An ultrasonic inspection technique using a specially designed electromagnetic acoustic transducer (EMAT) launches and receives longitudinal ultrasonic waves into a thin metal wall or thin metal foil seal of a container, causing it to vibrate and launch ultrasonic compressional waves into liquid contained therein. The contents of plastic containers having a metal foil seal forming one wall are easily inspected. The EMAT establishes a magnetic field in the surface of the metal parallel to the surface. Radio frequency (RF) eddy currents are also induced by the EMAT in the surface of the metal. A Lorentz force is generated in the metal surface according the vector product of J, the current density, and H, the magnetic field, and the force generated by the interaction of the perpendicular components of the magnetic field H and the eddy currents J is directed normally to the surface of the metal. This normal force oscillates with the frequency of the induced eddy currents creating ultrasonic compressional waves which propagate normal to the surface of the metal. In such thin-walled metal containers or thin metal foil seals, where the thickness of the metal is much shorter than the ultrasonic wavelength in the metal, the generation and reception process is analogous to the operation of a loudspeaker in air. In this application, the thin metal wall or foil acts as a membrane, with the Lorentz forces generated in the wall or foil causing the metal membrane to vibrate, generating ultrasonic waves in the liquid. Because the thin wall or foil is much more compliant than a thick piece of metal, much larger displacements are generated at the metal-liquid interface than for the thick-wall case, resulting in much larger signal amplitudes than in the thick-wall case.

The present invention relates in general to the use of ultrasonics to inspect liquids in containers and, in particular, to a method and apparatus for ultrasonically inspecting liquids in containers to determine the condition of the liquids wherein the ultrasonic waves are produced by electromagnetic acoustic transducers (EMATs).
The use of ultrasonics to inspect liquids inside containers using conventional ultrasonic testing methods is well established in the art. In such testing, a piezoelectric (or similar) transducer is coupled to the wall of the container using some form of coupling media such a liquid. The ultrasonic sound waves then propagate through the wall of the container and into the liquid inside the container. The sound wave may then reflect from a solid object in the liquid, or a liquid-air interface, or the opposite wall of the container, and be detected by the ultrasonic transducer. In other applications, a pitch-catch arrangement of two transducers on opposite sides of the container is used to launch and detect the ultrasound. A wide range of measurements and liquids using ultrasonics is possible. Some of the possible measurements include liquid height, detection and imaging of solid objects in liquids (for example medical ultrasonic imaging of internal organs), velocity measurements of liquid flow, and attenuation measurements to determine the condition of the liquid.
Nagata et al. (U.S. Pat. No. 4,821,573) discloses a method and apparatus for ultrasonically inspecting the food contents of a package. An ultrasonic transmitter-receiver system is disposed on at least one side of the package and the occurrence or degree of degradation of the contents is determined based upon the output data from the system. The invention is stated to be particularly useful to inspect foods, pharmaceutical agents, feedstuffs and so-on, and they may be of any desired consistency but only if it is freely-flowable, such as a homogenous solution, a dispersion, a paste, or the like. Before the package is subjected to the ultrasonic inspection, it is preferably shaken so as to disperse the headspace (plenum within the packaging material) into the contents. However, depending upon the types of contents, the shaking process may be omitted. This system may be disposed either in contact with the exterior surface of the package or a short distance therefrom and may be disposed on the exterior wall surface of a water tank when the packages are subjected to ultrasonic inspection while immersed in water. Transmitters can be disposed on only one side of the package with the ultrasonic receiver on the other side, or the ultrasonic transmitter and receiver can both be disposed on the same side of the package so that the receiver receives a reflected ultrasonic wave. By measuring differences in sonic velocities between a transmission wave and a reception wave or the sonic velocity of a reception wave, the time from transmission to reception, and/or the degree of attenuation of the ultrasonic energy, the occurrence and degree of degradation of the contents can be evaluated. The useful wavelength of the ultrasonic waves disclosed is about 0.5 MHz to about 20 MHz. While only a single frequency can be employed at a given time, the accuracy of the evaluation is said to be improved by using a few selected frequencies for the transmission wave. Various sets of tests results based on measurements of reflected waves, transmitted waves, and the like are provided to show how various signals can be related to the condition of the food product contents.
As indicated in the various references cited on the face of Nagata et al., sonic or ultrasonic assessment of the condition of foodstuffs has been around for some time.
Clark et al. (U.S. Pat. No. 2,277,037) discloses a fruit ripeness tester which measures the degree of ripeness of fruit such as melons and pineapples by the measurement and calibration of the vibration characteristics of such objects.
Martner et al. (U.S. Pat. No. 3,357,556) discloses a method and apparatus for testing canned liquid material without removing the material from the can, and is particularly suited for the inspection of batch-prepared infant formula. The system is used to detect alterations in viscosity distribution such as by formation of curds or semi-solid bodies or the like, or increases in viscosity as a liquid material ages which is referred to as "age-thickening". The cans containing the liquid are rolled along a horizontal path at a preselected constant speed and in the path is disposed a narrow barrier having a height that is small with respect to the diameter of the can. By proper adjustment of the height of the barrier, cans containing a liquid material that is satisfactory will pass over the barrier whereas cans containing spoiled or aged-thickened contents will be arrested by the barrier. The "slushing" or flow pattern of the canned liquid material within the cans is responsible for cans "bouncing" off of the barrier and rolling backwardly.
Baird (U.S. Pat. No. 3,553,636) discloses a non-contacting ultrasonic interface viscosity and percent solid detecting device wherein the transducer is mounted out of contact with the processed liquid. Changes in ultrasonic attenuation characteristics are used as indications of changes in viscosity, percent solids, and/or interface level condition of the liquid contained within a vessel.
Kreula et at. (U.S. Pat. No. 3,913,383) discloses a method and apparatus for testing the contents of packages containing liquid product. Packages of interest are sealed and contained liquid food products have physical properties that can change as a consequence of deterioration of the product. The package to be tested is placed on a movable support which is subjected to a sudden movement of short duration. A characteristic dependent on the movement of the support is detected, and signals are generated in response to the detected characteristics and compared with the preselected reference signals. In essence, the hydrodynamic behavior of the contents of the package are used to determine whether or not the contents have changed or spoiled.
Edwards (U.S. Pat. No. 4,208,915) discloses a method for determining foreign material in food products using ultrasonic sound. A plurality of transducers are disposed in a rotatable cylinder having a liquid couplant. The cylinder has a surrounding flexible wall which is compressed on top of the surface of the food products. The sound frequencies are transmitted through the food products and received back by a receiver in the transducers for monitoring any variance in the frequency which indicates foreign material in the food products. Black et at. (U.S. Pat. No. 4,384,476) discloses a method and apparatus for ultrasonically inspecting foodstuffs in which the fluid is passed through a curtain of ultrasonic sound. Reflection or absorption of the ultrasonic sound by extraneous materials is detected by ultrasonic sound receiving means and appropriate indication of such detection is given. The foodstuffs being inspected, however, are inspected as they flow pass the inspection point, and have not yet been packaged.
Jarman et al. (U.S. Pat. No. 5,372,42) discloses an ultrasonic inspection method for determining the seal integrity of the bond lines in sealed containers. These particular packages have a lid bonded to a container rim and it is the seal between the lid and the container that is to be inspected. The container rim is disposed between an ultrasonic transmitter system and an ultrasonic receiver system for inspection.
Wertz et al. (U.S. Pat. No. 5,167,157) discloses an ultrasonic method and apparatus for inspecting laminated products, particularly to determine the thickness of the innermost layers of the article. The mean of the measurements from each transducer placed on either side of the multilayered article is calculated to determine these thicknesses. The articles themselves are laminated plastic articles.
Hayward et al. (U.S. Pat. Nos. 3,832,885 and 3,802,252). Hayward et al. '885 discloses a method and apparatus for inspecting sealed containers, such as vacuum-packed cans of food, which involves repeatedly energizing electromagnetic transducer coils mounted in close proximity to the containers to cause the enclosures of the containers to vibrate at a frequency that is the function of the internal pressures within the container. Sounds produced by the vibrating enclosures provides a tonal pattern distinctive of the presence or absence of a container with an unsatisfactory internal pressure. Changes in the internal pressure are indicative of leakage or food spoilage or corrosion of the container. Hayward et al. '252 is drawn to an apparatus and method for monitoring the pressure or vacuum in a sealed container which consists of striking the can with a magnetic pulse of force to cause it to vibrate freely and thereby generate an acoustic ping sensed by an electrical pick-up device. The frequency of the ping is a function of the internal pressure in the container and the frequency spectrum of the signal output of the pick-up device is examined at a discriminator circuit to determine if the signal output contains selected frequencies at an energy level indicative of the desired pressure level. If not, the container is rejected. Measures are taken to render the signal output of the pick-up device insensitive to both the ambient noise and the large noise pulse generated while the can is being subjected to the magnetic pulse of force and also so that only the purest part of the signal generated in response to the acoustic ping is examined by the discriminator circuit.
A liquid or gel couplant is required for conventional ultrasonic testing of liquids in containers, which represents an additional cost. However, conventional ultrasonics using liquid or gel couplants are not practical at high temperatures. Additionally, in some cases, the surface of a container to be inspected may be contaminated with hazardous materials which would cause the couplant used in conventional ultrasonic testing to become contaminated requiring it to be treated as hazardous material for clean up and disposal. Finally, some metal or partially metal containers have an outer layer of non-conductive material such as paint, wrappers, labels, lids, or coating that would prevent the coupling of ultrasound into the container from a conventional ultrasonic transducer.
Electromagnetic acoustic transducers (EMATs) are sensors which are capable of launching and receiving sound waves in metals without a coupling media or even without contact with the surface of a workpiece being inspected. The ultrasound is launched and received in the surface of the metal by the interaction of magnet fields and eddy currents generated by the EMAT. EMATs are finding a wide range of nondestructive testing applications for metals. One previous application of EMATs to liquid measurements is known. In this case an EMAT was used to launch two types of plate wave modes in the metallic wall of a vessel containing a liquid. One mode was the N=1 Shear Horizontal (SH1) mode. The other mode was the N=O Symmetric (SO) Lamb wave mode. The SH1 mode propagates in the wall of the vessel, producing only shearing displacements at the liquid-metal interface inside the vessel. Because a liquid cannot support a shear force, the SH1 mode is not attenuated by the liquid as it propagates. The SO mode produces substantial displacements normal to the surface of the metal at the metal-liquid interface as it propagates. Because a liquid does support compressional waves which are generated by displacements normal to the surface of the metal at the metal-liquid interface, the SO mode is attenuated by the liquid as it propagates. By placing a transmitter EMAT and a receiver EMAT a fixed distance apart vertically on the wall of the vessel, and measuring the relative amplitudes of the two modes, an indication of the liquid level between the two transducers can be obtained.
As previously noted, certain types of liquid containers have an outer layer that prevents inspection of the liquid contents therein using traditional ultrasonic techniques. Some containers are provided with outer plastic lids, caps or the like which leave an air gap between the outside surface of the container and the lid sealing the liquid contents. Traditional ultrasonic inspection techniques requiting physical coupling between the transducer and the workpiece being inspected cannot inspect through such air gaps. Some types of containers have thin metal walls or at least one thin metal foil wall.
It is thus apparent that an improved technique for the ultrasonic inspection of liquids in these types of containers is needed and would be welcomed by the industry.

