An optical system having an optical fiber path suitable for propagating an optical signal at least in a first direction, and a plurality M of optical amplifiers disposed along the optical fiber path so as to divide the optical fiber path in N spans of optical fiber. The spans of optical fiber all have substantially a length Lamp and have at least one transmission optical fiber having an effective length Leff. An optical phase conjugation device is associated to one of the amplifiers of the plurality of amplifiers and is disposed in combination with a dispersion compensator. The compensator is disposed upstream from the amplifier associated to the optical phase conjugation device and is adapted for introducing an accumulated dispersion such as to substantially compensate the dispersion accumulated in a portion having a length (Lamp−Leff) of the span immediately upstream from the amplifier associated to the optical phase conjugation device.

1. Field of the Invention
The present invention relates to an optical transmission system using an optical phase conjugation device.
2. Description of the Related Art
Long-distance optical transmission systems have been constructed by using erbium-doped fiber amplifiers (EDFAs) as in-line optical repeaters. Signal attenuation due to fiber loss is periodically compensated for by the optical amplifier gain to overcome the limitation of transmission distance. Since, in such systems, signal power is maintained at a high level along the entire system length owing to the periodic amplification, the dependence of fiber refractive index on optical power can no longer be ignored. This nonlinear effect, called the Kerr effect, leads to the self-phase modulation (SPM) of optical pulses, which in turn interplays with the group-velocity dispersion (GVD), or chromatic dispersion, in the fiber, causing nonlinear waveform distortion. In order to realize long-distance (e.g. 1000–2000 km or more) signal transmission at high data transmission rate (e.g. 40 Gbit/s or more) this waveform distortion must be counteracted.
Optical phase conjugation (OPC) is a known technique for chromatic dispersion compensation. Details may be found in G. P. Agrawal, "Fiber-Optic Communication Systems", A Wiley Interscience Publication, (1997), at paragraph 9.7. As explained by Agrawal, under certain conditions, OPC can compensate simultaneously for both GVD and SPM. Pulse propagation in a lossy optical fiber is governed by the Non-Linear Schrödinger Equation (NLSE)
                                                        ∂              A                                      ∂              z                                +                                    ⅈ              2                                                  β              2                                                                                ∂                  2                                                A                                            ∂                                  t                  2                                                                    =                              ⅈ                                      γ              _                                                                                A                2                                                                A                    -                                    1              2                                    α                                                                          A                                              [        1        ]            where A=A(z, t) represents a slowly varying amplitude of a pulse envelope, β2 is the GVD coefficient of the optical fiber, related to the dispersion parameter D by the following relation
                    D        =                              -                                          2                                π                                                                                c                                            λ                2                                                                    β            2                                              [        2        ]             γ is the nonlinear coefficient of the optical fiber, i.e. governs the SPM, and α accounts for the fiber loss. When α=0 (loss less case), A* satisfies the same equation when one takes the complex conjugate of eq. [1] and changes z to −z. As a result, midspan OPC can compensate for SPM and GVD simultaneously. Clearly, such case is immaterial, as fiber losses cannot be practically avoided.
In order to study the impact of the fiber loss, the following substitution may be madeA(z,t)=B(z,t)exp(−αz/2)  [3]so that eq. [1] can be written as
                                                        ∂              B                                      ∂              z                                +                                    ⅈ              2                                                  β              2                                                                                ∂                  2                                                B                                            ∂                                  t                  2                                                                    =                  ⅈγ                                                              z                                                            B                                      2                              B                                    [        4        ]            where γ(z)= γ exp(−αz). By taking the complex conjugate of eq. [4] and changing z to −z, it can be seen that perfect SPM compensation can occur only if γ(z)=γ(L−z), where L is the total system length. This condition cannot be satisfied for α≠0.
One may think that the problem can be solved by amplifying the signal after midspan OPC such that the signal power becomes equal to the input power before the signal is launched in the second-half section of the fiber link. Although such an approach can reduce the impact of SPM, actually it does not lead to a satisfactory compensation of the SPM. Perfect SPM compensation can occur only if the power variations are symmetric around the midspan point where the OPC is performed so that γ(z)=γ(L−z) in eq. [4]. In practice, signal transmission does not satisfy this property. One can come close to SPM compensation if the signal is amplified often enough that the power does not vary by a large amount during each amplification stage. This approach is, however, not practical since it requires closely spaced amplifiers.
S. Watanabe, in U.S. Pat. No. 6,175,435, considers a phase conjugator disposed between a transmission line I (of length L1) and a transmission line II (of length L2). After a series of calculations, he obtains the following equations for GVD and SPM compensation:D1L1=D2L2  [5]γ1 P1L1=γ2 P2L2  [6]where P1 and P2 denote the average powers in the transmission lines I and II, respectively. Also, D1 and γ1 denote the dispersion parameter and the nonlinear coefficient in the transmission line I, respectively; and D2 and γ2 denote the dispersion parameter and the nonlinear coefficient in the transmission line II, respectively. According to the patent, complete compensation can be realized by providing, at positions equivalently symmetrical with respect to the phase conjugator, the same ratio of the optical Kerr effect to the dispersion. An increase of this ratio along the transmission line can be attained by gradually decreasing the dispersion or gradually increasing the optical Kerr effect. It is possible to change the dispersion value by adequately designing the fiber. For example, the above ratio is changeable by changing the zero dispersion wavelength of a dispersion shift fiber (DSF) or by changing the relative refractive index between the core and the clad of the fiber or the core diameter thereof. Meanwhile, change of the optical Kerr effect can be achieved by changing the nonlinear refractive index of the light intensity. According to Watanabe, a suitable optical fiber can be manufactured by continuously changing at least one fiber parameter selected from the loss, nonlinear refractive index, mode field diameter and dispersion.
In Applicant's opinion, the use of such kinds of "special" fibers does not represent an optimal solution, as such fibers may be complex to manufacture. Further, such method does not apply to optical systems already installed, unless a substitution of all the fibers of the system is performed.
C. Lorattanasane et al., in "Design Theory of Long-Distance Optical Transmission Systems Using Midway Optical Phase Conjugation", Journal of Lightwave Technology, vol. 15, no. 6, pages 948–955 (1997), describe a design method for suppressing the residual waveform distortion due to periodic power variation in an optical amplifier chain and to dispersion value fluctuation from span to span along a midway optical phase conjugation system. According to the authors, the amplifier spacing must be short relative to the nonlinearity length and signal pulses must be transmitted within appropriate windows of fiber dispersion. Computer simulation results reported in the article show that short amplifier spacing (40–50 km) is required for long-distance systems, whereas, for short-distance systems less than 1000 km, the amplifier spacing as long as 100 km is possible.
In Applicant's opinion, an amplifier spacing as long as 100 km also for long distance systems, having a length higher than 1000 km, is preferred, in order to reduce the number of installed amplifiers.
WO patent application no. 99/05805, to British Telecommunications PLC, discloses a method for symmetrised mid-span spectral inversion (MSSI), where the high power regions in the optical communication system are symmetrised about the MSSI means. The amplifiers are positioned so as to have the high-power regions in the two sections of the transmission link symmetrical about the mid-point of the transmission network, where MSSI is performed. These high-power regions are the length of fiber immediately after the fiber amplifier which is substantially equal to the effective nonlinear length (Leff) of the optical transmission link. The distance from the amplifier preceding the phase conjugator to the phase conjugator is LA and the distance from the phase conjugator to the subsequent amplifier is LB. The distances LA and LB are given by
                              L          A                =                                                                              L                  amp                                +                                  L                  eff                                            2                                                                                L              B                                =                                                    L                amp                            -                              L                eff                                      2                                              [        7        ]            where Lamp=LA+LB is the amplifier spacing. In an example, Lamp is 80 km, Leff is 21.5 km, so that the MSSI equipment would be sited at a distance of ≈51 km from the preceding amplifier. With an odd number of spans, if it is not possible to place the MSSI equipment at a location other than an amplifier site, the author suggests to add a length of fiber Lamp−Leff kilometers long immediately after the MSSI equipment at the amplifier location. Thus a length of fiber of 58.5 km would be added. With an even number of spans, the MSSI equipment is sited immediately upstream of the optical amplifier and a length of fiber Leff kilometers long is sited immediately upstream of the MSSI equipment. The author admits it may be necessary to insert additional amplifiers to give the symmetrical positioning of the high-power regions or if the optical signal levels are sufficiently low so as to cause bit error rate degradation.
In Applicant's opinion, a positioning of the optical phase conjugator very far from an amplifier (e.g. about 50 km) has a drawback in that the optical line has to be provided with a dedicated site for the MSSI equipment, in addition to the amplifier sites. Even when lengths of fibers are added as suggested in the '805 patent application in order to place the MSSI equipment at an amplifier site, the necessity arises of providing additional amplifiers to take into account the long length of the added fiber (in particular with an odd number of spans). Such combination of long added fiber and additional amplifiers may, in turn, unbalance the power distribution along the line, so that nonlinearity compensation may be hindered.

