Parallel ML processing of an analog signal in a RLL-coded channel in which (1) vectors for a current state of the channel and the next state of the channel are computed using Walsh transform vector coefficients of the analog signal; (2) current state vectors and next state vectors and values of vectors precomputed in analog matched filters are used to generate vector scalar products which are compared against preselected threshold values for generating binary decision outputs that are used in digital sequential finite state machines to generate ML symbol decisions; and (3) ML symbol decisions are fed back and used to subtract the intersymbol interference value of the current state vector from the vector of the next state to transform the next state vector into an updated current state vector.

In a read channel, a read head (inductive or magnetoresistive) generates an analog signal from data stored in binary form on a disk. Each transition in the orientation of the recorded binary data results in a peak in the analog signal. In a channel using peak detection, the electronic components of the read channel must reliably detect the peaks in the analog signal in order to reconstruct the binary data. A peak is detected (1) if the signal changes its sign, (2) if it exceeds a threshold, and (3) if its derivative is zero.
Published European Patent Application 0 463 752 A2 discloses a pattern-matching circuit which compares bit by bit a given multibit binary data pattern against templates of various multibit patterns and then outputs as the most likely multibit pattern that one which most closely matches the given pattern. However, it does not teach matching of a binary pattern to an analog signal.
U.S. Pat. No. 4,945,538 discloses a signal processing channel which processes an analog read signal after it is converted by an analog-to-digital converter into digitized sample values. Appropriate values of functional expressions of the digitized sample values are precomputed for a preselected number of sample values ahead of a then current sample value for bit-by-bit maximum-likelihood (ML) detection. However, it does not disclose or suggest analog multibit ML detection, feedback of the ML decision for the purpose of intersymbol interference subtraction, or clock offset correction.
Commonly assigned U.S. Ser. No. 08/327,062, filed Oct. 21, 1994, discloses a signal processing channel in which a run-length-limited (RLL)-coded analog read signal is integrated and weighted by a preselected set of staircase amplifier gain factors to provide a plurality of staggered analog signals, each of which is constant for an identical preselected period of time (such as a half-bit period) but offset timewise in equal increments for detecting multibit patterns instead of single bits. However, it does not provide ML detection and/or feedback and it requires a half-bit clock. J. Walsh, "A Closed Set of Normal Orthogonal Functions", American Journal of Mathematics, Vol. 45, pp. 5-24 (1923), explains what are hereinafter referred to as the "Walsh functions" and "Walsh transform coefficients".
A. H. Morton et al., "PRML Technology Delivers More Bytes for the Buck", Data Storage, May/June 1995, pp. 45-48, discuss PRML technology and (at page 48) describe the advantages of an EEPR4 RLL (1,7)-coded channel for writing and the need for a high-speed clock with such a channel when reading. This problem when reading is alleviated by applicants'invention embodying a multibit ML symbol detector.
No prior art known to applicants discloses parallel ML processing of an analog signal in a RLL-coded channel in which (1) vectors for a current state of the channel and the next state of the channel are computed using Walsh transform vector coefficients of the analog signal; (2) current state vectors and next state vectors and values of constant vectors precomputed in analog matched filters are used to generate vector scalar products which are compared against preselected threshold values for generating binary decision outputs that are used in digital sequential finite-state machines that implement Boolean logic expressions to generate ML symbol decisions; and (3) ML symbol decisions are fed back and used to subtract the intersymbol interference value of the current state vector from the vector of the next state to transform the next state vector into an updated current state vector as well as to generate clock phase offset correction signals.

Maximum-likelihood symbol detection for RLL-coded data


The application generally relates to the attenuation of a RNA virus or of a clone thereof and involves the alteration of sequence space, more particularly the reduction, of mutational robustness of said RNA virus or clone. The means of the application are more particularly dedicated to the attenuation of an infectious RNA virus or clone, for the production of immunogenic composition or vaccine. More particularly, the means of the application involve the replacement of codon(s) by different codon(s), which is(are) selected to differ by only one nucleotide from a codon STOP, more particularly by different but synonymous codon(s), which is(are) selected to differ by only one nucleotide from a codon STOP.

RNA viruses have very high mutation frequencies. When a RNA virus replicates, nucleotide mutations are generated resulting in a population of variants. The consensus sequence, which is used to define a RNA virus, represents the genetic average of every nucleotide position along the genome. The population of RNA virus variants is a network of variants organized in sequence space around the consensus sequence. This mutant spectrum is often referred to as quasispecies.
This genetic diversity creates a cloud of mutations that are potentially beneficial to viral survival, whereby creating an antigenic drift that requires frequent updates of vaccines and providing the basis for resistance to antivirals. It is known that altering the ability of a RNA virus to generate a normal mutation frequency, reduces viral fitness (i.e., the relative ability of a given virus to generate progeny viruses, taking into account all aspects of the virus life cycle including replication) and attenuates the virus during in vivo infection.
Reducing the fitness of RNA viruses may also be achieved by affecting replication or translation, through a variety of means, including altering codon pair bias.
Another feature that may affect RNA virus fitness is mutational robustness and/or sequence space. Mutational robustness is the ability to conserve phenotype in light of genetic changes (neutral mutation). However, little is known about the effects induced by alteration of RNA virus mutational robustness. Some studies addressed the indirect alteration of RNA virus mutational robustness, using constructs designed to alter fitness by other mechanisms, such as codon deoptimization (e.g., alteration of codon bias and codon pair bias). Therefore, these studies did not address mutational robustness per se (Lauring et al. 2012; Coleman et al. 2008).
The attenuation of RNA viruses for vaccine production faces the problem of genetic instability and of the associated risk of genetic reversion or mutation to a pathogenic phenotype.
The conventional method for RNA virus attenuation currently involves the introduction of random gene mutation or passages in unnatural conditions, whereby introducing more mutations than those actually required for attenuation, but lowering the risk of genetic reversion. This step is mostly empirical and is rather specific of the particular RNA virus type or species under attenuation.
Hence, the current method for RNA virus attenuation involves events, which depend on chance and cannot be universally applied to a variety of virus types.
The application provides means for RNA virus attenuation, which are non-empirical and which can be applied to all RNA viruses.
The means of the application are rationally based on the alteration of mutational robustness and/or of the localization of the virus in sequence space.

RNA virus attenuation by alteration of mutational robustness and sequence space


A process for producing a component includes providing a composition comprising hard material particles and a binder metal, and sintering the composition at a sintering temperature of from 1250° C. to 1400° C. for a period of from 3 to 15 minutes. The hard material particles comprise an inner core comprising fused tungsten carbide and an outer shell comprising tungsten carbide. The binder metal is selected from the group consisting of Co, Ni, Fe and alloys comprising at least one metal selected from Co, Ni and Fe.

Fused tungsten carbide (FWC) is, owing to its extreme wear resistance, a preferred material for components which are subjected to highly erosive and/or abrasive conditions, such as welded wear protection layers or drill bits for oil and gas exploration. The excellent wear resistance of fused tungsten carbide is based on its particular microstructure which is made up of alternating lamellae consisting of tungsten carbide (WC) and ditungsten carbide (W2C). Fused tungsten carbide is usually processed by infiltration with copper-based solders or welding by means of spontaneously flowing nickel-containing alloys. Owing to the processing by infiltration or by welding, the content of the metallic binder phase is usually 20-40% by weight. In comparison, the binder content (binder=Co or Ni) of commercial WC—Co or WC—Ni cemented hard materials is significantly lower at 3-15%. For the purposes of the present invention, a cemented hard material is a sintered component which essentially comprises a hard material, for example, a carbide such as tungsten carbide, and a metallic binder such as cobalt or nickel. Since the wear properties of FWC are superior to WC, a demand exists for fused tungsten carbide for making cemented hard materials having a significantly lower binder content of <20% industrially usable.
The reason for the lack of usability of fused tungsten carbides in cemented hard materials is essentially that:                a) the fused tungsten carbide particles are dissolved by diffusion in Co in the solid state and also in the liquid phase which arises during sintering and consists essentially of cobalt and/or nickel;        b) the advantageous lamellar structure is thermally/chemically transformed during the sintering process; and        c) the component cannot be sintered so as to be free of pores.
DE 199 24 683 C2 describes the use of fused tungsten carbide in the head of a round-shaft chisel. In DE 199 24 683 C2, the chisel head is produced by infiltration and not by sintering.

This patent is subject to a terminal disclaimer.


A dual valve actuator mechanism for a fire extinguisher bottle in a milit vehicle. The mechanism includes an electrical trigger system for operating the valve automatically in response to energization of an electronic optical fire sensor; alternately the electrical trigger system can be operated by closure of a manual switch from within the vehicle interior. A second cable system is provided to operate the valve manually from a point external to the vehicle, as when the vehicle is unoccupied at onset of the flame or when the soldiers are forced to exit the vehicle to avoid inhalation of fumes or vapors. Unfortunately the valve actuation stroke is very small, on the order of two-tenth inch or less. The present invention relates to a lost-motion connection in the cable for lengthening the stroke necessary to operate the valve; this prevents inadvertant valve actuation due to vehicle vibrations or installation tolerances.