Electromagnetic acoustic transducer (EMAT) for ultrasonic inspection of liquids in containers


The invention relates to an integrated process for the production of ethylene and vinyl acetate (VAM), comprising contacting in a first reaction zone a gas stream comprising ethane and optionally ethylene with an oxygen-containing gas stream in the presence of a oxydehydrogenation catalyst under oxidative dehydrogenation conditions to produce a first product stream comprising ethane, ethylene, acetic acid and water, and optionally other compounds, separating said first product stream in a vapor permeation unit into a second stream comprising water and a third stream comprising ethane, ethylene, acetic acid, and optionally other gaseous compounds, contacting in a second reaction zone all or at least a portion of said third stream with a stream comprising concentrated acetic acid and with an oxygen-containing gas stream in the presence of a VAM catalyst, to produce a fourth product stream comprising vinyl acetate, acetic acid, ethane, ethylene, water, carbon dioxide, and optionally other compounds, separating said fourth product stream in a vinyl acetate separation zone into a fifth stream comprising vinylacetate, acetic acid, water and optionally other condensable compounds, and a sixth stream comprising ethylene, ethane, carbon dioxide and optionally other gaseous compounds, and recovering vinyl acetate from said fifth stream. The invention further relates to a reaction system for carrying out the process.

It is known to oxidatively dehydrogenate alkanes, such as ethane, to produce ethylene in an oxidative dehydrogenation (oxydehydrogenation; ODH) process. Examples of ethane ODH processes, including catalysts and other process conditions, are disclosed in U.S. Pat. No. 7,091,377, WO2003064035, US20040147393, WO2010096909 and US20100256432. Mixed metal oxide catalysts containing molybdenum (Mo), vanadium (V), niobium (Nb) and optionally tellurium (Te) can be used as such oxydehydrogenation catalysts. The dehydrogenated equivalent of ethane may be further oxidized under the same conditions into acetic acid.
Presently, the process can achieve over 90% ethylene selectivity to ethylene at over 50% conversion. The process is also typically producing acetic acid (AA, ˜5 mol % selectivity) together with carbon dioxide (CO2).
In the above processes, the acetic acid thus produced is generally considered as waste products. Although they could be condensed together with water from the reactor effluent as an aqueous carboxylic acid (ca. 10 wt %) stream, the low relative volatility of carboxylic acids to water renders distillative separation of carboxylic acid and water troublesome, as this would require very large condensate recycle and/or separation trains.
Accordingly, current ODH processes are designed for minimal acetic acid co-production. However, proper valorization of acetic acid could allow "relaxing" acetic acid specifications, thereby widening the operating window to accommodate e.g. higher pressures, lower temperatures and/or easier management of heat release and explosion risks in the ODH process. For example, relaxing the acetic acid specification to 10 mol % selectivity could deliver an aqueous side-stream containing 20 wt % acetic acid.
WO1998005620 describes an integrated process for the production of acetic acid and/or vinyl acetate which comprises the steps: (a) contacting in a first reaction zone a gaseous feedstock comprising ethylene and/or ethane and optionally steam with a molecular oxygen-containing gas in the presence of a catalyst active for the oxidation of ethylene to acetic acid and/or ethane to acetic acid and ethylene to produce a first product stream comprising acetic acid, water and ethylene (either as unconverted ethylene and/or as co-produced ethylene) and optionally also ethane, carbon monoxide, carbon dioxide and/or nitrogen; (b) contacting in a second reaction zone in the presence or absence of additional ethylene and/or acetic acid at least a portion of the first gaseous product stream comprising at least acetic acid and ethylene and optionally also one or more of water, ethane, carbon monoxide, carbon dioxide and/or nitrogen with a molecular oxygen-containing gas in the presence of a catalyst active for the production of vinyl acetate to produce a second product stream comprising vinyl acetate, water, acetic acid and optionally ethylene; (c) separating the product stream from step (b) by distillation into an overhead azeotrope fraction comprising vinyl acetate and water and a base fraction comprising acetic acid; (d) either (i) recovering acetic acid from the base fraction separated in step (c) and optionally recycling the azeotrope fraction separated in step (c) after partial or complete separation of the water therefrom to step (c), or (ii) recovering vinyl acetate from the azeotrope fraction separated in step (c) and optionally recycling the base fraction separated in step (c) to step (b), or (iii) recovering acetic acid from the base fraction separated in step (c) and recovering vinyl acetate from the overhead azeotrope fraction recovered in step (c).
WO2000069802 describes a process for the production of vinyl acetate monomer comprising the steps of: (1) contacting a gaseous feed mixture of ethane or ethylene or ethane/ethylene, steam and a molecular oxygen containing gas in the presence of a first catalyst active for oxidation of ethane, ethylene or ethane/ethylene to produce a selective stream of acetic acid, ethylene, carbon dioxide and water and (2) converting a second feed mixture comprising ethylene, acetic acid and oxygen to vinyl acetate monomer in the presence of a second catalyst active for the production of vinyl acetate, wherein said process does not include an intermediate separation step to remove the CO between the two reaction steps.
WO2001090042 describes an integrated process for the production of vinyl acetate which comprises the steps of: a) contacting in a first reaction zone a gaseous feedstock comprising essentially ethane with a molecular oxygen-containing gas in the presence of a catalyst to produce a first product stream comprising acetic acid and ethylene; b) contacting in a second reaction zone the first gaseous product stream with a molecular oxygen-containing gas in the presence of a catalyst to produce a second product stream comprising vinyl acetate; c) separating the product stream from step (b) and recovering vinyl acetate from the product stream from step (b).
These prior art processes generally suffer from poor selectivity to vinyl acetate due to the presence of considerable amounts of water in the effluent of the oxidative dehydrogenation reaction.
It is desirable to provide an ethane oxidative dehydrogenation process, wherein the acetic acid side stream thus produced is valorized by conversion to vinyl acetate in a technically advantageous, efficient and economically affordable manner.

