First and second bumps electrically connected at first and second positions along a conductive run borne by a flexible substrate are respectively oriented for contact with a pad of a die under test and a pad of a tester structure. Second and third conductive regions are electrically connected respectively to the power and ground terminals of a power source and an electrical device. The second and third regions are spaced from a first conductive region to filter high-frequency noise components from power and ground potentials provided by the power source,

This invention relates to membrane probing of circuits.
Circuits to be probed may include those which are formed as part of "dice" arranged in rows and columns on a silicon wafer during the process of making integrated circuits (IC's). Each die includes as many as a hundred or more aluminum input/output (I/O) pads for connecting the circuit on the die to the outside world. The pads are typically tiny and closely spaced, e.g., on the order of 100 microns center-to-center (pitch).
The performance and/or integrity of the dice circuits may be tested before the dice are cut out of the wafer and packaged. Testing is typically done by conductive probes that make physical and electrical contact with the die pads. Generally, the probes are either hard pins (e.g., tungsten), or hard bumps formed on a membrane surface. The close spacing of the die pads requires that the probes be carefully aligned, often by hand or by using a special visual alignment system. During testing, the probes are forced into contact with the pads.
Often, the sharp probe tips are wiped across the pads to abrade or scratch a thin layer of insulating aluminum oxide (which sometimes forms on the pads), thus exposing non-oxidized portions of the pads. Because the probe tips become dirty from this and other processes, they are periodically cleaned with an abrasive such as sandpaper.
During testing, the probes relay the appropriate power, data, and other signals between the die and a tester. The frequency at which these test signals are communicated (and thus also the testing rate) is determined at least in part by the inductance of the probes and the impedance of the electrical interconnections between the die and the tester.


A wing, or similar article of airfoil section, has a variable geometry surface for the active control of shock strength and transonic wave drag. In one embodiment, the wing has a region of distensible skin (4) aft of the line of maximum section, which extends along the span of the wing in those areas that experience drag. Pressure means (10, 20, 30) within the wing outwardly deflect the distensible region and produce a local bulge in the expansion surface. This bulge induces pre-shock compression and reduces the effect of the shock. The bulge is retracted by the natural elasticity of the skin material (which can be a conventional aluminum alloy) upon removal of the applied pressure. In another embodiment, the wing has a ramp portion (14) which is outwardly deflectable for the same purpose. The invention is applicable to supercritical and natural laminar flow wings.

1. Field of the Invention
The present invention relates to an article, such as an aircraft wing, having an aerofoil section with a variable geometry expansion surface for the control of shock strength.
The invention is particularly applicable to wings for transport aircraft where it is intended to combat transonic wave drag, to which such wings are susceptible when the aircraft is flown in off-design conditions. However, the invention may also find use in the wings of other aircraft types as well as possibly for control surfaces rather than wings.
2. DISCUSSION OF PRIOR ART
It is well known that air-flows over aircraft wings at high subsonic free stream Mach numbers exhibit shock waves due to localised excursions into supersonic flow. The supercritical wing forms of modern transport aircraft ensure that the effects of such shock waves are minimised at the design cruise Mach number, altitude and coefficient of lift. However, it is recognised that these shock waves can increase significantly in strength with small departures from the design conditions, such as a change in the angle of incidence or an increase in Mach number. These shock waves create drag, which is known as transonic wave drag, and can lead to the breakdown of ordered flow. Operation under these conditions is obviously undesirable since it increases aircraft fuel consumption. Moreover, the flow breakdown may cause problems of aircraft control or reduction in aircraft structural life through buffet loading.
In other, non-supercritical, wing sections designed for natural laminar flow, the aerofoil section necessary to maintain the laminar boundary layer as far aft as possible (for the benefit in drag reduction that this conveys) produces transonic wave drag which unfortunately increases rapidly in strength as either Mach number or lift coefficient rise above the design condition value. This places a severe limitation on the operating band of Mach numbers and lift coefficients for laminar flow aircraft.
Various solutions have been proposed to alleviate the problem of transonic wave drag associated with aircraft wings. One approach has been to incorporate perforations or slots in the expansion surface of the wing at both the upstream and downstream sides of the shock location, with these being linked through a plenum chamber inside the wing. This arrangement makes use of the pressure differential that exists in the airflow adjacent the wing. Air is bled from the higher pressure region downstream of the shock and reintroduced in jets upstream of the shock. These jets create a ramp to oncoming flow and thereby cause compression waves which weaken the shock. One of the drawbacks of this solution is that a boundary layer drag penalty is imposed across the entire range of flight conditions, due to the presence of these holes or slots. This drag penalty may outweigh the advantage gained by reduction of transonic wave drag in terms of overall operating costs.
Another approach to reduction of transonic wave drag and associated buffeting is to configure the aerofoil section so as to produce the same pre-shock compression achieved by the method described above. For example, at page 673 of the Journal of Aircraft Volume 25, No 8, dated August 1988, Tai and co-workers disclose an aerofoil with a bulge on the expansion surface at a position approximating to that of the shock wave.
However all aerofoil sections represent a compromise between various conflicting requirements and it is unlikely that any specific configuration optimised with this specific end in view would have a beneficial or neutral effect across the whole range of flight conditions. It is more likely to be the case that, in securing a reduction in the off-design point wave drag, some increase in viscous or wave drag is caused at another condition. Accordingly it is unlikely that a wing of this nature would be of such advantage as to extend the flight envelope whilst reducing overall fuel consumption.

Airfoil with variable geometry expansion surface

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


An image reading apparatus is provided which is capable of correctly reproducing a read image, by correcting variation in read data derived from variation in light intensity and variation in sensitivity, using reading means capable of logarithmic conversion such as an LOG CCD. As variation in read data caused by insufficient light intensity in a shade region of an original is corrected, even when there is a shade in an original image having halftone gradation, satisfactory image reproduction is possible. Since variation in read data caused by insufficient light intensity at the time of zooming is corrected, image quality is not degraded even when electrical zooming is performed. Further, variation in read data caused by fluctuation in light intensity, variation in photosensitivity and types of original is corrected, AD conversion with uniform resolution is possible even when output levels differ because of light distribution variation of a light source or variation in sensitivity of sensors.

1. Field of the Invention
The present invention relates to an image reading apparatus and, more specifically, to an image reading apparatus used for a digital copying machine or the like.
2. Description of the Related Art
When a bound original such as a book (hereinafter referred to as a book original) is copied, sometimes there is a shade at a central portion. Therefore, in a conventional image reading apparatus, a method has been proposed in which a shade region at the central portion of the book original image is detected, and a threshold value for binarization is switched so as to eliminate fogging of the background.
The above described conventional method of switching the threshold value for binarization is effective when the original is a text original in which image data are dominantly white or black. However, an image data having halftone gradation such as in the case of a photo original cannot be reproduced clearly.
Various methods for zooming (changing magnification of) a read image have been proposed in conventional image reading apparatuses.
For example, Japanese Patent Laying-Open No. 7-273979 discloses a method of zooming a read image by changing speed of scanning. Japanese Patent Laying-Open No. 6-134451 discloses a method of zooming an image by approximation, by interpolating read data in equal magnification. Further, a method of zooming a read image by switching line period for reading and by correcting variation in sensor output derived from variation in time of storage by means of a circuit gain has been generally known.
However, of the conventional methods of zooming read image, the method of changing scanning speed leads to increased cost and complicated control, since the accuracy in scanning must be improved for switching the scanning speed. In the method of zooming an image by approximation by interpolation of read data in equal magnification, zooming is after all an approximation since data is interpolated by image processing, inevitably causing degradation in image quality. Further, in the method of switching line period for reading and correcting variation of sensor outputs derived from the variation in time of storage using a circuit gain, lowering of the sensor output when the time of storage reduces is corrected by circuit gain, resulting in degraded image quality.
In a conventional image reading apparatus, canceling in the number of bits in calculation occurs in image processing of a subsequent stage, and therefore, CCD outputs are A/D converted with the number of bits set larger than necessary, and after image processing, lower bits of the data are discarded.
However, in the conventional method of discarding lower bits of data after image processing, though rounding error in calculation (multiplication and division) can be canceled, quantization error between peak and other portions of light intensity occurs, due to difference in sensor outputs caused by light distribution variation of the light source, for example.


A method of automatically correcting magnification and/or non linearity of scanning electron microscope has the steps of loading a reference material in the microscope, inputting a pitch of the reference material and a nominal magnification of the microscope, obtaining an image of the reference material, determining a pitch and/or a linearity of the image of the reference material, comparing the pitch of the image with the inputted pitch of the reference material to obtain a ratio indicative of the magnification and/or comparing the magnification in different locations across an image field indicative of the linearity, comparing the thusly determined magnification with the nominal magnification, and if an error of magnification exceeds a predetermined value, adjusting the scanning electron microscope.