In a known fire suppression system for military vehicles one or more pressure-resistant bottles are charged with a vaporizable fire-suppressant liquid, such as bromotrifluoromethane, at a pressure of approximately 750 p.s.i.; nitrogen is used as a pressurizing agent, as outlined generally in U.S. Pat. No. 3,915,237 granted to me on Oct. 28, 1975. Outflow of suppressant from each bottle toward the expanding flame is controlled by an electrically-operated valve secured directly to the bottle. The valve can be operated by an explosive squib, as shown for example in U.S. Pat. No. 3,491,783 to Linsalato or 3,474,809 to Gordon. The valve can also be a pilot-operated solenoid valve.
The valve has an outlet that communicates directly with the target zone in which the flame is expected to occur. Alternately the valve outlet may be connected to a pipe or tube leading to the expected flame area. There are generally two types of fires to be expected, namely slow-growth fires and near-explosive fires. Slow growth fires can occur in either the crew compartment or the engine compartment, due to a variety of different causes such as leakage of hydraulic fluid or liquid fuel, loosened electrical connections, or debris accumulation. Fires of near-explosive proportions can occur when an enemy shell passes through a fuel tank in the engine compartment or crew compartment; the fireball expands rapidly within milliseconds.
In order to best contain both the slow growth fires and the near-explosive fires in different areas of the vehicle it has been the practice to use an electrical valve trigger system that includes an electronic-optical fire sensor and a manual switch (located at the driver station). The optical fire sensor provides an automatic quick-acting response to near-explosive fireballs; the manual switch provides the driver with selective response to slow-growth fires. In addition, it has been the practice to provide each bottle with a second manual valve actuation system that can be operated from a point external to the vehicle. This second manual valve actuation system comprises a cable extending from the respective valve actuator through the hull wall to a pull-type handle located on the hull exterior surface (usually located at the front end of the vehicle). The pull-type handle is to be operated when the vehicle is unoccupied at the onset of the flame (in which case the soldiers might not have time to reach the switch at the driver station), or when conditions within the vehicle dictate that the soldiers exit the vehicle before attempting to extinguish the flame.
The valves now used in existing vehicle fire suppressant systems have actuator devices that travel only very short distances, on the order of one tenth or two tenth inch, before triggering the valve element to its flow-open position. With such a very short travel it is sometimes difficult to ensure a reliable actuation of the cable system, when needed. Problems arise due to such factors as premature triggering of the valve element due to initial installation errors, in-service vehicle vibration or vehicle turn forces, and inertia forces in the cable system. Another problem relates to the user's inability to reliably ascertain whether the valve is actually open; when the soldier exerts a pull action on the handle of the cable he is never quite certain that the very slight resultant handle movement has opened the valve or has merely taken up slack in the cable system.
The present invention is directed to a remotely-actuable cable system for a fire extinguisher valve, wherein the cable is subdivided into two separate cable sections joined together by a lost motion connection. The use of such a lost motion connection is advantageous in that it magnifies the motion required at the handle compared to the motion experienced at the valve actuator. For example, if we assume a lost motion of nine-tenth inch, then a one-tenth inch valve actuator motion requires a one inch handle pull motion. The user is able to accelerate the handle through a one inch motion distance and receive sensory feedback of a perceptible motion.
The lost motion connection envisioned by applicant preferably includes a compression spring arranged to exert a progressively increasing force on the valve actuator as the manual pulling force is applied to the handle at the outer end of the cable. The spring force and spring rate are selected so that the valve is actuated to the flow-open position before the handle reaches the full limit of its motion. Therefore, the user is certain that the valve is actuated even though the handle is not pulled through a complete stroke. Also, since a significant movement of the cable is necessary to actuate the valve there is a lessened likelihood that vehicle vibrational forces will prematurely trigger the valve to the flow-open condition.

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


A sun-visor for motor vehicles is described which has a flat, elongated sun-visor body which can be flipped from a position of non-use above a vehicle windshield into a position of use in front of the vehicle windshield. The sun-visor body carries a plate at one end region of its lengthwise direction. The plate can be swung out around a hinge on the visor body when the sun-visor body is in its position of use in order to impart the sun-visor body the normal size which protects against glare and can be swung inward in order to shorten the length of the sun-visor body before it is swung into the position of non-use.

The present invention relates to a sun-visor for motor vehicles which has a flat, elongated sun-visor body which can be flipped from a position of non-use above the windshield of a car into a position of use in front of the windshield.
Sun-visors for motor vehicles generally have a sun-visor body which is dimensioned so that sufficient protection against glare is obtained when the sun-visor is in its downwardly flipped position of use in front of the windshield. Some sun-visor bodies have additional anti-glare bodies which can be moved over those regions of the windshield that cannot be covered by the sun-visor body. Some additional anti-glare bodies which are articulated by hinges or pivots to the sun-visor bodies are also known for effectively enlarging the sun-visor bodies, for example, as shown in Japanese Patent Publication 62-184925. They additionally cover a part of the side window adjacent the windshield when the sunlight enters the car too strongly from the side.
In practice, problems have arisen during use of sun-visors with sun-visor bodies of normal size. In particular, these occur in convertibles in which locking elements located in the region of the A-columns are to be operated for either closing or release of the convertible top. Sun-visor bodies of normal size may be disturbing here, and they may no longer permit actuation of the locking elements. In order to eliminate this problem, sun-visor bodies which are shortened at one lateral side could be used, but this would create a new problem of insufficient protection against glare.


In a droplet ejecting device capable of being driven at a low voltage and having a simple structure with low manufacturing costs, the droplet ejecting device has multiple ejectors each for changing a pressure of ink held in an ink passage by the use of a pressure generator so as to eject the ink held in the ink passage through an ejection port. The ejection ports comprise a slit disposed across the multiple ink passages and the slit is formed into a tapered cross section thereby eliminating a required process for manufacturing the same number of tapered ejection ports as that of ink passages in the prior art. Therefore, it is possible to reduce the number of manufacturing processes, manufacturing costs, and a driving voltage.

1. Field of the Invention
The invention relates to a droplet ejecting device and, more particularly, to the structure of an ejection port.
2. Description of Related Art
A bubble jet type ink jet printer using an electrothermal converting element as a pressure generator and a piezoelectric type ink jet printer using an electromechanical converting element as a pressure generator have been recently noticed for the reason of low noise in comparison with an impact type printer. For example, in the piezoelectric ink jet printer, the capacity of an ink passage is changed according to dimensional displacement of a piezoelectric actuator. Ink held in the ink passage is ejected through an ejection port when the capacity is decreased, while ink is introduced into the ink passage when the capacity is increased. This is called a drop-on-demand system. A multiplicity of ejectors operating as described above are arranged close to each other. Ink is ejected from the ejector located in a predetermined position whereby a desired character or image is formed.
In an array 1 constituting a conventional droplet ejecting device, the assembly perspective view being shown in FIG. 6, a cover 6 is joined to a grooved plate 2 having numerous ink passages 4 formed of grooves defined by side walls 7. A nozzle plate 8 having ejection ports 10 corresponding one to one to the ink passages 4 is bonded to the end surface of the assembly constituted of the grooved plate 2 and the cover 6. Accordingly, it is necessary to form the same number of ejection ports 10 as that of ink passages 4 thereby inducing the problem of many manufacturing processes. In addition, in order to eject ink at low energy, each of the ejection ports 10 ought to be formed into a tapered shape contributive to a decrease in ink passing resistance, with attendant problems of complicated manufacture and high manufacturing costs.


A system and method for remediating a body of water and collecting suspended and dissolved solids therefrom are provided. The system includes a water-impervious lining positionable in a depression in or adjacent a body of water. The lining and depression define a treatment vessel, which includes a treatment portion, an outlet portion for containing treated water, and an outflow weir between the treatment portion and the outlet portion. Water to be treated is transported from the water body to the treatment portion. An entrapment element is delivered and mixed into the transported water, the entrapment element for capturing suspended and dissolved solids in the transported water and effecting a separation between the captured solids and water cleansed therefrom. The captured solids can be removed from the treatment basin, and the cleansed water can move through a channel in the outflow weir into the outlet portion.

1. Field of the Invention
The present invention relates to systems and methods for water remediation and biosolids collection, and, more particularly, to such systems and methods for remediating water and collecting water-borne solids using solids entrapment.
2. Description of Related Art
Dissolved air flotation (DAF) is a liquid process technology that uses micro-bubble airflotation to raise and remove suspended solids in an aqueous solution such as industrial process water, municipal waste water, and/or lake water.
DAF systems known in the art are constructed from steel or concrete tanks. Large liquid above-ground vessels require structural steel plate and backing stiffeners to preclude deformation of the tank walls during hydrostatic loading when full to operating levels. The steel vessels also require footings to transfer loads to soil with appropriate bearing capacities. Inert materials like 314 and 316 Stainless Steel or exotic epoxy coating systems are typically used to retard corrosion.
Wind mixing of shallow lakes causes loose non-photosynthetic sediment material to rise into the photic zone temporarily. This reactive nutrient-laden sediment often feeds the algae in the photic zone of an impaired (hypereutrophic) lake and causes a perpetual algal bloom, which can in some cases even be seen from space (the orbiting Space Shuttle can differentiate hypertrophic Lake Apopka in Florida from other lakes, for example). One means of water remediation is to remove, or harvest, suspended solids (SS) and the nutrients incorporated thereinto.
Traditional approaches for SS removal use large expanses (5,000-45,000 acres) of flooded wetland filters where quiescent conditions cause the SS to sink out and form soil. As soil decays, much of the settled-out nutrients go back into solution, causing inefficiency. If toxic cyanobacteria algae settle out in the wetland, toxins can become available to wildlife for years, both in soil and water. Still, this has been a preferred method for remediation where a great expanse of land is available.
A known difficulty in remediating water bodies is that systems must often operate where the soil is soft and wet, for example, adjacent or on lake shores. The expense associated with providing excavation, fill, and soil stabilization can be prohibitive, and the result unsightly in an area that is supposed to be being improved. Therefore, DAF systems have been considered unsuitable for on-site water body remediation. In addition, for at least some of the same reasons, using DAF technology in a water body has not been considered to be practicable.
Prior known DAF systems require a precise balancing of criteria such as inflow rate, coagulant delivery parameters, and sludge and flotation removal in order to function effectively. As larger DAF systems are known to be prohibitively expensive, the trend has been towards smaller vessels having specific geometries for optimizing filtration.
Other problems faced at the present time are the growing expense and decreasing supplies of fuel, and the disposal of biomass generated by bioremediation systems such as algal floways and other aquatic plant systems.
Therefore, it would be desirable to provide a system and method for remediating a body of water that is economical and effective, and that does not disturb an aesthetic appeal of the water body and the surrounding area. It would also be desirable to provide a system and method for disposing of collected biosolids and for generating fuel therefrom.