Optical transmission system using an optical phase conjugation device


Methods and apparatus of forming stiffening structures in a material are disclosed. In an example method, a first bend line is formed in the material and a portion of the material is drawn toward the first bend line to form an intermediate stiffening structure. A second bend line is then formed adjacent and parallel to the first bend line so that the intermediate stiffening structure is located between the first and second bend lines. A plurality of stiffening structures is then formed in the intermediate stiffening structure without substantially stretching the material.

Typically, roll-forming processes are used to manufacture components such as structural beams, siding, ductile structures, and/or any other component having a formed profile. A roll-forming process may be implemented using a roll-former machine or system having a sequenced plurality of forming passes. Each of the forming passes typically includes a roll assembly configured to contour, shape, bend, cut, and/or fold a moving material. The number of forming passes required to form a component may be dictated by the characteristics of the material (e.g., the material strength) and the profile of the formed component (e.g., the number of bends, folds, etc. needed to produce a finished component). The moving material may be, for example, a metallic strip material that is unwound from coiled strip stock and moved through the roll-former system. As the material moves through the roll-former system, each of the forming passes performs a forming operation on the material to shape progressively the material to achieve a desired profile. For example, the cross-sectioned profile of a C-shaped component (well known in the art as a CEE) has the appearance of the letter C.
A roll-forming process may be a post-cut process or a pre-cut process. A post-cut process involves unwinding a strip material from a coil and feeding the strip material through a roll-former system. In some cases, the strip material is leveled, flattened, or otherwise conditioned prior to entering the roll-former system. A plurality of bending, folding, and/or forming operations is then performed on the strip material as it moves through the forming passes to produce a formed material having a desired profile. The formed material is then removed from the last forming pass and moved through a cutting or shearing press that cuts the formed material into sections having a predetermined length. In a pre-cut process, the strip material is passed through a cutting or shearing press prior to entering the roll-former system. In this manner, pieces of formed material having a pre-determined length are individually processed by the roll-former system.
Formed components are typically used in structure and building construction applications because of their lightweight properties and ability to withstand considerable tension, compression, and bending forces. Formed components are typically manufactured to withstand specified amounts of force before the components exhibit structural failure. Structural failure may occur in the form of buckling such as, for example, global buckling and local buckling. Global buckling generally refers to a structural failure of at least a substantial portion of a formed component. On the other hand, local buckling generally involves a structural failure of a localized portion or a relatively small portion of a formed component. If a formed component is subjected to a plurality of extreme forces causing multiple local bucklings, the multiple local bucklings may lead to global buckling.
The structural strength of a formed component can be determined by applying forces to the formed component in various directions and at various locations and measuring the amount of force required to cause structural failure. Varying the structural strength of formed components is traditionally accomplished in several different manners. One known manner in which manufacturers vary the structural strength of formed components involves producing formed components having different profiles (e.g., a U-profile, a C-profile, a Z-profile, an L-profile, a hat profile, etc.). Each profile provides different structural properties. Thus, certain profiles may be particularly suited for use in particular applications.
Another known manner used to vary the structural strength of formed components involves varying the properties of the materials used to form the components. For example, manufacturers may vary material strength, hardness, thickness, etc. Although selecting certain material properties can be an effective manner of varying the structural strength of formed components, the amount by which the material properties can be varied is often limited by the technology or methods (e.g., roll-forming methods) used to form the components. More specifically, roll-forming machines may not be capable of providing the bending forces required to bend materials that are too strong or too thick. Additionally, varying material properties such as, for example, material thickness may result in formed components that are too costly.
Yet another known method used to vary the structural strength of formed components involves forming a plurality of adjacent parallel rib-like or bead-like features extending along a length of a formed component. The rib-like or bead-like features are typically stamped into a strip material prior to forming a formed component. However, stamping significantly stretches and thins the strip material, which may weaken the material near the rib-like features and can make it difficult to control precisely the overall dimensions of a finished component made from the material.

Methods and apparatus for forming stiffening structures in a strip material


An air quality and temperature responsive air conditioning system wherein modules are employed to precondition the air for humidity control, to heat and cool the air, and to bypass the supply air in excess of the demand of a multiplicity of comfort zones with thermostat control, and featuring a bypass module characterized by parallel ducting, one ducting which is restricted by a damper responsive to a supply air back pressure sensor, and one ducting which is opened by a damper responsive to an air quality sensor.

This invention relates to central air conditioning with multi zone controllers for serving separate comfort air spaces, it being a general object of this invention to independently control air temperature and air quality. Air is conditioned herein by the controlled application of chilled and/or hot water, however it is to be understood that mechanical refrigeration and gas fired or electric furnaces can be employed. Air quality is conditioned herein by the controlled filtration of return air (RA), an advantageous feature of this system being bypass of excess supply air through run-around ducting, in response to closure of one or more zone dampers, and characterized by a bypass damper means that prevents excess supply air pressure, it being an object of this invention to provide a bypass filtration module that replaced the prior art bypass and in the form of a unit that is installed in the run-around ducting. A feature of this bypass filtration module is its coordinated functions in response to zone controller closures as well as air quality deterioration in any one or more of the separate comfort air spaces serviced by this system.
It is an object of this invention to combine variable air volume (VAV) and a bypass filtration system (BPFS), operable with a multiplicity of zone controllers and each of which services a separate conditioned zone. The zone controller draws air from a continuously operating central air conditioning unit, a cooling and heating unit that receives outside air (OSA) and return air (RA) and which delivers supply air (SA) at substantially constant volume and at a controlled temperature, and at a controlled pressure by means of a recirculation duct in which the bypass-filtration module is installed for air quality and temperature control. The zone controllers discharge conditioned supply air on demand in response to thermostat controls in each separate zone, the central air conditioning unit being activated when there is a demand, and any surplus conditioned air is recirculated through the bypass-filtration module herein disclosed. In accordance with this invention, the bypass-filtration module is comprised of parallel ducting and each controlled by a positionable air flow restrictor means, one of which responds to return air pressure, and one of which responds to an air quality sensor (AQS). In practice, there is a pressure sensor at the delivery of the central air conditioning unit, and there is at least one air quality sensor in a conditioned or related zone and preferably in the return air (RA) duct as shown herein. Accordingly, it is an object of this invention to coordinate both the supply of tempered air (heated or cooled) and the quality thereof.
Distribution of air tempered by the central air conditioning unit is by zone damper means in each of the zone controllers, the volume of supply air discharged being governed by a thermostat in the separate zone served by said controllers. As the conditioned air demand decreases, supply air flow is restricted so as to cause pressure to increase in the supply air duct and which is sensed and a signal transmitted to a bypass air flow restrictor means of the bypass-filtration module, for recirculating a commensurate air volume while meeting air flow demand from the supply air duct. The air flow restrictor means is a variably positionable motorized damper.
Quality of air is determined to exist by any one of a number of contaminant-gas sensors. That is, particulate matter and/or gasses such as carbon dioxide are detected and their proportionate density determined. And, when a certain threshold of density of a contaminant is determined, the air quality sensor (AQS) responds and a signal is transmitted to the filtration air flow restrictor means of the bypass-filtration module, for processing a recirculated air volume commensurate with the demand signal. It is an object therefore, to provide filter means in the bypass-filtration module, a means for removing particulate matter and/or means for removing certain contaminant gasses. In practice, filter packs of varied mesh are employed, and carbon filter packs or the like to remove certain gasses.

Air quality-temperature controlled central conditioner and multi-zone conditioning


An arrangement efficiently renders forwarding decisions for a packet using a forwarding database dictionary of an intermediate node configured to optimize space consumed by addresses stored therein as well as to reduce time required to search those addresses. The arrangement generally includes a lookup mechanism comprising a search engine coupled to a set of registers and to the dictionary. The register set, in turn, comprises a number of registers operating in parallel to compare values specified by a number of bits with a predetermined starting point of an input string. The specified values are preferably representative of address prefixes stored in the dictionary and the input string is a destination address of the packet.