The present invention relates to a method of automatically correcting magnification and non-linearity of scanning electron microscope.
When a magnification and/or non-linearity of scanning electron microscope deviates from nominal values, it is necessary to perform the correction of these parameters with a desired precisions.
No known methods are known for performing automatic correction of the magnification and/or non linearity. It is believed that it is exceptionally important to perform the automatic correction of these parameters.
Accordingly, it is an object of present invention to provide an automatic correction of magnification and/or non-linearity of an electronic microscope to achieve the nominal values of these parameters.
In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention, resides, briefly stated, in a method of a method of automatically correcting magnification and non-linearity of scanning electron microscope, in which the following steps are performed:
A method of automatically correcting magnification and/or non linearity of scanning electron microscope has the steps of loading a reference material in the microscope, inputting a pitch of the reference material and a nominal magnification of the microscope, obtaining an image of the reference material, determining a pitch and/or a linearity of the image of the reference material, comparing the pitch of the image with the inputted pitch of the reference material to obtain a ratio indicative of the magnification and/or comparing the magnification in different locations across an image field indicative of the linearity, comparing the thusly determined magnification with the nominal magnification, and if an error of magnification exceeds a predetermined value, adjusting the scanning electron microscope.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

Method of automatically correcting magnification and non-linearity of scanning electron microscope


A system/process for code-marking and/or machine entering/reading a system of assigned coded reference markers for the relocation, access and retrieval of publication vessels and the desired information upon demand for either paginated or non-paginated vessel types. The system/process consisting of reading/entering either pre-coded and/or machine coding at least one marker (10) for the system before, during or after the marker is adheringly applied to the pre-determined/determined publication vessel(s) (50). The coding may be generated by at least one of the main printer (46) and/or sub-printer on at least one selected face (11,12) of at least one marker, where various forms of machine readable information may distinguish one category of coded markers, individually coded markers or selected marker coded faces thereof from each other to at least one publication vessel for the system. Such machine coding maybe provided from the exterior and/or interior of each marker member, may be directly applied to the face of the desired marker or may be indirectly attached to the marker face or faces by the application of at least one adhering label (20) which carries such readable information thereon the surface. Each marker member having at least one machine readable field (25,26), identification field and/or information field on at least one face consisting of at least one machine readable element (30,30a). Machine reading selected faces of selected markers to relocate, retrieve and access certain publication vessels from storage position and/or specific information within the confines of the respective publication to which the corresponding marker represents thereto.

In general, there are two methods to file paginated and non-paginated publications; both publication types are information-containing vessels which are found in the school, home or office and lend themselves to being utililzed as a personal library of current reference source material capable of being accessed at any given moment, but, however, with manual difficulty. One method is to insert publication vessels into their own file folder, then placing the file folders juxtaposed in file drawers. The other method is to individually place them juxtaposed in a storage receptacle which may be a floor container or shelf file system.
Although both aforesaid filing methods have been found acceptable practice for the home, office and institution use, limitations exist when attempting to re-locate, retrieve and access or inventory voluminous publication vessels stored collectively in file. Typically the publication's binding type has determined the groupings of filed publication vessels. For instance, perfect bound periodicals are stored with their binding facing outward toward the asile whereby information is found and readable along the elongated backbone spine. Conversely, saddle-stitched mechanical design bindings do not offer nor provide such a planar area feature to allow the printing of such information. In the later case, the user is required to randomly pull each issue from its place in file, each from its juxtaposed position to read pertinent issue information located on the outside front cover panel. Therefore, it is to be noted, that by mechanical design, the perfect bound (glued spine) and saddle-stitiched spines are consequently incomparable when stored collectively in a desired storage receptacle environment. It is highly uncommon to find in many homes or offices, people that save particular reference source publication back issues, would separate and establish isolated filing procedures to distinguish one binding type from another, similar to what a library or institution might provide in the way of shelf or drawer file receptacles. Also, due to the variated sizes of non-paginated publication vessels such as, audio cassettes, video cassettes, computer floppy discs, compact discs and micro cassettes, inventory control, indexing, relocation and retrieval are similar problematic concerns for which the present invention resolves.
Further, should the employment of a file drawer method be used, the consumer is expected to purchase or obtain a file folder prior to the publication insertion therein; the file folder being the common vehicle to "create" compatability among both perfect bound and saddle-stitched publications which are generally of standard length and width dimensions categorically (typically less than the physical size of the receiving file folder itself). As for compact disc-containers, stamp and coin collection albums and other non-paginated publications they are/may be stored uniformily with the imprinted perfect binding spines which might be found on shelf files, facing the asile, as well. The ability to relocate and inventory either or both paginated and non-paginated publications vessels using adheringly applied index-markers bearing a variety of forms of information on the exterior and/or within the marker substrate or by self-attaching labels with machine readable information is key in this specification. This system/process permits rapid relocation, retrieval and access of certain desired publications upon demand.
In storage filing of publications having both perfect bound type or saddle-stitched bindings, there is a deficiency to distinguish one issue from another in such a mixed arrangement since there are no "end tabs" or "side tabs" which would provide such distinguishment when the publications are stored juxtaposed in file (without being inserted into a file folder jacket.) Commonly, saddle-stitched publications are positioned in storage with the fore-edge (the edge opposite the spine) facing the user thus protecting the publication cover from detachment during withdrawl and insertion. Yet, however, the problem of individual publication identification remains unaddressed. Regardless if such a collective mix of publications were filed with their unlike binding types exposed to the reader, the problem of relocating and easily inventorying the juxtaposed publications in storage still exists, when demand arises and therefore remains a manual, time-consuming task.
There are principal readable systems/types of machine readers to be used in the system of retrieving, re-locating and accessing publication information. These are by either or the combination of employment of "machine" readable elements by man, mechanical and/or electrical device being visually (scannable) readable graphics/characters of recognition such as numeric, alphabetic, alpha-numeric, color-coding and/or combinations thereof; and machine readable information which includes graphic recognition, character recognition, such as bar codes, alphbetic, numeric and alpha-numeric codes individually or in combination with each other. Also, other machine readers may read magnetic inks/characters, electro-conductive inks/characters, infra-red/ultraviolet sensitive coding, marker's audible and/or inaudible signal coding, holographic coding, electronic generating/receiving signal coding including a variety of olfactory reading equipment (i.e. smoke detectors, fragrance, gas testing/sensing equipment).
Computers, having memory storage capabilities, are utilized to assist the re-location, retrieval, access and/or inventory control of the certain publication(s) information desired upon demand and its/their physical whereabouts such as floppy discs, cassettes etc. which are tracked and searched in computer memory. This system/process to re-locate and retrieve one or more desired publications may be accomplished by using one or more types of machine readers as aforestated, even perhaps by laser readers/scanner code entry, key board coding entry or any other type of suitable code reader herein described to enter such file information into the computer for later recall. It can be also noted, that data marker entry may be capable of cross-reference data link to source certain publications in file by one or more of the following methods; using reference characters, graphic coding, color-coding, electro-conductive substrate(s), electrical generation/pulse coding generation, olfactory sensory method coding, infra-red/ultraviolet coding, magnetic coding and mechanical coding. Each capable of source linking individually or cooperatively as desired, for computer interaction in the process of relocating, retrieving and accessing certain publication(s) and/or specific publication information upon demand.
Other manual systems are found to tremendously laborious, time-consuming and less efficient for the researcher requiring the desired information, especially when "mixed" publication types are stored collectively in a file receptacle or multitude of receptacles over a period of months or years. This lack of time and inability to relocate and retrieve the needed and desired information upon demand may truly discourage the researcher and the information "hunt" which may well prove to be a worthless attempt ending the task. Therefore, with the present retrieval system/process for paginated or non-paginated publications, such publications are less likely to be discarded early before its useful life has been exhausted.
Typically paginated publications such as periodicals, books, discs, etc. include a table of contents, generally, or perhaps an index listing of subject matter, such as advertisers or feature a roster of page numbers of "featured" articles contained within the issue. It is unique to utilize with or find included with a publication machine readable indexing/reference markers for retrieving and relocating filed publications in storage. Machine reading the markers for the system may be randomly performed or selected in a series for the publications in file to provide rapid re-location, inventory control and immediate access of the desired publication as needed by the user, as applicant describes in now issued U.S. Pat. No. 5,080,399.
Canadian Patent 925,764 shows a label for a file fold folder flap. The label is shown to be one-sided and printed information thereon, such as a name and two color-coded areas which are representative of the first two initials of the surname. However, no consideration is given in that patent to the machine reading of information set out on the label for individual index markers employing such machine read information by (a) regulating by identifying a publication through such machine reading step the input to generate, assign and/or direct the placement of index/reference markers being pre-determined, determined, post-determined for the certain publication, for example, may be a bordering surface area (margin); (b) controlling from such machine entering step, the generation of at least one machine readable field directly on marker member(s) or on at least one label for at least one marker's face; (c) controlling the input entering step, optionally, to generate, assign and/or direct the placement of custom-identified marker(s) and/or label(s) for marker(s) to post-determined/pre-determined position on certain publication(s).
U.S. Pat. No. 3,949,363 discloses various types of bar code, magnetic ink character recognition and optical character recognition printing used on cheques and the like. The particulars of the coded information may be read from the cheque; however, there is no discussion about using read information from one or more apparatus marker members (which may be separably removable from the parent publication) adheringly affixed thereto a respective publication in selected paginated series and/or to distinguish a categorical group of publications, and/or publication(s) individually of either paginated or non-paginated types for the system. The index/reference markers being read randomly and/or in series by such machine code reader or machine input entering to perform at least one of generating a marker/label, assigning a machine readable code to file-reference certain publication(s) and/or specific information contained within desired pages of the publication(s). The system/process engaged for the purpose of inventorying, maintenance and re-location and retrieval of certain publication(s) as desired to the system and/or specific information contained within such publication source(s).
The system/process, according to the present invention, overcomes a number of problems associated with publication re-location and retrieval of specific articles and the physical publications for the system by providing an index-marking and/or machine means readable system of coding the marker's exterior/interior substrate directly or indirectly coding the marker by means of at least one form. Also label(s) and/or markers may each be adheringly applied by at least one of at least one adhesive layer (pressure sensitive or dormantly activatible substrate), statically adhering attaching means, and magnetic attaching, non-adhesive marker engaged to the publication by a user. The engaged marker or markers to a publication vessel not only permits assigned identification to such publication vessel for filing purposes and later ease in re-location of the certain publication(s)/specific information contained therein, but also permits inventory control through machine reading information coding provided from the marker and/or from at least one face of at least one marker being multi-faced. In this reading of the index-marker's readable information, a computer may be programmed to generate and/or assign machine readable information coding of an array of varieties described herein, being produced in accordance with data input of the entered and/or read information permitting the application of at least one machine readable code field as assigned/pre-determined to at least one marker member for the system, before, during or after such indexing-markers are adhered to their determined/pre-determined position on at least one certain publication for the system. U.S. Pat. No. 4,204,639 discloses the use of additional labels applied to a file folder being of the color coded type to provide all the attendant advantages thereof. The same patentee, Barber, in U.S. Pat. No. 4,329,191 defines a process for labelling a system of file folders which comprises printing a set of indicia in a single field on one face of a pressure sensitive permanent label, where the indicia is both machine and visually readable and a mechanical labeller is programmable to control the application of labels to the same file folder by the input from such machin reading step in application of individual color coded labels to the file folder flap, where each color-code represents one label as applied, has indicium corresponding to one of the machine read indicia.
Further, Barber's U.S. Pat. No. 4,580,815 discloses a composite strip for the subsequent application of a discret series of labels applied to such composite strip before its application to the edge of the substrate; the composite strip advantageously used in combination with a tab extension to provide an add-on assembly. Barber shows limitations in the above cited disclosures mentioned which specifically define the application of labels, each with a single color-code, for alphabetically labelling specifically file folders, namely. However, there is no discussion about using a system/process for code-marking and/or machine reading a system of index/reference/game/coupon markers, in various combinations, for the relocation, access and retrieval of publication information upon demand of either paginated or non-paginated vessel types. The system/process consisting of reading coded/pre-coded markers and/or machine coding at least one marker member for the system, before, during or after the marker is adheringly applied to the predetermined/determined certain publication(s). The coding may be generated by the main printer and/or sub-printer on at least one selected marker and/or marker's face, where various forms of machine readable information may distinguish one category of coded markers, individually coded markers or selected marker coded faces thereof from each other to at least one publication vessel for the system. Such coding may be self-generating from the exterior and/or interior of each marker member, may be directly applied to the face of the desired marker or may be indirectly attached to the marker face or faces by the application of at least one adhering label which carries such readable information thereon/therewithin. Each marker member having at least one readable machine field on at least one face consisting of at least one machine readable element. Optionally, machine reading selected faces of selected markers to relocate, retrieve and access certain publication vessels from storage position and/or specific information within the confines of the respective publication to which the corresponding marker represents thereon for the purpose of inventory control maintenance, additionally. As this specification relates to publication vessels, it is to noted that file folders are excluded from the defined claims herein and from the target category of articles namely--paginated and non-paginated publication vessels. The present invention further provides and indexing system which is comparable to both shelf/drawer system and other file storage receptacles; by comparison, Barber, is only concerned with a labelling system for "shelf file folders" of which his patented specification is restricted thereto.