Water remediation and biosolids collection system and associated methods


Methods and systems for improved interaction between media devices and accessory devices are disclosed. In one embodiment, the improved interaction can operate to configure a user interface of a media device dependent on the type or condition of an accessory device. In the same or another embodiment, the improved interaction can exchange status information between a media device and an accessory device that can influence operation of either or both of the devices.

1. Field of the Invention
The present invention relates to media devices and, more particularly, to portable media devices, such as portable media players, that receive accessory devices.
2. Description of the Related Art
A media player stores media assets, such as audio tracks or photos, that can be played or displayed on the media player. One example of a media player is the iPod® media player, which is available from Apple Computer, Inc. of Cupertino, Calif. Often, a media player acquires its media assets from a host computer that serves to enable a user to manage media assets. As an example, the host computer can execute a media management application to manage media assets. One example of a media management application is iTunes® produced by Apple Computer, Inc.
A media player typically includes one or more connectors or ports that can be used to interface to the media player. For example, the connector or port can enable the media player to (i) couple to a host computer, (ii) be inserted into a docking system, or (iii) receive an accessory device. There are today many different types of accessory devices that can interconnect to the media player. For example, a remote control can be connected to the connector or port to allow the user to remotely control the media player. As another example, an automobile can include a connector and the media player can be inserted onto the connector such that an automobile media system can interact with the media player, thereby allowing the media content on the media player to be played within the automobile media system. As still another example, a media player can be connected to a speaker dock which can then serve as a portable media system.
Notwithstanding the foregoing, there is a need for improved interaction between media devices and accessory devices.

Media delivery system with improved interaction


A self-priming vane pump includes a cylindrical rotor disposed in a cavity in a housing including inlet and outlet ports. The rotor defines a plurality of axially extending slots which each receive one of a like plurality of vanes. A garter spring or similar resilient annulus is disposed within the rotor and provides a radially outwardly directed force on the vanes which maintains their contact with the cavity walls during pump start-up and rapidly self-primes the pump. The spring or annulus rests against a shoulder within the hollow rotor and is retained therein by a pressed in collar.

The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Gear pumps and gerotor pumps are often the preferred choice for a fixed or positive displacement pump in applications requiring flows and pressures of low to medium nominal values. One drawback of such pumps, however, is their efficiency. Due to their construction, there is backflow or leakage through the meshing rotors and around the ends of the rotors when they are operating which results in reduced forward flow and thus reduced pumping efficiency.
Fixed displacement vane pumps perform in the same flow and pressures ranges and exhibit improved efficiency due to reduced leakage and backflow. Such reduced leakage and backflow are the result of better sealing between the outer edges of the vanes and the walls of the rotor cavity. However, since contact between the pump vanes and pump cavity and thus the seal quality is primarily the result of centrifugal force and line pressure acting on the center of the rotor, both of which push the vanes outward to seal on the wall of the pump cavity, the seal quality improves with higher rotational speeds and higher line pressure and degrades with lower speeds and lower line pressure. This aspect of vane pump operation is especially problematic at startup of an unprimed pump. Since at startup, the pump will typically be operating at reduced speed and zero pressure, seal quality is low and this problem in exacerbated by the unprimed state of the pump such that establishment of priming and delivery of pressurized fluid may take an undesirably long period of time.
The present invention provides a solution to the dual problems of startup of an unprimed vane pump.


An alloy having excellent corrosion resistance and abrasion resistance, is provided comprising a matrix metal phase comprised of at least one member selected from an Fe-base alloy, a Co-base alloy and a Ni-base alloy and, present in the matrix metal phase, 10 to 65%, in terms of the area, of a substantially homogeneously crystallized and/or precipitated VC particle phase having a particle diameter of 5 .mu.m or less.. A surface-modified metallic member, is also provided comprising a metallic member and the above-described alloy, the alloy being integrally coated on the surface of the metallic member at its desired portion.

The present invention relates to an alloy material excellent in both the corrosion resistance and abrasion resistance, a method for producing the same, a material for use in the production of the same, a metallic member using the same and a method for improving the corrosion resistance and abrasion resistance of the surface of said metallic member.
In general, in order to improve the corrosion resistance and abrasion resistance of metallic members constituting machinery, the surface of the metallic members has hitherto been modified, for example, by hardening or plating materials for constituting the metallic members, such as stainless steel.
Besides the above-described surface treatment method, various proposals have been made in recent years of a method wherein particular hard particles are added to metallic materials for constituting metallic members. Examples of such methods include a method as described in Japanese Patent Laid-Open Publication No. 181470/1983, wherein hard particles of WC, NbC, TiC, CrC, VC, etc. are added in a matrix metal comprising a Ni-base, Co-base or Fe-base alloy or to the surface of the matrix to improve the hardness or abrasion resistance of the matrix metal. The present inventors have found that although this method is effective to some extent in improving the abrasion resistance, it is not always satisfactory because the toughness of the alloy is disadvantageously lowered. For example, hard particles, such as NbC (melting point: 3480.degree. C.) and TiC (melting point: 3180.degree. C.), have a high melting point and is hard to melt, so that it is difficult to avoid the addition of the hard particles in an unmelted state. For this reason, there occurs a problem that, in the step of forming a corrosion-resistant and abrasion-resistant layer, the hard particles remain in a relatively large form in the matrix metal, which unfavorably gives rise to a lowering in the toughness of the metallic material.
Also, melting of a carbide as the additive in the matrix metal often leads to embrittlement of materials. For example, it is known that, when MoC or WC is melted together with a Ni-base, Co-base or Fe-base alloy, a brittle (fragile) M.sub.6 C compound crystallizes. The crystallization of the brittle,compound does not contribute to an improvement in the abrasion resistance and further results in embrittlement of the matrix metal.
Japanese Patent Laid-Open Publication No. 157796/1988 discloses a method for producing a roll for hot rolling. This method is directed toward the production of a roll having abrasion resistance and cracking resistance and being excellent in the toughness by adding a VC powder to an iron-base alloy, and the addition of a VC powder in an amount of 10% by weight or more to an iron-base alloy is essential to this method. In this method, however, an improvement in the hardenability is contemplated. According to the knowledge of the present inventors, when an Fe-base alloy is used as a parent metal, the addition of VC to the parent metal unavoidably gives rise to the formation of large amounts of a plurality of carbides, such as WC and CrC, so that the effect contemplated in the present invention is not always attained. Further, this method is not a technique for recrystallizing or reprecipitating VC in a particular state and is not always effective in improving both the abrasion resistance and corrosion resistance.
Further, in the conventional method, when hard particles are added, the temperature rise should be limited to the minimized degree necessary for the deposition of the matrix metal for the purpose of inhibiting the crystallization of the above-described fragile compounds. Further, in order to attain this purpose, it is necessary to increase the particle diameter of hard particles to be added to some extent. An increase in the particle diameter, however, makes it difficult to attain a homogeneous dispersion, which results in a lowering in the toughness of the metallic material. As described above, the presence of coarse hard particles in a heterogeneous distribution in the matrix metal causes these hard particles to easily fall off when they are subjected to frictional movement.
The above-described problems of heterogeneous distribution of hard particles and falling-off of hard particles attributable to the heterogeneous distribution of the hard particles are accelerated also by a difference in the specific gravity between the matrix metal and the hard particles. For example, the possibility of occurrence of aggregation or heterogeneous distribution of the hard particles becomes particularly high when an Fe-base alloy is used as the matrix metal with Al.sub.2 O.sub.3, SiC or TiC being used as the hard particle. Further, when a Cr-base carbide is used as the hard particle, a carbide of Cr recrystallized or reprecipitated in the step of cooling after heating aggregates and grows into a coarse carbide particle, which leads to a problem that the hard particles become liable to fall off from the matrix metal.
International Publication WO91/09980 discloses a method for producing an alloy having excellent resistance to corrosion and abrasion, which comprises subjecting a powder mixture comprising a metallic powder of at least one alloy selected from Fe-base, Co-base and Ni-base alloys and a vanadium carbide powder having a particle diameter of 60 to 100 .mu.m to melting and/or repetition of re-melting with a heat source having a high energy density. The use of the powder having a relatively large particle diameter has an advantage of facilitating the alloying. In this method, however, although fine vanadium carbide particles having a diameter of 10 .mu.m or less crystallize and precipitate, since some vanadium carbide particles remain unmelted, the troublesome melting step should be repeated many times to melt the vanadium carbide particles remaining unmelted. Further, observation under a microscope by the present inventors has revealed that part of the unmelted vanadium carbide is present in a massive form nevertheless, so that a fine vanadium carbide particle phase heterogeneously distributes, which unfavorably makes it impossible to attain an intended abrasion resistance and often causes occurrences of cracking and peeling due to local breaking.

