Disclosed herein is an optical sensor design and method for continually interrogating that sensor to produce an accurate representation of a dynamic event (such as a change in strain, pressure or temperature) being monitored by the sensor. The sensor design preferably constitutes continuous wave optical source/detection equipment coupled in series to a first fiber Bragg grating (FBG), a long period grating (LPG), and a second FBG formed in an optical waveguide. The LPG broadly attenuates light in the vicinity of the Bragg reflection wavelength λ2B of the second FBG, and this attenuation profile shifts in wavelength in accordance with the dynamic event being monitored. Perturbation of the attenuation profile thus attenuates the intensity of the light reflected from the second FBG, i.e., I(λB2), because such reflected light must pass (twice) through the LPG. Accordingly, continually monitoring I(λB2) as a function of time allows the dynamic event to be recreated and processed accordingly. If necessary, I(λB2) can be normalized by dividing it by the intensity of the Bragg reflection wavelength from the first FBG, I(λB1), to discard attenuation within the system not related to the dynamic event being monitored.

Optical sensors are well known in the art, and have utility in a number of different measurement applications. For example, and as shown in FIG. 1, a fiber Bragg grating 10 (FBG 10) formed in an optical fiber 12 or other optical waveguide can be used to measure pressure or temperature. A FBG, as is known, is a periodic or aperiodic variation in the effective refractive index of a core of an optical waveguide, similar to that described in U.S. Pat. Nos. 4,725,110 and 4,807,950 entitled "Method For Impressing Gratings Within Fiber Optics," to Glenn et al. and U.S. Pat. No. 5,388,173, entitled "Method And Apparatus For Forming Aperiodic Gratings In Optical Fibers," to Glenn, which are incorporated by reference in their entireties.
FBG 10, when interrogated by broadband light from an optical source/detector 14, will reflect a narrow band of this light (essentially a single wavelength), called the Bragg reflection wavelength, λB, in accordance with the equation λB∝2neffΛ, where neff denotes the index of refraction of the core of the waveguide, and A denotes the spacing of the variations in the refractive index of the core (i.e., the grating spacing). Because strain along the axis of an FBG affects its grating spacing Λ, and because temperature effects both the index of refraction neff and the grating spacing Λ (in the latter case, due to thermal expansion or contraction), FBG 10 can be used as either as pressure or temperature sensor by assessing the magnitude of the shift in its Bragg reflection wavelength. FBG 10 is usually partially transmissive so that a portion of the light at the Bragg reflection wavelength (and light of all other wavelengths that is not affected by the FBG 10) transmits through the FBG 10, which allows further sensors along the optical fiber 12 (not shown) to be interrogated in a multiplexing approach to determine the pressures and/or temperatures present in those locations.
When interrogating the FBG 10, the optical source/detector 14 can be operated in a continuous wave mode, where light is continuously fed to the FBG 10 and its reflections are continuously monitored, or the light can be pulsed. In a pulsed scheme, the frequency of the pulses needs to be sufficiently short to detect changes in the parameter being measured. For example, when measuring temperature in a given application, such as within an oil/gas well, it is noted that temperature does not change very rapidly, or at least it is usually not of interest to the well operator to detect such rapid changes if they occur. Accordingly, light pulses need to be sent from the optical source/detector 14 only occasionally, for example, every second, which provides an update of the temperature at the location of FBG 10 every second.
However, some parameters of interest to detect occur on much smaller time scale. For example, if the FBG 10 is used to measure a dynamic event, such as a pressure wave indicative of seismic activity occurring within the oil/gas well, sampling needs to take place more frequently. For example, a seismic pressure wave may contain frequency components as high as f=1000 Hz, and therefore would require interrogating the FBG 10 one the order of at least 2f times a second to properly resolve these higher order frequency components and to provide an accurate picture of the detected pressure wave. However, such high frequency rate pulsed sampling may not be possible in a practical application. For example, the FBG 10 will likely in an oil/gas application be wavelength-division or time-division multiplexed to other optical sensors such as flow rate meters, speed of sound meters, or other pressure or temperature sensors, and such meters or sensors may themselves contain FBGs which will produce reflections. (Examples of such other meters or sensors, and ways of multiplexing and interrogating them, are disclosed in the following U.S. patents or patent application, which are hereby incorporated by reference in their entireties: Ser. No. 09/740,760, filed Nov. 29, 2000; Ser. No. 09/726,059, filed Nov. 29, 2000; Ser. No. 10/115,727, filed Apr. 3, 2002; U.S. Pat. No. 6,354,147, issued Mar. 12, 2002). High rate sampling of FBG 10 could interfere with interrogation of the other optical sensors or meters multiplexed with FBG 10, and/or confused the reflected signals, making it difficult to determine which reflections pertain to which meter or sensor.
As alluded to above, one solution to the problem of interrogating the FBG 10 to monitor dynamic events is to interrogate the FBG 10 with a continuous wave light source. Continuous wave interrogation produces a continuous reflection of Bragg wavelengths shifts from the FBG 10, which can be monitored as a function of time. However, continually monitoring Bragg wavelength shifts is difficult in many applications, and requires detectors and signal processing schemes that are not always economical in practice.
Accordingly, there is room for improvement in the art of optical sensors. The art would benefit from a sensor design which can monitor dynamic events in real time, and which is interrogatable using methods that are easily implemented and reliable.

Optical sensor using a long period grating suitable for dynamic interrogation


In one aspect, the invention is directed to a conduit laying system for laying conduit, including a vehicle, a trench former, a conduit feed system and a base material handling system. The trench former is configured for forming a trench. The conduit feed system includes a conduit feed passage having a conduit feed passage inlet for receiving at least one conduit and a conduit feed passage outlet positioned to deposit the at least one conduit in the trench. The base material handling system includes a base material hopper and at least one base material passage. The at least one base material passage is positioned to receive base material from the base material hopper and to discharge base material in the trench around the at least one conduit. The base material handling system, the conduit feed system and the trench former are driven by the vehicle.

Laying electrical cables underground is typically accomplished by digging a trench and laying the cable in the trench. The trench may be dug using a backhoe loader or the like and the cable may be laid in the trench manually, while being fed from a reel that is mounted on a truck. Typically, such work is slow, and relatively labour intensive.
Systems have been proposed to lay cable in an open trench, however, such systems suffer from a variety of shortcomings. For example, in some instances, no means for protecting the cable in the trench is provided. Accordingly, the cable is at risk of puncture or other damage from exposed rocks and the like in the trench.
It would be advantageous to provide a system that lays cable or other types of conduit while protecting it from damage.


An apparatus and method of dynamically tracking a soft tissue target with ultrasound images, without the use of fiducial markers. In one embodiment, the apparatus includes an ultrasound imager to generate a reference ultrasound and a first ultrasound image having a soft tissue target, and a processing device coupled to the ultrasound imager to receive the reference ultrasound image and the first ultrasound image, to register the first ultrasound image with the reference ultrasound image, and to determine a displacement of the soft tissue target based on registration of the first ultrasound image with the reference ultrasound image.

A tumor is an abnormal growth of tissue resulting from the uncontrolled, progressive multiplication of cells, serving no physiological function. A tumor may be malignant (cancerous) or benign. A malignant tumor is one that spreads cancerous cells to other parts of the body (metastasizes) through blood vessels or the lymphatic system. A benign tumor does not metastasize, but can still be life-threatening if it impinges on critical body structures such as nerves, blood vessels and organs (especially the brain).
A non-invasive method for tumor treatment is external beam radiation therapy. In one type of external beam radiation therapy, an external radiation source is used to direct a sequence of x-ray beams at a tumor site from multiple angles, with the patient positioned so the tumor is at the center of rotation (isocenter) of the beam. As the angle of the radiation source is changed, every beam passes through the tumor site, but passes through a different area of healthy tissue on its way to the tumor. As a result, the cumulative radiation dose at the tumor is high and the average radiation dose to healthy tissue is low. The term radiotherapy refers to a procedure in which radiation is applied to a target region for therapeutic, rather than necrotic, purposes. The amount of radiation utilized in radiotherapy treatment sessions is typically about an order of magnitude smaller, as compared to the amount used in a radiosurgery session. Radiotherapy is typically characterized by a low dose per treatment (e.g., 100-200 centi-Gray (cGy)), short treatment times (e.g., 10 to 30 minutes per treatment) and hyperfractionation (e.g., 30 to 45 days of treatment). For convenience, the term "radiation treatment" is used herein to mean radiosurgery and/or radiotherapy unless otherwise noted by the magnitude of the radiation
One problem encountered in external beam radiation treatment is that pathological anatomies (e.g., a tumor) may move during treatment, which decreases accurate target localization (i.e., accurate tracking of the position of the target). Most notably, soft tissue targets tend to move with patient breathing during radiation treatment delivery sessions. Respiratory motion can move a tumor in the chest or abdomen, for example, by more than 3 centimeters (cm). In the presence of such respiratory motion, for example, it is difficult to achieve the goal of precisely and accurately delivering the radiation dose to the target, while avoiding surrounding healthy tissue. In external beam radiation treatment, accurate delivery of the radiation beams to the pathological anatomy being treated can be critical, in order to achieve the radiation dose distribution that was computed during the treatment planning stage.
One conventional solution for addressing the problem of tumor motion due to respiration is the use of gating techniques. Gating techniques dose not directly compensate for breathing motion, in that the radiation beam is not moved while it is being directed in the patient. Rather, the radiation beam is turned off when the tumor is thought to have moved from its reference position. However, a disadvantage of using a gating technique is that it significantly increases the amount to time required for delivering the radiation treatment. Another disadvantage is such an approach may result in inaccurate treatment of the tumor due to the assumptions made in tumor position.
One conventional solution for tracking motion of a target utilizes external markers (e.g., infrared emitters) placed on the outside of a patient (e.g., on the skin). The external markers are tracked automatically using an optical (e.g., infrared) tracking system. However, external markers cannot adequately reflect internal displacements caused by breathing motion. Large external patient motion may occur together with very small internal motion. For example, the internal target may move much slower than the skin surface.
Another conventional solution for tracking motion of a target involves the use of implanted fiducials. Typically, radiopaque fiducial markers (e.g., gold seeds or stainless steel screws) are implanted in close proximity to, or within, a target organ prior to treatment and used as reference points during treatment delivery. Stereo x-ray imaging is used during treatment to compute the precise spatial location of these fiducial markers (e.g., once every 10 seconds). However, internal markers alone may not be sufficient for accurate tracking. Yet another conventional solution combines the tracking of internal fiducial markers with the tracking of external markers in which x-ray imaging of the internal fiducial markers is synchronized with the optical tracking of the external markers. However, such a combined tracking approach still has the disadvantage of requiring the tracking of internal fiducial markers.
The tracking of internal fiducial markers can be difficult for the patient, because high accuracy tends to be achieved by using bone-implanted fiducial markers. The implanting of fiducial markers in bone requires a difficult and painful invasive procedure, especially for the C-spine, which may frequently lead to clinical complications. In addition, tracking bone-implanted fiducial markers may still may not provide accurate results for movement or deformation of soft tissue targets. Moreover, whether the fiducial marker is implanted in the bone or injected through a biopsy needle into soft tissue in the vicinity of the target area under computerized tomography (CT) monitoring, the patient must still undergo such invasive procedures before radiation treatment.
A conventional technique that tracks the motion of a tumor without the use of implanted fiducial markers is described in A. Schweikard, H Shiomi, J. Adler, Respiration Tracking in Radiosurgery Without Fiducials, Int J Medical Robotics and Computer Assisted Surgery, January 2005, 19-27. The described fiducial-less tracking technique use deformation algorithms on CT data sets, combined with registration of digitally reconstructed radiographs (DRR) and intra-treatment X-ray images of nearby bony landmarks (where the tumor itself may not be visible in the x-ray image in most cases) to obtain intermittent information on the tumor location. This target location information is then combined with conventional correlation techniques to achieve real-time tracking.
One disadvantage with all the above described conventional methods is that, with the exception of external marker tracking, they require the repeated exposure of the patient to non-therapeutic radiation from the intra-treatment x-rays that are taken to obtain intermittent information on the fiducial or target location.