System for machine reading/index marking publications


An anchor head assembly comprising a main body member with a plurality of cavities having the shape of a frustum of a cone in an exterior section and a corresponding number of cavities which may also have the shape of a frustum of a cone in an interior section. The cavities are orientated such that the narrow ends of those in the exterior section are of a different diameter than and face the narrow ends of those in the interior section. The interior section is dome-shaped so as to facilitate the fabrication of the cavities therein and to facilitate the splaying of strands or tendons as they are passed into and through the cavities in both the interior and exterior sections. The dome-shaped section also facilitates self-centering of the anchor head assembly in a bearing plate. Wedge members are used for capturing the strands and tendons in the cavities in the exterior section of the anchor head assembly. A hexagonally shaped exterior section and the dome-shaped interior section also provides for a lighter weight anchor head than has been heretofore available and the strength of the anchor head is improved using austempered cast iron fabrication techniques.

1. Field of the Invention
The present invention relates, in general, to multistrand post-tensioning cable systems for use in fabricating a wide variety of concrete structures, such as bridges, parking garages, buildings and the like and in particular to a novel multistrand anchor head assembly for use in such systems.
2. Description of the Related Art
A typical multistrand post-tensioning cable system used in the fabrication of various concrete structures, such as those described above, comprises a bearing plate and an anchor head. The bearing plate comprises either a rectangular or a cylindrical member having a rear or bearing surface for bearing against a concrete structure. The bearing plate has a bore centrally located therein having an interior end and an exterior end. The interior end of the bore is provided for receiving a plurality of strands or tendons captured in and extending from corresponding strand or tendon anchoring apparatus in a remote concrete structure. The exterior end of the bore is provided for receiving an anchor head which is provided with means for capturing the ends of the strands or tendons received in the interior end of the bore.
The typical anchor head comprises either a rectangular or a cylindrical member having a rear or bearing surface which is inserted in and/or bears against the bearing plate. It is provided with a plurality of strand or tendon receiving cavities for receiving and capturing, with the help of wedge-shaped members, a corresponding number of strands or tendons.
The conventional anchor head typically is made from a relatively massive and heavy casting or forging of ductile iron or mild steel sufficient to withstand the tremendous compressive forces imparted to it via the strands or tendons captured therein. Its front and rear surfaces are generally planar and no attempt has been made heretofore to remove excessive material therefrom or to provide any sort of self-centering capability.
A typical strand receiving cavity in the conventional anchor head comprises a first or interior cylindrical cavity and a second or exterior cavity having the shape of a frustum of a cone in which a strand, after passing through the first cavity, is captured using two or more wedge-shape members.
In addition to the weight and massiveness of the prior known anchor head and the lack of any self-centering features therein, a further disadvantage of the prior known anchor head is that the bundle of strands in the cable captured therein must be splayed at the anchor head and that the cylindrical shape of the first cavity in the conventional anchor head tends to impart bending moments to the strands which increase in magnitude as a function of the distance a strand is from the center of the bundle. These bending moments are found to impart an undesirably large amount of stress and fatigue to the strands in the bundle, particularly in the outermost strands therein.


A cam disk for use in a loading cam mechanism of a toroidal type continuously variable transmission comprises a first projecting portion, a second projecting portion, a flange portion, a cam surface, a bearing raceway and a corner section. The cam disk has metal flows along the cam surface, metal flows along a surface of the raceway, and metal flows along a surface of the corner section. To produce the cam disk, material is shaped into a predetermined form through a first forging step using a first die unit, a second forging step using a second die unit, a third forging step using a third die unit, a finishing step, etc. The metal flows are also formed in these steps.