Alloy having excellent corrosion resistance and abrasion resistance


An improved cylinder for pumps of the type where a plunger moves within a cylinder forcing fluid through a port in a cap fitted into one end of the cylinder. A multiple diameter cap encircled by a multiple diameter sleeve transmits the pressure force acting on the largest surface area of the cap through the sleeve to a smaller area acting on the packing seal. Since the pressure multiplied by the area is a constant, a higher pressure is applied to a smaller area at the seals; and with a higher pressure acting on the seals than existing in the working fluid, a seal is created to prevent passage of the fluid.

1. Field of the Invention
The present invention relates to high pressure pumps which operate above 10,000 p.s.i. of the type having a reciprocating plunger or shaft portion.
2. Description of the Prior Art
Pumps for pumping liquids and gases under high pressures typically have one or more cylinders, each cylinder having a reciprocating piston or plunger within. Usually a piston refers to a body which moves within a cylinder having seals or rings which are attached to and travel with the piston. A plunger usually moves relative to a seal attached to a cylinder. Normally a closure having a port therethrough is attached to the distal end of the cylinder. Leakage of fluid around the piston or plunger can typically be prevented by various seals and packings. The seals range from simple O-rings to multiple rings of various materials such as elastomers, polymers, rubber, reinforced combinations thereof, brass and teflon. Such a complex seal is disclosed, for example, in U.S. Pat. No. 2,991,003 to R. S. Peterson.
Very often seals are positioned between the moving plunger and the cylinder wall. Consequently, there is relative movement between the seal and the plunger. The art has recognized that if known types of plunger sealing rings are constructed of a soft enough material to provide an effective seal, the seals rapidly become worn and lose their efficiency. On the other hand, if the seals are constructed of a relatively hard material to withstand wear they generally do not provide a good seal. In addition, hard seals may cause scratching or galling of the surfaces which slide past the seal. As the pressure of the pumped fluid is increased the problem of seals is magnified. As a result, in many pumps the pressure is limited by the effectiveness of the seals.
The art has attempted to reduce the wearing and galling problems associated with harder seals by increasing the hardness of the cylinder or plunger surfaces. This can be done by various surface hardening treatments, coating the wall with carbide or using higher strength alloys. All of these techniques increase the cost of the pump and make manufacturing more difficult. Carbide coatings are also brittle and are intolerant of high tensile stress. Furthermore, in some pumps the corrosiveness of the working fluid may limit the choice of alloys. Consequently, there is a need for a relatively low cost sealing system for high pressure pumps particularly for those pumps which operate at pressures above 10,000 p.s.i. There is also a need for a sealing system which is not dependent upon the metals chosen for the cylinder.
Professor Bridgeman in his book The Physics of High Pressure, McMillan Publishing Company, N.Y., 1931, proposed a seal which relied upon a principle of unsupported area sometimes called Bridgeman's principle. Bridgeman states that in order to effect a seal, the hydrostatic pressure in the packing must be maintained at a pressure higher than pressure to be sealed. Prior to the present invention, the art has made only limited application of Bridgeman's principle to piston designs particularly high pressure pumps. For example, in U.S. Pat. No. 4,382,750 to Robertson et al. a free piston compressor for gases and liquids is disclosed in which the positive pressure of the incoming fluid holds a free piston against the piston rod during the intake stroke. Leakage of hydraulic fluid around the piston is prevented by a packing and associated bushing. Although the operation of this bushing and packing are not explained in the specification, one can see from the drawings that Bridgeman's principle is applicable to this system.
The art has commonly relied upon mechanically loaded packings, such as Amagat's fully enclosed packing for high pressure pumps. In a mechanically loaded design, the axial load is supplied by a preloaded gland or flange and is not increased by increasing operating pressure. Under such conditions, the packing wears at much the same rate at low pressure as it does under high pressure. This occurs because the packing pressure does not depend upon the operating pressure. Likewise, operating pressure is limited to something less than the preload pressure of the packing. Consequently, operations at high pressure, 60,000 p.s.i. for example, in systems that have mechanically loaded seals require seals having tremendous preloads. For that reason, there is need for a high pressure pump which does not require a highly preloaded packing and which can operate at pressures of 60,000 p.s.i. and higher.

Cylinder with sleeve compacter seals for high pressure pumps


A messaging status associated with a first user is determined. A messaging status associated with a second user is set based upon, at least in part, the determined messaging status associated with the first user.

This disclosure relates to messaging systems, and more particularly to controlling indicated user messaging status in messaging systems.
Instant messaging provides real-time text based communication between two or more users interacting via computers or mobile devices. The more immediate and direct interaction provided by instant messaging often tends to more closely resemble a conversation, as compared to the more "letter like" format of email. The direct interaction between users can provide highly effective and convenient collaboration. For example, problems of unanswered emails and unreturned phone messages can be avoided. Additionally, instant messaging allows people to instantly determine the availability of other user, e.g., for having a conversation, etc.
While instant messaging can be a very useful tool for communication and collaboration, there are times when a user does not wish to be bothered or interrupted. This convenience is provided by a "do not disturb" ("DND") feature in the instant messaging application. Similarly, other messaging status indicators, such as "offline," "in meeting," or the like, may be used to indicate an instant messaging user's availability for interaction.

International Business Machines Corporation


A fragmentation projectile in one aspect has a frontal cavity and defined fragments of medium to high density. The fragments are nearly form fitting together to form a compact projectile until its impact on the target. To achieve these specific mechanical properties, Additive Manufacturing (AM) methods are applied.

1. Field of the Invention
The invention relates to a fragmentation projectile with a frontal cavity and defined fragments of medium to high density.
2. Description of the Related Art
Projectiles which split in a specific manner in the target are referred to as fragmentation projectiles. Such a projectile is known from the EP-B1-1 196 734 and features large recesses at its tip which are unfavorable from an aerodynamics point of view. The attempt is made to close the hole-type recesses in the tip by means of covers, plugs, etc. in such a manner that the aerodynamics is improved, but this leads to nonsymmetries. These nonsymmetries prove to be particularly unfavorable in soft targets, where tumbling movements and undesired fragmentation effects occur which can in turn cause major injuries and/or collateral damage.

Fragmentation projectile and method for its manufacturing


Improved dunnage made from spiral coils of paper that are recyclable and biodegradable, or from other thin, flexible, resilient strips. The coils are cylindrical or cylindrical with a transverse fold, and are randomly oriented in a container to provide cushioning for packaged articles. The coils are formed at the time of use by modifying the material used to cause it to coil and forming strips from the material. This eliminates the need for storage of bulky dunnage. Paper used to form the coils is stretched to cause it to coil. Apparatus concurrently forms plural coils from a web.

It is common to protect articles being shipped in containers by filling extra space in the container with so called dunnage to isolate the articles from the container walls and inhibit movement of the articles within the container. Retailers, and especially those who specialize in catalog sales, typically use boxes that are not specifically designed in size or shape for particular articles and therefore they include substantial amounts of packing or dunnage in the boxes along with the article or articles shipped to reduce the risk of breakage.
Cushioning dunnage, such as excelsior, shredded newsprint, and the like has been in long use. More sophisticated materials and forms have also been proposed, such as the helical coil-like or tubular-like dunnage made from paper web shown in U.S. Pat. No. 3,650,877, or helically convoluted synthetic strands as shown in U.S. Pat. No. 3,347,036. Recent popular materials are plastic bubble sheets, particles or shapes of materials such as polystyrene, and other open-or closed-cell foamed materials.
All packaging is coming under attack because of disposal problems, especially due to the lack of adequate landfill facilities and the non-biodegradable properties of the popular plastic packing materials. The quantity of plastic dunnage used in packaging is so great, and the ability to recycle it is so poor, that the disposal problem is becoming unmanageable. While some industrial uses of polystyrene particles, to take one current example of a widely used dunnage material, permit collection and re-use, the great majority of such material is used for packing retail products that are widely distributed directly to consumers, who individually never receive enough to justify collection and recycling; yet in total, the amount of polystyrene packing used is making its disposal a major problem. The same is true of bubble pack. A further problem with such materials is the space they require for storage prior to use. The nature of the plastic dunnage is such that it takes as much space while stored as it does in use. Retailers and especially mail-order houses, find it necessary to provide large rooms or warehouses merely to hold the dunnage needed for shipping their products. This adds substantially to the packaging costs. Some of the non-plastic dunnage used, such as shredded newsprint, lacks structural strength and is easily compressed, and is disliked by retailers and customers because of the dirt and mess associated with its use, as well as the space it occupies unless the retailer does its own shredding, which still involves a less desirable packing operation than dispensing small plastic particles into a package.


Methods, an uplink module (130), downlink module (160), an entry module (170) and a management module (147) for managing packets in a communication system (100) based on Software Defined Networking are disclosed. A data plane of the communication system (100) comprises a forwarding module (140), a service module (145) and the entry module (170) and a control plane of the communication system (100) comprises the management module (147). The entry module (170) receives (8) an Internet Protocol “IP” packet from the peer device (180), wherein the IP packet includes a destination IP address associated with the mobile device (120). The entry module (170) obtains (9), from the management module (147), a location value specifying the radio network node (110) associated with the destination IP address. The entry module (170) associates (10) the location value with the IP packet, wherein the location value is related to a location tag name, indicating the radio network node (110) that serves the mobile device (120), thereby obtaining a packet. The entry module (170) sends (11) the packet, via the forwarding module (140), towards the radio network node (110) as indicated by the location value of the location tag name. Corresponding computer programs and carriers therefor are also disclosed.