Dynamic tracking of soft tissue targets with ultrasound images, without using fiducial markers


A leak detection apparatus and method and a wafer electroplating method are provided. An air tightness state of a reaction chamber in a wafer electroplating device is detected in advance before a wafer electroplating process is performed, namely whether leak occurs at the reaction chamber is judged by inputting a detection gas to the reaction chamber and detecting a gas pressure value of the detection gas, and whether to perform the wafer electroplating process is determined according to a judgment result.

In a manufacturing process of a semiconductor device, electroplating is a common method for depositing a metal film on a substrate. Particularly in an advanced packaging technology, electroplating is usually adopted to form copper columns, welding spots, etc., on substrates to allow the interconnection between chip substrates. Electroplating has the advantages of simple process, low cost, ease of batch production, etc.
In batch production of wafer-level packaging, wafer electroplating is an important process step for chip manufacturing. For example, in a horizontal electroplating manner, a wafer is usually arranged horizontally, each position on a surface to be electroplated is at the same depth in an electroplating solution. The pressure at each position of the surface to be electroplated is the same, and the electroplating uniformity is high. However, for the horizontal electroplating manner, relatively high requirements on, for example, the placement flatness of the wafer and air tightness of the electroplating device are made to a horizontal electroplating device. For example, abrasions or losses, caused by natural heating or forced heating, of some sealing components in the horizontal electroplating device may cause leak and other phenomena, and consequently, the electroplating solution originally at a front surface of the wafer may be leaked to a back surface of the wafer, which causes pollution on the wafer, and/or damage of electroplating device, etc.

Leak detection apparatus and method and wafer electroplating method


Optimized sound waves presented to the listener by headphones, notwithstanding differences in ear geometry and headphone positioning. A test signal causes an acoustic sensor to receive sound waves actually formed in the listener's ear cavity. A response from the sensor is compared with an expected ear cavity transfer function, from which desired adjustments to the audio signal are determined. The audio signal might be received from an application program, calibrated by an interface software element, and adjusted thereby, before forwarding to the headphones. Calibration might be performed from when the headphones are positioned, or dynamically in response to changes in the transfer function.

Headphones are designed to produce sound waves to be presented to a listener's ear. Those sound waves are produced by a diaphragm, such as for example in a headphone cup. The diaphragm is coupled to a driver, which is responsive to an audio signal. The audio signal is produced by an audio signal source, such as an MP3 player or another entertainment device.
Ideally, the sound waves presented to the listener's ear are faithful to the original audio signal. However, the shape and size of the human ear performs a transfer function on sound waves presented to the outside of the ear. When designed, known headphones are optimized for an ear geometry that is intended to be representative of most human ears, such as for example the KEMAR standard (including the pinna, the outside part of the ear, sometimes referred to as the auricle, and the concha, the bowl-shaped part of the pinna, the latter of which generally forms a cavity for receiving sound waves). Similarly, when designed, known headphones are optimized for an expected position of the headphone with respect to that ear geometry, which is generally responsive to a relative shape of the headphone or its cushion with respect to the shape and size of the ear.
One problem in the known art is that, while designed for a standard ear geometry that is representative of most human ears, known headphones only approximate the actual ear geometry of any particular listener. Most real human ears differ at least somewhat from the standard ear geometry used for design, as a consequence of variation among the ear shapes and sizes of different people. This has the effect that the standard ear geometry will often not be a faithful representation of the listener's actual ear.
Similarly, another problem in the known art is that, while designed for a standard ear geometry that is representative of most human ears, known headphones only approximate the actual position of the headphone with respect to that ear geometry. When in actual use, most real listeners position their headphones at least somewhat differently from the standard used for design, also as a consequence of variation among the ear shapes and sizes of different people, as well as a consequence of variation in the user's choice of headphone position. This also has the effect that the position the headphones were designed for will often not be a faithful representation of the actual position used by the listener. This is also a consequence of variation among different people, their ear shapes and sizes, and the most comfortable position they might individually select for using their headphones.
The known art has the drawback that the sound waves presented to the listener can differ substantially from their ideal presentation, due to the headphones having been designed only for an expected average ear and an expected headphone position.


A study is made of the changeover time of the voltage between an electrode and a metal work piece buried in the ground and protected against corrosion by an electric current. For this study, it is intended momentarily to interrupt the circulation of the protective current, to read the voltage between the work piece and the electrode, to pass these readings to an analog filter, to smooth these filtered signals by substituting them with values corresponding to a continuous and monotonic postulated function, and then to mathematically reconstruct the change in the voltage signals between the work piece and electrode such as it would be without filtering.

Cathodic protection is the most widespread. To provide this protection a circulation of electric current is usually created between the metal work and the solution surrounding it, a circulation such that the direction of the current flows from the solution to the metal, thus promoting the cathodic reaction in the region of the work to be protected, while transferring the oxidation reaction to the counter-electrode, thus forming an anode.
There are also cases in which the work forms an anode and the counter-electrode a cathode, (protection of certain metals, such as aluminium, which can be passivated in the electrolyte, via an "anodic protection" current).
Be that as it may, when a "cathodic" or "anodic" protection is applied to a work in contact with the ground (or another electrolytic medium) the effectiveness of the protection is usually measured by the value of the potential difference between the work and the electrolyte.
In actual fact, this voltage is measured between the metal of the protected work and a so-called "reference" complementary electrode in contact with the electrolyte. In practice, it is preferable to place this reference electrode some distance from the surface presumed to be protected.
The measurement of this voltage therefore includes a term due to the potential gradient in the ground.
Knowledge of the real metal/ground potential requires this undesirable term to be eliminated from the measurements.
A means usually used for this purpose consists in measuring this potential, after momentarily cutting the imposed protective current. A method which numerous practitioners have gone over to consists in cutting the protective current for about 3 seconds, the measurement(s) being made between 2 and 3 seconds after cutoff, and in then re-establishing the protective current for about 30 seconds, before a new cutoff.
It is therefore known nowadays that in order to check in particular the state of immunity as regards corrosion of a buried metal work, measurements must be made of potential of the work relative to the ground, protective current cut off, in order to eliminate from the measurement in particular the ohmic drop due to the f low of the current into the ground. Cancellation of this drop is in practice done in less than about one millisecond at the time of cutoff. It can therefore be considered as practically instantaneous.
When the work goes from the "under imposed protective current" situation to the zero current situation, a modification also occurs in the potential of the work relative to the ground. This modification is considered to be due to electrochemical phenomena occurring essentially at the interface between the metal and the ground.
Knowledge of the potential jump which occurs at the moment of cutting of the protective current makes it possible to know what the actual potential was in the situation of active protection of the work.
Quantitative knowledge of the amplitudes and rates of change immediately after cutoff makes it possible to determine what electrochemical phenomena are involved when the work, on leaving the protective situation, changes to a corrosion situation.

Method and apparatus for analyzing the state of protection against corrosion of a work under cathodic protection


This invention relates to a personal computer having enhanced memory access capabilities, a memory element enabling such enhancement, and a method of operation of a personal computer. The invention contemplates that enhanced capabilities will be attained by enabling a choice between error detection technologies used.