The present invention relates to a cam disk for a toroidal type continuously variable transmission used as a transmission of a vehicle such as an automobile.
Conventionally, a stage transmission which comprises speed change gears is used as a transmission of an automobile. This type of transmission has a plurality of gears. The combination of gears is changed to transmit torque from an input shaft to an output shaft at a desired transmission ratio. In the conventional transmission, torque is changed stage by stage, when the speed is changed. Thus, the conventional transmission is disadvantageous in that the power transmission efficiency is low and that vibration occurs when the speed is changed. To overcome these disadvantages, in recent years, a continuously variable transmission is put to practical use. With the continuously variable transmission, no vibration occurs when the speed is changed. In addition, since the power transmission efficiency is higher than that of the aforementioned conventional transmission, the fuel efficiency of the engine is improved.
As an example of the continuously variable transmissions, conventionally, a toroidal type continuously variable transmission 120 as shown in FIG. 14 has been proposed. This type of transmission comprises an input disk 102, an output disk 103a, power rollers 103b rotationally in contact with the disks 102 and 103a, a loading cam mechanism 106, etc. The input disk 102 is rotated in association with the input shaft 101. The input shaft 101 is connected to a drive shaft 122 rotated by an engine serving as a power source. The output disk 103a is rotated in association with an output shaft (not shown). The loading cam mechanism 106 presses the input disk 102 and the output disk 103a in such directions that the disks get closer to each other.
A toroidal type continuously variable transmission with a single cavity comprises a pair of an input disk 102 and an output disk 103a. A toroidal type continuously variable transmission with double cavities comprises two pairs of input disks 102 and output disks 103a. FIG. 14 shows a part of a double-cavity toroidal type continuously variable transmission 120. The transmission 120 has a first cavity 108 including first input and output disks 102 and 103a and power rollers 103b, and a second cavity including second input and output disks and power rollers (not shown). The loading cam mechanism 106 is provided, for example, on the side of a power source for driving the input disk 102 of the first cavity 108. The loading cam mechanism 106 has a cam disk 104 and a roller 105 serving as pressing means. The cam disk 104 is rotatably supported by an input shaft 101 via a ball 125. The roller 105 is rotatable between the cam disk 104 and the input disk 102 about an axis M1 crossing an axis P1 of the input shaft 101. The input disk 102 is pressed against the output disk 103a via the roller 105.
The cam disk 104 shown in FIG. 14 integrally comprises a first projecting portion 112, a second projecting portion 113, a flange portion 114 and a cam surface 115. The first and second projecting portions 112 and 113 are projected from a central portion of the disk 104 in both axial directions of the disk 104. The thickness of the flange portion 114 is gradually reduced from the first projecting portion 112 toward the peripheral portion. The roller 105 is brought into contact with the cam surface 115. In the central portion of the cam disk 104, a fitting hole 116 is formed, through which the input shaft 101 is inserted. A continuous raceway 117 is formed in the overall inner circumference of the fitting hole 116. A continuous raceway 118 is formed in the overall outer circumference of the input shaft 101. The raceways 117 and 118 have arc-shaped cross sections corresponding to the outer diameter of the ball 125.
A line segment N1 connecting bottoms 117a and 118b of the raceways 117 and 118 is inclined with respect to the axis P1 of the input shaft 101. When the first input disk 102 is pressed by the roller 105 in the direction toward the first output disk 103a, the counterforce is applied to the input shaft 101 via the ball 125, thereby pressing the input shaft 101 toward the power source. As a result, the second input disk (not shown) is pressed toward the second output disk. The input shaft 101 and the cam disk 104 are rotatable with respect to each other via the ball 125 rotatably held between the raceways 117 and 118.
The cam disk 104 comprises teeth 112a formed integral with an end portion of the first projecting portion 112. The teeth 112a mesh with teeth 122a formed in the drive shaft 122, so that the cam disk 104 is rotated together with the drive shaft 122. In other words, the rotation of the drive shaft 122 is transmitted to the cam disk 104 via the teeth 112a and 122a. As a result, the first input disk 102 and the second input disk are rotated. The rotation of the first input disk 102 is transmitted to the first output disk 103a via the first power roller 103b. The rotation of the second input disk is transmitted to the second output disk via the second power roller. As a result, the output axis is rotated.
The toroidal type continuously variable transmission 120 can transmit higher torque than the conventional belt type continuously variable transmission described above. However, considerable compressive stress and tensile stress act on the cam disk 104. More specifically, when the input disk 102 is pressed toward the output disk 103a by the roller 105, much greater compressive stress and tensile stress act on the cam disk 104 as compared to the case of a general mechanical member on which stress is exerted repeatedly, such as, a gear or a bearing.
Particularly in regions enclosed by the dot-chain lines H1 in FIG. 14, considerable compressive stress acts on the cam surface 115 and the raceway 117. Further, the outer circumference of the flange portion 114 of the cam disk 104 is warped away from the input disk 102 by the counterforce applied to the cam disk 104 when the roller 105 press the input disk 105 toward the output disk 103a. For this reason, great tensile stress acts on a region enclosed by the dot-chain line H2 in FIG. 14, i.e., a corner section 119 where the second projecting portion 113 intersects the cam surface 115. In the teeth 112a which mesh with the teeth 122a of the drive shaft 122, great compressive stress acts on a top end portion of the teeth 112a enclosed by the dot-chain line H3 in FIG. 14. Great tensile stress also acts on a root portion of the teeth 112a enclosed by the dot-chain line H4.
Conventionally, in one method for producing the cam disk 104 described above, a solid material 126 as shown in FIG. 15 or a hollow material is cut-worked. The material 126 is shaped into a column by, for example, rolling. In another method, the material is shaped into a form approximate to the cam disk 104 by forging, and subjected to the finishing process, such as grinding. In the method of producing the cam disk 104 by a cutting process from the material, the production yield is very low and a considerable period of time is required for the process. As a result, the production cost is increased.
The material 126, shaped through the steps of melting, casting and rolling, may contain a relatively much impurities in a portion 126a, 30% or less of the diameter of the material from the center. Further, the material 126, which has been subjected to plastic working such as rolling, has metal flows G formed along the axis I of the material 126. A metal flow means a line of texture formed in the metal when crystal grains are aligned in a direction during the process of plastically working the metal texture. The metal flow is also called a flow line. The texture obtained by a preferred orientation of the crystal grains is called deformation texture or fiber texture. Such texture has anisotropy and different mechanical properties depending on directions.
When the material 126 having the metal flows G as shown in FIG. 15 is cut-worked, thereby producing the cam disk 104 as shown in FIG. 16, metal flows G1 are formed along an axis I1 of the cam disk 104. In this case, the metal flows G1 are interrupted by the cam surface 115, the surface of the corner section 119, the surface of the raceway 117, etc., and so-called end flows E are formed. The angle .theta.10 between the cam surface 115 and the metal flows G1 is as large as, for example, 90.degree.. The angle .theta.11 between the tangent of the raceway 117 and the metal flow G1 is as large as, for example, 30.degree. or larger. Moreover, the central portion 126a of the material 126, containing a relatively great deal of impurities, may be exposed on the surface of the raceway 117.
Thus, in the cam disk 104 produced mainly by the cut-work process, a great deal of impurities may be contained or the end flows E may exist in the cam surface 115 and the surfaces of the raceway 117 and the corner section 119, on which much stress is exerted. In this case, the cam disk 104 is liable to break along the metal flows G1. This results in reduction in lifetime of the cam disk 104 and the toroidal type continuously variable transmission having the cam disk 104.
On the other hand, the material (work) 126 may be first shaped into a form approximate to the cam disk 104 by die forging and the n subjected to a cutting process. In this method, since only one kind of die is used, the metal flows cannot be formed along the cam surface 115 or the surfaces of the corner section 119 and the raceway 117. As a result, end flows a re formed on these surfaces. Moreover, the central portion 126a of the material 126, containing a relatively great deal of impurities, may be exposed on the cam surface 115 and the surfaces of the corner section 119 and the raceway 117. Therefore, the cam disk 104 formed by this method also tends to have a short lifetime. In addition, according to this method, the die used in forging is in contact with the work for a long period of time. For this reason, since the die is influenced by high heat generated during the forging process, the surface hardness of the die is lowered and the lifetime of the die is liable to be shortened. Further, in the case where the work (material 126) is shaped into a form approximate to the cam disk 104 by die forging, the conventional die does not have a structure for holding the work. Therefore, the work is easily displaced from the center of the die, with the result that the work accuracy may be lowered.
When die forging is performed with one kind of die, underfill, burr or flash is liable to occur in a corner inside the die. Therefore, it is difficult to shape the material to a desired form. To shape the material 126 to a form approximate to the cam disk 104 in one forging process, a high pressure is required. However, if an excessive pressure is applied, the die may be damaged. Further, to reduce the margin for cutting the work in a cutting process after the forging process, it is necessary to reduce wear of the die. Thus, in the method where first the material is shaped into a form approximate to the cam disk 104 by one die forging process and then subjected to a cutting process, the lifetime of the die may be reduced and the production cost may be increased.
In the double-cavity half toroidal type continuously variable transmission 120 described above, if the transmission torque of the first cavity 108 and the transmission torque of the second cavity are different, simultaneity in changing the speed of the two cavities may be adversely influenced. In addition, if the transmission torques of the cavities are different, one of the cavities must transmit torque greater than the design value. In this case, slippage occurs on contact surfaces between the power roller 103b and the disks 102 and 103a. For these reasons, it is desirable that the transmission torques of the first cavity 108 and the second cavity be equal so far as possible.
The cam disk 104 produced by the conventional method as described above has end flows on the surface of the raceway 117. Therefore, when the ball 125 is rotated while it is in contact with the surface of the raceway 117 at a high pressure, flaking easily occurs on the surface of the raceway 117. When flaking occurs, the friction between the ball 125 and the raceway 117 is increased. When the friction between the ball 125 and the raceway 117 is increased, the first input disk 102 is liable to rotate along with the cam disk 104. As a result, the transmission torques of the first cavity 108 and the second cavity become different, which is not preferable for the reason described above.
Further, in the teeth 112a, as described above, considerable compressive stress acts at the distal end portion and considerable tensile stress acts on the root portion. Therefore, the teeth 112a tend to break along the metal flows, resulting in reduction in lifetime of the cam disk 104.