Today's mobile network architecture, a so called Evolved Packet Core (EPC) architecture, is described in Third Generation Partnership Project (3GPP) Technical Specification (TS) 23.401 and 3GPP TS 23.402. An overview of the EPC architecture 100 is illustrated in FIG. 1. An user equipment (UE) 101 (or mobile device) attaches to a network, e.g. via a radio access network such as evolved-UMTS Terrestrial Radio Access Network (UTRAN) 102, where UMTS stands for Universal Mobile Telecommunications System, and receives an Internet Protocol (IP) address. The UE uses that IP address to communicate with peers on a Packet Data Network (PDN) 103. Such PDN is in most cases the Internet, but could also be an operator's IP service like IP Multimedia Subsystem (IMS), Public-switched telephone network Simulation Subsystem (PSS) or the like. The PGW (PDN Gateway) 104 provides access towards one or more PDNs 103. There is a logical IP tunnel, called PDN connection, between UE and PGW.
All traffic of a PDN connection is routed through one and the same PGW 104. The IP address of that PDN connection, i.e. the UE's IP address, topologically belongs to the PGW 104. The PGW 104 thus acts as an anchor point for that IP address. Wherever the UE 101 moves, the anchor point remains the same. This way the peer on Internet, such as the PDN 103, does not notice the movement of the UE 101.
A PDN connection consists of three segments: the segment between UE and Base Station (BS), in FIG. 1 denoted as E-UTRAN 102, the segment between the BS 102 and SGW (Serving Gateway) 105, and the segment between the SGW 105 and the PGW 104. The latter two are implemented by General Packet Radio Service (GPRS) Tunnelling Protocol (GTP) tunneling (http://en.wikipedia.org/wiki/GPRS_Tunnelling_Protocol). E.g. a downstream IP user data packet (i.e. a packet towards the UE) between the PGW 104 and the SGW 105 is encapsulated in a GTP header and an outer IP transport header. The GTP header contains a Tunnel Endpoint ID (TEID) indicating which user, i.e. which UE 101, this packet belongs to. The outer IP transport header has the SGW 105 has destination address. There is a similar setup between the SGW 105 and the BS 102, but there a downlink packet has the BS address set as destination address in the transport IP header.
FIG. 1 illustrates further entities, such as Mobility Management Entity (MME) 106, Home Subscription System (HSS) 107, Serving GPRS Support Node (SGSN) 108, Policy and Charging Rules Function (PCRF) 109 for completeness. Moreover, two other exemplifying radio access networks, i.e. UTRAN 110 and GSM EDGE Radio Access Network (GERAN) 111, where GSM denotes Global System for mobile communication and EDGE denotes Enhanced Data Rates for GSM Evolution, are shown.
On transport level there may be additional layers, not shown in FIG. 1. E.g. the BS 102 and the SGW 105 may be in different sites, and the transport of packets between the sites may be performed through an encrypted transport tunnel. In such a setup, there may be a security gateway on both ends of the transport tunnel performing the encryption and decryption.
In order to fulfill upcoming requirements on the EPC architecture 100, it is believed that a completely redesigned architecture is required.
One such redesigned architecture is proposed to be based on Software Defined Networking (SDN). With software defined networking, a so called control plane is separated from a so called user plane, or data plane. A vision is that such architecture leads to a cheaper and more flexible network deployment. Networking services, such as network address translation, deep packet inspection, access control and the like, are no longer provided as monolithic boxes, but split up into the user plane performing the forwarding of user plane packets, and the control plane instructing the user plane how to perform the forwarding. A route, or path, that packets of a specific user, or even a specific flow of a user, takes through a collection of user plane forwarding elements is also known as a service chain.
Service chaining is today mainly used in a context where the end device does not move from a service chaining perspective. Typically, this is a fixed network environment or a mobile network where service chaining is used only above an anchor point.
In a service chaining environment where the end device does move, as would be the case when SDN is used in the above mentioned redesigned core architecture for a mobile wireless communication system, some new requirements are placed on the forwarding of the packets of that device. In particular, packets may get forwarded by a different set of forwarding elements after the moving. This implies that some kind of reconfiguration is needed in order to forward the packets of that device to the new location of that device.
Consider the network example in FIG. 2, in which a device, i.e. a UE such as a UEa 201 in the Figure, moves from a source base station (BS1) 202 to a target base station (BS3) 204. There are four base stations 202-205 and a number of Forwarding Elements (FEs), i.e. FE1 206 though FE7 212. The Forwarding Elements FE1-FE7 206-212 may be organized in this way for topological reasons; i.e. a first Forwarding Element (FE1) 206 may be close to the source base station (BS1) 202 but far from the target base station (BS3) 204.
Let's assume that the UEa 201 communicates with a peer 213, such as a computer, another UE, a server or the like, behind a further Forwarding Element (FE7) 212. In a naive implementation, each Forwarding Element in the UE-peer chain (of Forwarding Elements: FE1 206-FE2 207-FE5 210-FE6 211-FE7 212) will have at least one entry for the UEa 201. Worst case, there may be a single entry for every flow of the UEa 201. Now assume that the UEa 201 moves from the BS1 202 to the BS3 204. This would require new entries for the UEa 201 in a third Forwarding Element (FE3) 208 and a fourth Forwarding Element (FE4) 209. It would also require an update to the UEa 201 entries in a fifth Forwarding Element (FE5) 210, such that packets towards the UEa 201 are now forwarded to the FE4 209 instead of to a second Forwarding Element (FE2) 207. And finally, the entries of the UEa 201 in a first Forwarding Element (FE1) 202 and the FE 2 207 would need to be removed. All this causes a lot of control plane signaling towards the Forwarding Elements and node(s) controlling the Forwarding Elements. This is not a scalable solution.
SoftCell (ftp://ftp.cs.princeton.edu/techreports 2013/950. proposes one solution to this scalability problem. FIG. 3 is used to explain how the aspect of mobility with service chaining is solved in the SoftCell approach.
SoftCell defines an Access Switch (AS), such as AS1 320, AS2 321, AS3 322 and AS4 324 in FIG. 3, that are close to base stations, such as a source base station (BS1) 310. The Access Switch is logically located between the base stations and first Forwarding Elements, such as FE1 340 and FE3 342. The AS could be co-located with the BS, and could in fact be the first Forwarding Elements, again such as FE 1 340 and FE3 2 combined with a User Plane Function (UPF). In this terminology, the Forwarding Element performs solely the packet forwarding and the UPF performs some kind of operation on the packet and may even alter the packet. Combined they may perform one of the network services mentioned above.
The AS performs packet classification on traffic of UEs. Each packet is mapped to a policy. The policy defines which chain that packet belong to; i.e. which FEs and UPFs that packet needs to traverse. Packets are then aggregated onto three dimensions: policy, location (a base station ID) and UE ID. These aggregation dimensions can then selectively be used thereby limiting the number of entries in the FEs. E.g., FE5 344 in the figure above can base its downlink forwarding decisions on the location dimension, and does not need to take the UE dimension into account. FE 345 can base its uplink forwarding decision on the policy dimension, and does not need to take into account the location and UE dimension.
SoftCell proposes to code the three dimensions of policy, base station ID and UE ID in the source IP address and port of uplink packets. It is the AS that does this encoding. So the AS translates the source IP address and port used by the UE into a new source IP address and port, similar to a Network Address Translation (NAT) function. Between AS and peer this new IP address and port pair is used. The downlink packet from the peer includes new IP address and port as destination address. As the IP address topologically belongs to the AS, the downlink packet will arrive at the same AS. The AS then translates back to the original IP address and port known by the UE.
Now assume that a device, such as a UEa 301, moves from the BS1 310 to the BS2 311 in FIG. 3. The UEa 301 would thus move from a first Access Switch (AS1) 320 to a second Access Switch (AS2) 321. SoftCell proposes to keep existing flows routed via the AS1 320, in order to avoid a perceived IP address change for ongoing flows. So, for a flow that started when the UEa 301 was still on the BS1 310, the flow gets routed via the BS2 311 and the AS1 320 after the move. Only new flows get routed via the BS2 311 and the AS 2 321.
The SoftCell approach has a couple of disadvantages:                The encoding of the three dimensions into an IP address and port pair only works for flows that originate from the UEa 301. Because the peer is not aware of any encoding scheme, the SoftCell approach does not work for flows that originate from the peer.        After the UEa 301 has moved to a new BS, such as the BS2 311, existing flows are still routed via the AS1 320 associated with the old BS, i.e. the BS1 310. This introduces sub-optimal routing of such flows. This is in particular a disadvantage for long-lasting flows.        Assume that the UEa 301 has a number of active flows towards a peer. It then moves to a new BS, such as the BS2 311, and starts an additional flow. Then the peer 350 will perceive a new source address for the additional flow, even though that flow originates from the same UEa 301. This may confuse the peer 350 in certain scenarios.        SoftCell is basically introducing a Network Address Translation (NAT). This is acceptable for IPv4, as there already are so many NATs employed for IPv4 anyway, but is less appealing for IPv6.        Another solution is needed that removes these limitations from SoftCell, while at the same time keeping the advantages of SoftCell; i.e. scalable signaling towards the Forwarding Elements by aggregating flows.

Methods and modules for managing packets in a software defined network


A work vehicle includes a stepless speed changer device having a drive pulley receiving input of power of an engine, a driven pulley, and an endless rotary body wound around and entrained between the drive pulley and the driven pulley and an accommodating body having an accommodation space for accommodating the drive pulley, the driven pulley and the endless rotary body. The accommodation space includes an air passage for causing air introduced from the outside to flow from the driven pulley side to the drive pulley side to be eventually discharged to the outside.