Personal computer systems in general and IBM personal computers in particular have attained widespread use for providing computer power to many segments of today's modern society. Personal computer systems can usually be defined as a desk top, floor standing, or portable microcomputer that consists of a system unit having a single system processor and associated volatile and non-volatile memory, a display monitor, a keyboard, one or more diskette drives, a fixed disk storage, and an optional printer. One of the distinguishing characteristics of these systems is the use of a motherboard or system planar to electrically connect these components together. These systems are designed primarily to give independent computing power to a single user and are inexpensively priced for purchase by individuals or small businesses. Examples of such personal computer systems are IBM's PERSONAL COMPUTER AT and IBM's PERSONAL SYSTEM/2 Models 25, 30, L40SX, 50, 55, 65, 70, 80, 90 and 95.
These systems can be classified into two general families. The first family, usually referred to as Family I Models, use a bus architecture exemplified by the IBM PERSONAL COMPUTER AT and other "IBM compatible" machines. The second family, referred to as Family II Models, use IBM's MICRO CHANNEL bus architecture exemplified by IBM's PERSONAL SYSTEM/2 Models 50 through 95. The Family I models typically have used the popular INTEL 8088 or 8086 microprocessor as the system processor. These processors have the ability to address one megabyte of memory. The Family II models typically use the high speed INTEL 80286, 80386, and 80486 microprocessors which can operate in a real mode to emulate the slower speed INTEL 8086 microprocessor or a protected mode which extends the addressing range from 1 megabyte to 4 Gigabytes for some models. In essence, the real mode feature of the 80286, 80386, and 80486 processors provide hardware compatibility with software written for the 8086 and 8088 microprocessors.
Data being processed in high performance personal computers such as some of those mentioned above is conventionally written to, stored in and read from dynamic random access memory (DRAM) using conventional data storage technology. While such technology has been quite successful, persons skilled in the arts of computer design and use have known for some time that all DRAM has inherent soft errors. That is, data written to, stored in or read from DRAM will contain errors over time. The degree to which such error interfere with personal computer operation will vary with the particular application for which the computer is being used. An error rate acceptable for a personal computer used only for word processing may be found completely unacceptable for a personal computer used as a file server supporting financial record keeping and analysis applications necessary to the operation of an ongoing business venture.
Recognizing the inherency of DRAM data or soft errors, most personal computer design have adopted some known technology for guarding against adverse effects of such errors. The most common such technology is known as parity checking or parity. With parity checking, each predetermined number of bits of data used for transferring or storing information is accompanied by a parity bit used to validate the accuracy of the data bits. One typical arrangement uses one parity bit for eight data bits. Typically, such a parity design will detect an error of a single bit in a byte (eight bits). An alternate technology is known as error correcting code or ECC. ECC (depending upon its implementation) can detect errors of one or more bits in a word and can correct errors of one bit in a word. ECC typically adds to the data bits defining a word from four to seven bits used in the error detection and correction routines. ECC is, as a general matter, known and the present invention relies upon such known technology.
Prior to the present invention, personal computer designers and users essentially have been faced with the parity or ECC choice at a very early level in determining personal computer system capabilities. In particular, a user concerned with achieving high levels of reliability (in the sense of minimizing the impact of DRAM soft errors) would be compelled to select a machine designed to have ECC capability, even if many applications to be supported by that machine would be satisfactorily served by parity memory.
Further, there has been a trend over recent time toward packaging of memory elements in more readily handled forms. With increasing density of memory elements, in terms of quantities of data words stored, memory elements have moved from single chips to single inline memory modules (SIMM) and toward what has become known as DRAM cards. A DRAM card is a packaging of memory elements mounted on a substrate within a protective sleeve or enclosure and coupled to the remainder of a computer system by an appropriate pin and socket connection. In one form, such a DRAM card may have dimensions of approximately fifty four millimeters wide by eighty five millimeters long by three millimeters thick. It is contemplated that such dimensions may vary and will be reduced as technological advances permit. One advantage of DRAM cards is that such memory elements are readily removed and replaced from computer systems and may be handled by users almost as easily as the well known floppy disks with which all personal computer users are familiar. However, even with such development of the applicable technology, parity and ECC memory elements have remained non-interchangeable. That is, a user of a machine first configured for parity memory elements and wishing to change to ECC memory elements would be required to remove and replace all memory elements to effect the desired conversion.

Personal computer wherein ECC and partly error checking can be selectively chosen for memory elements installed in the system, memory elements enabling selective choice of error checking, and method


A carrier apparatus for use with an optical engine of a projection device is disclosed. The carrier apparatus includes a main frame and a support frame which is removably disclosed on the main frame. An adjustable mechanism includes a push device and an adjustable device. The push device is disposed onto an end portion of the support frame, while the adjustable device is disposed onto the push device. Operating the adjustable device can locally change the height of the support frame with respect to the main frame, thereby precisely positioning the optical engine in a suitable manner so that the image projected on the screen can be uniform without distortion.

1. Field of the Invention
The present invention relates to a carrier apparatus. In particular, it relates to a carrier apparatus for use with the optical engine of a projection apparatus. The height of the optical engine is adjustable with respect to the main frame.
2. Descriptions of the Related Art
In recent years, projector markets have well developed, quickly improving the quality of the products. Projectors play important roles in home entertainment and conference environments. However, because projectors are precise optical devices, any deviation from the light paths generated from the optical elements can cause imperfect output images, thus, reducing the imaging quality of the product.
Using a rear projection apparatus as an example, an optical engine must usually be attached to a carrier apparatus for fixation onto the housing of the projection apparatus. Even though the optical paths inside the optical engine have been ideally set and precisely adjusted, it is still very possible for the whole displayed image to tilt (which means the height of the image is uneven), even after the optical engine is associated with the carrier apparatus. In this case, the image displayed by the optical engine will be presented as a non-uniform rectangle (generally, a trapezoid), or even distorted to an irregular shape. This results in the decrease of the end product quality and therefore makes the product less competitive.
In general, the rear projection device is quite bulky. It is very difficult for a consumer, who has no specialized tools, to adjust the interior optical engine so that it is uniform in height and able to present a better image output. Thus, the adjustment work should be done before the products leave the factory. In the case of a malfunction, the product would need to be sent back to the factory for repair because the professional technicians would be able to implement the adjustment work. The factory technicians would than, among other traditional measures, insert support cushions or pads into the space between the optical engine and the carrier apparatus to assist in uniformly adjusting the level of the optical engine in light of the carrier apparatus. Unfortunately, this adjustment creates an unstable product. The process is also cost- and time-ineffective, making the projection product less competitive in the market.
Thus, it is critical to invent a product that not only simplifies the assembly and repair process, but also precisely and readily adjusts the relative level of an optical engine.


A semiconductor memory device has a data output device. The data output device is provided with a slew rate control unit for detecting the number of transitions of a plurality of output data to output slew rate control information; and an output driving unit for driving the plurality of output data with a pull-up drivability and a pull-down drivability adjusted based on the slew rate control information.

The present invention relates to a semiconductor device, and more particularly, to a semiconductor memory device including an output driver for outputting internal data to external.
A semiconductor memory device includes millions of memory cells. The semiconductor memory device basically performs a write operation to the memory cells and an input/output operation for reading out stored data of the memory cell to output them to external. To read out the stored data from the memory cell, the semiconductor memory device requires an output driver for outputting the stored data to the external.
FIG. 1 is a block diagram of a conventional output driver in a semiconductor memory device.
As shown, the conventional output driver includes a pre-driver 110 and a push-pull amplifier 120. The pre-driver 110 defines a logic state of an output data signal OUT and maintains the push-pull amplifier 120 of a high impedance (HI-Z) state when the output data signal OUT is not outputted. Herein, a first operating voltage VDDQ is a power source voltage having a high voltage, and a second operating voltage VSSQ is a ground voltage having a low voltage.
In the pre-driver 110, a signal at an up-data input node UP_DATA maintains a logic high level when the output data signal OUT is outputted as a logic high level, and a signal at a down-data input node DOWN_DATA maintains a logic low level when the output data signal OUT is outputted as a logic low level.
When the signal at the up-data input node UP_DATA becomes a logic low level and the signal at the down-data input node DOWN_DATA becomes a logic high level, all transistors included in the push-pull amplifier 120 are turned off. As a result, the output data signal OUT becomes a high impedance (HI-Z) state so that the output data is not outputted.
When both signals of the up-data input node UP_DATA and the down-data input node DOWN_DATA become a logic high level, a PMOS transistor of the push-pull amplifier 120 is turned on but an NMOS transistor of the push-pull amplifier 120 is turned off. As a result, the output data signal OUT is outputted with a logic high level.
When both signals of the up-data input node UP_DATA and the down-data input node DOWN_DATA become a logic low level, the PMOS transistor of the push-pull amplifier 120 is turned off but the NMOS transistor of the push-pull amplifier 120 is turned on. As a result, the output data signal OUT is outputted with a logic low level.
In general, a slew rate can be represented by a slop of the output data signal showing the ratio of a voltage to a time. For example, the slew rate may be expressed as "3V/ns" denoting a speed activated with amplitude of 3 V during 1 ns.
To transfer data between a semiconductor memory device and a system using the semiconductor memory device at high speed, an output driver of the semiconductor memory device maintains a uniform drivability. Thus, a maximum value and a minimum value of the slew rate of the output driver is preset, and the slew rate of the output driver should be larger than the maximum value regardless of logic states of the output data. On the contrary, if the slew rate of the output driver is too larger, current consumption of the output driver instantaneously increases. As a result, an operating voltage decreases and a ringing phenomenon occurs due to resistance and inductance of a power line. Accordingly, it is important to uniformly maintain the slew rate of the output driver.