Cam disk for toroidal type continuously variable transmission


An apparatus is provided, which includes a memory interface circuit, a clock signal generating circuit, and a plurality of memory circuits. The memory circuits are operatively coupled and arranged in an order on a plurality of memory modules, such that the memory module positioned at the beginning of the order is coupled to an output of the clock signal generating circuit and the memory interface circuit. The memory module that is positioned at the end of the order is unique in that it includes a clock signal terminating circuit connected to the last memory integrated circuit. With this configuration, a clock loop is formed by directly routing the clock signal from the output of the clock signal generating circuit through each of the memory modules in the order (without connecting to any of the intervening memory integrated circuits) to the memory integrated circuit positioned at the end of the order. Then, the clock signal is asserted on the previous memory modules by routing it back through the memory integrated circuits thereon, in reverse order to the memory integrated circuit positioned at the beginning of the order and from there to the memory interface circuit. To complete the clock loop, the clock signal is again asserted by routing it from the memory interface circuit back through the memory integrated circuits in order to the memory integrated circuit positioned at the end of the order. Finally, the clock signal is terminated at the clock signal terminating circuit on the memory module positioned at the end of the order.

The present invention is directed to bus systems, more particularly to improved methods and arrangements for providing clock signals in multiple channel modules and bus systems.
Conventional bus systems are typically implemented in single channel architectures. While conventional bus systems have been implemented using modules, the modules in such systems have merely been arranged in a serial relationship on a motherboard. For example, consider the bus system shown in FIG. 1. This bus system is characterized by a master 11 mounted on a motherboard 10. A number of connectors 13 are also mounted on motherboard 10. Each connector 13 is adapted to receive a module 14 comprising one or more integrated circuits 15. Thus, by means of a connector 13, a module 14 is mechanically mounted and electrically connected within the bus system.
One or more bus(es) 16 forms the communications channel between master 11 and a termination resistor 12. Bus 16 typically comprises a number of signals lines communicating control information, address information, and/or data. The signal lines forming bus 16 traverse the motherboard and/or the modules to electrically connect the integrated circuits 15 to master 11.
There are numerous problems associated with such conventional bus systems. For example, the serial arrangement of the connectors and associated modules creates a relatively lengthy communications channel. Since there are many factors limiting the maximum practical length of a communications channel, channel length should, wherever reasonably possible, be minimized.
Conventional bus systems are also characterized by numerous electrical connection points between the connectors and the bus portions traversing the motherboard, between the modules and the connectors, and between the integrated circuits and the bus portion traversing the modules. Improperly matched electrical connections often produce impedance discontinuities that tend to degrade signal transmission characteristics on the bus. Accordingly, the number of impedance discontinuities associated with the bus connections should be minimized.
Such conventional bus systems present a very static architecture, which may not lend itself to the efficient utilization of available space within a larger system. For example, a maximum, pre-set number of connectors is typically provided within the conventional bus system, regardless of the actual number of modules initially contemplated for the bus system. Upgrading the bus system to include additional modules requires that a sufficient number of connectors be provided up to the maximum length (or capacity) of the channel. Typically, empty connectors are filled with dummy modules until they are needed. Absent these spare connectors, upgrading the bus system to include an additional module would require that the motherboard be replaced.
The static architecture of the conventional bus system provides a xe2x80x9cone size fits allxe2x80x9d approach to larger systems incorporating the bus system. The serial arrangement of connectors and modules on a motherboard may produce an undesirably large footprint within the larger system. Further, this configuration does not lend itself to irregular or crowded spaces within the larger system.
Of further concern is the routing of clock signals. High-speed clock signals require special treatment, in that they are particularly susceptible to reflections based on discontinuities in the clock loop circuit. Thus, there is a need for improved clock routing schemes that can support, not only static architectures, but also modular architectures.
The present invention provides improved clock routing methods and arrangements suitable for use with modular components.
The above stated needs and others are met, for example, by an apparatus that includes a memory interface circuit, a clock signal generating circuit, and a plurality of memory circuits. The memory circuits are operatively coupled and arranged in an order on a plurality of memory modules, such that the memory module positioned at the beginning of the order is coupled to an output of the clock signal generating circuit and the memory interface circuit. The memory module that is positioned at the end of the order is unique in that it includes a clock signal terminating circuit connected to the last memory integrated circuit. With this configuration, a clock loop is formed by directly routing the clock signal from the output of the clock signal generating circuit through each of the memory modules in the order (without connecting to any of the intervening memory integrated circuits) to the memory integrated circuit positioned at the end of the order. Then, the clock signal is asserted on the previous memory modules by routing it back through the memory integrated circuits thereon, in reverse order to the memory integrated circuit positioned at the beginning of the order and from there to the memory interface circuit. To complete the clock loop, the clock signal is again asserted by routing it from the memory interface circuit back through the memory integrated circuits in order to the memory integrated circuit positioned at the end of the order. Finally, the clock signal is terminated at the clock signal terminating circuit on the memory module positioned at the end of the order.
By employing certain layouts, the memory module positioned at the end of the order can be moved between various positions depending upon the number/arrangement of memory integrated circuits. For example, a terminating memory module may be the only memory module in the order, at which point it can be operatively configured in a first slot of a multiple slot arrangement. However, should additional memory modules be required this terminating memory module can be moved to a slot firer in the order to allow for the additional memory modules there between. Certain exemplary configurations of such arrangements are shown in the detailed description. These exemplary implementations have a three-slot order. However, those skilled in the art will recognize that orders of three or greater slots/memory modules can be supported by the clock routing schemes in accordance with the present invention.

Clock routing in multiple channel modules and bus systems


The spool carrier of a double twist textile twister is held in space by connecting it to two rotatable assemblies which rotate respectively about a centered axis and an oblique axis. The obliquely oriented assembly is connected to the spool carrier by means of bearings in a bearing housing, the exterior surface of which has two oppositely facing, transversely oriented convex cylindrical surfaces. A base on the spool carrier has depending portions with planar interior faces which engage the convex cylindrical surfaces with a minimum of play.

The invention is concerned with double-twist twister mechanisms, and it is applicable to twisters of the type disclosed in U.S. Pat. No. 4,158,282, issued June 19, 1979, to Jean-Paul Guertin et al.
This type of mechanism has a rotatable centered assembly which includes the rotating spindle, and a rotatable oblique assembly which rotates about an axis which is oblique to the rotational axis of the centered assembly. The opposite ends of the oblique assembly are rotatable, respectively, in the stationary main frame and in a spool carrier. The spool carrier is also rotatably connected to one end of the centered assembly, thereby immobilizing the spool carrier in space. The two assemblies overlap each other in the sense that each of them has at least one part crossing the other. They are coupled to each other by appropriate means, a suitable flexible coupling for this purpose being described in French Pat. No. 78 11 428, corresponding to U.S. Pat. No. 4,209,967, and which is incorporated herein by reference.
In such mechanisms, the connection of the oblique assembly to the spool carrier is quite important and critical, as the rotational axis of the oblique assembly where it connects to the spool carrier must be situated precisely in axial alignment with the rotational axis of the oblique assembly in the fixed frame. Such alignment is difficult to attain due to the accumulation of numerous tolerances involved in the installation process. One solution to this problem, described in the French Certificate of Addition 78 04 321 which corresponds to U.S. Pat. No. 4,158,282, is to enable the end of the centered assembly to slide in a ball-and-socket joint. A support is radially displaceable and can be fixed to the spool carrier after the mechanism is installed and functioning at a moderate speed. This permits self-alignment of the various parts, which thus makes it possible to take up the play of the various tolerances. Nevertheless, the assembling of these various pieces with narrow tolerances is a relatively slow and delicate process, as is the adjustment which has just been described. Furthermore, when deformation of the pieces occurs as a result of shocks, expansion or normal wear, it becomes necessary to carry out another such systematic adjustment.
The purpose of the present invention is to eliminate the preceding disadvantages by providing a structure which permits the oblique assembly to be connected to the spool carrier with a reduced number of pieces which are easy to install and which automatically effect a permanent self-alignment without undue vibrations at normal operating speeds.

SKF Compagnie d'Applications Mechaniques


A fresh air unit. The unit comprises: a housing having an airstream flowing therethrough; a pre-cooling portion, and dehumidification portion. The pre-cooling portion is located within the housing and reduces the temperature and specific humidity of a gas in the airstream to a target zone on a psychrometric chart. The dehumidification portion is also located in the housing downstream of the pre-cooling portion. The dehumidification portion removes a selected amount of moisture from the gas and reheats the gas a selected amount of sensible heat gain.