Ethane oxidative dehydrogenation with co-production of vinyl acetate


An articulating composite surface covering mat and process of forming the mat are provided. The mat has multiple units having a regular, natural or irregular appearance, and each unit a flexible geogrid extending therethrough. Gaps are formed in the spacing between the units. A method of forming the mat includes forming the mat upside-down on a bottom surface of a bottom mold, locating a geogrid in a cavity defined between either or both of the bottom mold and a top mold, and placing the top mold over the bottom mold to form the mold assembly, sealingly engaging the transverse walls of the bottom mold and top mold where there is no geogrid, and adding the filler to the mold assembly.

Surface covering mats are often comprised of stone, brick, plastic, or concrete that are arranged to form a covering over a surface. These surface covering mats may be utilized for many reasons including as a surface for walking, for vehicular traffic, as a decorative element or as a protective surface. Surface covering mats that are predominately concrete or other rigid materials are generally not flexible, are difficult to install, or are unable to articulate over uneven surfaces, particularly on slopes. Terrain on a development site often includes hills and slopes that may be constructed of relatively stable or stabilized engineered soil that requires additional protection from elements such as wind, rain, and snow to stay in place over time and with little added maintenance. Conventional protective applications for these uneven surfaces are generally difficult and/or expensive to install, aesthetically unpleasing or difficult to maintain. Conventional methods typically utilize plants and grasses, hand placed natural stone, manufactured block, mechanically placed block or a mechanically sprayed-on concrete shell such as gunite.
Utilizing plants and grasses in conjunction with surface coverings on slopes is sometimes aesthetically desirable. Additionally, the roots of plants help to protect the surface by holding it together. Depending on site conditions and geographic regions, plants are difficult to grow and maintain due to location, cold, heat, lack of moisture or other conditions.
When utilizing hand placed natural stone, every stone is a different shape size and thickness requiring them to be handled individually. Each stone must be carefully fitted together and embedded into the soil to help prevent it from sliding or rolling and also to achieve the desired visual aesthetic in the exposed surface. Hand placed stonework is slow to install and also generally requires the installer to be a skilled craftsman with knowledge of stone cutting, fitting and placement. For these and other reasons, hand placing stone is generally known to be difficult and slow, especially on slopes, making the work expensive.
When manufactured blocks are used, they are normally used as ballast over geogrid to hold it in place. Geogrids, used widely in Civil Engineering applications to provide tensile reinforcement of soil, are geosynthetic materials made from polymers such as polypropylene, polyethylene or polyester which are formed as an open grid that allow soil to strike through the apertures allowing the two materials to interlock together to give a composite behavior. In a typical installation, geogrid is first applied directly over the slopes and then covered with protective ballasting elements such as gravel, stone or blocks. On slopes, gravel has limited appeal unless the grid contains large holding pockets to contain the gravel, making the grid expensive. Additionally, these installations are sometimes considered unsightly and difficult to install. Stone is rarely used because of its irregular nature. Manufactured block requires that each block be hand placed or, if mechanical installation is used, the blocks need to be cabled together prior to installation. This requires the block to first be individually placed on a flat surface then cabled together into large mats. These mats then must be moved to the area of installation by using a crane to lift the mats onto flatbed trucks for transport to the installation site where another crane must lift the mats into position. These mats are large and their final cabled shapes require them to be pre-engineered to fit specific places on the site.
When gunite is used, a wire or plastic mesh is applied over the slope and then concrete is sprayed over the mesh, providing a thin yet solid surface covering held together by the mesh. The process is fast, and compared to other methods, comparably inexpensive. However, the visual appearance of gunite is not usually desirable. Further, since application of gunite results in a solid shell over the surface, sometimes erosion may happen in the soil beneath the gunite covering which cannot be seen from the surface. This is a problem because if the erosion beneath the shell removes soil, the gunite can crack or collapse which leaves the slope unsightly, potentially dangerous and expensive to repair.
SUMMARY In accordance with the present invention, an articulating composite surface covering mat includes multiple units having a natural or irregular appearance and formed of a filler, each having an irregular peripheral shape and a flexible geogrid extending between and through the units. Irregular gaps are formed between the multiple units and have irregular spacing as measured horizontally at the geogrid. A peripheral surface of the mat is defined by segments of peripheral surfaces of at least some of the multiple units. The peripheral surface of the mat has at least three sides, at least two sides including the segments of the peripheral surfaces of the multiple units defining S-curve geometry. At least two of the three sides of the mat has a center point, and a first segment of the side is a 180-rotation of a second segment of the side about the center point.
A process for the formation of an articulating composite surface covering mat that includes spaced apart units that are held together by a geogrid includes the step of disposing a bottom mold on a substantially level surface, where the bottom mold has a generally planar bottom surface that defines the top surface of the formed mat, and the where the bottom mold has transverse walls extending from the bottom surface. Additional steps include locating a geogrid onto at least one cavity that is defined by the bottom mold or a top mold or a combination of both the bottom and the top molds, such that the geogrid is generally horizontal, where the geogrid extends into each of the spaced apart units to be formed. Another step includes placing the top mold over the bottom mold to form the mold assembly, where the bottom mold and the top mold define the cavity therebetween for receiving the geogrid, and where the top mold has a generally planar top surface and transverse walls extending therefrom. A further step includes sealingly engaging at least a portion of the transverse walls of the top mold with corresponding transverse walls of the bottom mold at a location of no geogrid therebetween, and adding a filler to the mold assembly through openings in the top mold.
A process for the formation of multiple articulating composite surface covering mats, where each mat includes spaced apart units that are held together by a geogrid and define a mat peripheral surface, includes the steps of disposing a bottom mold on a substantially level surface, where the bottom mold has a generally planar bottom surface that defines the top surface of the formed mat, and transverse walls extending from the bottom surface of the bottom mold. A first portion of the transverse walls in the bottom mold define the spaced apart units to be formed, and a second portion of the transverse walls in the bottom mold define the mat peripheral surfaces of the multiple mats to be formed. Further steps include locating a geogrid horizontally onto at least one cavity defined by the bottom mold or the top mold or a combination of both the bottom and top molds, where the geogrid extends over the first portion of transverse walls defining the spaced apart units and into each of the spaced apart units within each of the multiple mats, but where the geogrid does not extend over the second portion of the transverse walls defining the peripheral surfaces of the multiple mats to be formed. Additional steps include placing the top mold over the bottom mold to form the mold assembly, where the bottom mold and the top mold define the cavity therebetween for receiving the geogrid, and where the top mold has a generally planar top surface and transverse walls extending therefrom. More steps include engaging the transverse walls of the top mold with the second portion of transverse walls of the bottom mold at the peripheral surface of the multiple mats to be formed, and adding the filler to the mold assembly at an opening in the generally planar top surface of the top mold.
A process for the formation of differently shaped articulating composite surface covering mats which each comprise spaced apart units that are held together by a geogrid is also provided. The process includes providing multiple mold assemblies that each define differently shaped spaced apart units, where the mold assemblies have a top mold and a bottom mold each having transverse walls that include cavity walls and sealing walls. The process also includes placing a universal geogrid having positive space and negative space into one of the multiple mold assemblies, where the universal geogrid is received in one of the multiple mold assemblies such that the positive space of the universal geogrid is received in a cavity defined between the cavity walls of at least one of the top mold and the bottom mold, and the negative space of the universal geogrid at least one of located at the engagement of the sealing walls of the top mold and the bottom mold. Further, the universal geogrid is receivable into at least two of the multiple mold assemblies that define differently shaped spaced apart units such that the positive space of the universal geogrid is received in the cavity defined between the cavity walls of at least one of the top mold and the bottom mold, and the negative space of the universal geogrid is located at the engagement of the sealing walls of the top mold and the bottom mold.

Articulating composite surface covering mat and method of making


A computer-implemented data transmission method and system are provided. A first transformed password (PWD) is acquired from the first node, wherein the first transformed PWD is derived from an original PWD. An encrypted message is acquired from the first node, the encrypted message being encrypted with a public key of the first node. A private key of the first node is recovered according to the first transformed PWD, the private key having been encrypted with the first transformed PWD and stored in the second node in advance. The encrypted message is decrypted with the recovered private key to obtain a decrypted message for processing.

In the complicated business environment and an era of digitalization, it is very common that various messages may be transferred sequentially through multiple layers to achieve a business purpose. The prolonged chain with multiple parties causes two concerns: 1) the mutual parties may not trust each other; 2) the longer the chain is, the more likely that a malicious attacker will pretend to be one of the parties and bring trouble.
To address the concerns, all the messages may be transferred under a "https" like protocol AND a third CA institution is required to issue a certificate to each device. However, one disadvantage may be that paying the certificate fee for so many devices is not economic, and another disadvantage may be that the "https" like protocol requires several rounds of communication which is time consuming.
In some scenarios, the transmission and authentication should be automatically performed. Therefore, a signature may be verified in each node of the multilayer system and each node may hold a private key in cleartext for verifying the signature. That is, each time a node receives a message, the node will verify the signature of the sender. After verifying, the node may sign its own message and dispatch the message to the next node. One disadvantage of this kind of solution may be that a cleartext private key, stored at the node which uses the private key, makes the node vulnerable to attack. It is because a hacker can easily get the private key of each node and may change the content of all the messages and sign the changed messages with the hacked private key. However, if the cleartext private key were not stored at the node for executing the signing process, the process could not be executed automatically.
Therefore, how to enhance user authentication experience in the multi-layer system, such as how to achieve automation while ensuring security, is a challenge in modern days.