Semiconductor memory device including output driver


A method and apparatus are provided for encoding and decoding a communication signal. Processes for encoding and decoding the communication signal use a first low density parity-check code (LDPC) construction and a second low density parity-check code construction that differs from the first low density parity-check code construction. Multilevel coding (MLC) is applied to protect each address bit of a signal point by an individual LDPC code. In one embodiment, the first level is coded with a progressive edge-growth LDPC code, the second level is coded with a Reed-Solomon LDPC code and the third level is left uncoded.

A communication channel, whether it is a fiber optic channel, a co-axial channel, a wire channel, a wireless channel, or a bus connecting locations in a system over which large amounts of data are transferred, can add noise and errors to information being transmitted over the channel. To correct for errors added by the communication channel, information can be sent in the form of codewords. In order to improve the performance of digital transmission schemes, coded modulation may be used to jointly optimize coding and modulation.
A variety of schemes for encoding and decoding a codeword for propagation through a communication channel exist. Some schemes may provide accuracy, and other schemes may provide fast decoding. In high speed data communication what is needed is a coded modulation scheme that provides for fast decoding procedures and effective error performance, but at the same time can be implemented without a significant amount of complexity.

Multilevel low density parity-check coded modulation


A multibeam scanner capable of scanning an image forming area with constant beam amounts of laser beams. The multibeam scanner of the invention performs automatic power control (APC) on each of a plurality of beam emitting points one by one during corresponding time durations, respectively, in a non-image forming area. The laser beam emitted last among the plurality of laser beams is controlled to reach a predetermined beam detecting position within the corresponding time duration. Before scanning the image forming area, the multibeam scanner determines a scan start timing upon the detection of the laser beam emitted at the beam detecting position, which has been stabilized during APC. This arrangement allows the laser diode to avoid wasting time again and again, as rise time for stabilizing the laser beam for performing APC and for identifying the scan start timing, and to secure the time durations as long as possible. It is therefore possible to perform APC against the laser diodes properly during the sufficient time durations and, at the same time, possible to determine the scan start timing precisely by detecting the stabilized laser beam.

1. Field of Invention
The invention relates to a multibeam scanner capable of scanning with constant light amounts of laser beams at a high scan cycle.
2. Description of Related Art
As is well-known in the art, a laser beam scanner is put to a number of uses. For example, a laser printer uses a laser beam scanner comprising a laser diode for emitting a laser beam. The laser beam scanner modulates the laser beam based on image signal and deflects the modulated laser beam by using a deflector, such as a polygon mirror, thereby sequentially scanning a photosensitive medium with the laser beam in a main-scanning direction to form a scanning line on the photosensitive medium. At the same time, the laser beam scanner moves the photosensitive medium in a moving direction opposite to a sub-scanning direction to form successive scanning lines. In such a scanning operation, a latent image is formed on the photosensitive medium, developed with toner as a visible image and, then, transferred to a recording sheet by a fixing unit.
However, the laser diode has a fundamental difficulty in stabilizing the light amount emitted. Even if the laser diode is driven with a constant driving current, the temperature of the laser diode increases due to its light emission. The luminous efficiency of the laser diode decreases with the temperature increase.
Therefore, in order to overcome such a drawback, there is performed, as disclosed in Japanese Patent Application No. 63-42432, automatic power control (APC) for feeding a driving current to the laser diode, so that the laser diode always emits the laser beam of appropriate light amount. More specifically, in APC, a control circuit controls the laser diode to emit the laser beam, whereat a photoreceptor detects the emitted laser diode and determines the light amount of the laser beam to give a feedback on the light amount to the control circuit. Upon reception of the feedback, the control circuit properly controls a constant-current circuit to feed an appropriate driving current based on the received feedback, so that the laser diode emits a laser beam of appropriate light amount.
Further, there is provided a beam detector (BD) positioned a predetermined distance before the scan start position in the laser scanner. The BD enables the start of scanning with the laser beam, deflected by the deflector at high speed, on the photosensitive medium. After a predetermined time duration has elapsed since the timing at which the BD detected the laser beam, the laser beam scanner starts scanning the photosensitive medium with the laser beam modulated based on image signals. As the BD only detects a laser beam of more than a threshold light amount, the variations in light amounts of the laser beam may cause a detection fault to destroy the above-mentioned timing. It is therefore preferable that such scan start timing detection is performed by the BD after completing APC.
There is enough time for a single-beam scanner comprising a single laser diode, which has been mentioned above, to perform APC and to detect the scan start timing after finishing forming a scanning line and before starting to form a next scanning line.
Against the above-described backdrop, there has been recently proposed a multibeam scanner that comprises a plurality of laser diodes for emitting a plurality of laser beams simultaneously. This multibeam scanner has an advantage of scanning the photosensitive medium with the laser beams, along a plurality of scanning lines, in the main-scanning direction simultaneously, and thereby is capable of exposing the photosensitive medium in a very short time.
The multibeam scanner may have therein a plurality of photoreceptors to detect the respective light amounts of the plurality of laser beams. It is, however, still difficult for the multibeam scanner to detect the light amounts of the laser beams while avoiding interference between the laser beams, because the laser beams are emitted in very close proximity to each other. The multibeam scanner will have to have an extremely complicated structure to resolve the above-mentioned problem.
The multibeam scanner can have a simple structure with a single BD, but cannot perform APC for all the laser diodes simultaneously. Thus, it is necessary to perform APC separately for every laser diode as disclosed in, for example, Japanese Patent No. 63-42432. FIG. 8 is a timing chart illustrating control timing for such a conventional multibeam scanner. The horizontal axis in FIG. 8 represents elapsed time. xe2x80x9cSOS (start of scanning)xe2x80x9d and xe2x80x9cEOS (end of scanning)xe2x80x9d stand for the start timing and the end timing of scanning, respectively. Further, timings for switching on and off laser diodes LD1, LD2 to emit laser beams are represented under headings of xe2x80x9cLD1xe2x80x9d and xe2x80x9cLD2xe2x80x9d, respectively. Timings of performing APC for the LD1 and LD2 are represented under headings xe2x80x9cAPC/LD1xe2x80x9d and xe2x80x9cAPC/LD2xe2x80x9d, respectively, and the timing at which the BD detects the laser beam is represented under a heading of xe2x80x9cBDxe2x80x9d.
As shown in FIG. 8, in the case where there are secured time durations separately for performing APC for the LD1 and LD2 and a time duration of BD beam detection, it is inevitable that the time durations for performing APC are shortened. Accordingly, the multibeam scanner does not have enough time to perform APC to precisely determine driving currents for the LD1 and LD2, and is incapable of stabilizing the laser beams emitted therefrom. There have been attempts to work around such a problem, in terms of circuitry of the multibeam scanner, by providing an A/D converter. However, this complicates the structure of the multibeam scanner and, at the same time, makes its cost-performance worse.
Also, in the case where the multibeam scanner scans at short scan cycle by, for example, speeding up the rotation of polygon mirror, the multibeam scanner does not get sufficient time for performing APC for the laser diodes. Thus, the laser beams will not be sufficiently stabilized.
The invention has been developed to resolve the above-mentioned and other problems, and especially to provide a multibeam scanner capable of scanning with laser beams with steady light amounts at a high scan cycle.
According to the invention, there is provided a multibeam scanner for scanning an image forming area with a plurality of laser beams and forming a plurality of scanning lines corresponding to the plurality of laser beams, comprising:
a plurality of beam emitting points that emit a plurality of laser beams, respectively;
a scan position changing unit that changes scan positions which the laser beams scan in the image forming area and in a non-image forming area;
a timing controller that controls, in synchronism with the scan position changing unit, each of the plurality of beam emitting points to emit the laser beam during a respective beam emitting period one by one in the non-image forming area, the timing controller controlling the beam emitting point that last emits the laser beam among the plurality of the beam emitting points to emit the laser beam at a predetermined beam detecting position in the non-image forming area during its beam emitting period;
a photoreceptor that detects each of the laser beams emitted one by one under the control of the timing controller, and outputs a beam amount signal indicating a beam amount of the laser beam;
a beam amount controller that controls, based on the corresponding beam amount signals, the beam amounts of the laser beams emitted by the beam emitting points, respectively;
a scan start timing detector that detects the last emitted laser beam at the predetermined beam detecting position in the non-image forming area, and determines a scan start timing based upon the detection of the laser beam at the beam detecting position; and
a scan controller that controls the beam emitting points, based on the scan start timing, to emit the laser beams, each of which beam amounts being controlled by the beam amount controller, thereby forming the plurality of scanning lines in the image forming area.
According to the invention, the multibeam scanner performs APC on each of the plurality of beam emitting points one by one during corresponding time durations, respectively, in the non-image forming area. The laser beam emitted last among the plurality of laser beams is controlled to reach the beam detecting position within the corresponding time duration by the timing controller. The beam detector detects the laser beam emitted at the beam detecting position, which has been stabilized during APC, and determines the scan start timing with very high precision.
In other words, the time duration provided to the beam emitting point that last emits the laser beam under the control of the timing controller, is used not only for performing APC for that last emitted laser beam, but also for identifying the scan start timing by using the beam detector. This allows the laser diodes to avoid wasting time again and again, as rise time for stabilizing the laser beam, and to secure the time durations as long as possible. It is therefore possible to perform APC against the laser diodes properly during the sufficient time durations and, at the same time, possible to determine the scan start timing precisely by detecting the stabilized laser beam.


A computer-implemented method of transferring a data string from an application to a data protection device. To provide a computer-implemented method of transferring a data string from an application to a data protection device that the database query contains the data string and the database query is coded in a database language.