Field of the Invention
The present invention relates to a work vehicle.
Description of the Related Art
A conventional work vehicle is disclosed in e.g. Japanese Unexamined Patent Application Publication No. 2012-51505. The conventional work vehicle includes a stepless speed changer device having a drive pulley ("a drive rotary body" in this document) receiving input of power of an engine, a driven pulley ("a driven rotary body" in the document), and an endless rotary body wound around and entrained between the drive pulley and the driven pulley. The work vehicle further includes an accommodating body ("a "speed changer case", etc. in the document) having an accommodation space for accommodating the drive pulley, the driven pulley and the endless rotary body (an "endless belt" in the document).
When the stepless speed changer device is driven, heat due to friction is generated between the drive rotary body and the endless rotary body and also between the driven rotary body and the endless rotary body. For discharging this heat, in the accommodation space of the accommodating body, there is provided an air passage for causing air introduced from the outside to flow from the drive pulley side to the driven pulley side to be eventually discharged to the outside.
However, with the above-described conventional technique, due to e.g. presence of a structural object(s) obstructive to the introduction of air into the accommodation space, there was a tendency of the amount of cooling air drawn into the accommodation space being relatively small. For this reason, there would tend to occur shortage of amount of air in the air passage of the accommodation space, thus insufficient cooling of the stepless speed changer device.
In view of the above respect, there has been a need for a work vehicle capable of effecting cooling of a stepless speed changer device in a favorable manner.


A method and apparatus for determining the size and shape to which a finished lens used to make an eyeglass lens is to be cut. Coordinates which define the outer perimeter of a lens are determined by illuminating either an eyeglass frame or a lens. An image of the shadow of the frame or lens is captured by an imaging device. A first linear polarizing filter is positioned optically between a light source and the membrane. A second linear polarizing filter, oriented at 180.degree. from the first filter, is placed optically between the membrane and the camera. Thus, the first and second polarizing filters allow a high definition image to be attained for substantially transparent plastic. A general purpose computer: (1) identifies the edges of the image so as to define the perimeter; (2) orients the image by identifying an orientation line placed upon a lens, if the image is of a lens which is not within a frame; and (3) measures the distance between lenses if an eyeglass frame is being measured. If an eyeglass frame is being measured, then a depth gauge indicator is used to measure the depth of a groove in the frame into which a lens is recessed when mounted in the eyeglass frame. Once the coordinates of the lens are determined, they may be verified by comparison with the frames or lens from which they were derived. Further, the coordinates of the outer perimeter of the edged lens may be determined to verify the accuracy of the operation.

1. Reid of the Invention
This invention relates to a method and apparatus for measuring eyeglass frames and lenses, and more particularly, to a method and apparatus for digitizing the coordinates of the outer edge of an eyeglass lens or the inner edge of an eyeglass frame by digitizing an image of a shadow of the lens or frame.
2. Description of Related Art
In the past, it was common for lenses used in eyeglasses to be ground by an optician. Grinding eyeglass lenses by hand is precise work that requires considerable skill and time. Grinding eyeglass lenses was commonly done by a limited number of specialists to whom a prescription would be sent. Additionally, the person grinding the lenses would need to be sent the associated eyeglass frame so that the lenses could be shaped to fit the frame.
More recently, it has become popular to stock standard lenses (referred to as "finished lenses") which are ground, cast, or otherwise made to conform to different prescriptions in quantity by a manufacturer. Such finished lenses may be polished, if necessary, and then distributed to optical outlets in order to reduce the time required to fill an eyeglass prescription, and to allow such prescriptions to be filled by people with less skill than is required to grind a lens to a prescribed curvature. By stocking finished lenses which are preground to most prescriptions at optical outlets which are conveniently located, the time required to fill an optical prescription is greatly reduced. Furthermore, since finished lenses can be manufactured in very large quantities, the cost of manufacture is also greatly reduced.
However, due to the large diversity in types and shapes of eyeglass frames, once a pair of finished lenses have been chosen, each finished lens must still be custom cut to fit within an eyeglass frame. No standards have been established in the eyeglass industry to control the shapes and sizes of lenses. Therefore, finished lenses are commonly fit to a frame by a process known as "edging". Initially, edging was performed by hand by skilled artisans. More recently, it has been common for a device known as an "edger" to be used. For example, one prior art method uses a tool which makes contact with, and mechanically traces the shape of, an eyeglass frame into which finished lenses are to be placed. The eyeglass frame is thus used to generate a template which can then be used to guide an edger. As the shape of the template is mechanically traced, a cutting arm is guided to cut the finished lens to fit within the eyeglass frame.
Alternatively, a prior art digitizer may be used to identify the shape and size of a lens and communicate digital data representative of the size and shape to which a lens must be edged to fit within a particular eyeglass frame. Such prior art digitizers make contact with the eyeglass frame and follow the contour of the frame to determine the size and shape of a lens that will fit within the frame.
The process is somewhat different when edging lenses for "frameless glasses", which do not have a complete enclosed frame which can be used to generate a template. In this case, an appropriate "dummy" lens is selected from a set of standard lens shapes and sizes and is used as the template. The edger mechanically traces the outside of the dummy lens, thus using the dummy lens as the template.
While the process of edging a finished lens using an edger is much more accurate and less difficult than manually edging a finished lens, the accuracy of the prior art edgers is such that finished lenses are not always edged properly. This is due in large part to the fact that each of the prior art methods rely upon mechanical contact with an eyeglass frame to determine the size and shape to which a finished lens is to be edged.
The present invention is a non-contact method and apparatus for determining the shape to which a finished lens should be cut in order to fit the finished lens within an eyeglass frame without the use of a template and with a relatively low level of user training and skill.

Method and apparatus for non-contact digitazation of frames and lenses


An optical micrometer measuring system adapted to gauge minute distances between spaced points on an object under test and to indicate the results in digital terms. The system includes a compound microscope having a stage for supporting the object, the object being illuminated and being focused by an objective onto a real image plane to produce an aerial object image which is viewable in magnified form by an operator through an eyepiece. Associated with the microscope is a projector which creates an illuminated image of a pointer, optical means being provided to superimpose the pointer image over the aerial object image. Operatively coupled to the projector is a micrometer controllable by the operator to translate the pointer image between any two points of interest on the object image. The distance travelled by the pointer image is digitally indicated by an analog-to-digital read-out coupled to the micrometer to provide the desired reading.

1. Field of Invention
This invention relates generally to optical micrometer systems for precisely measuring minute distances between spaced points on an object being tested, and more particularly to a system of this type which produces an illuminated aerial image of the object and optically superimposes thereon an illuminated image of a pointer whose position is shiftable by an operator to determine the distance travelled by the pointer image in going from one point to another on the object image.
2. Prior Art
Though the invention is applicable to the measurement of minute distances between any two points or lines on an object such as a biological specimen or a precision-machined part, it has particular value in conjunction with microelectronic or integrated circuit devices in which the passive and active electrical components of a circuit such as solid-state diodes or transistors are created on a silicon substrate, the components being interconnected by a pattern of conductive lines formed on the substrate.
In test procedures related to the production of such microelectronic devices, one must measure the width of the various conductive lines which are included in the line pattern as well as the spacing between lines. In this rapidly evolving field, in order to reduce the cost and dimensions of such devices, the direction is toward a greater density of components on a given substrate, this being accompanied by a compression of the conductive line pattern. As a consequence, the conductive line formations are thinner, with closer spacings therebetween.
Since it is vital that line widths and spacings in integrated circuits conform with design specifications, the formation of finer lines and closer line spacings has further narrowed the acceptable margin of error in measurement techniques for determining whether the line pattern is in compliance with the specifications therefor.
It is known to use optical micrometers to carry out measurements on integrated circuits. Two types of optical micrometers are currently in widespread use. One is the so-called filar micrometer, such as the Digital Filar Micrometer Eyepiece manufactured by E. Leitz, Inc. of Rockleigh, N.J., and the other being the image-shearing micrometer, such as the Image-Shearing Measuring and Direct Dimensional Read-Out System manufactured by Vickers Instrument, Inc. of Malden, Mass.
In a filar micrometer, a cross hair of filar is physically placed at the real image plane of a compound optical microscope and both are imaged on the retina of the eye. The motion-producing mechanism for the filar is operatively coupled to a digital electronic micrometer for measurement of line width or line spacing on the object image.
Because the operator, via his eye, must determine the placement of the filar, this requirement often gives rise to erroneous readings. In practice this type of measurement is subject to a fairly high order of human subjectivity. No two operators possess the same degree of visual acuity, and operator fatigue and the optophysiological requirements for repeatability are such as to render the filar micrometer a relatively imprecise measuring instrument.
A further problem with a filar micrometer is that there is generally insufficient access to the real image plane for the filar and the associated micrometer mechanism. The physical presence of the filar and micrometer mechanism in the image plane renders standard binocular vision inconvenient.
In the image-shearing optical micrometer, a beam-splitter acts to divide the imaging light beam into two parts and to create two identical images of the object under test. These images are shifted or sheared with respect to each other by an amount controlled by a micrometer. The degree of shear is directly proportional to rotation of the micrometer drum and can be read from a digital read-out associated therewith.
When the shear is zero, the illuminated double images of the object are exactly superimposed and are seen through the eyepiece as a single, relatively dark image against a bright field. If the shear is such that the two images overlap, then the amount of shear is less than the object dimension, this being indicated by the fact that the overlapping zone is as dark as superimposed images, whereas the non-overlapping areas of the two images are less dark. When, however, the two images just touch each other, each image is less dark than in the case of superimposed images, and the amount of shear is exactly equal to the object dimension. Thus when the object being tested is a photo-mask of a conductive line pattern of an integrated circuit, the condutive lines in one image will be contiguous with the corresponding conductive lines in the other image only when the amount of shear is exactly equal to the line thickness.
Since the precision of the image-shearing measurement technique depends on finding the point at which the images just touch--and this is indicated to the operator in terms of light intensity--in practice the subjectivity of the typical operator makes it difficult to discern this exact point. Also, due to the doubling of every image point, this leads to confusion and fatigue.
The following prior art patents are of interest in connection with the present invention: Boughton, U.S. Pat. Nos. 3,582,178; Vanden Brack et al., 4,099,881; McGivern, 3,398,631 and Fassin, 1,974,606.