Communication in a computer network involves the exchange of data between two or more entities interconnected by communication links and subnetworks. These entities are typically software programs executing on hardware computer platforms, such as end nodes and intermediate nodes. An example of an intermediate node is a switch or router which interconnects the links and subnetworks to enable transmission of data between the end nodes. The nodes typically communicate by exchanging discrete packets of data according to predefined protocols. In this context, a protocol consists of a set of rules defining how the nodes interact with each other.
Most networks are typically organized as a protocol stack of hardware and software "layers" within each node of the network. The protocol stack layers interact to format data for transfer between, e.g., a source node and a destination node communicating over the network. Specifically, predetermined services are performed on the data as it passes through each layer and the layers communicate with each other by means of the predefined protocols. This layered design permits each layer to offer selected services to other layers using a standardized interface that shields those layers from the details of actual implementation of the services.
One such selected service is a connectionless network service that is generally implemented by a network layer protocol. Network layer protocols are concerned with the routing of packets from the source node to the destination node and, in particular, comprise those algorithms and protocols used by routers when cooperating to calculate paths through a network topology. A routing algorithm is that portion of the network layer software responsible for determining an output communication link over which an incoming packet should be transmitted. To that end, each router maintains a forwarding database table with entries indicating where to forward the packets in accordance with routing algorithm results. The forwarding database entries are typically accessed by referencing addresses of the destination nodes.
Examples of conventional network layer protocols are the ISO Connectionless Network Layer Protocol (CLNP), the Internet (IP) network layer protocol and the Internetwork Packet Exchange (IPX), whereas an example of a conventional routing algorithm is the Dijkstra algorithm. A by-product of execution of the Dijkstra algorithm is a determination of the next hop, e.g., intermediate router, associated with a particular calculated path.
Each protocol stack layer of a transmitting node adds information in the form of a header field to the data packet generated by a sending process of the node as the packet descends the protocol stack. The header fields defined by the network layer services are generally the same primarily because the same information are typically contained in each packet. For example, these headers typically contain fixed-length, hierarchical network layer addresses configured to accommodate relatively large numbers of nodes and subnetworks.
A destination address is used by the routers to determine the route of the packet. When a packet is received at the router, the network layer extracts the destination address from the packet, finds a forwarding database table entry that matches the destination address, determines the next hop that the packet should take based upon the destination address, appends a new network layer header onto the packet (as necessary) and passes the modified packet to a lower protocol stack layer that is responsible for the output communication link associated with the next hop.
Since network layer addresses are hierarchical in nature, network layer protocols that perform routing functions at the same routing level of a network make next hop determinations based upon a similar portion of the destination address referred to as the destination address prefix. Routers store the destination address prefixes in dictionaries of their forwarding databases as tree data structures that are manipulated by a conventional Trie algorithm. To determine the next hop, network layer protocols implement a longest-matching-address-prefix ("longest match") algorithm that searches the dictionary for an entry corresponding to the destination address located in the network layer header.
The tree structure typically comprises a large number of branches each representing a string of the hierarchical destination address fields. The branches of the database have different address field values and/or terminate with a different number of address fields. The longest match algorithm must traverse numerous branches during this address matching process to determine the next hop. Because of the hierarchical characteristics of destination addresses, there may be several destination address prefixes in the dictionary that match at least a portion of a particular destination address. Accordingly, the longest address in the forwarding database dictionary must be found.
The time required to search the dictionary is proportional to the average length of the destination address in the database. In a typical implementation of the Trie algorithm, a fixed portion of the destination address is parsed at discrete steps, e.g., one bit or 4 bits at a time. A problem is that addresses often have a substantial number of bits, particularly in large, hierarchically-arranged networks. Parsing such a long address in small increments results in too many "lookups" into the database table, a process that is often too slow to keep up with table access bandwidth. On the other hand, parsing the address in longer increments, e.g., 16 bits, can result in a substantial number of choices that consume a substantial amount of table space.
It is thus apparent that, due to the lengths of the destination addresses and the manner in which the longest match algorithm navigates the forwarding database dictionary, address matching functions contribute significantly to the overhead associated with the packet forwarding process performed by network layer protocols; this, in turn, adversely affects the router's efficiency. The present invention is directed towards an efficient and accurate means for finding the longest match in a forwarding database dictionary that matches an address in a packet to be forwarded by an intermediate node.

Method and apparatus for determining a longest matching prefix from a dictionary of prefixes


An electronic device able to detect a user in close proximity. The device may be a wireless data input device, for example, a radio frequency computer mouse. The device has power management features that do not require complex hardware or software to implement. For example, an antenna that is normally used for radio transmission is monitored. The power management features of the electronic device are able to detect a change in an operating characteristic of the antenna that is indicative of a user in close proximity thereto. For example, when the user touches a computer mouse, the resonant frequency of a circuit comprising the antenna changes due to capacitive loading of the antenna. The power management features cause the electronic device to be operated in a sleep mode or a radio transmission mode, depending on whether the user is detected.

Many electronic devices benefit from being able to detect an object, such as a user, in close proximity to the electronic device. For example, the state in which an electronic device operates can be based, at least in part, on user proximity. In one approach, by detecting the absence of a user, the electronic device can operate in a power down mode. This is especially useful for battery operated devices.
Wireless communications devices are one example of an electronic device that can benefit from detecting the presence or absence of a user. Wireless communications devices have proliferated due to their convenience. However, power consumption is a major issue in such devices because many wireless communications devices are battery operated.
One conventional technique for saving power in a wireless communication device 105 is illustrated in FIG. 1. This conventional technique uses an oscillator 110 coupled to an antenna 115. When the user 120 comes into close proximity with the antenna 115 coupled to the oscillator 110, the capacitance of the oscillator antenna 115 is altered, which causes the frequency of the oscillator 110 to change. The detect/control circuit 140 detects the frequency change and increases the power to the transceiver 130. Thus, the change in oscillator frequency indicates that a user 120 is in close proximity to the oscillator antenna 115. However, this conventional technique requires the oscillator antenna 115 be physically separate from the antenna 125 of the radio transceiver 130. Electronic devices, such as wireless mice, have limited space for antennas. Thus, the two separate antennas must compete for space. Having competing antennas in a limited space has the potential to degrade performance of the radio transceiver. Moreover, the oscillator, its antenna, and associated circuitry add to the complexity and expense of the electronic device.
Conventional wireless communication devices consume more power than is desirable. Devices to limit power consumption are available, but they suffer from additional problems. Conventional power management circuitry is often complex and expensive. Moreover, the circuitry of conventional power management devices sometimes interferes with the normal operation of the device in which the power management circuitry resides.

Resonant frequency user proximity detection

Avago Technologie ECBU IP (Singapore) Pte. Ltd.


A switching device for adjusting the impedance of a self-inductance (3) forming part for example of the radiator of a VHF/UHF antenna for aircraft switchable by short-circuiting a part of the self-inductance. A PIN diode (12) is raised to a blocking or a transmitting voltage in response to control signals which are transmitted thereto by an optical link (8). Preferably the optical signals are transmitted to a hybrid opto-electronic circuit, which renders the PIN diode operative in conjunction with insulated conductors (11, 13) plated on the self-inductance and raised to the desired voltage.

The present invention relates to an electronic switching device for an antenna switchable in the VHF and UHF frequency ranges, for example 100 to 156 MHz for the VHF range and 225 to 400 MHz for the UHF range.
Such antennas are often, but not exclusively, used on board civil or military aircraft.
In the reference FR-A 2 552 587 (which corresponds to U.S. Pat. No. 4,656,483 in the name of Herve JAQUET) there is described a switchable antenna which comprises a capacitive element spaced from a flat reflector forming the ground, a first self-inductance located between the capacitive element and a feed through the flat reflector, and connected to a transmitter-receiver, this first self-inductance being formed from several sections, each associated with a switch which enables certain sections to be short-circuited at will for operation in the VHF range and all sections for operation in the UHF range. The antenna described in this reference further comprises a second self-inductance which can be connected by a switch between the first self-inductance and the ground plane in the VHF range and disconnected in the UHF range, as well as conductive sleeves inserted between the capacitive element and the ground plane, on either side of the self-inductances.
The switches associated with the sections of the first self-inductance and with the second self-inductance advantageously comprise PIN diodes. In conventional manner bias voltages for controlling the bias of these diodes are injected by means of conductors which feed through the ground plane and in which high-frequency isolating self-inductances are provided.
This arrangement, as applied to antennas, has several disadvantages:
perturbations in the response of the antenna due to the proximity of the conductive wire, PA1 limited frequency bandwidth of the switch, because this is dependent on the impedance of the self-inductance for blocking high-frequency voltages PA1 inadequate resistance of the self-inductances to large high-frequency over-voltages, if they comprise a ferrite core, PA1 loss of output caused by the blocking self-inductances, PA1 risk of introducing radio interference below the surface of the support vehicle of the antenna by way of the conductive bias wires.
In order to limit these problems it is proposed in the document cited at the beginning of this specification to protect the conductors transmitting the bias voltages for the diodes by making them pass coaxially to the inside of conductors of certain parts of the self-inductance, formed by a metal tube wound in a spiral,. This ingenious solution does not completely avoid the recited problems because the protection of these conductors is not complete, in particular between the self-inductance and the passages through the ground plane.
The object of the present invention is to provide a switching device which does not have the above disadvantages or only exhibits them in a greatly reduced manner compared with the prior art.