Data protection devices are known from the state of the art in many different configurations and variants. Such data protection devices serve to subject parts of data to be processed in an application to a data protection operation. An example of such a data protection operation is, for example, the replacement of a credit card number as a data string in a data set by a token as a placeholder which does not permit an attacker to arrive at any conclusion about the actual card number. Further examples of a data protection operation are the generation of a hash value or validation of a secret number (PIN) as is usual in relation to card payments.
A purpose for such devices is to guarantee the necessary security of the data protection operation that is typically carried out outside the actual application. Such a separation between the application for data processing and the data protection device for carrying out the data protection operation also makes it possible to implement highly complex data protection operations without burdening the application.
It will be noted, however, that the data string to which the data protection operation is to be applied has to be transferred from the application to the data protection device, in which case the data protection device must transfer a response string back to the application. For that purpose known data protection devices have programming interfaces which are proprietary for the respective data protection device and are frequently highly complex, for example, PKCS #11, which are available to the programmers of the respective application in order to implement transfer of the data string to the data protection device in the application. Frequently, however, a data protection device is to be provided for a large number of applications programmed in different languages. In that case it would be necessary for the producer of the data protection device to provide a specific programming interface for each programming language of a respective application. By virtue of the complexity, the cost, and effort on the part of the producer of the data protection device, however, that is not a market standard procedure. As a result, the user of the data protection device usually does not have any possible way of using the data protection device in a simple fashion from all applications. In addition, it is usually not simply possible for the user to change from a data protection device of one manufacturer to a data protection device of another manufacturer as the programming, interfaces are completely different. The PKCS #11 standard has also not contributed to true standardisation as it is highly complex, and usually also requires a special library for each operating system and therefore has been comparatively little adapted.

Computer-implemented method of transferring a data string from an application to a data protection device


A circuit includes a bipolar transistor circuit including a first node, a second node, and a plurality of bipolar transistors coupled in parallel between the first node and the second node. The circuit further includes a drive circuit configured to switch on a first group of the plurality of bipolar transistors, the first group including a first subgroup and a second subgroup and each of the first subgroup and the second subgroup including one or more of the bipolar transistors. The drive circuit is further configured to switch off the first subgroup at the end of a first time period and switch off the second subgroup at a time instant before the end of the first time period.

Bipolar transistors such as IGBTs (Insulated Gate Bipolar Transistors) are widely used in different applications in the automotive and industrial field. For example, in motor control or drives applications, IGBTs are often used in a power stage for driving a load. Within such applications, the IGBTs may be cyclically switched on and off.
In electronic circuits, especially in power circuits that drive a load, diodes can be employed as free-wheeling elements that may prevent damage to transistors by suppressing voltage spikes or transients which may occur in switching operations.
In operation of bipolar semiconductor device, such as bipolar transistors and diodes, conduction losses occur. These conduction losses are dependent on a voltage across the respective device and current through the device.
Further, a charge carrier plasma with n-type charge carriers and p-type charge carriers is stored in a bipolar semiconductor device when the semiconductor device is in a conducting state, that is, when the semiconductor device is conducting a current. When an operation state of the semiconductor device changes from a conducting state to a non-conducting state these charges have to be removed from the respective device. This process is often referred to as reverse recovery process. During the reverse recovery process, the charge carriers flowing out of the device cause a reverse current. This reverse current multiplied with the voltage across the device during the reverse recovery process equals the power losses resulting from the reverse recovery process. The time integral of these losses equals the energy that is dissipated each time the device changes from the conducting state to the non-conducting state.
For example, in a half bridge circuit, that includes two semiconductor devices connected in series, losses are not only induced in the device that switches off but also in the other device that is going to take over the load current as this device sees typically a very high voltage, this device may e.g. be a freewheeling diode.
In general, at a given current rating and a given voltage blocking capability, devices with a low forward voltage (and low conduction losses) have a higher reverse recovery charge, and vice versa. Usually, the current rating of a device is chosen in accordance with the highest currents occurring in an application in which the device is implemented. A device with a high current rating has a large chip size and has a high reverse recovery charge. When the device operates at currents below the current rating, the device is over-dimensioned so that at low currents relatively high losses resulting from the reverse recovery charge occur.
It is therefore desirable to reduce transistor and diode losses in electronic circuit applications, in particular in power electronics applications.

Circuit with a plurality of bipolar transistors and method for controlling such a circuit


A motherboard of flexible display panel and the method for manufacturing the flexible display panel are provided, the motherboard of flexible display panel includes a carrier substrate and at least one flexible display panel unit formed on the carrier substrate; the flexible display panel unit includes a liner layer, a flexible substrate and a display element; the liner layer includes a first zone and a second zone, the liner layer of the first zone has a laser absorptivity lower than that of the liner layer of the second zone, and the liner layer of the second zone has a critical energy no larger than that of the liner layer of the first zone; the first zone is located at the edge region of the flexible display panel unit.

With the development of the techniques, the flexible display device has been widely used more and more. The flexible display device comprises an organic light-emitting diode display unit, an electrophoretic display device and the like. Due to the fact that the base substrate of the flexible display panel is a flexible substrate, it is difficult to form other display element thereon. The manufacture of a flexible display panel is primarily made in such a way that a carrier substrate (commonly a glass substrate) is taken as the carrier supporting the flexible substrate, then display element are formed on the flexible substrate, and finally, the flexible display panel and the glass substrate are separated from each other so as to obtain a flexible display panel.

Motherboard of flexible display panel and method for manufacturing flexible display panel


An object detection device comprises an active sensor, an amplifying circuit configured to divide and amplify a sensor signal outputted from said active sensor with respect to each a plurality of frequency bands through each amplifier, and a determining unit determining the presence or absence of a detection target object by comparing an output of said amplifying circuit with a predetermined threshold value. A noise determining unit controls a switching circuit so as to turn off a switch inserted between said determining unit and an amplifier having a band pass including a noise of a particular frequency, when determining that the noise of the particular frequency is produced constantly by using an analysis result outputted from a frequency analyzer detecting intensity of each frequency of the sensor signal.

In the past, there have been proposed an illumination system, which comprises a lighting apparatus and an object detection device comprising a sensor (a motion sensor). Then, the illumination system detects the presence or absence of a detection target object (e.g., a person) in a predetermined detection area via the object detection device, and activates the lighting apparatus during a predetermined time period upon detecting the presence. Thus, the illumination system can activate or deactivate the lighting apparatus automatically, and can prevent a user from forgetting to turn the lighting apparatus off and then can improve convenience and energy conservation. Especially, the illumination system is generally used in locations, such as stairs and passages of establishments, where it is necessary to activate the lighting apparatus to ensure security of a passerby, and where there is no problem if the lighting apparatus is activated only when there is the passerby.
Incidentally, in this kind of the illumination system, in the past, a PIR (Passive Infrared Ray) sensor mainly has been used for the object detection device. The PIR sensor is a passive type sensor, and senses temperature variations caused by a person's motion in a detection area, and outputs a sensor signal. This sensor is relatively cheap and can be used easily.
However, when the above illumination system with the sensor is installed in a location, such as a high ceiling in a factory, a distance from the sensor to the detection target object increases. Therefore, it is difficult to use the PIR sensor having a relatively short sensing distance. So, an active sensor having a relatively long sensing distance is used in such a location. The active sensor itself transmits a detection wave such as an electromagnetic wave, and then receives the detection wave reflected by the detection target object, and thereby detects the presence or absence of the detection target object in the detection area
For example, the active sensor includes a millimeter-wave sensor which transmits a millimeter wave as the detection wave and a distance measuring sensor. The millimeter-wave sensor comprises a Doppler sensor. The Doppler sensor transmits the millimeter wave to the detection area, and then receives the millimeter wave reflected by the detection target object moving in the detection area, and then outputs a sensor signal having a frequency, which is equivalent to a frequency difference between the transmitted millimeter wave and the received millimeter wave. The object detection device comprising the sensor determines the presence or absence of object moving in the detection area, based on the sensor signal outputted from the sensor, and controls to a lighting state of the lighting apparatus (e.g., see Japanese Patent Application Laid-Open No. 2009-168778).
However, if there is a noise source producing a noise of a particular frequency around the object detection device with the active sensor, the noise decreases a signal-to-noise ratio of the object detection device. Therefore, there is a problem that the sensor signal is buried in the noise and the object detection device can not detect the sensor signal, and thus sensitivity of detection decreases.

Object detection device and illumination system provided therewith

PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.


An oscillation circuit has: a first MOS transistor having a gate connected to a first node and a source connected to the ground; a second MOS transistor having a gate connected to a second node and a source connected to the ground; a current supply circuit supplying a control current; a threshold correction circuit supplying a correction current; and a charge-discharge circuit which supplies a charge current which is a superposition of the control current and the correction current to the first node and the second node alternately in response to potentials of drains of the first and the second MOS transistors. The threshold correction circuit increases the correction current as threshold voltages of the first and the second MOS transistors become large.