The present disclosure relates to an α-aminoamide derivative compound and a pharmaceutical composition containing the same, for treating a neurodegenerative diseases.

Parkinson's disease is a progressive disease which is the second most common neurodegenerative disease. It is estimated that there are about 6.3 million Parkinson's disease patients globally, with about 1 out of 1,000 people. Although Parkinson's disease occurs common in the elderly, it occurs in young people too. Parkinson's disease is not easily distinguished from other diseases because the symptoms develop slowly. It is not easily detected in early stages and is accompanied by abnormal clinical symptoms such as tremor, stiffness, slowing of movement, postural instability, stooped posture, freezing of gait, depression, sleep disorder, dysuria, dementia, etc.
Although the cause of Parkinson's disease is not clear, it is known to be caused by deficiency in dopamine resulting from the loss of neurons that secrete the neurotransmitter dopamine in the brain. At present, the levodopa therapy of administering levodopa which is converted into dopamine in the body is commonly used. Although levodopa is the most effective therapeutic agent for Parkinson's disease, decreased drug efficacy or various motor disorders can occur during treatment. As alternative medications, COMT inhibitors, MAO-B inhibitors, etc., which maintain the concentration of dopamine in the brain by inhibiting the metabolism of dopamine, are used.
It is known that MAO-B not only plays an important role in dopamine metabolism in the brain but also inhibits damage to cranial nerve cells. Although there is no clear evidence that the MAO-B inhibitor actually delays the progress of Parkinson's disease, it is known that inhibition of MAO-B leads to inhibition of denaturation or destruction of dopaminergic neurons because it plays an important role in the onset of Parkinson's disease by MPTP or similar environmental toxicants. Also, there are evidences from animal and clinical tests that the MAO-B inhibitor has an effect of protecting the brain unlike other drugs.
Selegiline, which is approved as the most representative MAO-B inhibitor, is prescribed as a therapeutic agent for Parkinson's disease. However, it causes hepatotoxicity because it is metabolized to amphetamine and the irreversible inhibitor is accompanied by various side effects. Since rasagiline (Azilect) was first marketed in 2005 in Israel, it was marketed in about 50 countries including Europe, USA, etc. Azilect is free from amphetamine side effects and exhibits better efficacy than other dopaminergic drugs. However, although rasagiline also exhibits superior effect of inhibiting MAO-B like selegiline as an irreversible MAO-B inhibitor, it has a safety problem. Therefore, drugs that can effectively and reversibly inhibit the activity of MAO-B while solving the above-described disadvantages are being developed. However, no noticeable reversible inhibitor is available yet.
Obesity refers to a medical condition in which excess body fat has accumulated to the extent that it may have a negative effect on health. It is a condition in which excess energy has accumulated due to the difference in energy intake and energy expenditure. Obesity increases the likelihood of various diseases.
Because the previous studies on the hypothalamus regarding the regulation of food intake have been conducted centered on neurons as part of the brain, the understanding of the diet/obesity regulation by the brain has been limited. Therefore, study on glial cells (glia) which account for a greater part is necessary for a comprehensive understanding of the brain function. Recently, astrocytes which are the most abundant of the glial cells are spotlighted as cells that can activate or suppress nearby neurons by secreting various signaling molecules such as GABA (gamma-aminobutyric acid), glutamate, D-serine, ATP, etc. Astrocytes of the hypothalamus, which closely interact with POMC (pro-opiomelanocortin) neurons and express leptin receptors, can also contribute to leptin signaling.
In the hypothalamus, there exist two groups of POMC neurons, one that stimulates appetite and the other that stimulates energy consumption. Under normal situations, the astrocytes help the activation of nearby POMC neurons which stimulate energy consumption. However, in obesity, they turn to reactive astrocytes due to excessive leptin signals and putrescine is turned to GABA and secreted by MAO-B (monoamine oxidase B). In addition, the POMC neurons that stimulate energy consumption express GABAa receptors outside synapses including the a4, a5 and a6 subunits due to excessive leptin signals and are affected by the GABA secreted by the reactive astrocytes. As a result, the POMC neurons are inhibited and energy consumption is decreased, leading to accumulation of fats.
If MAO-B, which is the enzyme responsible for production of GABA, is inhibited, the production and secretion of GABA are inhibited and energy consumption is promoted as the POMC neurons are activated again. However, the POMC neurons that suppress appetite are not affected by GABA because they do not express GABAa receptors outside synapses. Therefore, the MAO-B inhibitors act on the POMC neurons which selectively excite energy consumption, thereby exhibiting an effect of treating obesity. However, most of the existing MAO-B inhibitors exhibit various side effects as irreversible inhibitors. Although drugs that can reversibly inhibit MAO-B are studied and developed for this reason, no noticeable reversible MAO-B inhibitor that can effectively act on obesity is available yet.

Alpha-aminoamide derivative compound and pharmaceutical composition comprising same


A pair of spaced parallel continuous conveyor chains, provided with equally spaced transverse tow bars, move along a continuous path so as to move the bars through a loading zone, then over a weighing platform of a scale and, then, successively over discharge zones in which receptacles are disposed. Each bar pulls a loosely pivoted article carrying cup having a support pin riding on a rail to hold the cup in a horizontal position. The cup has a central cavity, within which an article is deposited when the cup is in the loading zone, from which the article is discharged when the pin is released and the cup hangs suspended from its bar. Skids carried by the weighing scale receive and totally support the cup on the weighing scale. Movable bridge struts extend between segments of the rail and are movable to drop pin to pivot the cup in one of successive dump zones. A sensor, in combination with a microcomputer, dictates when each bridge strut is opened for dropping the article in a selected dump zone.. The process includes moving the articles successively along a path averaging the weight of each article, selecting a dump zone for depositing the article in, totalizing the weight for each zone and then selecting according to optimum weight, the last article for each zone so as to provide at least a predescribed weight of articles while minimize weight overloading for each zone.

1. Field of the Invention:
This invention relates to an article sorting machine and is more particularly concerned with a process and apparatus for weighing and sorting articles.
2. Description of the Prior Art:
In the past pivoted cups carried by conveyors have been used for receiving individual articles, such as fruits or vegetables, to be weighed and sorted. Such a cup is usually pivotally carried by its proximal end and weighed by weighing the distal or loose end of the cup, it being assumed that the cavity of each cup will orient the article with the article's center of gravity at the center of the cavity. If the article is asymetrical, however, the article may be weighed light or heavy, depending upon whether its center of gravity is toward the proximal end or the distal end of the cup. Furthermore, when such weighing devices are employed, each receptacle to be filled is fed sufficient articles to come just up to weight and then a final article of random weight is added so as to provide the weight sufficient to satisfy the labelled weight and allow for evaporation in transit and storage. No effort was made to select the last article so as to minimize weight overage.

Process and apparatus for weighing and sorting articles


A dry rolling element bearing assembly for rotatably mounting a flight vehicle engine shaft to a housing. Rolling elements (such as ball bearings) are positioned between inner and outer races. Stop devices axial position the inner and outer races. A mounting device positions the inner race radially outward from the shaft so as to create a first annular air space between them. The mount has a flexible portion and has a support ring portion which contacts the outer surface of the inner race with a radial interference fit. A similar mounting device positions the outer race radially inward from the housing. Air directing devices direct cooling air impingingly against bearing surfaces.