Electronic switching device for an antenna switchable in the VHF and UHF frequency ranges


A toy capable of emitting clapping noise, emitting scent, and emitting light. The toy is constructed with an elongated central member and a plurality of resilient ribs which are attached at one of their ends to the elongated central member and are attached at their other end to a sliding collar. The sliding collar is free to slide along the elongated member thereby causing the resilient ribs to move radially outwardly with respect to the longitudinal axis of the elongated central member.

Novelty devices such as pennants, pinwheels, and like devices are commonly used by spectators who attend sporting events such as baseball, basketball, football etc. These novelty devices are designed to be waved or otherwise displayed by the patrons and often produce audible and visual effects which aid the user in expressing excitement during the event of interest.
The novelty device of the present invention combines audio, visual, and olfactory effects, is safe to use, and relatively inexpensive to produce.


The invention relates to a holding and resting device for medical instruments having essentially cylindrical instrument bodies, in particular endoscopic instruments, with a base body that can be secured for instance to an operating table and an instrument input to be inserted into the base body and in which the instrument body can be secured by clamping. To create a holding and resting device for medical instruments having essentially cylindrical instrument bodies, which is of simple construction and can be activated quickly and safely, it is proposed with the invention that the instrument input includes a ring-shaped tension casing with at least two holder arms as well as a tension nut that works together with the tension casing.

Holding and resting devices of this type are, for instance, positioned on operating tables to allow the operator during the operation to safely lie down and pick up instruments again, for instance a laparoscope or endoscope, without requiring operating personnel for the task. It is important in such holding devices that they secure the medical instrument that is to be inserted, securely and as immovably as possible, especially to prevent the instruments from falling down.
A holding and resting device familiar from practical use includes for this purpose an instrument input, in which the instrument body of the medical instrument that is to be held can be secured by clamping, and the clamped holding is effected by a tension screw that, after several rotations, narrows the instrument input in such a way that the instrument body is securely held. This known holding and resting device ensures a secure fixing of the medical instrument to be inserted, but it is complicated for the operator to manipulate, because releasing the tension screw takes time first of all and secondly can be performed in most cases only by both hands.

Holding and resting device for medical instruments having essentially cylindrical instrumental bodies


Some embodiments include a method for initially configuring a network appliance. The method can detect, by the network appliance, a subscriber network. The method can transmit, to a remote configuration service via the subscriber network, a request for configuration information for the network appliance, and receive, via the subscriber network, the configuration information, wherein the configuration information includes first parameters for the subscriber network, and second parameters for an access network for connecting computing devices to the network appliance. The method can also perform an automated initial configuration of the network appliance using the configuration information, wherein the automated configuration does not require user input, and wherein the automated configuration includes using the first parameters and the second parameters to configure the network appliance for use with the access network and the subscriber network.

Coffee shops and other small enterprises frequently offer internet service to their customers. To make such internet services available, small enterprises typically purchase telecom services from large-scale telecom providers. These telecom services enable connectivity to telecom networks, and use of telecom components that process network traffic originating at small enterprises. Some small enterprises (a.k.a. small venues) authenticate prospective network users by forwarding access requests to remote private authentication servers. Such authentication may require that the small venue embed expensive components in the telecom network (e.g., regional authentication gateways running on telecom hardware.) Furthermore, large telecom companies do not typically offer small venues a wide range of service options. For example, large telecom companies may not let small venues select various network and billing policies that control network traffic and customer billing at the small venue. As a result, small venue operators could benefit from new systems that facilitate highly customizable network connectivity services.
Even though large telecom companies may provide services to small venues, small venues still may have to purchase and configure equipment for providing network services to their customers. For example, small venues may need to set-up local area WiFi access points that provide wireless connectivity to telecom networks. Small venue operators may not have technical expertise necessary for properly configuring and maintaining such networking equipment. As a result, small venue operators could benefit from new systems that make configuring network equipment easier.

Automated configuration for network appliances


A hardened image is removed from printing plates by a solution of formic acid and hydrofluoric acid. In one embodiment, the solution further includes a buffer solution to maintain the oleophilic properties of the substrate for printing.

This invention relates to printing plates and, more particularly, to the removal of hardened images from printing plates.
A printing plate is prepared for printing by coating an aluminum substrate with a light sensitive film. If the plate is a "negative" plate, the coating hardens when exposed to ultraviolet light; the coating softens for a "positive" plate. The softened areas are then removed by a specific chemical developer, usually an alkaline base product, and the underlying substrate is ink receptive and ready for printing operations.
In some instances, however, there is an error in the image that has been formed on a plate, or it is desired to alter the image for some reason. A new plate might be used to create the new image. but is it desirable to delete the error and correct the image that has been formed so that the entire process does not have to be repeated. It will be appreciated that any image deletion material must completely remove the hardened emulsion in the area to be corrected and to leave the substrate surface prepared for printing. Aluminum plates have an anodized surface that is damaged by some error deletion compounds; some compounds also change the hydrophilic and oleophilic (ink receptive) characteristics of the aluminum plate. Such changes effect the capability of the aluminum plate to produce images of acceptable quality.
There are a number of different imaging processes and plates, e.g., long run plates, fast exposure plates, and laser plates. Also, computer-to-plate (CTP) technology enables a printer to go directly from the copy to an aluminum printing plate. To realize the cost and labor savings of CTP technology, there is a need to delete image errors on the plate in the press. Existing correction solutions do not adequately remove the hardened image material from these plate and do not remove the image in a time compatible with a production environment.
Accordingly, it is an object of the present invention to provide an image deletion solution that is effective to remove hardened images from printing plates without affecting the printing properties of the plates.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

Printing plate image deletion composition


The semiconductor device includes a circuit, such as, an ECL circuit for comparing input signals with a reference potential determined as a circuit threshold value and outputting an output signal according to the comparison result. The semiconductor device further includes a switching circuit for switching the reference potential level between ordinary operation and burn-in operation of the ECL circuit. The time required for the burn-in operation can be reduced markedly.