1. Field of the Invention
The present invention relates to an oscillation circuit. In particular, the present invention relates to an oscillation circuit including an astable multivibrator.
2. Description of the Related Art
An oscillation circuit is often configured with an astable multivibrator. A typical astable multivibrator charges and discharges two capacitors alternately to generate oscillation waveforms. A circuit for charging and discharging these capacitors is mounted in such the astable multivibrator. The voltages applied to the capacitors are fed back to the charge-discharge circuit, and the charge-discharge circuit charges and discharges the two capacitors in response to the applied voltages.
Oscillation frequency of the astable multivibrator is determined by the time required for charging and discharging the two capacitors. This charge-discharge time can be controlled easily by adjusting a charging current for charging the capacitor. Therefore, the oscillation frequency is often controlled by the charging current. The charging current can be used for controlling the oscillation frequency, and hence is referred to as a control current. In a VCO (Voltage Controlled Oscillator), a control current corresponding to a control voltage is generated and its oscillation frequency is controlled by the control current.
It is important that there is consistency between oscillation frequencies of a plurality of oscillation circuits. When a considerable number of semiconductor devices having the oscillation circuit are manufactured, large variation in the oscillation frequencies causes malfunctions in many semiconductor devices.
Japanese Unexamined Patent Publication JP-Sho-62-274913 (Patent document No. 1) indicates that variation in threshold voltages of MOS transistors in a circuit for supplying a control current charging the capacitors causes the variation in the oscillation frequencies. The patent document No. 1 discloses a voltage controlled oscillator which suppresses such a variation in the oscillation frequencies by canceling the variation in the threshold voltages of the MOS transistors.
Variation in the threshold voltages of MOS transistors that configures a feedback path for providing a feedback of the applied voltages to the capacitors to the charge-discharge circuit (for example, the MOS transistors that configures the inverter N3, N4 in FIG. 1 in the patent document No. 1) can also cause the variation in the oscillation frequencies. It is preferable in the oscillation circuit that the influences of the variation in the threshold voltages of the MOS transistors constituting the feedback path is eliminated and the variation in the oscillation frequencies is reduced.

Oscillation circuit and operation method thereof


Herein is reported a polypeptide comprising a first polypeptide and a second polypeptide each comprising in N-terminal to C-terminal direction at least a portion of an immunoglobulin hinge region, which comprises one or more cysteine residues, an immunoglobulin CH2-domain and an immunoglobulin CH3-domain, wherein the first, the second, or the first and the second polypeptide comprise the mutation Y436A (numbering according to the EU index).

The demand for cost efficient production processes has led to the necessity of optimization of the downstream purification, including one or more affinity chromatography steps. Larger volumes to be processed and harder requirements for the cleaning-in-place (CIP) protocols are some of the features that need to be solved (Hober, S., J. Chrom. B. 848 (2007) 40-47).
The purification of monoclonal antibodies by means of selective Fc-region affinity ligands is the most promising methodology for the large-scale production of therapeutic monoclonal antibodies. In fact, this procedure does not require establishing any interaction with the antigen specific part of the antibody, i.e. the Fab domain, which is, thus, left intact and can retain its properties (see Salvalaglio, M., et al., J. Chrom. A 1216 (2009) 8678-8686).
Due to its selectiveness, an affinity-purification step is employed early in the purification chain and thereby the number of successive unit operations can be reduced (see Hober supra; MacLennan, J., Biotechnol. 13 (1995) 1180; Harakas, N. K., Bioprocess Technol. 18 (1994) 259).
The ligands most adopted to bind selectively IgG are Staphylococcal protein A and protein G, which are able to establish highly selective interactions with the Fc-region of most IgGs in a region known as "consensus binding site" (CBS) (DeLano, W. L., et al., Science 287 (2000) 1279), which is located at the hinge region between the CH2 and CH3 domains of the Fc-region.
Staphylococcal protein A (SPA) is a cell wall associated protein domain exposed on the surface of the Gram-positive bacterium Staphylococcus aureus. SPA has high affinity to IgG from various species, for instance human, rabbit and guinea pig IgG but only weak interaction with bovine and mouse IgG (see the following Table) (see Hober supra; Duhamel, R. C., et al., J. Immunol. Methods 31 (1979) 211; Björk, L. and Kronvall, G., Immunol. J. 133 (1984) 969; Richman, D. D., et al., J. Immunol. 128 (1982) 2300; Amersham Pharmacia Biotech, Handbook, Antibody Purification (2000)).
speciessubclassprotein A bindinghumanIgG1++IgG2++IgG3−−IgG4++IgAvariableIgD−IgMvariablerabbitno distinction++guinea pigIgG1++IgG2++bovine+mouseIgG1+IgG2a++IgG2b+IgG3+IgMvariablechickenIgY−++: strong binding/+: medium binding/−: weak or no interaction
The heavy chain hinge-region between the CH2 and CH3 domains of IgG is able to bind several proteins beyond protein A, such as the neonatal Fc receptor (FcRn) (see DeLano and Salvalaglio supra).
The SPA CBS comprehends a hydrophobic pocket on the surface of the antibody. The residues composing the IgG CBS are Ile 253, Ser 254, Met 252, Met 423, Tyr 326, His 435, Asn 434, His 433, Arg 255 and Glu 380 (numbering of the IgG heavy chain residues according to the Kabat EU index numbering system). The charged amino acids (Arg 255, Glu 380) are placed around a hydrophobic knob formed by Ile 253 and Ser 254. This (can) result in the establishment of polar and hydrophilic interactions (see Salvalaglio supra).
In general, the protein A-IgG interaction can be described using two main binding sites: the first is positioned in the heavy chain CH2 domain and is characterized by hydrophobic interactions between Phe 132, Leu 136, Ile 150 (of protein A) and the IgG hydrophobic knob constituted by Ile 253 and Ser 254, and by one electrostatic interaction between Lys 154 (protein A) and Thr 256 (IgG). The second site is located in the heavy chain CH3 domain and is dominated by electrostatic interactions between Gln 129 and Tyr 133 (protein A) and His 433, Asn 434, and His 435 (IgG) (see Salvalaglio supra).
Lindhofer, H., et al. (J. Immunol. 155 (1995) 219-225) report preferential species-restricted heavy/light chain pairing in rat/mouse quadromas.
Jedenberg, L., et al. (J. Immunol. Meth. 201 (1997) 25-34) reported that SPA-binding analyses of two Fc variants (Fc13 and Fc31, each containing an isotypic dipeptide substitution from the respective other isotype) showed that Fc1 and Fc31 interact with SPA, while Fc3 and Fc13 lack detectable SPA binding. The rendered SPA binding of the Fc-region variant Fc31 is concluded to result from the introduced dipeptide substitution R435H and F436Y.
Today, the focus with respect to therapeutic monoclonal antibodies is on the generation and use of bispecific or even multispecific antibodies specifically binding to two or more targets (antigens).
The basic challenge in generating multispecific heterodimeric IgG antibodies from four antibody chains (two different heavy chains and two different light chains) in one expression cell line is the so-called chain association issue (see Klein, C., et al., mAbs 4 (2012) 653-663). The required use of different chains as the left and the right arm of the multispecific antibody leads to antibody mixtures upon expression in one cell: the two heavy chains are able to (theoretically) associate in four different combinations (two thereof are identical), and each of those can associate in a stochastic manner with the light chains, resulting in 24 (=a total of 16) theoretically possible chain combinations. Of the 16 theoretically possible combinations ten can be found of which only one corresponds to the desired functional bispecific antibody (De Lau, W. B., et al., J. Immunol. 146 (1991) 906-914). The difficulties in isolating this desired bispecific antibody out of complex mixtures and the inherent poor yield of 12.5% at a theoretical maximum make the production of a bispecific antibody in one expression cell line extremely challenging.
To overcome the chain association issue and enforce the correct association of the two different heavy chains, in the late 1990s Carter et al. from Genentech invented an approach termed "knobs-into-holes" (KiH) (see Carter, P., J. Immunol. Meth. 248 (2001) 7-15; Merchant, A. M., et al., Nat. Biotechnol. 16 (1998) 677-681; Zhu, Z., et al., Prot. Sci. 6 (1997) 781-788; Ridgway, J. B., et al., Prot. Eng. 9 (1996) 617-621; Atwell, S., et al., J. Mol. Biol. 270(1997) 26-35; and U.S. Pat. No. 7,183,076). Basically, the concept relies on modifications of the interface between the two CH3 domains of the two heavy chains of an antibody where most interactions occur. A bulky residue is introduced into the CH3 domain of one antibody heavy chain and acts similarly to a key ("knob"). In the other heavy chain, a "hole" is formed that is able to accommodate this bulky residue, mimicking a lock. The resulting heterodimeric Fc-region can be further stabilized by the introduction/formation of artificial disulfide bridges. Notably, all KiH mutations are buried within the CH3 domains and not "visible" to the immune system. In addition, properties of antibodies with KiH mutations such as (thermal) stability, FcγR binding and effector functions (e.g., ADCC, FcRn binding) and pharmacokinetic (PK) behavior are not affected.
Correct heavy chain association with heterodimerization yields above 97% can be achieved by introducing six mutations: S354C, T366W in the "knob" heavy chain and Y349C, T366S, L368A, Y407V in the "hole" heavy chain (see Carter supra; numbering of the residues according to the Kabat EU index numbering system). While hole-hole homodimers may occur, knob-knob homodimers typically are not observed. Hole-hole dimers can either be depleted by selective purification procedures or by procedures as outlined below.
While the issue of random heavy chain association has been addressed, also correct light chain association has to be ensured. Similar to the KiH CH3 domain approach, efforts have been undertaken to investigate asymmetric light chain-heavy chain interactions that might ultimately lead to full bispecific IgGs.
Roche recently developed the CrossMab approach as a possibility to enforce correct light chain pairing in bispecific heterodimeric IgG antibodies when combining it with the KiH technology (see Klein supra; Schaefer. W., et al., Proc. Natl. Acad. Sci. USA 108 (2011) 11187-11192; Cain, C., SciBX 4 (2011) 1-4). This allows the generation of bispecific or even multispecific antibodies in a generic fashion. In this format, one arm of the intended bispecific antibody is left untouched. In the second arm, the whole Fab region, or the VH-VL domains or the CH1-CL domains are exchanged by domain crossover between the heavy and light chain. As a consequence, the newly formed "crossed" light chain does not associate with the (normal, i.e. not-crossed) heavy chain Fab region of the other arm of the bispecific antibody any longer. Thus, the correct "light chain" association can be enforced by this minimal change in domain arrangement (see Schaefer supra).
Zhu et al. introduced several sterically complementary mutations, as well as disulfide bridges, in the two VL/VH interfaces of diabody variants. When the mutations VL Y87A/F98M and VH V37F/L45W were introduced into the anti-p185HER2 VL/VH interface, a heterodimeric diabody was recovered with >90% yield while maintaining overall yield and affinity compared with the parental diabody (see Zhu supra).
Researchers from Chugai have similarly designed bispecific diabodies by introduction of mutations into the VH-VL interfaces (mainly conversion of Q39 in VH and Q38 in VL to charged residues) to foster correct light chain association (WO 2006/106905; Igawa, T., et al., Prot. Eng. Des. Sel. 23 (2010) 667-677).
In WO2011097603 a common light chain mouse is reported.
In WO2010151792 a bispecific antibody format providing ease of isolation is provided, comprising immunoglobulin heavy chain variable domains that are differentially modified, i.e. heterodimeric, in the CH3 domain, wherein the differential modifications are non-immunogenic or substantially non-immunogenic with respect to the CH3 modifications, and at least one of the modifications results in a differential affinity for the bispecific antibody for an affinity reagent such as protein A, and the bispecific antibody is isolable from a disrupted cell, from medium, or from a mixture of antibodies based on its affinity for protein A.
The neonatal Fc-receptor (FcRn) is important for the metabolic fate of antibodies of the IgG class in vivo. The FcRn functions to salvage IgG from the lysosomal degradation pathway, resulting in reduced clearance and increased half-life. It is a heterodimeric protein consisting of two polypeptides: a 50 kDa class I major histocompatibility complex-like protein (α-FcRn) and a 15 kDa β2-microglobulin (β2m). FcRn binds with high affinity to the CH2-CH3 portion of the Fc-region of an antibody of the class IgG. The interaction between an antibody of the class IgG and the FcRn is pH dependent and occurs in a 1:2 stoichiometry, i.e. one IgG antibody molecule can interact with two FcRn molecules via its two heavy chain Fc-region polypeptides (see e.g. Huber, A. H., et al., J. Mol. Biol. 230 (1993) 1077-1083).
Thus, the in vitro FcRn binding properties/characteristics of an IgG are indicative of its in vivo pharmacokinetic properties in the blood circulation.
In the interaction between the FcRn and the Fc-region of an antibody of the IgG class different amino acid residues of the heavy chain CH2- and CH3-domain are participating.
Different mutations that influence the FcRn binding and therewith the half-life in the blood circulation are known. Fc-region residues critical to the mouse Fc-region-mouse FcRn interaction have been identified by site-directed mutagenesis (see e.g. Dall'Acqua, W. F., et al. J. Immunol 169 (2002) 5171-5180). Residues I253, H310, H433, N434 and H435 (numbering according to Kabat EU index numbering system) are involved in the interaction (Medesan, C., et al., Eur. J. Immunol. 26 (1996) 2533-2536; Firan, M., et al., Int. Immunol. 13 (2001) 993-1002; Kim, J. K., et al., Eur. J. Immunol. 24 (1994) 542-548). Residues I253, H310, and H435 were found to be critical for the interaction of human Fc-region with murine FcRn (Kim, J. K., et al., Eur. J. Immunol. 29 (1999) 2819-2885).
Methods to increase Fc-region (and likewise IgG) binding to FcRn have been performed by mutating various amino acid residues in the Fc-region: Thr 250, Met 252, Ser 254, Thr 256, Thr 307, Glu 380, Met 428, His 433, and Asn 434 (see Kuo, T. T., et al., J. Clin. Immunol. 30 (2010) 777-789; Ropeenian, D. C., et al., Nat. Rev. Immunol. 7 (2007) 715-725).
The combination of the mutations M252Y, S254T, T256E have been described by Dall'Acqua et al. to improve FcRn binding by protein-protein interaction studies (Dall'Acqua, W. F., et al. J. Biol. Chem. 281 (2006) 23514-23524). Studies of the human Fc-region-human FcRn complex have shown that residues I253, S254, H435 and Y436 are crucial for the interaction (Firan, M., et al., Int. Immunol. 13 (2001) 993-1002; Shields, R. L., et al., J. Biol. Chem. 276 (2001) 6591-6604). In Yeung, Y. A., et al. (J. Immunol. 182 (2009) 7667-7671) various mutants of residues 248 to 259 and 301 to 317 and 376 to 382 and 424 to 437 have been reported and examined.
In WO 2014/006217 dimeric proteins with triple mutations are reported. Crystal structure at 2.8 Angstrom of an FcRn/heterodimeric Fc complex regarding the mechanism of pH-dependent binding was reported by Martin, W., et al. (Mol. Cell. 7 (2001) 867-877). In U.S. Pat. No. 6,277,375, immunoglobulin like domains with increased half-lives are reported. Shields, R. L., et al., reported high resolution mapping of the binding site on human IgG1 for Fc gamma RI, Fc gamma RII, Fc gamma RIII, and FcRn and design of IgG1 variants with improved binding to the Fc gamma R (Biochem. Mol. Biol. 276 (2001) 6591-6604). The delineation of the amino acid residues involved in transcytosis and catabolism of mouse IgG1 was reported by Medesan, C., et al. (J. Immunol. 158 (1997) 2211-2217). In US 2010/0272720 antibody fusion proteins with a modified FcRn binding site are reported. The production of heterodimeric proteins is reported in WO 2013/060867. Qiao, S.-W., et al. reported the dependence of antibody-mediated presentation of antigen on FcRn (Proc. Natl. Acad. Sci. USA 105 (2008) 9337-9342.