The present invention focuses on a dedicated outdoor air treatment and ventilation system to deliver properly conditioned outdoor air in HVAC systems using terminal equipment such as fan coils, water source heat pumps and blower coils. The primary benefit of using this type of system is the ability to properly heat, cool and/or dehumidify the outdoor ventilation air independently of the other equipment in the system.
Poor indoor air quality can pose many risks for the building designer, owner and manager. The quality of the indoor environment can affect the health and productivity of the building occupants and even affect the integrity of the building structure itself. A building's indoor air quality is the result of the activities of a wide variety of individuals over the lifetime of a building, the atmosphere surrounding the building, the building materials themselves, and the way in which the building is maintained and operated. The interaction of these variables make achieving acceptable indoor air quality a complex, multi-faceted problem. Although complex, the fundamental factors which directly influence indoor air quality can be divided into four categories: (a) contaminant source control, (b) indoor relative humidity control, (c) proper ventilation, and (d) adequate filtration.
Ventilation is the process of introducing conditioned outside air into a building for the purpose of diluting contaminants generated within the spaces and of providing makeup air to replace air which is lost to building exhaust. The amount of ventilation air so required is established by building codes and industry standards, and varies with the intended use of the occupied spaces. Most building codes reference ASHRAE Standard 62-89 "Ventilation for Acceptable Indoor Air Quality" either in part or in entirety as a minimum requirement for ventilation system design. This standard is hereby incorporated by reference. ASHRAE Standard 62-89 recommends that "relative humidity in habitable spaces be maintained between 30 and 60 percent to minimize the growth of allergenic and pathogenic organisms". Additionally, indoor relative humidity levels above 60 percent promote the growth of mold and mildew, can trigger allergenic reactions in some people, and have an obvious effect on personal comfort. Extended periods of high humidity can damage furnishings and even damage the building structure itself. Controlling moisture levels within the building and the HVAC system is the most practical way to manage microbial growth.
The increased attention to indoor air quality (IAQ) is causing system designers to look more carefully at the ventilation and humidity control aspects of mechanical system designs particularly including dedicated outdoor air treatment and ventilation systems. These types of systems separate the outdoor air conditioning duties from the recirculated air conditioning duties. For simplicity, the present invention is discussed in terms of constant volume systems but is also intended to encompass variable air volume (VAV) systems.
Constant volume (CV) systems deliver a constant volume of airflow to a space at a temperature that varies in response to the thermal (or sensible load) requirements of the space. Examples of equipment commonly used in CV applications include direct expansion rooftop units, indoor air handlers, outdoor air handlers, and terminal products such as fan coils, unit ventilators, water source heat pumps, and blower coil units.
Constant volume systems are traditionally controlled based on space sensible temperature only. Any control of latent energy such as humidity is a byproduct of the sensible cooling process. Basic psychrometrics dictate that, to reduce space relative humidity, the supply air must be at a lower dewpoint than the space. At high space sensible loads, the leaving air temperature of the cooling coil is low, usually below the target dewpoint, resulting in adequate dehumidification. However, when the sensible load of the space is low (i.e., under part load conditions), the controller of the constant volume system responds by increasing the leaving air temperature to avoid overcooling the space. If the dewpoint of the air leaving the cooling coil is now above the targeted dewpoint for the space, inadequate dehumidification of the space occurs.
One approach to dealing with the reduced latent capacity of a constant volume system under these part load conditions is to separate the system outdoor and recirculated air paths. In such an arrangement, a dedicated central unit heats, cools and/or dehumidifies the outdoor air to an approximate comfortable temperature (65-80.degree. F.) and an approximate low dewpoint (42-53.degree. F.) dictated by the desires of the building owner or operator. Under most operating conditions, the outdoor air unit over cools the outdoor air to remove the required moisture and then reheats it back up to a room neutral condition of about 65-80.degree. F. to avoid over cooling the space and unnecessary reheating at the terminal unit. Often the energy to reheat the entering outdoor air is recovered energy from the cooling process such as condenser heat.
Prior art systems have not been optimized to control the sensible and latent cooling of a unit providing outside air. Additionally, the sizing of the heat exchange coils in such a unit has not been optimized.

Sizing and control of fresh air dehumidification unit


Provided is a tomography apparatus including: a data acquisitor configured to obtain a first image by using tomography data acquired as a first X-ray generator for generating X-rays having a first energy rotates around an object over a first angular range and obtain a second image by using tomography data acquired as a second X-ray generator for generating X-rays having a second energy rotates around the object over a second angular range; a controller configured to acquire motion information representing an amount of motion of the object over time by using the first and second images; and an image reconstructor configured to reconstruct a target image showing the object at a target time point by using the motion information.

1. Field
The present disclosure relates to tomography apparatuses and methods of reconstructing tomography images.
2. Description of the Related Art
Medical imaging apparatuses are used to acquire images showing an internal structure of an object. The medical imaging apparatuses are non-invasive examination apparatuses that capture and process images of details of structures, tissue, fluid flow, etc., inside a body and provide the images to a user. A user, e.g., a medical practitioner, may use medical images output from the medical imaging apparatuses to diagnose a patient's condition and diseases.
A computed tomography (CT) apparatus is a representative example of an apparatus for imaging an object by emitting X-rays toward a patient.
A CT apparatus is capable of providing a cross-sectional image of an object and may represent an internal structure (e.g., organs such as a kidney, a lung, etc.) of the object without superimposition of adjacent structures, as compared to a general X-ray apparatus. Due to these advantages, the CT apparatus is widely used for precise diagnosis of diseases. A medical image obtained by a tomography apparatus is hereinafter referred to as a tomography image.
A tomography apparatus performs tomography scanning on an object to acquire raw data. The acquired raw data is used to reconstruct a tomography image. The raw data may be projection data obtained by projecting an X-ray onto the object, or may be a sinogram representing a set of projection data.
For example, to obtain a tomography image, image reconstruction may be performed using a sinogram obtained by performing tomography scanning. Tomography image reconstruction will now be described in detail with reference to FIGS. 1A and 1B.
FIGS. 1A and 1B are diagrams for explaining capturing and reconstruction of a CT image.
In detail, FIG. 1A is a diagram for explaining about a CT scan performed by a CT apparatus. During the CT scan, the CT apparatus acquires raw data while rotating around an object 25. FIG. 1B is a diagram for explaining about a sinogram acquired during a CT scan and a CT image reconstructed from the sinogram.
A CT apparatus generates and emits, via an X-ray generator, an X-ray towards an object, and detects, via an X-ray detector, the X-ray that has passed through the object. The X-ray detector may also generate raw data corresponding to the detected X-ray.
In detail, referring to FIG. 1A, an X-ray generator 20 in a CT apparatus emits an X-ray towards the object 25. During a CT scan performed by the CT apparatus, the X-ray generator 20 rotates around the object 25 and acquires a plurality of raw data 30 through 32 corresponding to angles of rotation of the X-ray generator 20. In detail, the X-ray generator 20 acquires the plurality of raw data 30 through 32 by detecting X-rays emitted toward the object 25 at positions P1 through P3, respectively. In this case, raw data may be projection data.
The X-ray generator 20 has to rotate 180 degrees or greater during a CT scan in order to produce a cross-sectional CT image.
Referring to FIG. 1B, a sinogram 40 may be acquired from a combination of the plurality of the raw data 30 through 32 acquired by the X-ray generator 20 that moves at predetermined angular intervals as described with reference to FIG. 1A. The sinogram 40 is acquired by performing a CT scan as the X-ray generator 20 rotates for one period. The sinogram 40 corresponding to the one period may be used to produce a cross-sectional CT image. The one period may be a time period for the X-ray generator 20 to rotate by an angle that is greater than or equal to 180 degrees or by an angle that is greater than or equal to 360 degrees depending on specifications for a CT system.
A CT image 50 is reconstructed by performing filtered backprojection (FBP) on the sinogram 40.
In general, it takes about 0.2 seconds for the X-ray generator 20 to rotate 180 degrees.
When an object to be scanned moves, motion of an object may occur even during one period. Due to the motion of the object, motion artifacts occur in a reconstructed CT image.
When motion artifacts occur, an outermost edge of an object may be unclear and may overlap with itself or others in a reconstructed CT image, and an inner edge of the object may be blurred within the CT image due to motion of the object.
These motion artifacts in a CT image may reduce the quality of the CT image and accordingly, degrade the accuracy of analysis of an image and diagnosis of a disease by a user, e.g., a medical practitioner.
Thus, when a CT scan is performed on a moving object, it is of great importance to reconstruct a CT image with minimized motion artifacts.

Apparatus and method for reconstructing tomography images using motion information


A method for estimating and removing a time varying DC-offset includes the steps of dividing the received burst into blocks (902), then finding the maximum and minimum values in each block (904). Once the maximums and minimum values have been found, the upper and lower envelopes are determined (906). The DC-offset path is then calculated by taking the average of the upper and lower envelope (908). Once determined, the DC-offset path information is used in order to subtract the DC-offset from the desired signal.