1. Field of the Invention
The present invention relates to a semiconductor device such as an ECL (emitter coupled logic) circuit and a burn-in method thereof. Here, the burn-in implies an activation of a circuit prior to an actual operation in order to stabilize the circuit characteristics and to find a defective circuit at the initial stage thereof.
2. Description of the Prior Art
The circuit configuration and function of the ECL circuit will be described first, that is an example for which a conventional burn-in method has been applied and the burn-in method of the present invention will be applied.
FIG. 16 shows an example of the ECL circuit. In this ECL circuit provided with an OR/NOR gate for three inputs A, B and C, when any one of the three inputs A, B and C becomes high beyond a reference potential V.sub.ref1 (determined as a circuit threshold value), only one transistor (whose input is high) of three transistors Q7.sub.a, Q7.sub.b and Q7.sub.c is turned on and the remaining other transistors and a transistor Q6 are all turned off, so that a current I.sub.CS of a constant current source 60 flows through only one current path (the turned-on transistor) of three current paths P1, P2 and P3. Therefore, a potential at a node NZ becomes higher than that at a node /NZ, so that an output Z of the ECL circuit changes to an "H" (High) level by an emitter follower output stage composed of a transistor Q5.sub.a and a resistor R.sub.a2, and another output /Z of the ECL circuit changes to an "L" (Low) level by another emitter follower output stage composed of a transistor Q5.sub.b and a resistor R.sub.b2.
On the other hand, when all the three inputs A, B and C are low below the reference potential V.sub.ref1, the transistors Q7.sub.a, Q7.sub.b and Q7.sub.c, are turned off and the transistor Q6 is turned on, so that the current I.sub.CS of the constant current source 60 flows through the current path P4. Therefore, a potential at the node NZ becomes lower than that at the node /NZ, so that the output Z of the ECL circuit changes to the "L" level by the above-mentioned emitter follower output stage, and the other output /Z of the ECL circuit changes to the "H" level by the other emitter follower output stage. As described above, a logical sum (=A+B+C) of three inputs A, B and C can be outputted from the output Z of the ECL circuit, and a NOT logical sum (=/(A+B+C)) of three inputs A, B and C can be outputted from the output /Z of the ECL circuit. Further, in the above-mentioned ECL circuit, the reference potential V.sub.ref1 is set to an intermediate level (e.g., V.sub.IM1 =(V.sub.IH1 +V.sub.IL1)/2) between the "H" level (e.g., V.sub.IH1 =-0.8 V) of the input signals A, B and C and the "L" level (e.g., V.sub.IL1 =-1.4 V) thereof, as shown in FIG. 17.
Further, FIG. 18 shows another example of the ECL circuit. This ECL circuit is a two-input multiplexer for passing any one of two inputs A and B through an output Z on the basis of a select signal S. This ECL circuit requires two reference potentials V.sub.ref1 and V.sub.ref2. FIG. 19 shows the relationship among the two reference potentials V.sub.ref1 and V.sub.ref2 and two "H" levels (V.sub.IH1, V.sub.IH2) and two "L" levels (V.sub.IL1, V.sub.IL2) of two input signals A and B. In more detail, the reference potential V.sub.ref1 is an intermediate level between V.sub.IH1 and V.sub.IL1 and the reference potential V.sub.ref2 is an intermediate level between V.sub.IH2 and V.sub.IL2, respectively. Here, V.sub.IH2 =V.sub.IH1 -.PHI. and V.sub.IL2 =V.sub.IL1 -.PHI., respectively, where-.PHI. a V.sub.BE of is equal to a base-emitter voltage bipolar transistor/ (0.8 V, in general).
FIG. 20 shows a bathtub-like curve which represents the change in failure rate of the ECL circuit with the lapse of time. In this bathtub-like characteristic curve, the failure rate can be classified into three periods of initial failure period, accidental failure period and wear-out failure period with the lapse of time. In the initial failure period, the failure due to a design miss or process defects existing in the circuit potentially is actualized at the start of use of the circuit. In the accidental failure period, various failures of the composing elements (which are not actualized in the initial failure period) are actualized in combination at roughly a constant failure rate. In the wear-out failure period, the failure rate due to aged composing elements rises with the lapse of time.
In order to reduce the defective product rate below a constant specified level after the products have been shipped, it is necessary for the maker to stabilize the failure rate at a low level. This process is referred to as a burn-in process. In the case of the burn-in process of the integrated circuit in general, non-defective chips classified according to functions are sealed into packages, and further activated by inputting various test patterns which can realize various actual circuit operation as much as possible so that the failure factors related to the initial defectiveness can be actualized. In the cases of the ECL circuits as shown in FIGS. 16 and 18, for instance, the input signals (test patterns) are switched so that current can be passed through the respective current paths P1, P2, P3 and P4, respectively, in order that the defectiveness factors potentially existing in the respective current paths can be actualized.
A conventional burn-in method will be described herein below with reference to FIG. 16. The four test patterns shown in Table 1 will be applied to the input terminals A, B and C for the burn-in process to make currents pass through the respective current paths P1, P2, P3 and P4 of the OR gate for three inputs of the ECL circuit shown in FIG. 16.
TABLE 1 ______________________________________ POTENTIAL OF TERMINAL A B C CURRENT PATH ______________________________________ H L L P1 L H L P2 L L H P3 L L L P4 ______________________________________
However, in the case of the integrated circuit (IC) device in which a plurality of ECL circuits are connected to each other, extensive and bulky test patterns must be inputted to the device via a large number of input terminals to make currents pass through all of the circuit elements of the device.
For example, in the case of the circuit shown in FIG. 21 which is composed by connecting two of the OR gates of FIG. 16 in series, six test patterns as shown in TABLE 2 must be inputted to the input terminals A1, B1 and C1 of the first OR gate OR1 and the terminals B2 and C2 of the second OR gate for burn-in process.
TABLE 2 ______________________________________ CURRENT POTENTIAL OF TERMINAL PATH A1 B1 C1 B2 C2 OR1 OR2 ______________________________________ H L L L L P1 P1 L H L L L P2 P1 L L H L L P3 P1 L L L H L P4 P2 L L L L H P4 P3 L L L L L P4 P4 ______________________________________
A recent general-scale integrated circuit (LSI) device in general is provided with hundreds of input terminals. The number of test patterns for the burn-in process to the LSI device is in the range of thousands and ten thousands steps and the time required for the process per chip of the LSI device is in the range of several hours and tens of hours.
Since hundreds of chips are generally arranged on a wafer, when it takes one hour for the burn-in process per hip, it will take about a thousand hours (about 42 days) per wafer and this is unpractical.
For that reason, conventionally, after each chip is sealed into a package, a large number of packages are mounted on a burn-in board and simultaneously brought into under the burn-in process.
In the conventional burn-in method described above, however, there exist the following problems: (1) As described above, after each chip is sealed into a package, the burn-in process is performed because it takes time to perform the process to a wafer. Since the sealing of the chips into packages is relatively costly, when the chips are determined to be defective in the burn-in process, the package cost becomes wasteful. This will be the cause of a big problem because ECL circuits are mostly sealed into expensive packages for aiming at high performance. (2) Various burn-in boards must be prepared according to each product or each package. (3) Since various test patterns must be inputted to a large number of input terminals, relatively expensive pulse generators are required in the burn-in process. (4) Extensive and bulky test patterns must be inputted into all of circuits elements of a chip in order to pass current there through and to check the defective factors. Relatively longer hours are thus required for the burn-in process.
The above-mentioned problems have become serious more and more with the recent advance of the diversification of the chip (package), the increasing number of the pins, the decreasing delivery lead time, etc.

Semiconductor device and burn-in method thereof


A portable baggage compartment that will fit snugly within the confines of a passenger airplane and conform to the shape of the plane's interior curvature is contemplated by this device. The device will be made from suitable material that can be securely fastened to the interior compartment of an airplane. The device will comply with all Government regulations and will be comprised of a series of compartments that can be used to stow material.

A. Field of the Invention
This invention relates to providing a compartment for storing items needed or desired for a flight on a private jet or similarly sized aircraft.
B. Prior Art
There are various types of baggage compartments installed on airplanes and jets for storing baggage and other carryon items. A very typical compartment is the overhead compartment found in many commercial airlines. This type of compartment is taught in Sergiy U.S. Pat. No. 6,622,965. The Sergiy overhead compartment teaches a cover with an opening mechanism that prevents undesired opening during flight. This is particularly important for safety since items and luggage are being stored above the heads of passengers.
Another type of device utilizes in aircraft is a collapsible mobile platform taught in Ritts et al. ("Ritts") U.S. Patent Application Publication Number 2006/0124802. Ritts describes a structure to be used on the interior of an aircraft for galleys, lavatory, or privacy cabin. However, Ritts teaches against pre-assembled structures and is not intended to fit against the concave wall of an aircraft.


A one-time use camera, including: mechanical members for photographing; a front cover member; a rear cover member, light-tightly joined with the front cover member, for covering the mechanical members; and a rear grip protrusion, accommodated to the rear cover member, for providing an user-holding portion of the one-time use camera.

The present invention relates to a one-time use camera into which a roll of film has previously been loaded, and more specifically, to a one-time use camera having a finger-rest to more securely hold the camera.
There has been a recent tendency in which size of the one-time use cameras is reduced in consideration of portability. In conjunction with this size reduction, there is the increased possibility of the photographic lens being inadvertently covered by the operator's fingers, since the length of the camera to hold the one-time use camera is reduced. As a countermeasure, there is a one-time use camera in which a protrusion or a recess is provided on only a front cover of the camera body. An example of a conventional one-time use camera is shown in FIG. 5, which is a perspective view showing an appearance of a conventional one-time use camera, viewed from its rear side. The appearance of the one-time use camera 10 is structured of a front cover 30 and a mated rear cover 40, and further, a paper material of 5-planes. In the front part, a grip protrusion or recess, not shown in the drawing, is provided on the front cover 30. Further, a photographic lens and a view-finder window portion, not shown in the drawing, are also provided there. A shutter button 67 is provided on the upper surface of the one-time use camera. The rear of the one-time use camera is structured of a flat surface rear cover. Further, a film winding knob 50 and an eye-piece 62 for the view-finder are also provided on the rear of the unit.
However, in conventional one-time use cameras, the position for the thumb is not determined by a grip-protrusion or recess on the front cover, and is unstable, which is a problem.