Fc-region variants with improved protein A-binding


A fixture support assembly for supporting a lighting or fan fixture on a drop ceiling having a grid supporting structure. The assembly includes a U-shaped bar with an upward directed channel and a channel bottom, two end brackets integral with the bar, a clamp member slidable within the channel, and an electrical box. The end brackets include an inner leg for resting on the horizontal ledges of adjacent T-rails and outer legs for loosely fitting over the top of the T-rails. A slot is provided in the channel bottom extending from one end to slightly past the center of the bar. A fastening arrangement connects the electrical box to the clamp member and in a loosened state enables positioning of the electrical box with respect to the bar.

An adjustable mounting bracket for supporting electrical fixtures was disclosed in co-pending U.S. application Ser. No. 11/089,386, filed Mar. 24, 2005, which is commonly owned by the assignee of the present invention and the contents of which are incorporated herein in their entirety by reference thereto. The adjustable mounting bracket of U.S. Ser. No. 11/089,386 enabled rapid mounting of an electrical fixture on the T-rails of a drop ceiling with the load suspended from structurally sound portions of the assembly rather than from the electrical box.
The present invention is a fixture support assembly that facilitates rapid hanging of an electrical fixture from the grid arrangement of a suspended or drop ceiling and also is of simplified construction to enable production at low cost.

Adjustable fixture mounting bracket for suspended ceiling


An update block for an adaptive RAM-based equalizer filter configuration includes a multiplier, an adder, and a plurality of delay units. The multiplier, adder, and delay units are coupled in an manner so as to have the capability to perform full-rate equalizer filter coefficient adaptation. In accordance with another embodiment of the invention, a method of updating a coefficient signal for an adaptive RAM-based equalizer filter configuration is provided. The method selectively variably delays an error signal sample produced by the adaptive RAM-based equalizer filter configuration and an equalizer filter input signal sample and computes with selectively variably error signal sample and the selectively variably delayed equalizer filter input signal sample. Finally, the coefficient signal is updated by adding the product to the coefficient signal.

As is well-known, an equalizer filter may be implemented in either the direct form or the transpose form. See, for example, Chapter 9 of Principles of CMOS VLSI Design, by N. Weste and K. Eshraghian, available from Addison-Wesley Publishing Company, 1994, herein incorporated by reference. The transpose form is frequently employed because it provides a pipelined filter structure. An equalizer filter or equalizer filter configuration in this form typically employs one multiply-accumulate (MAC) unit and one delay register per tap of the equalizer filter. However, an equalizer filter may exploit the feature that the clock frequency of the MAC units employed in the equalizer filter may exceed the input data rate or signal sample rate for the filter. In such a structure or configuration, if the clock frequency of the MAC units is F times faster than the signal sample rate, F being a positive integer, fewer MAC units may be employed because the operation of the MAC units may be time-multiplexed. Therefore, a single MAC unit may be utilized in a manner to implement several taps of the filter, referred to in this context as a "filter block." In addition, a random access memory-based (RAM-based) filter architecture may exploit this time-multiplexing approach and also reduce the number of delay registers needed by using random access memory instead.
In an adaptive Least-Mean-Squared (LMS) equalizer employing a RAM-based filter architecture, referred to in this context as a RAM-based equalizer filter configuration, the equalizer filter coefficients are typically assumed to be available from storage. Thus, the adaptation or updating of the coefficients is typically performed "off-line" by an update block. The problem with such an approach is that it reduces the convergence rate of the equalizer output signal due, at least in part, to the delay introduced by "off-line" equalizer filter coefficient adaptation. It may also require additional memory. Therefore, a need exists for an update block or equalizer filter coefficient adaptation technique in which the convergence rate may be improved.

