produced by a headphone is highly dependent on the design of its transducer(s). However, there are other parameters in the design of headphones, and in particular, in in-the-ear earbuds, that affect sound quality as well. In general, sound waves originating from a transducer must propagate through a volume of air before reaching the listener's eardrums. During this time, the sound waves can be corrupted by a variety of factors, such as ambient noise and energy loss. One particularly important factor that degrades sound quality in in-the-ear earbuds is resonance. Because in-the-ear earbuds are inserted into the ear canal, they form an air tight cavity between the earbud and the ear canal. This cavity can act like a resonator that preferentially energizes and amplifies sound waves of certain frequencies (the resonant frequencies). When a wave at one of these resonant frequencies propagates down the earbud and ear canal, it is reflected back in such a way that the amplitudes of the incident and reflected waves are in phase and additive. This creates a standing wave and distorts the original sound wave that was produced by the transducer. The result is undesirable distortion of the audio content being played by the headphones. Thus, there is a need in the art for in-the-ear earbuds that combat the detrimental effects of resonance to sound quality.

In-the-ear porting structures for earbud


A piezoelectric inkjet head structure includes an upper cover plate, a lower cover plate, a piezoelectric actuating module, a nozzle plate and a seal layer. The piezoelectric actuating module includes an upper piezoelectric chip, a lower piezoelectric chip, a first electrode, a second electrode, a conductive layer and a plurality of flow channels. The entrances of the flow channels of the upper piezoelectric chip and the lower piezoelectric chip are separated from each other by the same spacing interval. The entrances of the flow channels of the upper piezoelectric chip and the entrances of the flow channels of the lower piezoelectric chip are arranged in a staggered form. During operation of the piezoelectric actuating module, ink liquid is introduced into the flow channels of the piezoelectric actuating module from the upper cover plate and the lower cover plate, and then ejected out of the nozzles.

With increasing development of an inkjet technology, the inkjet technology is not only used in the traditional printer market but also used in flat panel displays and semiconductor manufacturing processes in recent years. However, for reducing the fabricating cost and saving the process time, researchers are seeking new inkjet technologies. As known, a piezoelectric inkjet technology is one of the most widely-used new inkjet technologies.
Conventionally, the piezoelectric inkjet head structure comprises a nozzle plate, a cover plate and a piezoelectric actuating module. Please refer to FIGS. 1A and 1B. The conventional piezoelectric actuating module 1 comprises an upper piezoelectric chip 11, a lower piezoelectric chip 12, and two electrodes 13 and 14. The electrode 13 is disposed on the upper piezoelectric chip 11. The electrode 14 is disposed on the lower piezoelectric chip 12. In addition, a conductive layer 15 is arranged between the two electrodes 13 and 14. For example, the conductive layer 15 is a conductive adhesive for connecting the two electrodes 13 and 14 with each other. The conventional piezoelectric actuating module 1 further comprises a plurality of flow channels 16a, 16b and 16c. These flow channels 16a, 16b and 16c extend downwardly from the upper piezoelectric chip 11 to the lower piezoelectric chip 12. The entrances 161 of these flow channels are all located at the upper piezoelectric chip 11.
Please refer to FIG. 1B, which schematically illustrates the actions of the conventional piezoelectric actuating module. During operation of the piezoelectric actuating module 1, the electrodes 13 and 14 generate an electric field. According to the positive and negative voltages, the electric field causes deformation of the upper piezoelectric chip 11 and the lower piezoelectric chip 12. As shown in FIG. 1B, when opposite voltages are applied on both sides of the upper piezoelectric chip 11 and the lower piezoelectric chip 12, the flow channel 16b is expanded. As the flow channel 16b is expanded, the flow channels 16a and 16c at bilateral sides of the flow channel 16b are compressed. Consequently, the ink liquid (not shown) contained in the flow channels 16a and 16c will be ejected out through a nozzle (not shown). Moreover, since the flow channel 16b is expanded, the ink liquid (not shown) will be introduced into the flow channel 16b. By alternately changing the positive and negative voltages, the ink liquid can be ejected out through different flow channels 16 and corresponding nozzles (not shown).
In the conventional piezoelectric actuating module 1 as shown in FIGS. 1A and 1B, the flow channels 16a, 16b and 16c are extended downwardly from the upper piezoelectric chip 11 to the lower piezoelectric chip 12, and the entrances 161 of these flow channels are all located at the upper piezoelectric chip 11. Consequently, the base part 121 between every two adjacent ones of the flow channels 16a, 16b and 16c is relatively weak. Since the flow channels 16a, 16b and 16c are expanded or compressed during the operations of the conventional piezoelectric actuating module 1, the base parts 121 beside the flow channels 16a, 16b and 16c are adversely affected. Since the base parts 121 are frequently subject to deformation and compression, the base parts 121 are readily damaged. Under this circumstance, the performance of the conventional piezoelectric actuating module 1 is deteriorated, and thus the piezoelectric inkjet head structure is possibly damaged.
Therefore, there is a need of providing a piezoelectric inkjet head structure with a strong structural strength so as to minimize the damaging possibility.


A method to transform the function of a circuit is provided. The method provides a first register-transfer level (RTL) document and a second RTL document, provides a first gate level (GTL) netlist and a second GTL netlist, compares the two RTL documents to identify the instances to be modified, locates the instances to be modified in the first GTL netlist, and transforms the function of the circuit by patching the circuit such that the patched first GTL netlist is equivalent to the second GTL netlist. The method improves performance and efficiency of the transformation by reducing the number of instances to be input into the engineering change order (ECO) engine, and also minimizes change in circuit design.

Modern circuits (such as integrated circuits (ICs)) are enormously complicated. For example, an average desktop computer chip can have over 1 billion transistors. Due to the complexity and high cost, IC design is often outsourced to a third party that completes the circuit design by using hardware that incorporates software (such as Electronic design automation (EDA) or Computer Aided Design (CAD) tools). Such outsourcing provides opportunities for attackers to take over the designed IC by introducing malicious alterations or hardware Trojans (HTs), which causes serious security concerns especially for security-critical applications such as military applications. A HT can cause malfunction for a circuit into which the HT is embedded or destroy a system incorporating such circuit, lower circuit reliability and leak confidential information.
New methods and apparatus that assist in advancing technological and security needs and industrial applications in circuit technology, IC design, verification, and fabrication processes are desirable.
In addition, in designing very large-scale integration (VLSI) circuits, the function of the IC may have to be changed some time after its initial design for various reasons such as to improve its performance, to introduce new features or to mask HT. Such change is generally implemented by performing engineering change orders (ECO). However, existing ECO techniques are slow and inefficient. Therefore, new methods and apparatus for transforming the function of an IC is desired.

Methods and apparatus for transforming the function of an integrated circuit