A method for determining the writing power of data recording devices. First, the inner circle and outer circle of recording media are processed with optimum power calibration (OPC) to obtain an inner circle optimum writing power and an outer circle optimum writing power respectively. The writing power is determined according to the inner circle optimum writing power, outer circle optimum writing power, and/or the time of write speed is raised from the minimum write speed to the maximum write speed of the data recording device.

1. Field of the Invention
The present invention relates to a method for determining the writing power of data recording devices, and particularly to a method for determining the writing power of data recording devices according to the inner circle and outer circle optimum writing powers of recording media.
2. Description of the Related Art
Recently, optical storage media, such as compact disc (CD) and recordable compact disc (CD-R and CD-RW) has gained significant standing in the evolution of data storage. With the development of optical storage media, data can be recorded and backed up into high capacity, light discs, taking the place of traditional data storage media.
FIG. 1 shows a block diagram of a disc servo system. The optical head 11 reads reflection signals from the disc 10. After the signal is amplified and processed by the RF (Radio Frequency) IC 12, the FE (Focus Error) signal, TE (Track Error) signal and relative data and signals are input to DSP (Digital Signal Processor) and the micro processor 13.
Then, the micro processor 13 computes servo drive signals by analyzing the received data, and outputs the signals to corresponding servos (Focusing Servo 14, Tracking Servo 15 and Spindle Motor Servo 16) for controlling the actuators (Focusing Actuator 17, Tracking Actuator 18, Sled Motor 19 and Spindle Motor 20) to ensure accuracy when reading or writing (recording) data.
In the process of writing recordable discs, the data is read from hard disk or CD-ROM by the host via the Integrated Drive Electronics (IDE) interface. Then, the data is sent to the buffer memory of data recording devices via IDE interface or Small Computer System Interface (SCSI). Finally, the data in the buffer memory is written to recording media by the data recording devices.
The data recording device always gradually raises its write speed to the maximum write speed or user defined speed according to the preset time regions in Zone Constant Linear Velocity (ZCLV) mode. FIG. 2 shows the variation of write speed of conventional data recording devices. As shown in FIG. 2, the write speed is 16 in the time region 0˜t1, the write speed is raised from 16 to 20 in the time region t1˜t2, from 20 to 24 in the time region t2˜t3, and, after time t3, from 24 to the maximum write speed 32 and maintained until the recording finishes.
In addition, FIG. 3 shows the variation of write speed of another example of conventional data recording devices. As shown in FIG. 3, the write speed is gradually raised from 16 to 32 in the time region 0˜t4 and maintained until the recording finishes.
The writing power (laser power) of the optical head is an important factor in influencing the writing result (success or failure). Conventionally, the writing power is determined according to the inner circle optimum writing power and the power difference of each time region. The power difference is dependent on recording media and predefined in the database. In the case of FIG. 2, after Optimum Power Calibration (OPC), the inner circle optimum writing power of a recording media of brand A is P0. The power difference in the time region t1˜t2 is ΔP1, the power difference in the time region t2˜t3 is ΔP2, and the power difference after t3 is ΔP3 corresponding to the recording media are predefine in the database. Therefore, the writing power is P0 when writing at write speed 16, P0+ΔP1 when writing at write speed 20, P0+ΔP2 when writing at write speed 24, and P0+ΔP3 when writing at write speed 32.
However, the quality of recording media is difficult to maintain, for example, the dye or consistency thereof in the inner circle or outer circle of the recording media may be different. The writing power is not appropriate and the writing may fail if only the inner circle optimum writing power is considered. Further, it is complicated to define the power difference for all types of recording media in the database.

Method for determining writing power of data recording devices


Vulcanized rubber parts suitable to dampen vibrations generated by mechanical devices are disclosed. The parts are based on a cured composition comprising one or a mixture of a diolefin polymers, e.g., natural rubber, a halogenated copolymer of a C.sub.4 to C.sub.7 isomonoolefin, e.g., isobutylene, and a para-alkylstyrene, filler and a curing system. The vulcanized parts exhibit improved aging and high temperature resistance and reduced deterioration of dynamic properties after long term exposure to high temperatures.

Machines such as automobile, truck or jet engines, compressors and industrial air conditioners, automotive exhaust systems and like dynamic devices generate significant vibration during operation. This vibration will be transmitted directly to support structures with which the dynamic devices is mounted or associated, e.g., an automobile or aircraft frame, a compressor frame, or a floor or rooftop. In order to minimize transfer of vibration from the operating dynamic device to the associated support structure, i.e., isolate the vibrations, it is common to interpose vibration damping and/or isolation means between the dynamic device and the associated support structure. Examples of such vibration damping and/or isolation means would be vibration-absorbing, elastomeric automobile or truck engine mounts placed between the brackets which are used to bolt the engine to the associated auto or truck frame, exhaust hangers, pads interposed between an air conditioner or compressor and a frame or floor and the like.
Vibration damping and/or isolation materials known in the art include vulcanized shapes, e.g., squares, rectangles or cylindrical shapes prepared from vulcanized rubber. These dampening and/or isolation devices can be solid rubber, foamed rubber or solid rubber enclosing a fluid-containing cavity. Suitable rubbers which have heretofore been used in such applications include halogenated and non-halogenated butyl rubber (copolymer of isobutylene with up to 10 wt % isoprene), natural rubber and synthetic elastomeric polymers and copolymers of butadiene.
In addition, EPA 0533746 discloses vibration damping materials based on a vulcanized mixture containing a halogenated copolymer of a C.sub.4 to C.sub.7 isomonoolefin and para-alkystyrene, carbon black, a plasticizer oil and a curing system.
Although natural rubber is an elastomer of choice in some applications because of its superior dynamic properties, i.e., good tensile, modulus and spring rate (stress/strain) properties, the aging and high temperature resistance of cured parts based on natural rubber vulcanizates are poor, thereby limiting the effective life of such parts. For example, engine mounts associated with modem engines must be able to withstand temperatures as high as 150.degree. C. for periods in the range of 1,000 to 5,000 hours without significant loss of dynamic properties, in order to meet current and anticipated automotive standards.

Motor or engine mount from mixtures of elastomers and halogenated polymers


The present invention provides a flexible storage system through the use of portable, removable canisters holding multiple storage subsystems.

1. Field of the Invention
The present invention relates to storage systems capable of holding large quantities of information.
2. Background Art
Data storage systems provide long term, low cost storage for data. Many of these systems utilize hard disks for short term storage and removable tapes for long term storage. "Hard disks" refer to disks, magnetic, optical or otherwise, that combine data storage media with an access head and at least some support electronics. For simplicity, these will be referred to as simply "disks." These disks offer shorter latency and higher throughput rates than tapes or removable disks. However, these disks have traditionally been higher in cost per bit.
Recent advances in disk technology has decreased the cost per bit of hard disks. What is needed is a long term storage system that takes advantage of these improvements to create greater efficiencies in storage systems.


There is disclosed a method, apparatus and computer program product for generating a queriable text. User role map information is applied to the source hierarchical text. The role mapped text is separated into a structure component and a content component. The content component is compressed. A method for processing intermediate and original form query also is disclosed.

An example of hierarchical text data is an XML document. XML documents are made up of storage units called entities, which contain either parsed or unparsed data. Parsed data is made up of characters, some of which form character data, and some of which form markup. Markup encodes a description of the document's storage layout and logical structure. XML provides a mechanism to impose constraints on the storage layout and logical structure. Physically, the document is composed of units called entities. An entity may refer to other entities to cause their inclusion in the document. A document begins in a "root" or document entity. Logically, the document is composed of declarations, elements, comments, character references, and processing instructions, all of which are indicated in the document by explicit markup. An attribute provides more information about elements, often giving information that is not part of the data itself.
Work has previously been done on the compression of XML documents: see for example H. Liefke and D. Sciciu, An efficient compressor for XML data, in Proc. 2000 ACM SIGMOD Conference, pages 153-164, 2000. This work describes a tool, called XMill, for compressing XML data. XMill incorporates various existing and user defined compressors to enable data type specific compressors, e.g., numbers, strings, enumerated types.
One known compression approach also has considered enabling queries on a subset of compressed documents: P. Tolani and J. R. Haritsa, A query-friendly XML compressor, Proc. 18th IEEE International Conference on Data Engineering, pages 225-234, 2002. But while this approach enables querying of the compressed document, but there is no notion of encryption (thus, no decryption either).
There is also a recent work that delves into the problems of compression, navigation and searching of XML documents: P. Ferragina, F. Luccio, G. Manzini and S. Muthukrishnan, Compressing and Searching XML Data Via Two Zips, Proc. Of World Wide Web Conference, 2006. However, there is again no notion of encryption (and thus no decryption either).