International Business Machines Corporation


The warning arrow of the present invention is in the nature of a frame to be temporarily mounted either directly to the body of the vehicle or to the underside of its trunk lid. In a preferred embodiment, the warning arrow is composed of a brightly-colored fabric material for high daytime visibility, and with the arrow being outlined by a plurality of light-reflective filaments for nighttime illumination by the beams of oncoming vehicular headlights. In accordance with the invention, a plurality of self-adhering fabric strips couple to the frame of the mount, either to magnetically secure the warning arrow to the body of the vehicle, or to extend it between its raised trunk lid and a point within its then opened trunk.

As is well known and understood, when traffic emergencies call for the deployment of police, fire or emergency medical personnel, some means is required to warn oncoming motorists of that emergency condition, and to divert their motor vehicles away from the lane of traffic where the emergency exists. As is also well known and understood, a comparable situation exists where a motorist pulls off a roadway, parks the vehicle in question, and leaves it sitting there. In those situations, some type of energizing source--be it fuel power or electrical power--is required to warn an oncoming motorist, especially if the emergency situation, or the mere parking on the shoulder of the road, occurs at night. As will also be apparent, any such type of warning indication must be highly visible at extended distances, whether one is concerned with daytime usage or evening usage. It would also be advantageous if any such warning device were self-contained.

Light-reflective warning arrow mount for automotive vehicles


There are provided an outer panel, an inner panel, a second reinforcement provided in the main closed-cross section and cooperates with the outer panel to form a sub closed-cross section extending longitudinally, a bead portion formed at a portion of the inner panel which is located at a position corresponding to the second reinforcement, and configured to be a starting point causing bending of a front side frame toward the second reinforcement when a collision load is applied in a vehicle collision, and a second attaching member provided at a position located on a front-end side of the front side frame relatively to the second reinforcement and configured to make the second reinforcement crushable in a bending direction in the vehicle collision. The second attaching member comprises a knot-shaped member provided inside the main closed-cross section.

The present invention relates to a frame structure for a vehicle comprising a reinforcing member which is provided in a main closed-cross section and cooperates with one of an outer panel and an inner panel to form a sub closed-cross section extending in a longitudinal direction.
Conventionally, a structure in which a crash can (a crash box) configured to be axially-compressively deformable is provided at a tip portion of a high-tensile steel-plate made front side frame and plural impact-absorbing mechanisms configured to be bendable initiatively are provided over a range from a midway portion of the front side frame to a rear end portion of the front side frame has been used to increase the impact energy absorption in a vehicle frontal collision, thereby achieving passenger's protection. In such impact-absorbing mechanisms, since an impact load absorbed through bending deformation of the front side frame shares most of the energy absorption after the axially-compressive deformation of the crash can, energy absorption characteristics through the bending deformation affects the EA (Energy Absorption) performance more than energy absorption characteristics through the compressive deformation.
In a frame structure disclosed in Japanese Patent Laid-Open publication No. 2016-113084, a first reinforcing member which cooperates with a main closed cross section to form five sub closed cross sections which are vertically adjacent to each other comprises a first partition wall portion including a first compression-side partition portion and a first tension-side partition portion and a second partition wall portion including a second compression-side partition portion and a second tension-side partition portion, a vertical distance between tension-side ridgeline portions facing each other is set to be smaller than a vertical distance between compression-side ridgeline portions facing each other, and when a difference between a lateral width of the first and second compression-side partition portions and a lateral width of the first and second tension-side partition portions at a front end portion of a front-side area is set to be smaller than a difference between a lateral width of the first and second compression-side partition portions and a lateral width of the first and second tension-side partition portions at a rear-half portion of the front-side area in a case where a load is inputted. Thereby, the tension-side ridgeline portions facing each other contact early after buckling of the frame happens, so that the respective partition wall portions cooperate with each other to constitute a truss structure on a tension side, thereby suppressing a sectional collapse caused by the bending deformation.
The frame structure of the above-described patent document can increase an allowable-limit load up to the plastic zone (area) of a material, so that the EA efficiency in the bending deformation of the frame properly increases. However, while the above-described frame structure of the patent document increases the EA efficiency due to the bending strength that the reinforcing member has, the axially-compressive deformation is not considered at all in this frame structure, so that the compressive strength that the reinforcing member has may not sufficiently contribute to the increase of the EA efficiency in the bending deformation of the frame. That is, if the impact load was absorbed by using the compressive strength of the reinforcing member in addition to the bending strength, the EA efficiency could be further increased and therefore the load absorption could be increased properly.


Simultaneous forward and reverse blood group testing is described using both a visual detection system and a fluorescent based labeling and detection system. Forward and reverse tests could be performed separately, but A and B agglutinates can be detected and discriminated simultaneously.