Receivers based on the direct conversion architecture are very appealing because they require fewer components and therefore are less complex than traditional super-heterodyne receivers. Direct conversion receivers however suffer from a very serious problem, which is DC-offset. Direct conversion receivers take a radio frequency (RF) signal and translates it into base-band. So if there is any DC-offset added to the received signal by the mixer (or any other component in the receiver), the DC component of the received signal will be lost because there is no intermediate frequency (IF) filter. Direct conversion receivers are very susceptible to the presence of inteferers (blocking signals within the receive band) that through self-mixing can produce a DC-offset that is added to the received signal.
If the received signal has zero mean, and the DC-offset remains constant, it is possible to solve this problem by averaging the received signal along a sufficiently long period, and then removing that average from the received signal. The DC-offset problem worsens when the DC-offset varies with time. If the DC-offset variation is slow, it is possible to update the estimated DC-offset by repeating the averaging process after a certain period or in a continuous manner. Temperature changes, etc can cause slow variations of the DC-offset. However, if the DC-offset varies too fast, the former procedure will stop working, because a signal can have zero mean over its total duration, but locally it will not have zero mean unless the signal is constant and zero. When the DC-offset changes very fast, it is called a time-varying or dynamic DC-offset, as opposed to the static or slowly-varying DC-offset which can be solved using a technique as described in U.S. Pat. No. 5,422,889 and entitled Offset Correction Circuit.
Because a blocking signal can appear at any time, the DC-offset component that will be added to the received signal can also appear at any time. As a consequence it is called "dynamic" DC-offset, because it will change depending on the arrival time of the blocking signal. This phenomenon is usually referred to as AM suppression. A typical dynamic DC-offset profile is shown in FIG. 2 for the I (in-phase) component of the signal. Signal 202 shows a GMSK I signal which is the desired signal. Signal 204 is the distorted signal having been affected by a DC offset. Line 206 highlights the dynamic DC-offset. The AM delay is shown by line 208, while the AM level is shown by line 210.
In the presence of a time varying DC-offset, the receiver performance degrades quite a bit with the amount of degradation depending on the DC-offset variation and the speed of the variation. That is why solving for time-varying DC-offset problems is one of the more critical problems to be resolved in a direct conversion receiver. One of the main reasons for the apparition of time-varying DC-offsets in TDMA direct conversion (also called homodyne) receivers is the presence of TDMA interferes, that through self-mixing or even order non-linearities, can produce a DC-offset that is added to the received signal. This is something that does not happen with super-heterodyne receivers. Because such an interferer can appear at any time, the DC-offset component that it will add to the received signal can also appear at any time. As a consequence, it is called a "time-varying" DC-offset, because it will change depending on the arrival time of the interfering signal.
Currently one of the most successful wireless communication systems in the world is the GSM system. GSM devices, such as portable radiotelephones (also called handheld devices), must pass tests to prove conformance with the GSM standard. One of those tests is called the "AM suppression test". To pass the AM suppression test, the bit error rate (BER) performance of the handheld must not be degraded significantly in the presence of a very powerful TDMA interferer signal. It is clear from the previous explanation that a homodyne receiver will not be able to pass the AM suppression test if the receiver does not implement a good time-varying DC-offset correction method, because the interferer signal will generate a time-varying DC-offset that will be added to the received signal. A need thus exist in the art, for a method for correcting for a time varying DC-offset.

Method for estimating and removing a time-varying DC-offset


A method of and system for steering an arc and/or torch head in a weld joint is provided. The system includes a torch head that creates an arc in a weld groove formed in at least one workpiece. The system also includes a control unit that includes a feedback system that monitors at least one of a voltage of the arc, a current of the arc, a power output of the torch power supply, and a contact tip to weld distance. The control unit outputs a feedback signal corresponding to the monitoring. The control unit also includes a comparison circuit that compares the feedback signal with at least one predetermined value corresponding to a position of at least one of the arc and the torch head in the weld groove. The control unit further includes an arc steering system that outputs a steering signal based on the comparison.

In related art arc welding systems such as gas-shielded tungsten arc welding (GTAW), gas-shielded metal arc welding (GMAW), plasma arc welding (PAW), etc., weld quality will be adversely affected if the torch head is not properly positioned with respect to the weld groove walls. For example, because ferrous materials of the weld-groove sidewalls can interfere with the arc, the arc of a torch head that is improperly positioned can shift to a sidewall rather than the bottom of the weld. Conversely, if the torch head is positioned too far away from the sidewall, the filler material will not be properly deposited against the sidewall. Further, even a torch head that has been properly positioned at the start of the welding process may need to be readjusted during the welding process. This is because the alignment of the sidewalls of the workpieces may not be straight and true and the relative position of the torch head with respect to the weld groove sidewall could change, i.e., the distance between the welding head and a groove sidewall could get smaller or larger, as the torch head travels the length of the weld groove. In addition, in some cases, the width of the weld groove could also vary along its length due to deviations in machining the weld groove. Accordingly, to account for misalignment and width variations in the weld groove, the position of the torch head and/or the width of the arc oscillation may need to be adjusted in situations where mechanical oscillation, magnetic oscillation and/or ground switching are used. Therefore, even in an "automated" welding process, an operator may need to watch the welding operation and constantly adjust the position of the torch head and/or the width of the arc oscillation.
Further limitations and disadvantages of conventional, traditional, and proposed approaches will become apparent to one of skill in the art, through comparison of such approaches with embodiments of the present invention as set forth in the remainder of the present application with reference to the drawings.


A concrete placing apparatus comprises jacks arranged in line along a wall to be erected, and U-shaped frames mounted on these jacks and connected with each other by scaffolds positioned along and on both sides of the line of arrangement of the jacks. The apparatus also includes driving carriages disposed on the scaffolds for movement therealong. Each carriage carries a feed hopper, a moulding board, and a concrete compacting means. According to the invention at least one of the moulding boards is provided with a drive for moving it in the direction transverse to the line of arrangement of the jacks. This drive is connected with the moulding board by means of a rod. The concrete compacting means is constructed in the form of a vibrating chute positioned under the feed hopper and above the moulding board and provided with a vibrating means for oscillating this chute along the direction of movement of the moulding board. The vibrating chute is mounted on the same carriage with the moulding board having a drive and consists of two parts attached to each other for extending in the direction of movement of this moulding board, so as to enable varying the passage area of the vibrating chute according to the change in the distance between a respective moulding board and the line of arrangement of jacks.

1. Field of the Invention
The present invention relates to construction machinery, and particularly to a concrete placing apparatus. The invention is applicable in the building industry for casting solid concrete and reinforced concrete walls.
2. Description of the Prior Art
There is known a variety of formworks which are used for casting solid walls. The USSR Author's Certificate No. N 224032 (Int. Cl. E04G 11/12) describes a collapsible formwork which comprises jacks, formwork boarding mounted on both sides of the wall being cast, and U-shaped frames suspended on the jacks and provided with rollers to move on the formwork boarding.
Erecting a wall with the aid of such formwork is effected as follows. The concrete mix is poured into the formwork, and lifting the frames with the working deck as the wall grows in height, the lower part of formwork boarding is dismantled and mounted over the upper end of the formwork.
However, using the above collapsible formwork necessitates alternate dismantling and mounting the formwork boording during the whole operation, which entails increased consumption of labour and time.
Higher efficiency can be achieved with the aid of a sliding formwork (cf. "Opalubka," Politechnicheskiy Slovar, Moskwa, "Sowetskaya Encyclopedia," 1978, p. 328). The formwork of this type generally comprises the same elements as the formwork described above.
The U-shaped frames in this sliding formwork are not provided with rollers, and the formwork boarding is rigidly attached to the frames. In this case the formwork is lifted together with the frames, thereby providing for continuous casting of the wall. This type of formwork also has a number of disadvantages. First, this formwork is mounted along the whole length of the wall being erected and in the case of large walls, is large and heavy, thus complicating the whole concrete placing operation. It should also be noted that with the increase of length of the formwork boarding the amount of friction between the latter and the concrete also increases. Second, the above formwork, does not permit casting a wall with variable cross-section, and in particular is not adapted for producing offsets on the walls for the floor slabs or relieving slabs in the case of retaining walls to rest on. Third, this formwork doesn't permit erecting a wall using two different concrete compositions simultaneously, for example, a wall wherein the face side is made from the high-grade concrete and the back side from the low-grade concrete, or from light-weight and heavy-weight concretes respectively. This formwork does not permit, for the same reason, casting a wall with the face and back sides having different colours. Due to all these reasons the above formwork cannot provide savings either in labour or in materials.
For erecting solid concrete walls there are also used concrete placing apparatus, which provide for speeding up the erection operation. The USSR Author's Certificate No. N 654,786 describes a concrete placing apparatus for casting solid walls, permitting most of the difficulties associated with the above formworks to be overcome.
This concrete placing apparatus comprises jacks arranged in line along the wall being cast, U-shaped frames mounted on these jacks and connected with each other by means of scaffolds positioned along and on both sides of the line of arrangement of the jacks, and driving carriages mounted on these scaffolds for movement therealong, and carrying each a feed hopper, a moulding board and a concrete compacting means.
The concrete compacting means is a surface vibrator disposed behind the feed hopper and adapted for compacting freshly placed concrete.
The presence of carriages in this apparatus makes unnecessary using long moulding boards in the case of long walls, thus decreasing the size and weight of the apparatus.
Furthermore, owing to the presence of several feed hoopers mounted on the carriages positioned on both sides of the wall, the latter can be cast using two different concrete mixes simultaneously.
This concrete placing apparatus, however, also has a number of disadvantages. For example, it does not permit casing a wall with a variable cross section. In addition, the surface-type vibrators, which compact the concrete mix by impacting it after it has been placed, excite vibration of the previously placed concrete, thus preventing the latter from rapid setting, and thereby slowing down the operation.