International Business Machines Corporation


An apparatus (20) for recording a color image, comprises an image sensor (22) having a plurality of pixels (24) formed in a monolithic substrate. Each of the plurality of pixels (24) includes three floating gate semiconductor devices (80, 82, 84). A color tunable filter (30) is positioned between a photosensitive semiconductor device (86) and an electromagnetic radiation source. A FET transistor (130) has a drain (134) connected to the cathode (120) of the photodiode (86), and a source (136) connected to the anode (118) of the photodiode (86) and to control gates (94, 104, 114) of each of the three floating gate semiconductor devices (80, 82, 84). The color tunable filter (30) allows all desired combinations of colors to pass while each of the three floating gate semiconductor devices (80, 82, 84) are respectively selected to store the color image.

Presently, semiconductor based image sensors are widely used, especially in digital cameras. These cameras exist as both stand-alone devices and as integrated in other multipurpose electronic devices such as cell phones or personal digital assistants (PDAs).
The marketplace continues to drive for improvements in image capture. These improvements include not only the quality of the captured images, such as improved color accuracy and resolution, but also the lowest possible cost and smallest size.
A common method to capture color information in cameras using semiconductor based image sensors is to employee a mosaic, such as a Bayer pattern, of alternating red, green, and blue pixels. The light reaching these pixels is filtered by corresponding red, green, or blue light filter films made out of materials such as polyimide. However, this method causes several problems. First, conventional RGB filters significantly attenuate the light. It is common for the green and red filters to have less than 40% transmittance and the blue filter to have less than 25% transmittance. This reduction in transmitted light leads to a major decrease in the sensitivity of the sensor array. Second, the film filters commonly used have considerable spectrum overlap. For example, the red filter allows some green light to pass, the green filter allows some red and blue light to pass, and the blue filter allows some green light and red light to pass. This makes determination of the true colors of an image very difficult. Third, the general use of a mosaic of pixels, such as a Bayer pattern, to determine color, degrades the potential spatial resolution of a given array. The amount of degradation depends on lighting conditions but can approach 75% for high resolution systems. For example, a lens with a module transfer function (MTF) value of 0.7 at 100 lp/mm may only provide an MTF of 0.7 at 25 lp/mm for a module with a Bayer mosaic semiconductor image sensor.
Another known method for capturing color information involves Foveon sensors. With the Foveon design, color filtering is achieved by selective absorption of the light through the sensor semiconductor substrate. Like the systems using color films, the Foveon type system still suffers from considerable color spectrum overlap between the different color sensors, thus making the determination of true color by the system difficult. For example, the signal from a blue sensor will have about 35% green light contribution and 10% red light contribution under sunlight conditions. This problem is further aggravated by the fact that the contribution from each color will change under different lighting conditions such as office light vs. sunlight.
Another known method for color filtering that could be applied to imagers is disclosed in U.S. Patent Application Publication 2005/0099373 A1. This method uses a conventional passive color comprised of circularly polarizing selective reflection bands of at least four cholesteric filters together with three liquid crystal switches and related retarder layers. Because this filter only works with polarized light, it is not suitable for cameras used in outdoor and most indoor photography as sunlight and most artificial light sources generate non-polarized light.
Accordingly, it is desirable to provide a new color image sensor system. This system employs a tunable stack of liquid crystal display (LCD) filters which are used to pass a sequence of different colors of light to a sensor array. The system also employs a sensor array optimized to store sequential light information. Furthermore, other desirable features and characteristics of the present disclosure will become apparent from the subsequent detailed description of the disclosure and the appended claims, taken in conjunction with the accompanying drawings and this background.

Color image sensor with tunable color filter


Disclosed is a laser wavelength conversion apparatus. The apparatus includes a focusing lens formed of a birefringent material and configured to have a same refractive index for an infrared laser beam and a green laser beam having different polarization directions and focus the infrared laser beam and the green laser beam without a chromatic aberration, and a sum frequency generator configured to combine the infrared laser beam and the green laser beam focused by the focusing lens to generate an ultraviolet laser beam. The apparatus of the present invention can solve a problem due to a chromatic aberration of the focusing lens, thereby improving a wavelength conversion efficiency and a beam quality.

1. Technical Field
The present invention relates to a laser wavelength conversion apparatus, and more particularly, to a laser wavelength conversion apparatus which converts a wavelength of a laser beam to be applicable to precise machining.
2. Description of the Related Art
As a method for high-speed precise machining, ultraviolet laser machining is known in the art. In order to obtain an ultraviolet laser beam, a method of converting an infrared laser beam may be used.
In the method of converting an infrared laser beam into an ultraviolet laser beam, first, an infrared laser beam is subjected to partial wavelength conversion into a green laser beam through a second harmonic generator (SHG). Then, the green laser beam and the infrared laser beam are focused and combined through a sum frequency generator (SFG), thereby generating an ultraviolet laser beam. As the sum frequency generator, a non-linear optical material may be used. For example, lithium triborate (LBO) may be used.
To perform high-speed precise machining, an ultraviolet laser beam is required to have high repetition rate, high power, and high beam quality. In the case where the ultraviolet laser beam is generated by converting the wavelength of the infrared laser beam, the high repetition rate of the infrared laser beam causes decrease in pulse energy and peak power, and thus the size of the laser beam must be reduced by focusing the laser beam appropriately in order to increase wavelength conversion efficiency.
However, as the laser beam becomes smaller, chromatic aberration of a focusing lens becomes serious. When an infrared laser beam and a green laser beam are focused by an ultraviolet generating material, the infrared laser beam and the green laser beam are generally focused at different positions due to chromatic aberration of the focusing lens. In this case, interaction between the beams becomes weaker and causes deterioration in conversion efficiency for an ultraviolet beam. This phenomenon becomes more serious as the size of the focused beam size is reduced.
In order to solve such a problem, a method of using a concave mirror instead of a lens (see High efficiency generation of 355 nm radiation by extra-cavity frequency conversion: Optics Communications 283 (2010) 3497-3499) has been proposed in the related art. However, this technique has problems in that beam alignment is complicated and astigmatism of a spherical mirror occurs.

GWANGJU INSTITUTE OF SCIENCE AND TECHNOLOGY


The present invention is a system and method for performing real-time infection control over a computer network. The method comprises obtaining a sample of a microorganism at a health care facility, sequencing a first region of a nucleic acid from the microorganism sample, comparing the first sequenced region with historical sequence data stored in a database, determining a measure of phylogenetic relatedness between the microorganism sample and historical samples stored in the database, and providing infection control information based on the phylogenetic relatedness determination to the health care facility, thereby allowing the health care facility to use the infection control information to control or prevent the spread of an infection.