Throughout this application, various patents and papers are referenced. The disclosures thereof in their entireties are hereby incorporated by reference into this application in order to more fully describe the state of the art as known to those skilled therein as of the date of the invention described and claimed herein.
This invention relates to the field of blood group determination, and particularly to the simultaneous determination of forward and reverse blood group testing.
Blood group serology requires the determination of blood cell compatibility between a blood donor and a patient recipient before a transfusion or organ transplant involving the patient. Blood cell compatibility is determined by the non-occurrence of an immunological reaction between antibodies contained in the blood serum of a patient and antigens present on blood cells from the donor.
Many different blood group antigens are found on the surface of the red blood cells of every individual. These antigens, the products of inherited genes, exist in combinations that are likely to be unique between all individuals except identical twins. Blood grouping is generally the process of testing red cells to determine which antigens are present and which are absent, normally utilizing antibodies to the antigen tested for. Additionally, when a person does not have a particular red cell antigen on his or her red blood cells, his or her serum may contain an antibody to that antigen. Whether or not the antibody is present in the serum depends on whether the person's immune system has been previously challenged by, and responded to, that specific antigen or something very similar to it. For example, a person whose red blood cells are Type A, i.e., having "A" antigens on the red cells, will have anti-B antibodies in his or her serum. Thus, if such a person is given type B blood, an immunological reaction will occur with possible serious clinical consequences.
As an additional consideration, it should be noted that the human body is constantly exposed to antigens in pollens, food, bacteria and viruses. Some of these "natural" antigens are apparently so similar to human blood group antigens that they stimulate almost every susceptible person to produce antibodies. Thus, certain antibodies are expected in the serum of anyone whose red cells lack the reciprocal antigen. This is especially true of the ABO system. Accordingly, a second confirmatory test is often performed on the patient/donor sera. The test for expected antibodies of the ABO blood group system in sera is called "reverse" blood grouping.
Antibodies of the ABO blood grouping system are generally immunoglobulin M (IgM). These antibodies have ten antigen binding sites per molecule. The IgM antibody is large enough to span the distance between red blood cells, so that when they are centrifuged, the cells will be bound together in a lattice "cell-antibody-cell-antibody" and will remain clumped together in agglutinates. For example, if anti-A is added to blood group A or blood group AB cells and the mixture is centrifuged, the cells will remain in clumps when resuspended. With the same antibody, group 0 and group B cells will resuspend as individual cells. Agglutination caused by one antibody, such as an IgM antibody, is called direct agglutination.
In transfusion medicine, the most frequently performed test, for the reasons given above, is determination of the ABO blood group. The current state of the art is separately testing for A, B, and sometimes A+B together, antigens on the red cells (forward type); and confirmation (cross-check) testing for anti-A and anti-B antibodies in serum or plasma (reverse type). Thus a minimum of 4 separate tests, but as many as 7 separate tests (A, B, A+B antigens on the sample red cells; anti-A and anti-B in the sample serum/plasma using A1, A2, B, O reagent red cells) are routinely employed. The results from each of these typing exercises (forward and reverse types) have to agree. Thus, in the U.S. alone approximately 104 million tests are performed annually to determine the blood groups in blood centers.
Since the early 1900's, the general approach known as the "Landsteiner" method, (Landsteiner, Science 73:405 (1931)) together with the work of Ashby, (J. Exp. Med. 29:267 (1919)) and Coombs (Brit. J. Exp. Pathol. 26:255 (1945)), has been to add a patient's red blood cells to a standard laboratory test tube containing a blood group antibody (such as Anti-A or Anti-B), mix to allow antibody/antigen binding reactions to take place, and then to centrifuge. If the antigen tested for is present, the antibody/antigen binding will have taken place resulting in agglutination of the patient's red blood cells. The test tube is manually shaken to dislodge the centrifuged button of "clumped" cells at the bottom. A subjective determination is then made as to whether or not the dislodged cells are "clumped", and to what extent.
During the mid-1900's, attempts were made to simplify this technique to minimize the subjective nature of the test and to reduce mistakes. It was recognized that a somewhat permanent record of the results of compatibility testing could be had by employing wettable, either non-absorbent or in some cases absorbent, test slides or test cards having the requisite immunochemical reagents on at least a portion of their surfaces. In this regard, U.S. Pat. Nos. 2,770,572, 2,850,430, 3,074,853, 3,272,319, 3,424,558, 3,502,437 and 3,666,421 European Patent Application #0 104 881-A2 depict select examples of such test cards and related apparati. The advantages of blood grouping in microplates include easier manipulation of large numbers of samples, objective measurement of agglutination reactions using instruments and computer interfacing for compilation and management of results. A number of expensive and dedicated systems with computer-controlled robotics and high throughput spectrophotometric readers have been introduced for blood bank automation (Chung, et al., Transfusion 33:384 (1992)).
Commercial blood typing kits have been introduced with improved detection of red cell antigen and antibody reactions in special microtubes filled with reagents in gel form. (Lapierre, et al., Transfusion 30:109 (1990)). Utility of solid phase techniques to overcome the inherent problems in the use of hemagglutination as an end point for blood grouping was reviewed by Scott (Transfusion Med. Rev. 5:60 (1991)). Recently Growe et al. (Transfusion Med. Rev. 10:44 (1996)) reported the implementation and use of automated grouping of RBC antigen and serum antibody screening procedures applicable not only to blood centers but also for hospital transfusion laboratories. At least seven different wells with specific typing reagents have to be used in these methods for determining the blood group of a sample. All of the procedures used for large scale blood grouping essentially employed the agglutination based methods and also for the determination of only one antigen or antibody type in a single tube/well. Separately identifiable reactions using fluorescent labeled reagents have also been reported for blood typing applications in the U.S. Pat. Nos. 4,550,017 and 4,748,129.
Current procedures utilize agglutination of red cells as an endpoint. As discussed hereinabove, this is accomplished in test tubes, on slide surfaces, in microplates and in column agglutination tests. The latter 2 methods may be performed manually or by automated instrumentation. All methods require separation of serum (or plasma) from cells to perform both forward and reverse type.
It is therefore of interest to develop a method that performs both forward and reverse type in a single test, while preferably avoiding the need to separate the blood sample prior to testing. Such a method would make it possible for a blood bank technologist to simultaneously determine blood group antigens on red cells as well as antibodies of clinical significance in serum. Such a method would considerably decrease the number of individual tests performed i.e., provide a reduction of about 50 to 100 million tests per year in the number of tests performed in blood centers resulting in significant savings of time and cost. We have developed techniques to allow discrimination of the sample red blood cells (RBCs) from reagent RBCs so that their agglutinates are distinct. Additionally, the novel methods disclosed herein use labeled typing antibody reagent to distinguish their reaction from preformed antibody in the sample. The inventive tests are done without the need to separate the blood sample and thus can be done on whole blood (WB). The tests disclosed herein can be used on automated instruments, where further advantage is gained by not having to separate cells from serum. Further, the simultaneous detection of forward and reverse test reduces the number of tests required to type and confirm the type (forward & reverse test).
In the fluorescent labeling embodiment of the invention, in the forward test, the monoclonal antibody is labeled. For the reverse test the reagent red cells are labeled. Further advantage rests in the ability to distinguish (visually or via automated reader) mixed red cell populations. For instance, reverse test can be performed in 1 test instead of 2, resulting in a reduction of number of tests performed. A further application is the antibody screen, where a pool of 2 cells could be used together instead of 2 separate tests, resulting in a reduction of number of tests performed.
The ability to color cells for a visual system has applications to existing blood group test platforms using tubes, microplates, slides and Column Agglutination Technology (CAT), and test platforms such as the Vitros™ 250, 750 or 950 (Ortho-Clinical Diagnostics, Inc., Rochester, N.Y.) slide method.
Vyas et al. In U.S. Pat. No. 5,776,711 disclose a "simultaneous" ABO and RH(D) blood typing or antibody screening method. However, while similarly attempting to reduce the number of tests to perform an ABO blood group, the instant invention simultaneous performs the samples' red cell ABO status as well as presence of antibodies to A and/or B antigens. In addition, the instant invention utilized whole blood rather than separated serum and red cell components. The instant use of labeled reagent red cells also differs from the Vyas et al. use of synthetic beads.
Simultaneous analysis of ABO blood group can be carried out by labeling reagent red blood cells with appropriate fluorochromes and selecting appropriate monoclonal antibodies with fluorochrome labels. The cells and agglutinates can be measured by laser scanning cytometry on a microscope slide or equivalent. The cells on the slide are illuminated by a scanning laser light source. Typically, laser light sources used include blue argon ion lasers and/or red helium-neon lasers. Fluorescence and light scatter can be determined by the use of a Laser Scanning Cytometer (Compucyte, Cambridge, Mass.).
The use of laser scanning cytometry in the simultaneous determination of forward and reverse test is as follows. When a cell or group of cells (agglutinate) is scanned by the laser light beam, the illuminating light is scattered by the cell or group of cells and the intensity of scatter relates to cell (or agglutinate) size and shape. For example, individual red cells scatter less light than small agglutinates which in turn, scatter less light than large agglutinates.
Likewise, when a cell or group of cells (agglutinate) is scanned by the laser light beam, the illuminating light can induce fluorescence from fluorochrome(s) that have been associated with the cell. If a fluorochrome is relatively uniformly associated per cell with reagent red cells, the fluorescence intensity relates to agglutinate size. For example, individual red cells would fluoresce less than small agglutinates which in turn, would fluoresce less than large agglutinates.
Use of the combination of scattered light and fluorescence is more reliable than either parameter alone in discriminating different classes of agglutinates.
In addition to these two parameters, monoclonal antibodies that have been conjugated with a fluorochrome also may be used to label the cells (and agglutinates) of interest. The fluorescence emitted by the cells when excited by the illuminating laser beam yields additional information about the binding of these monoclonal antibodies to cells or agglutinates for distinguishing subpopulations of cells or agglutinates.
Five parameter (forward scatter, side scatter, and three fluorescence channels) dot plot analysis for simultaneous ABO determination is presented in FIGS. 1A–D.
It may be appreciated by those skilled in the art that flow cytometry or fluorescence microscopy could also be used to perform simultaneous analysis of ABO blood group.
In flow cytometry, the cells and agglutinates to be measured are introduced into the center of a fast moving fluid stream and forced to flow single file out of a small diameter orifice at uniform speeds. The particles are hydrodynamically focused to the center of the stream by a surrounding layer of sheath fluid. The cells within the stream pass a measurement station where they are illuminated by a light source and measurements are made at rates of 2.5×102 to 106 cells per minute. Laser light sources are used in the measurement of cells; typical laser light sources used include argon ion lasers (UV, blue and green light), krypton lasers (yellow and red light), helium-cadmium lasers (UV and blue light), and helium-neon lasers (red light). Fluorescence and light scatter can be determined by the use of a flow cytometer, for example, the CytoronAbsolute™ Flow Cytometer (Ortho-Clinical Diagnostics, Inc., Raritan, N.J.).
In fluorescence microscopy, the cells and agglutinates to be measured are read on a microscope slide or equivalent. The cells are typically illuminated by a white light source or a substantially monochromatic light source. Here, too, laser light sources may be used as the source of the monochromatic light. The presence of agglutinates may be assessed with the white light, and the associated fluorescence assessed with the monochromatic light and appropriate filters. Visual or automated reading may be used for one or both of these readings.
A visual detection technology can also be employed in the forward and reverse blood typing contemplated herein. Such a method, using a column agglutination test (CAT), may employ a BioVue™ cassette (Ortho-Clinical Diagnostics, Inc., Rochester, N.Y.). Such cassette contains columns to which has been added a microparticle matrix. Such matrix can be overlayed with suitable blood typing antibodies dispersed in buffer, forming the initial reaction zone.
CAT can employ automated reader systems to interpret the agglutination result. One such reader is present in the Ortho AutoVue™ (Ortho-Clinical Diagnostics, Inc., Rochester, N.Y.) a fully automated system to perform the CAT. The autoreader is a computerized imaging system consisting of a CCD (charged coupled device) monochrome video camera, and image processing board, and an IBM-compatible PC. The reader first acquires an image of the reaction that is digitised and processed by the image-processing software to extract the reaction features, which are then used by the reaction classification program. These features are used to separate reactions into negative and positive classes, and for translation into one of seven conventional reaction classes or grades. Discriminate analysis, a linear statistical pattern recognition tool, is used to distinguish between negative and weak reactions.
Yet another reader employed in CAT is the BioVue™ Reader 2 (Ortho-Clinical Diagnostics, Inc., Rochester, N.Y.). This Reader has an automated loader for twelve BioVue™ cassettes and has a halogen lamp source and image analysis features permitting cell identification based on RBC wavelength thereby interpreting the agglutination result. Image acquisition is performed by a CCD camera and a digitising board.