The present invention relates generally to bearing assemblies and more particularly, to a high temperature rolling element bearing assembly which does not require liquid lubrication.
A rolling element bearing assembly typically includes a rolling element bearing and mounting devices, with the rolling element bearing having roller bearings or ball bearings, rolling element retainers (also known as cages or separators), and inner and outer races, and with the mounting devices positioning the inner race with respect to a shaft and the outer race with respect to a housing. Conventional aircraft engine rolling element bearing assemblies are lubricated by oil having a limiting operating temperature of approximately 400 degrees F. Advanced engines for high Mach flight vehicles are projected to have bearing assembly environmental temperatures as high as 1000 degrees F. One approach that has been studied is the use of dry bearings. A dry bearing is a bearing which has no lubrication or has solid lubrication, such as a dry powder. Suggested bearing materials include ceramics such as silicon nitride which can survive high temperature environments.
For instance, in Lubrication Engineering, Vol. 37, No. 7, July, 1981, on pages 407-415 there is disclosed a rolling element bearing assembly in an article entitled "Operation of an All- Ceramic Mainshaft Roller Bearing in a J-402 Gas-Turbine Engine". The inner race is 0.0031 in. loose on the shaft at room temperature but attains a line fit at the maximum design temperature. The outer race is mounted in a compliant ring.
The inventors are also aware of work done in 1984 by others which proposed a dry rolling element bearing assembly design. The assembly included a ceramic inner race apparently held in contact with the metal engine shaft by a metal collar attachment mounted with an interference fit to the shaft and to the outer surface of the inner race allowing a more compliant inner race supporting system. The proposed design also included an outer race attached to a housing through an intermediate spacer material.
However, the ceramic bearing materials have coefficients of thermal expansion which are generally only one-third the value of the coefficients of thermal expansion of the steel shaft or housing. This mismatch in thermal expansion creates a major mounting problem since the ceramic bearing rings (inner and outer races) expand differentially relative to the shaft or housing, and large thermally induced stresses will lead to rapid failure of the more brittle ceramic components. Typically a bearing inner race is mounted on the shaft with an interference between the shaft outside diameter and the inner race bore. This generates a tensile hoop stress which can induce failure by a mechanism of crack propagation. Ceramic materials are less capable than metals of sustaining a tensile hoop stress without fracturing. The combination of low expansion and low fracture toughness makes it difficult to mount any ceramic race.
Another problem with dry rolling element bearing assemblies has been that they require greater cooling than do liquid lubricated bearing systems because of the dry bearings' higher friction which generates more concentrated heat. Also, removing heat from a dry bearing assembly by air cooling is more difficult than removing heat from a liquid lubricated bearing assembly by utilizing the liquid lubricant for heat removal. In Air Force Aero Propulsion Laboratory (Air Force Systems Command, Wright- Patterson Air Force Base, Ohio) Technical Report AFAPL-TR-74-77, Volume 1, Aug. 1974, entitled "High Temperature, High Speed, Solid Lubricated Bearing Technology Phase I--Heat Transfer" by Paul R. Bissett et al., impingement air cooling techniques were applied to solid lubricated rolling element bearing assemblies. Impingement cooling may be defined as cooling with one or more jets of air which strike a bearing surface to be cooled at an angle (ideally ninety degrees) with respect to such bearing surface.
What is needed is a high-temperature rolling element bearing assembly for the engines of advanced flight vehicles.


This invention discloses a method and apparatus for providing high speed optical tuning. With this invention, light is spatially routed through a tree of optical switches interconnected by waveguides to a selected fixed tuned optical filter in an array of such filters. Each of the optical switches can be controlled by a binary signal thereby permitting digitally controlled optical filtering.

A low-cost, high-speed, tunable optical filter with a wide tuning range and narrow band-width is required for high performance wavelength division multiplexed optical communication networks (N. Dono, P.E. Green, K. Liu, R. Ramaswami and F. Tong in IEEE Journal of Selected Areas in Communication, vol. 8 pp. 983-995, 1990). For such applications, the filter requirements are: optical bandwidth (>30 nm), tuning speed (<1 .mu.s), polarization insensitivity, compactness (.perspectiveto. few cm), low loss, low crosstalk and low cost. Of equal importance is the filter control; it should be digital and not require elaborate stabilization schemes. For a review of current tunable optical filter technology, see Kobrinski et al, IEEE Communication Magazine, pp. 53-63, 1989.
One of the more promising filtering schemes is to combine acousto-optical deflection and cascaded crossed wedge etalons, as proposed by F. Tong, D.F. Bowen and P.A. Humblet (European Conference on Optical Communication Digest, p. 61, 1991). Briefly, the incident beam that carries all the wavelengths is deflected by a dual-axis or two single-axis acousto-optical deflectors and is focussed onto a cascaded wedge etalon assembly. The direction of increasing wedge thickness of the first etalon is approximately 90.degree. to that of the second. The thickness of the first etalons is chosen such that it is .perspectiveto.10 times that of the second, thus generating a coarse-fine cascaded filter. The incident beam can be deflected to any point on the crossed wedge etalon assembly; at each point a particular wavelength is selected. Such a filter has been demonstrated to support .perspectiveto.600 equally spaced channels over a range of 60 nm centered at 1.55 .mu.m. The channel access time was .perspectiveto.2 .mu.s. The disadvantages of the device, however, are its large dimensions (.perspectiveto.1.5 m in length) and the fact that it cannot be mass-produced in a low cost compact form. Thus, it is not an attractive solution for computer communication applications.
There are three issues that place a lower limit on the dimensions of a crossed wedge etalon filter. First, the beam spot diameter at the etalons should be about 500 .mu.m to avoid diffraction. Second, locations on the etalons corresponding to neighboring channels must be separated by about 4 times the spot diameter to suppress crosstalk. These 2 issues lead to a minimum etalon lateral dimension of 6 cm for a 32.times.32 channel filter. Third, the length of the device is limited by the maximum deflection angle (.perspectiveto.3.degree.) of the acousto-optical deflector. The length could be reduced by means of telescopic lenses or mirrors but the filter would still remain large in the lateral dimension.
The above problems can be solved by using guided wave optics, rather than free space optics to avoid diffraction and crosstalk, and optical switches to spatially route the signals to avoid the difficulties associated with the acousto-optic deflector.
The invention herein uses a tree of optical switches to direct light onto an array of fixed tuned filters. Light is spatially routed through the tree by controlling the states of the switches such that all of the input light is routed into the particular array element which selects the desired wavelength. The outputs of the fixed tuned filters can be connected directly to photo-detectors, or if desired, the optical outputs can be coupled into a single optical output by traversing a similar tree of optical switches, but in reverse order.
Various materials and physical effects have been used to produce optical waveguides and switches for the 1.55 .mu.m optical band. In particular, field-effect and carrier-effect switches have been widely investigated.
Field effect optical switches have been fabricated in LiNbO.sub.3, LiTaO.sub.3, AlGaAs, GaInAsP, and organic polymers. A 16.times.16 LiNbO.sub.3 directional coupler switch array was discussed by P.J. Duthie and M.J. Wale in Electronics Letters, vol. 27, no. 14 pp. 1265-1266, 1991. A polarization independent LiNbO.sub.3 8.times.8 matrix switch was reported by H. Nishinoto, M. Iwasaki, S. Suzuki and M. Kondo in IEEE Photonics Technology Letters vol. 2 no. 9 pp. 634-636, 1990. A 4.times.4 GaAs/AlGaAs electro-optical matrix switch based on directional couplers was published by K. Komatsu, K. Hamamoto, M. Sugimoto, A. Ajisawa, Y. Kohga and A. Suzuki in IEEE Journal of Lightwave Technology, vol. 9, no. 7, pp. 871-878, 1991. A 2.times.2 X-type intersectional switch using multiple-quantum well GaInAsP structures on an InP substrate was demonstrated by K.G. Ravikumar, K.Shimomura, T. Kikugawa, A. Izumi, S. Arai, Y. Suematsu and K. Matsubara in Electronics Letters vol. 24, no. 7, pp. 415-416, 1988. Directional coupler switches made from electro-optically active organic polymers have been reported by E. Van Tomme, P. Van Daele, R. Baets, G.R. Mohlmann and M.B.J. Diemeer in Journal of Applied Physics, 69 (9), pp. 6273-6276, 1991.
For carrier-effect devices, X- and Y-junction optical switch structures have been fabricated on semiconductor substrates. A 4.times.4 optical switch with a total of 16 switching stages was fabricated using GaInAsP on an InP substrate with X-crossing and Y-branching structures. This was reported by H. Inoue, H. Nakamura, K. Morosawa, Y. Sasaki, T. Katsuyama and N. Chinone in IEEE Journal of Selected Areas in Communications vol. 6, no. 7 pp. 1262-1266, 1988. Amplifying sections were added in their later communication which appeared in IEEE Photonics Technology Letters vol. 2 no. 3, 1990. An X-intersectional optical switch was built and reported by K. Wakao, K. Nakai, M. Kuno and S. Yamakoshi in IEEE Journal in Selected Areas in Communications vol. 6, no. 7 pp. 1119-1204, 1988. A Y-junction optical switch was fabricated and reported by H. Yanagawa, K. Ueki and Y. Kamata in IEEE Journal of Lightwave Technology vol. 8 no. 8 pp. 1192-1197, 1990.
A variety of fixed tuned waveguide filters have been studied and are relevant to our invention. An array of 8 InGaAsP/InP Bragg grating filters, each with a passband of 2 nm and channel spacing of 5.7 nm, has been built and reported by C. Cremer, G. Heise, R. Marz, M. Schienle, G. Schulte-Roth and H. Unzetig in IEEE Journal of Lightwave Technology vol. 7, no. 11, pp. 1641-1645, 1989. A meander waveguide InGaAsP/InP filter of 16 nm passband has been fabricated and reported by C. Bornholdt, F. Kappe, R. Muller, N.-P. Nolting, F. Reier, R. Stenzel, H. Venghaus and C.M. Weinert in Applied Physics Letters, vol. 57, no. 24, pp. 2517-2519, 1990. A 40-channel channel dropping filter array, each with a passband of 10 GHz and a separation of 50 GHz, was proposed by H. Haus and Y. Lai in IEEE Journal of Lightwave Technology vol. 10, no. 1 pp. 57-61, 1992. The above three filter types do not have an amplitude response which is periodic in wavelength. Hence, they cannot be cascaded in a coarse/fine or vernier arrangement as will be explained below.
Since the Fabry-Perot filter does have a periodic response, it was chosen for the preferred embodiment of this invention.
U.S. Pat. No. 5,049,169 to Guerin et al. discloses a tree structure arrangement of optical filters but does not employ space division optical routing as described in the invention of this application.

Space-division switched waveguide array filter and method using same

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