A major problem in hospitals and health care facilities today is the prevalence of hospital-acquired infections. Infections picked up in institutions are referred to as "nosocomial" infections. 5-10% of patients who enter a hospital for treatment will acquire a nosocomial infection from bacteria in the hospital environment. This translates to two million people per year. Nosocomial infections cause 90,000 deaths per year in the United States alone.
The most problematic bacterial infection in hospitals today is Staphylococcus aureus (S. aureus). S. aureus is the leading cause of nosocomial infection in the United States. In New York City (NYC), methicillin-resistant S. aureus (MRSA) accounts for approximately 29% of nosocomial infections and 50% of associated deaths. S. aureus also causes a variety of diseases including abscesses, blood stream infections, food poisoning, wound infection, toxic shock syndrome, osteomyelitis, and endocarditis.
S. aureus has become highly resistant to antibiotic therapies. In fact, vancomycin is the only effective treatment against most methicillin-resistant S. aureus strains. It is predicted that S. aureus will eventually develop resistance to vancomycin. Other species of bacteria have already developed resistance to vancomycin. High-level resistance to vancomycin exists in both Enterococcus faecalis and Enterococcus faecium, two gram-positive species that have previously exchanged resistance genes with S. aureus. It is therefore predicted that high-level resistance will eventually transfer to S. aureus. Since 1997, sporadic cases of vancomycin intermediate resistant S. aureus (VISA strains) have appeared. In these few cases resistance developed over time as a consequence of repeated exposure to vancomycin, and not the result of acquiring vanA or vanB resistance operons.
The potential for a major epidemic exists if S. aureus develops resistance to vancomycin. It is clear from this bacteria's ability to cause outbreaks in hospitals that its spread will be difficult to control even with effective therapy. Because of the presence of VISA strains and the concern over high-level vancomycin resistance, it is of utmost importance that an effective method of controlling the spread of S. aureus infection be developed.
On Mar. 5, 2000, the CBS Evening News reported that hospital acquired infections cost the United States health care system over $5 billion per year. An earlier Lewin Group Report estimates that S. aureus costs hospitals in New York City alone upwards of $400 million dollars per year to control. Currently, most hospital visits in the United States are paid for by Health Maintenance Organizations (HMOs). Extended patient stays caused by complications unrelated to the intended procedure, such as hospital acquired infections, are often not covered by the HMO's. These extra costs are paid for by the hospitals. Hospital acquired infections equate to extended patient stays and extended patient treatment. In one New York City hospital, the average stay is 9 days. Reducing hospital infection rates would reduce the length of patient stays, and thus save a significant amount of money for hospitals, HMO's and ultimately patients.
20-40% of people carry S. aureus nasally. Normally, the effects of S. aureus are benign and people generally live with it with no harm. However, people who are carrying S. aureus have the ability to infect others via transmission to otherwise sterile sites. In a hospital setting, health care workers can pick up the bacteria from a patient and act as a vector, transmitting the bacteria to other individuals. For example, when a person has surgery, a doctor who carries S. aureus nasally can infect the patient, or the patient can infect himself, even if the patient is otherwise healthy. S. aureus and other pathogenic bacteria can also contaminate inanimate objects such as a dialysis machine, or a bronchoscope. The contaminated objects provide the source of the infection.
When a patient acquires an infection in a hospital, typically an isolate of the bacteria will be taken from the patient and sent to a laboratory. The laboratory performs phenotypic tests to determine the species of the bacteria and its antibiotic susceptibility profile, which provides the physician a guide to the proper antibiotic therapy. Phenotypic tests examine the physical and biological properties of the cell, as opposed to genotypic tests, which evaluate the DNA content of the cell's genes.
Unfortunately, many bacteria develop resistance to the drugs that are used to fight them. As a result of the high levels of antibiotic usage, hospitals provide a selective environment to add in the spread of drug resistant bacteria. Bacterial infections get worse over time because the bacteria become more resistant to the drugs used to treat them. The more resistant the bacteria get, the harder they are to eradicate and the more they linger in the hospital.
Hospitals and health care facilities today live with a baseline level of nosocomial infections among patients. Hospitals do not take active steps to control nosocomial infections until a significant number of patients acquire infections within a short period of time. When this happens, the hospital may begin to worry that it has an outbreak problem on its hands. A source of infection inside the hospital such as a patient or a dialysis machine could be spreading a virulent strain of bacteria.
Unfortunately, by the time that the hospital realizes that it has an outbreak problem, the outbreak probably has already been underway for months. Thus the hospital will already have expended a significant cost fighting the spread of infection, and will have to expend additional resources to eradicate the infection from the hospital.
When the infection has already become rampant, the hospital may try to combat the outbreak by locating the source of the infection. The source could be a patient in the hospital, a health care worker, an animal, a contaminated object, such as a bronchoscope, a prosthetic device, the plumbing in a dialysis machine, or a myriad of other locations. It is thus very important that the hospital be able to locate the source of the infection.
The hospital can attempt to locate the source of infection by determining the path of transmission of the infection. The hospital can potentially determine the path of transmission by subspeciating the bacteria. One way to subspeciate bacteria is to analyze the bacteria's DNA. This is referred to as "molecular" typing, or genotyping. Over time, a bacteria's DNA mutates, producing changes in the bacteria's DNA. Two isolates of bacteria taken from two different patients may appear to have identical physical properties or "phenotypic" characteristics. However, a closer examination of the bacterial DNA might reveal subtle differences that demonstrate that the two isolates are actually different subspecies or clonal types. As an example, genotypic tests compare the DNA of a given gene from two or more organism, whereas phenotypic tests compare the expression of those genes.
If the hospital determines that many patients are acquiring infections of the same species, then the hospital may suspect that it has an outbreak problem. In some cases drug susceptibility testing will determine that strains are different and that an outbreak has not occurred. Unfortunately, many outbreaks are cause by multidrug resistant organisms and which can not be distinguished based on drug susceptibility results. In these cases, sub-speciation data is necessary to distinguish strain types. Molecular typing is one effective way to subspeciate these strains. For example, suppose a number of patients in the burn ward of a hospital over the course of several months acquire S. aureus infections. Molecular typing reveals that all of the S. aureus isolates taken from the patients belong to the same or highly similar subspecies. In this case, the hospital would determine that there is likely a single point source of infection in the burn ward. However, if all of the patients have very different subspecies of S. aureus, then the infection is likely not coming from a single source, but may be coming from multiple sources and the breakdown of infection control practices.
Rarely do hospitals perform molecular typing to subspeciate bacteria (i.e. a DNA analysis) because they lack the tools and expertise. Also, in the age of HMO care, preventive typing does not constitute direct patient care; it is infection control. However, in the long run, the hospital pays increased costs because patient stays are longer as a direct result of nosocomial infections.
One method of molecular typing that is sometimes used by hospitals to subspeciate bacterial isolates is pulsed-field gel electrophoresis (PFGE). PFGE produce a pattern indicative of the organization of the bacterial chromosome. By comparing PFGE patterns from multiple isolates, the hospital can subspeciate the bacteria. The PFGE process involves cutting the bacterial chromosomal DNA into multiple macro-fragments of varying sizes and molecular weights. An image-based pattern results after these fragments are separated by pulsed-field electrophoresis.
One problem with PFGE is that it is difficult to compare PFGE patterns. To compare whether two bacteria belong to the same subspecies requires comparing two PFGE images. Typically, an individual compares two PFGE images by subjectively eyeing the two images to determine if they look identical. Comparing two images by the human eye is very subjective, and frequently does not produce accurate results. It is similar to comparing two photographs or comparing pictures of fingerprints by eye. Computer digitization and software programs which perform analog image matching are available that somewhat aid this process. However, this software image matching is still a subjective science and does not provide sufficient biological criteria to evaluate the degree of relatedness between different strains. Additionally, image-based methods remain difficult to standardize between laboratories.
Another problem with PFGE is that there may be DNA mutations that do not affect the pulsed-field gel pattern. In these instances, two bacterial isolates may appear to have to have identical PFGE patterns, and yet, in reality, may be of different clonal types. PFGE is also a laborious and time consuming technique, and it is difficult to store PFGE images in a database because they take up too much memory.
A technique known as multilocus sequence typing (MLST) has been developed for Nesseira gonorrhea, Streptococcus pneumonia and Staphylococcus aureus, based on the classic multi-locus enzyme electrophoresis (MLEE) method that population biologists used to study the genetic variability of a species. MLST characterizes microorganisms by sequencing approximately 500 base-pair fragments from each of 9-11 housekeeping genes. The problem with the use of MLST in controlling infections in a rapid manner is that the MLST approach proves to be too labor intensive, too time consuming, and too costly to compare in a clinical setting. Over 5000 base pairs must be compared for each isolate. There is also limited genetic variability in the housekeeping gene targets and discrimination is therefore not adequately suitable for rapid infection control.
What is needed is a system and method for performing molecular typing in real time that can effectively and accurately subspeciate infectious agents. What is also needed is a system and method for typing infectious agents that are suitable for use with an electronic database and for communication of data over a computer network. What is also needed is a system that responds to an outbreak at a very early stage rather than beginning weeks or months after an outbreak has already begun. What is also needed is a system and method that can effectively speciate and subspeciate bacteria and determine relatedness among various subspecies in order to effectively track the path of transmission of the bacterial infection. What is also needed is a computerized and centralized system among hospitals and health care facilities that can accurately and quickly track the spread of infection regionally and globally as well as at the local hospital level.

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System and method for tracking and controlling infections