Simultaneous determination of forward and reverse ABO blood group


Novel compositions useful as influenza immunogens are provided. The compositions enable a host response to immunogen sites normally not recognized by a host.

The current stable of licensed vaccines in the human and veterinary arenas is generally successful against what are termed "Class One pathogens." Class One pathogens (such as measles, mumps and rubella viruses) are those pathogens, which, in general: (1) infect or cause the most serious disease in infant, very young children, children, and young adults; (2) carry a relatively stable microbial genome; (3) have a natural history of disease which results in spontaneous recovery; and (4) induce durable memory, associated with polyclonal and multi-epitope antigen recognition.
In contrast, Class Two pathogens, such as, influenza virus, HIV-1, malaria parasites, Mycoplasma, such as those that cause tuberculosis, Trypanosomes, Schistosomes, Leishmania, Anaplasma, Enteroviruses, Astroviruses, Rhinoviruses, Norwalk viruses, toxigenic/pathogenic E. coli, Neisseria, Streptomyces, nontypeable Haemophilus influenza viruses, Hepatitis C virus, cancer cells etc. are characterized by quite opposite features. For example, Class Two pathogens: (1) tend to infect and are transmitted in a significantly extended host age range, with infections occurring and reoccurring from childhood through the geriatric period; (2) exhibit microbial genetic instability in defined regions of their genome (a hallmark of the successful evolution of such pathogens); (3) in some cases, include spontaneous recovery of disease that frequently still leaves the host vulnerable to multiple repeated annual infections and/or the establishment of either a chronic/active or chronic/latent infectious state; (4) induce oligoclonal, early immune responses that are directed to a very limited set of immunodominant epitopes which provide either narrow strain-specific protection, no protection and/or enhanced infection; and (5) cause immune dysregulation following infection or vaccination, e.g. epitope-blocking antibody, atypical primary immune response Ig subclasses, anamnestic cross-reactive recall and inappropriate TH1 and/or TH2 cytokine metabolism.
At the immunologic level, very different etiologic agents can yield diverse pathogenesis and disease outcome as observed, for example, with HIV-1 verses human rhinovirus. Highly successful immune system evading strategies, such as, Deceptive Imprinting, have evolved and are selected and maintained across host and microbial taxa. Thus, the operational failures of the vertebrate immune system, for example, arising from pathogen Deceptive Imprinting, are fundamentally the same whether infected with HIV-1 or with the common cold virus for an average of 2-6 times a year for 60 years.
Although some advances with regard to antigen delivery and expression have improved the immunogenicity of some Class Two microbial pathogens, current vaccine technologies have not readily translated into new, broadly effective and safe, licensed vaccines for use in humans. That may be due, in large part, to a poor understanding of the fundamental laws governing the vertebrate host defense system origin, repertoire development, maintenance, activation, senescence and co-evolution in similar and dissimilar environments.
What is lacking currently in human influenza vaccine development is a composition that induces immunity and protection which is less homotypic and subtype-dependent and would therefore not require the mixing and production of multiple subtypes in the current egg-based technology production scheme year to year. A suitable new product is an influenza recombinant HA or NA subunit vaccine that induces immune responses capable of cross-neutralizing both intra-subtype antigenic variants and hetero-subtypes of influenza virus.
Influenza is a NIAID Category C pathogen and causes 36,000 deaths and 220,000 hospitalizations in the U.S. every year. A respiratory disease, influenza spreads through droplets and/or contaminated fomites from the cough or sneeze of an infected person. Higher risk groups include children and the elderly, and having influenza commonly leads to secondary complications of influenza-related pneumonias, upper respiratory complications (otitis media in children) and other systems diseases (e.g. cardiovascular etc.). Influenza is the source of the worst pandemic in history; the Spanish flu of 1918 caused over 40 million deaths worldwide. In the U.S., the annual direct medical costs (hospitalization, office visits, medication etc.) of influenza are estimated at $4.6 billion. Furthermore, each year, up to 111 million workdays are lost because of influenza with an associated cost to American businesses of more than $7 billion a year in sick days and lost productivity. Total direct and indirect costs (work days lost, school days lost etc.) of a severe influenza epidemic are at least $12 billion per year.
Influenza virus, and when attended by secondary bacterial infections, has long been known to be a cause of excess morbidity and mortality. Complications include pneumonia, bronchitis, congestive heart failure, myocarditis, meningitis, encephalitis and myositis. Some groups of people at high risk for complications are those with chronic pulmonary or cardiovascular disorders, residents of chronic care facilities, including nursing homes, and those persons 85 years and older. (Recommendations of the Advisory Committee on Immunization Practices (ACIP) for Prevention and Control of Influenza. MMWR, 1996, Vol 45; and Thompson et al., JAMA 2003; 289:179-186). The geriatric population in the United Stated has doubled between the years 1976 and 1999, and is expected to rise over the next few years as the post World War II baby boomers age. People in that age bracket are 16 times more likely to die of an influenza-associated disease than are persons aged 65 to 69. Another important contributing factor to the increase of influenza-associated deaths in the 1990's is the predominance of the influenza A (H3N2) virus, a more virulent form of the recently circulating influenza viruses.
Influenza is a single-stranded ribonucleic acid (RNA) virus which mutates rapidly to form new virulent strains. The strains are classified into three groups, influenza A, B and C. The virus is further classified based on two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA), into 15 HA and 9 NA subtypes. Recent whole genome analysis of the human influenza virus sponsored by the NIAID/NIH and collected between 1996-2004 from New York State revealed that despite sharing the same HA, multiple, persistent, phylogenetically distinct lineages co-circulate in the same population resulting in reassortment and the generation of antigenically novel clades. While antigenic variance of HA is still the dominant selective pressure on human influenza A virus evolution, the finding that antigenically novel clades emerge by reassortment among persistent viral lineages rather than via antigenic drift is of major significance for the current dated annual method of influenza vaccine strain selection and production (Holmes et al., PLoS Biol. 2005 3(9):e300).
At the heart of the problem in the annual global virus tracking programs and subsequent "reactionary" vaccine production that ensues, is the issue of antigenic variation. Antigenic variation is an evolved mechanism to ensure rapid sequence variation of specific pathogen gene(s) encoding homologues of an individual protein antigen, usually involving multiple, related gene copies, resulting in a change in the structure of an antigen on the surface of the pathogen. Thus, the host immune system during infection or re-infection is less capable of recognizing the pathogen and must make new antibodies to recognize the changed antigens before the host can continue to combat the disease. As a result, the host cannot stay completely immune to the viral disease. That phenomenon stands as one of the more, if not, most formidable problem challenging modern vaccine development today.
Not surprisingly, the immune response generated after infection or vaccination with all currently licensed vaccines is highly subtype and strain specific. In practice, that means antibodies elicited during natural, experimental infection and vaccination are only capable of neutralizing the homologous virus. The subtype/strain-specific humoral immune response appears to be due to the relative immunodominance of various antigenic sites found on the globular head of the hemagglutinin molecule (Wiley et al., Nature, 1981; 289:373-378). More specifically, the antibody response has been mapped to five major antigenic sites within the globular head of the HA. Of the five HA epitopes (A-E), two sites, A and B, are the most immunodominant and also were associated with the highest amount of amino acid hypervariability, due, in part, to reoccurring point mutations, deletions and occasional introduction of N-linked glycosylation sites, known collectively as the "antigenic drift" of the virus (Cox & Bender, Semin. Virol. 1995; 6:359-70; Busch et al., Sci. 286:1921, 1999; Plotkin & Dushoff, PNAS 100:7152, 2003; and Munoz & Deem, Vaccine 23, 1144, 2005).
Original antigenic sin, first described in 1953 by Francis (Ann. Int. Med., 1953, 399:203) is a primary immune response, that when boosted not by the homologous, but by a cross-reacting vaccine or incoming viral subtype/strain, results in the newly formed antibodies reacting better with the previous antigen than with the incoming antigen.
The loss of immune specificity directed by that aleatory recall poses a real problem for the host immune system to mount equal and potent humoral responses to the changing virus both during an infection and between infections. Thus, it is not surprising that natural infection and vaccination fail to yield a more functional cross-reactive primary and anamnestic immunity as the repertoire development against those less immunogenic epitopes, which may be most conserved and capable of generating cross-strain immunity, are lower on the antigenic hierarchy. The immunologic phenomenon whereby immunodominant epitopes misdirect the immune response away from more conserved and less immunogenic regions on an antigen was initially termed "clonal dominance" (Kohler et al., J Acquir. Immune Defic. Syndr. 1992; 5:1158-68), which later was renamed as "Deceptive Imprinting" (Köhler et al., Immunol. Today 1994 (10):475-8).
The immunologic mechanisms for immunodominance behind deceptive imprinting are not fully understood, and no one mechanism yet fully explains how or why certain epitopes have evolved to be immunoregulatory and immunodominant. The range of immune responses observed in the phenomenon include the induction of highly strain/isolate-specific neutralizing antibody capable of inducing passive protection in experimental animal model-viral challenge systems all the way to the induction of a binding non-protective/non-neutralizing, blocking and even pathogen-enhancing antibody that, in some cases, prevents the host immune system from recognizing nearby adjacent epitopes to interfering with CD4 T cell help. The same decoying of the immune response through immunodominance resulting in a more narrowly focused set of epitopes is observed with T cells of the host helper and cytotoxic cell-mediated immunity (Gzyl et al., Virology 2004; 318(2):493-506; Kiszka et al., J. Virol. 2002 76(9):4222-32; and Goulder et al., J. Virol. 2000; 74(12):5679-90).
Vaccination is the best way to prevent the disease and the current trivalent killed virus and modified live (attenuated) influenza vaccines are developed every year based on world-wide epidemiological surveillance of active viral strains. Both vaccines contain influenza A and influenza B subtypes. The licensed influenza vaccines consist of inactivated whole or chemically split subunit preparations from two influenza A subtypes (H1N1 and H3N2) and one influenza B subtype. Production of influenza vaccines involves the adaptation of the selected variants for high yield in eggs by serial passage or reassortment with other high-yield strains. Selected influenza viruses are grown in chicken eggs, and the influenza virions purified from allantoic fluid. Whole or split virus preparations are then killed by treatment with an inactivating agent, such as formalin. More than 90% of the United States market for the vaccine is served by two companies, Aventis Pasteur with more than 50% market share and Chiron (PowderJect) (U. K.). An intranasal vaccine, FluMist®, was approved and first sold in 2003.
Limitations of the currently available influenza vaccines include:
(1) Reduced efficacy in the elderly. Among the elderly, the rate of protection against illness is lower, especially for those who are institutionalized (Gorse et al., J. Infec. Dis. 190:11-19, 2004). Significant antibody responses to a trivalent subvirion influenza vaccine were observed in less than 30 percent of subjects ≥65 years of age (Powers & Belshe, J. Infec. Dis. 167:584-592, 1993);
(2) Production in eggs. The current manufacturing process is dependent on chicken eggs. Influenza virus strains must replicate well in eggs and a large supply of eggs is required each year. Production is at risk each year because of the need to find a suitable virus combination;
(3) Inability to respond to late appearing and drift strains, such as A/Sydney/5/97 in the late nineties, or to respond to a potential pandemic strain, such as the Hong Kong H5N1 virus that appeared in 1997;
(4) Protection with current whole or split influenza vaccines is short-lived, and effectiveness wanes as genetic changes occur in the epidemic strains of influenza due to antigenic variation. Ideally, the vaccine strains are matched to the influenza virus strains causing disease. Changes can occur in the hemagglutinin of egg-grown influenza virus when compared to primary isolates from infected individuals (Oxford et al., J. Gen. Virol. 72:185-189, 1989; and Rocha et al., J. Gen. Virol. 74:2513-2518, 1993) reducing the potential effectiveness of the vaccine;
(5) The side effect of having the vaccine produced in eggs for those allergic to eggs; and
(6) The current licensed manufacturing system yields one vaccine per chicken egg infected with the influenza virus and the production time is approximately 24 weeks.
Thus, the current licensed influenza vaccines do not: (1) induce antibodies capable of neutralizing the common annually recurring antigenic variants circulating during an epidemic, as well as the sub-type and reassortment viruses; (2) illicit a strong immune response in the elderly; and (3) find wide applicability due to side effects, for example, some vaccines cannot be administered to children.