Concrete placing apparatus for casting solid walls


Embodiments of the present invention generally relate to systems and methods for implementing telecommunications. More specifically, various embodiments of the present invention provide methods for interconnecting real-time communication links. Such methods include receiving the status of at least two communication links. The communication links may be established between endpoints and bridges in a network. One of the bridges associated with one of the communication links is selected to operate as a host bridge based at least in part on the status of the communication links. Then, after receiving the status from at least two of the communication links, the selected host bridge is automatically caused to initiate another communication link with at least another bridge associated with one of the aforementioned communication links.

Embodiments of the present invention generally relate to systems and methods for implementing telecommunications. More specifically, embodiments of the present invention relate to systems and methods for dynamically linking telecommunication bridges.
Existing teleconferencing systems are capable of establishing a telephone conference call or teleconference between multiple individuals. One of the most common methods for establishing a teleconference involves a teleconference host or sponsor (i.e., the individual who desires to have a teleconference), to schedule the teleconference with a human teleconference operator in advance of the teleconference. The operator typically initiates a software application such as, Windows™ Operating Console that provides control of all calls occurring on a particular bridge. Using the software, the operator opens a pre-loaded instance of the call, and the necessary link line(s) for the proposed conference call are preconfigured in a table detailing the proposed call. At a pre-determined point in time, the operator dials to a second bridge, waits for the system or another operator to answer the call, and then manually links the calls by clicking an input on the operator's user screen. As will be appreciated, the aforementioned approach may be labor intensive, may not provide an ability to link calls on demand, and may involve various charges incurred while a call is pre-setup but not currently being utilized by callers.
Thus, for at least one or more of the aforementioned reasons, a need exists for advanced systems and methods for implementing telecommunication connections.

Systems and methods for dynamic bridge linking


An array processor is described consisting of a plurality of modules connected together in rows and columns. Each module has at least one special terminal which, as well as providing a connection for transfer of data between adjacent modules, also provides an output which is combined with similar signals from the other modules in the same row, to form a row response signal. Alternate modules in each row are rotated by 180.degree. with respect to each other, so that the special terminals on adjacent modules are connected in pairs. This reduces the complexity of the circuits for forming the row response signals.

This invention relates to array processors.
An array processor is defined herein as a data processing system comprising a plurality of processing elements which are operable in parallel upon separate data streams under the control of a common stream of control signals. Thus, all the elements perform basically the same sequence of operations (subject to possible modifications by activity bits within the individual elements or by control signals which are specific to particular groups of elements), but on different data. With such a processor, as many operations can be performed simultaneously as there are elements, and hence the data throughput can be very high.
Such a processor may be formed out of a plurality of identical modules, each module including one or more of said processing elements. Each module has a plurality of terminals and the modules may for example be connected together in rows and columns by means of data paths between these terminals, so as to permit transfer of data between adjacent modules. At least one of these terminals may also serve to provide an output signal which is combined (e.g. ANDed or ORed) with other signals from the same row (or column) to provide a row (or column) response signal.
Such a system is described, for example, in our British Patent Specification No. 1,445,714 published Aug. 11, 1976 and in our co-pending British Patent Application No. 10873/76 filed Mar. 18, 1976, now British Patent No. 1,536,933 published Dec. 29, 1978.
It is clear that, if the array contains a large number of modules, a large number of AND/OR gates and data paths is necessary to form the response signals. One object of the present invention is to reduce the number of such gates and data paths.


The example of implementation of the invention provides a method used for exploiting a natural gas hydrate reservoir and belongs to the field of natural gas hydrate reservoir exploitation. The method mainly comprises a heat-injecting vertical well and a production horizontal well. The production horizontal well is opened in a segmental manner. In combination with natural gas hydrate heat exploitation, heat flow injected into the vertical well is enabled to heat different positions of the natural gas hydrate reservoir to increase a recovery ratio of the natural gas hydrate reservoir. The method specifically comprises the steps of injecting a heat flow into the natural gas hydrate reservoir by utilizing the vertical well to promote decomposition of the hydrate; firstly opening a horizontal branch of the horizontal well fully and keeping depressurization exploitation. When gas production amount is reduced to a certain degree, dividing a segmentation number based on permeability of the natural gas hydrate reservoir and performing segmental exploitation on the horizontal branch from a toe end to a heel end to realize heat exploitation of the heterogeneous natural gas hydrate reservoir. The method makes full use of a horizontal well structure, reduces exploitation cost and provides effective measures for efficient exploitation of the heterogeneous natural gas hydrate reservoirs.

The natural gas hydrate, an unconventional gas resource, is paid widespread attention and researched by people in the world by virtue of the advantages of wide distribution, multiple types, big reserves and big energy density. Under the condition that difficulty in exploitation and utilization of traditional fossil energy resource rises at the current state, the natural gas hydrate is generally accepted as one of the most promising new efficient clean energies and has huge exploitation potential.
In a high-pressure and low-temperature environment, the natural gas and water may form a natural gas hydrate; when the condition for the existence of the natural gas is damaged, that is to say, the temperature rises at a given pressure or the pressure is dropped at the given temperature, the natural gas hydrate decomposes; the exploitation of the natural gas hydrate is to damage the phase balance of the natural gas hydrate to decompose the natural gas hydrate into natural gas and water for exploitation. In the exploitation of the natural gas hydrate, the horizontal well can enlarge the contact area efficiently, expand the decomposition range of the natural gas hydrate and accordingly increase the gas production rate; however, due to heterogeneity of the natural gas hydrate reservoir, a channeling phenomenon happens easily in the heat-injecting exploitation process, and the exploitation efficiency of the natural gas is affected seriously.

Method used for exploiting natural gas hydrate reservoir

CHINA UNIVERSITY OF PETROLEUM (EAST CHINA)


An asparagus carton and a unitary blank for forming it. The blank is of corrugated paperboard. The carton interior is tapered along opposite side walls by virtue of slanting side spacer panels. This yields a trapezoidal configuration of a part of the carton interior to more nearly correspond to the tapered form of a mass of asparagus. The carton is preferably loaded from the bottom. The asparagus may be inspected by opening a side wall panel, and may also be opened from the top. In addition to providing slanting side walls, the side spacer panels permit the loaded carton to be lifted through side wall openings without contacting the asparagus. In a first embodiment, the bottom of the carton may be opened by releasing a bottom tongue and slot latch arrangement, while in a second embodiment the bottom of the carton is defined by known interlocking panels.

This invention relates to an asparagus carton fashioned from a unitary blank of stiff, foldable, and resilient sheet material, such as corrugated paperboard or the like.
The paperboard carton art is aware of constructions for forming an asparagus carton from a unitary blank of paperboard. One construction is shown in U.S. Pat. No. 4,353,495 issued to OHo H. Jes. The Jes carton includes openings for the introduction of fluids to cool the asparagus after it has been placed in the carton. However, the Jes carton requires staples for assembly. There exists a need for a paperboard asparagus carton having opposite interior side slanted spacer panels, spaced a predetermined distance from two of the four side panels, for the purpose of protecting the contents of the carton and also to rigidify it with regard to vertical stacking strength, and which does not require staples for its erection.


An electric vacuum cleaner has an air discharge duct and an ozonizer arranged within the exhaust duct for defining air passages through which the exhaust air is constrained to flow and generating a corona discharge laterally across the air passages. Ozone is thereby generated and mixed with the exhaust air. The voltage which generates the corona discharge is varied in accordance with changes in room temperature in order to minimize changes in the quantity of ozone generated.

1. Field of The Invention
The present invention relates to an electric vacuum cleaner, more particularly to an electric vacuum cleaner which is provided with an ozonizer in an exhaust duct thereof and a able to purify the exhaust air by the oxidation power of ozone O.sub.3 generated by the ozonizer.
2. Description of Prior Art
Conventionally, the hitherto used electric vacuum cleaners have been generally provided with filters mounted ahead of exhaust ducts and adapted for filtering the exhaust air. However, the filters applied to the conventional vacuum cleaners cannot filter off noxious materials and odor, thereby causing them to exhaust along with the filtered exhaust air into the room. Therefore, there has been some problems that the noxious materials and odor exhausted from the conventional vacuum cleaners may be detrimental to a person's health, and possibly the room cleaned by the conventional vacuum cleaners needs to be separately ventilated by opening windows.
Also, there have been proposed vacuum cleaners with an ozonizer for solving the above-mentioned problems by purifying the exhaust air by the oxidation power of ozone generated by the ozonizer. A representative example of the prior art is disclosed in (Pyung) Japanese Laid-Open Utility Model Publication No. 1-76,744 (laid open on May 24, 1989.). The vacuum cleaner disclosed in the above Japanese Utility Model comprises a dust collection cell for collecting dust therein, a dust collection motor for generating a suction power forcing the dust to be sucked into the dust collection cell and an ozonizer for generating the ozone and supplying it to the dust collection cell. Also, this conventional vacuum cleaner is provided with ozone decomposing catalysts for decomposing the residual of the generated ozone.
However, in the conventional electric vacuum cleaner with an ozonizer, it is difficult to obtain enough quantity of ozone to completely purify the exhaust air containing the noxious materials and odor. Also, there is no way to compensate for variations in the generated quantity of the ozone, as caused by variations in room temperature.

Electric vacuum cleaner with an ozonizer