A method, system, and apparatus provide the ability to globally register point cloud scans. A first and a second three-dimensional (3D) point cloud are acquired. The point clouds have a subset of points in common and there is no prior knowledge on an alignment between the point clouds. Particular points that are likely to be identified in the other point cloud are detected. Information about a normal of each of the detected particular points is retrieved. A descriptor (that only describes 3D information) is built on each of the detected particular points. Matching pairs of descriptors are determined. Rigid transformation hypotheses are estimated (based on the matching pairs) and represent a transformation. The hypotheses are accumulated into a fitted space, selected based on density, and validated based on a scoring. One of the hypotheses is then selected as a registration.

1. Field of the Invention
The present invention relates generally to point cloud scans, and in particular, to a method, apparatus, and article of manufacture for automatically and efficiently conducting a global registration of large point cloud scans.
2. Description of the Related Art
(Note: This application references a number of different publications as indicated throughout the specification by reference numbers enclosed in brackets, e.g., [x]. A list of these different publications ordered according to these reference numbers can be found below in the section entitled "References." Each of these publications is incorporated by reference herein.)
For a few years now, the world of three-dimensional (3D) data faces a true revolution with many new devices easily available for both capturing data and visualizing data whether it be pure virtual 3D data for virtual reality applications or combined 3D and visual data for augmented reality. This new context with everyday new applications based on 3D information, more 3D data of many different types, and new sensors, presents many new challenges. Among these challenges, the first processing step (preceding almost always any other processing from 3D data) is the registration of data acquired by a sensor from different locations. Indeed, whatever the kind of sensors considered (Laser scanner, KINECT, etc.), no existing technology can acquire the whole 3D information of a scene all at once.
Thus, a 3D acquisition usually results in a set of 3D points (a 3D point cloud), with or without associated RGB information depending on the sensor, covering partially the spatial area of the full scene. One problem in the data acquisition process is the registration of multiple scans. Single scans, from different sensor positions, are acquired within a local coordinate frame defined by the instrument. For visualization and further data processing of the point cloud, the single scans must be transformed into a common coordinate frame. This process is termed as "registration." Given two or more 3D point clouds that have a subset of points in common, the goal of 3D registration is to compute the rigid transformation that aligns these point clouds, providing an estimation of the relative pose between them. This registration of partially overlapping 3D point clouds, usually considered pair by pair, taken from different views is thus an essential task in 3D computer vision and the basis of many algorithms in 3D vision applications.
There are two well identified challenges in this task of 3D registration:                Global registration: refers to the registration of a pair of 3D point clouds without initial guesses on the pose of one point cloud to the other, the pose is thus arbitrary; and        Local registration: refers to the registration of a pair of 3D point clouds from a valid initial estimate of the pose between the two clouds.
Many algorithms for registration have addressed these challenges in the last decades. It is commonly accepted in the community to classify the algorithms into two (2) distinctive classes [1] based on the challenge they address:                Coarse registration: consists of roughly aligning two scans without any clue about the initial alignment; and        Fine registration: from a given coarse alignment, a fine registration refines the result, generally by minimizing error iteratively.
The global registration usually requires both coarse and fine registration steps, while for the local registration challenge, it is often sufficient to consider a fine registration process only.
A popular type of approach involves iterative processing referred to as Iterative Closest Point (ICP) [2] and variants [3; 4; 5]. However, in practice, the original ICP methods tend to converge poorly when subjected to severe noise and large pose displacements without a good initial guess on scans alignment. Thus, ICP, or its variants, are often used for a fine registration stage in order to improve previous coarse registration but are not suitable as direct solutions for coarse registration.
Some other approaches try to get rid of any requirement for a good initial estimate by extracting invariant local features and finding correspondences. However, the main limitation of such methods is a lack of robustness to large baselines (large sensor viewpoint changes) and little overlap.
With the availability of several new consumer-grade 3D sensors, many solutions have been proposed to solve this problem and work pretty well for reasonably sized point clouds (few thousands of points) even with little overlap, noise and a pretty large baseline.
One of the main advantage of LiDAR (light imaging, detection and ranging) scans over ordinary point clouds is that they are acquired in a global 3D coordinate system. This way, Euclidean distance can be used to describe patterns in the scene. It considerably reduces the complexity of the problem by locking the scale. Furthermore, the LiDAR scans are almost noiseless.
There are many algorithms trying to solve the registration problem using either only geometrical information, or only visual information (e.g. RGB values attached to the 3D points), and eventually some use both. The main drawback is that most of the current solutions are not able to efficiently solve the global registration problem when all of the following constraints are present: large scale data, large baseline, little overlap, and no initial guess of the relative alignment.
To better understand these problems, a description of the related art may be useful.
A survey of the most significant contributions in the domain can be found in [1]. As described in this survey, all of the approaches of coarse registration can be compared considering the following main steps:
(1) Salient information detectors: The survey [1] presents Normal Space Sampling [3], Maximally Stable Volumes [6], Heat Kernel-based Features [7], MeshDoG [8], Intrinsic Shape Signatures [9], Key-Point Quality [10], and Harris3D [11];
(2) Salient information descriptors: The survey [1] presents Principal Curvature [12], Point Signature [13], Spin Image (Intrinsic Shape Signatures [9] and SHOT [14]), Improved Spin Image [15], Scale-Invariant Spin Image [16], Principal Component Analysis [17; 11; 16], Line-based algorithm [18], 3D Shape Contexts [19], Dynamical Systems [20], Integral Invariants [17], Curve Skeleton [21; 22], Point Feature Histograms [23], MeshHOG [8], Intrinsic Shape Signatures [9], Heat Kernel Signature [7; 24], and Rotational Projection Statistics [25];
(3) Searching strategies: The survey [1] presents Algebraic Surface Model [26], RANSAC-based Methods [27; 28; 29], Robust Global Registration [30], 4-points Congruent Sets [31], and Evolutionary Methods [32]; and
(4) Refinement: This step is mainly based on ICP [2] and its improvements [3; 4; 5]
The survey [1] not only reports the current state-of-the-art on coarse registration but it proposes a pipeline to classify these existing methods with respect to the aforementioned main steps. The survey [1] also defines a standard formal notation to provide a global point of view of the state-of-the-art.
One classic approach to describe the scans around salient detectors is based on normal distribution. This idea has already been taken into account in several approaches. For instance, an approach based on normals distribution has been proposed by Makadia & al. [4]. Normals are accumulated in an orientation histogram. Peaks are identified and create constellations, that are then aligned to directly give the rotation between two scans. Translation can be deduced right afterwards. The limitations identified in this approach are that overlap has to be important, and that normals from the overlap area must be discriminative regarding the distribution of normals through the whole point clouds while being consistent with this distribution.
One solution to address these limitations, when RGB information is available, is to combine 3D and RGB detection, description and matching. For instance, Zeisl et. al. [33] addressed these limitations by combining 3D information with standard vision matching using 2D SIFT. The idea in their paper is to project the scan in perspective views orientated towards "salient directions," that are identified as peaks on the normals distribution as in the previous work. However, this algorithm is challenged by point clouds with few planar areas, or surfaces presenting an important tilt when viewed from the scan location.
In cases such as scanner acquisitions, there may be lot of self-occlusions, leaving large parts of the scene hidden from the scanner. Since the occlusions are likely to be different from one viewpoint to another, one may utilize a smaller size for the neighborhood. However, using a smaller size for the neighborhood might not be suitable since the information held by such a neighborhood could vary a lot.
Another approach is set forth in Aiger et. al. [31]. Aiger [31] proposed a 4-Points Congruent Sets (4PCS) algorithm that does not use local description. Instead, [31] considers groups of 4 quasi-coplanar points in the point cloud. A shape descriptor is used that is based on the distances between these points and the intersection of the line segments they define. The selected points must be spread enough to guarantee algorithm stability, and close enough to ensure that the points are in the overlap area between the two viewpoints. The geometric configuration of four coplanar points is discriminant enough to create strong matches between the two point clouds. Aiger's work on the 4PCS algorithm inspired several other approaches still introducing the 4-Points Congruent Sets principle: the Super4PCS [34] is based on a smart indexing data organization reducing the algorithm complexity from quadratic to linear in the number or data points; Mohamad et. al. [35] generalizes 4PCS by allowing the two pairs to fall on two different planes that have an arbitrary distance between them, then by increasing this distance, the search space of matching hypotheses exponentially leads to a maximum run-time improvement of 83:10%.
However the Super4PCS is more complex to implement and the run-time improvement is almost always dividing 4PCS run-time by two. Similarly the Generalized 4PCS reach more than 80% of run-time improvement but this is only evaluated on datasets with less than 100K points.
Thus another idea to reduce the complexity of 4PCS could be to not anymore rely on 4-Points Congruent Sets rather relying on two points.
Indeed, the idea of a four component descriptor based on angles and distance between two points, has been first proposed by Drost et al. [36].
Drost [36] applied this descriptor, called Point Pair Feature (PPF), for efficient and robust 3D object recognition.
Another prior art approach is that of T. Birdal and S. Ilic [37] which proposes a full processing chain based on their PPF descriptor to address the problem of large scene scan registration.
In view of the above, what is needed is a global registration method that can be efficiently used with large scale data, large baseline, little overlap, and no/little pose information/relative assignment information.

Keypoint-based point-pair-feature for scalable automatic global registration of large RGB-D scans


A method and apparatus in a switching element for maintaining data used in operation of a communications system. Examples of such operations include serving sessions and routing calls. A local data structure is maintained within the switching element wherein the local data structure contains data used by the switching element in its operation in the communications system. Responsive to a requirement for needed data that is unavailable or out-of-date from the local data structure, a request is generated for the needed data from a server through a communications link from the switching element to the server.

The present invention relates generally to an improved telecommunications system and in particular to a method and apparatus for maintaining data, such as routing tables and software, used by network elements in a telecommunications network.
A communications network serves to transport information among a number of locations. The information to be transported is usually presented to the network in the form of time-domain electrical signals and may represent any combination of telephony, video, or computer data in a variety of formats. To transport such information, a typical communications network includes various physical sites, or xe2x80x9cnodes,xe2x80x9d and information conduits, called xe2x80x9clinks,xe2x80x9d that interconnect the nodes. Each link serves to carry information from one node to another node. Links are often implemented as electric cables, optical fibers, or radio paths. Each node typically contains some means for switching a stream of incoming data from one link onto one of many outgoing links. Nodes can thereby perform routing of information through the network via the associated links.
Various equipment, referred to as xe2x80x9cnetwork elementsxe2x80x9d, are placed at nodes along links for combining, separating, transforming, conditioning, and routing information signals. A xe2x80x9cswitching elementxe2x80x9d is a type of network element that causes information to follow a particular path through the network. The setting up of a path from a source node to a destination node is typically accomplished by switching elements within the network nodes. The behavior of each switching element is determined by software instructions and data tables accessed by a data processor controlling the switching element.
To ensure proper operation of the network, and particularly cooperation of nodes in performing routing of information, all switching elements in the network must have correct software instructions and data tables. Likewise, other types of network elements often use software and data tables to control their respective functions. Maintaining consistent operating information among all network elements is necessary for proper network operation but is a difficult task. In a large network, both data tables and software loads are often large and cumbersome to maintain. Furthermore, updates of switching data tables used by switching elements are frequently necessary due to constant changes in the topology of, and provisioning within, the network.
Network engineers keep a master table representing the interconnections among the switching elements in the nodes of a network. To perform routing of information through the network, each switching element must have access to some or all of the information in the master table. One way of providing this access is to have all switching elements consult a centralized table. A centralized table can be readily changed by network engineers to reflect the most up to date information about connectivity within the telecommunications network. A drawback with this type of system is that each node within the telecommunications network must constantly access the centralized table. This constant need for access to a centralized table leads to performance bottlenecks. Moreover, if the centralized table is rendered unavailable, then the entire network can be disabled.
The alternative approach of using distributed tables avoids some of the foregoing problems but introduces new problems as well. The main problem with using distributed tables is the difficulty in maintaining synchronization among table contents if, for example, a copy of the master table is replicated at each switching element. A mismatch in the table contents among various nodes in the telecommunications network may cause traffic to be mishandled and lost. This implies that changes to table contents must be made simultaneously through the network. In practice, the network cannot be disabled for any length of time to allow for contents of all tables to be updated. Furthermore, keeping a copy of the master table at each switch can be unwieldy because of the size of the table.
On the other hand, keeping more locally pertinent subsets of the master table complicates the process of managing customized contents of the table at each switching element.
Therefore, what is needed is an improved method and apparatus for maintaining operating information among network elements, such as routing information among switching elements, in a communications network.
The present invention provides a method and an apparatus in a communications system for maintaining data and software used in operating network elements within the communications system. As the need arises, data required by a network element is obtained from a network-wide data repository function that can provide the data. This need for the network element to obtain data from the data repository function may arise, for example, due to changes in network topology, operational status of the network, or availability of new information within the data repository function. For example, the network-wide data repository functions may dispense portions of a master routing table or revised software loads for the network elements. In a preferred embodiment, the network elements may selectively request subsets of the data contained in the network-wide data repository function and store the retrieved information locally for subsequent use by the network element.

Apparatus for providing data to switching elements in a communications system