Update block for an adaptive equalizer filter configuration


A method of manufacturing an electrolyte membrane for fuel cells with improved durability for fuel cells includes: preparing a substrate; applying a first ionomer solution onto the substrate; inserting a porous support into the first ionomer solution to impregnate the first ionomer solution in the porous support; allowing the first ionomer solution-impregnated porous support to stand; applying a second ionomer solution to the first ionomer solution-impregnated porous support; and drying the porous support.

Electrolyte membranes in proton exchange membrane fuel cells (PEMFCs) function to conduct protons. In order to conduct the protons, electrolyte membranes are manufactured using ionomers. The ionomers impregnate water to selectively transport protons produced at an anode to a cathode.
Electrolyte membranes undergo great shrinkage and expansion based on impregnation of water because they are made of ionomers. In an attempt to compensate for this phenomenon, electrolyte membranes are manufactured by impregnating ionomers using porous polytetrafluoroethylene (PTFE) as a support. Generally used porous PTFE is an expanded PTFE produced by expanding PTFE, which is simply referred to as "e-PTFE".
All pores of e-PTFE should be impregnated with ionomers in order to form channels through which protons are transported. However, small pores of e-PTFE cannot be easily filled due to considerably high inner pressure. Unfilled pores cannot form a channel, thus negatively affecting the performance and durability of fuel cells.
For this reason, there is increasing need for methods for manufacturing electrolyte membranes which are capable of preventing foaming to provide excellent durability and retain superior performance.
The above information disclosed in this Background section is provided only for enhancement of understanding of the background of the invention, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

Method of manufacturing electrolyte membrane with high-durability for fuel cell


An electrolytic ozone generating apparatus comprising a closely adhered electrode structure of. (i) an anode composed of an electrically conductive porous material carrying an ozone generating catalyst, PA0 (ii) a perfluorocarbonsulfonic acid ion-exchange membrane which is a solid electrolyte, and PA0 (iii) a cathode composed of a gas electrode carrying a catalyst, and PA0 means for supplying an oxygen-containing gas to the cathode side,. wherein the gas electrode as the cathode has a hydrophilic property and a hydrophobic property and carries a catalyst unevenly distributed therein at the ion-exchange membrane side, and a process for generating ozone using the apparatus. The electrolysis is conducted while supplying an oxygen-containing gas to the cathode side.

Ozone is widely used in various fields, such as water treatment, foods, medical hygiene, semiconductor production, etc., as a strong oxidizing agent. Ozone is usually produced by a discharging method or an electrolytic method but recently an electrolytic method capable of producing ozone in high concentration has been mainly used.
The electrolytic ozone generating method is the anodic electrolytic reaction according to the formula (1) below with the oxygen generating reaction according to the formula (2) below occurring as a side reaction. EQU 3H.sub.2 O.fwdarw.O.sub.3 +6H.sup.+ +6e (1) EQU 2H.sub.2 O.fwdarw.O.sub.2 +4H.sup.+ +4e (2)
On the other hand, the cathodic reaction is usually a hydrogen generating reaction according to the formula (3) below but by supplying an oxygen-containing gas, the oxygen reduction reaction of formula (4) can also occur. EQU 2H.sup.+ +2e.fwdarw.H.sub.2 ( 3) EQU O.sub.2 +4H.sup.+ +4e.fwdarw.2H.sub.2 O (4)
U.S. Pat. No. 4,416,747 discloses a process for generating hydrogen at the cathode side and ozone and oxygen at the anode side by carrying out an electrolysis using an ion-exchange membrane as the electrolyte. Also, U.S. Pat. No. 4,541,989 discloses a process for producing ozone without generation of hydrogen from a cathode using a tetrafluoroborate as the electrolyte, an oxygen reduction cathode as the cathode, and glassy carbon as the anode. Furthermore, JP-B-2-44908 (the term "JP-B" as used herein means an "examined published Japanese patent application") discloses a process for generating ozone by combining an ion-exchange membrane as the electrolyte and an oxygen reduction electrode.
However, in the process described in U.S. Pat. No. 4,416,747 described above, the hydrogen generated at the cathode is originally unnecessary and a means for treating hydrogen rather becomes necessary. In addition, there is a further disadvantage in that some of the hydrogen intermixes with an anodic gas containing oxygen and ozone through the membrane with the system becoming hazardous if the explosion limit is reached. Also, the intermixing of hydrogen is not only dangerous but also in the case that ozone is generated for washing semiconductors, a disadvantage occurs because the concentration of hydrogen in the oxygen is over several hundreds ppm. This is over the upper concentration limit of hydrogen, with the result that the ozone thus generated cannot be used for washing semiconductors.
Furthermore, the theoretical decomposition voltage for generating ozone by the combination of formula (1) and formula (2) described above is 1.5 V, which is higher than the decomposition voltage of 1.2 V using conventional water electrolysis by the combination of formula (2) and formula (3), the cell voltage under a practical electrolytic conditions, for example, 100 A/dm.sup.2, is high as about 3.3 V, and hence the amount of electric power consumed becomes very high.
Also, in the process described in U.S. Pat. No. 4,541,989 described above, to obtain ozone with good efficiency, it becomes necessary to maintain the electrolytic cells at a low temperature by cooling the electrolytic cells. However, although the working characteristics of the gas electrode used for oxygen reduction are excellent at high temperature, the working characteristics thereof are quite low at low temperatures. Thus, there is the disadvantage that the process can be operated from a practical standpoint at a low electric current density only.
Furthermore, the process described in JP-B-2-44908 described above can be safely used to produce ozone at a high concentration but there is the disadvantage that the electric current density must also be kept at a low density from the standpoint of the working characteristics and hence ozone cannot be produced with good efficiency.
For generating ozone with good efficiency, it is desirable to conduct the electrolysis at a relatively low temperature of not higher than 60.degree. C. and at a current density of at least 50 A/dm.sup.2 but hitherto, a gas electrode which sufficiently functions under these conditions has not yet been found.

Apparatus for electrolytic ozone generation


A shoring adapter configured for spreading cargo loads, in particular heavy cargo loads, to be loaded on board of a transport aircraft, includes at least one base portion configured to be placed on a standardized aircraft cargo pallet and a cargo adapter portion configured to accommodate the cargo load. In operation, the cargo adapter portion is mounted on top of the at least one base portion. The at least one base portion includes a lower frame assembly, an upper frame assembly and at least one elastic support assembly. The at least one elastic support assembly is arranged between the lower and upper frame assemblies such that, in operation, the upper frame assembly is elastically supported in a vertical direction by the at least one elastic support assembly on the lower frame assembly.

It is a legal requirement for aircraft operators to ensure that all aircraft limitations are not exceeded during operation. The European Union regulations specifying minimum safety and related procedures for commercial passenger and cargo fixed-wing aviation, EASA AIR OPS, specifies more exactly that "An operator must comply with additional structural limits such as the floor strength limitations, the maximum load per running metre, the maximum mass per cargo compartment, and/or the maximum seating limits . . . " (CAT POL MAB.100 (Commercial Air Transport Performance Operating Limitations Mass and Balance)/Mass and Balance—General, (c) Aeroplane loading).
Currently, the methods that are used to spread heavy cargo loads on board of civil transport aircraft are based on SAE document ARP5596. This document outlines the standard industry methods to calculate and perform shoring (load spreading) that is required on board of civil transport aircraft whenever a piece of cargo to be carried exceeds the aircraft's maximum allowable limits in area load, running load of both. It provides . . . the engineering methods needed to properly design a shoring arrangement.
This SAE document and the methods described within are used as a baseline for the aircraft type specific shoring manuals, such as e.g. "Boeing Shoring Guidelines for outsized Cargo" D043U325-01 (Boeing B747-8F), D6-35527 (Boeing B747-400).
In these documents, two main methods are described as effective ways of spreading the weight over a greater surface, and thus keeping the resulting aircraft floor loads within the limitations specified by the airframers AFM (aircraft flight manual): Free span shoring (ARP5596: chapter 4.3) (see also FIG. 1) and Pyramid shoring (ARP5596: chapter 5.3) (see also FIG. 2).
The free span shoring methods basically consist in locating the concentrated load on an arrangement of adequate stiffness materials providing a larger base in order to better distribute the total load over a larger area. The critical parameter in achieving this result is the total stiffness of the materials used, expressed as an EI value in lb×in2 (N×cm2), where:    E is the Young modulus of the material, in lb/in2 or N/cm2     I is the vertical moment of inertia of the individual piece of material", in cm4
The calculation method takes into account that the aircraft's floor structure is elastic and the fundamental parameter for computing any free span shoring arrangement is the floor's elasticity factor, which can be obtained only from the aircraft's manufacturer. The fundamental equations to be used for such computation are those for finite length beams on elastic foundations [source of equations in SAE document: "Formulas for stress and strain", Roark & Young, 1985, © McGraw Hill Inc. Publishers (section 7.5, Beams on elastic foundations)].
The main factor that influences the effectiveness of a shoring arrangement is given by:
  β  =            (              K                  4                    EI                    )              1      /      4      where K represents an aircraft floor elasticity factor
  (            l            b              i                    n        2              )an EI represents the shoring material stiffness (lb×in2)
The calculation method solves β by determining the minimum EI, whilst K is a given constant depending on aircraft type and floor section.
When the load is heavy and concentrated enough to require an impractical (freespan) shoring arrangement, pyramid shoring is a technique which allows enlarging the bearing length of the load, making it in fact equivalent to a longer one, in order to reduce primary shoring requirements.
The freespan shoring and the pyramid shoring both require to create customized solutions for each individual heavy shipment, leading to:    Long lead times required, due to required engineering calculation    High costs (material+manhours)    Not re-usable
It is therefore desirable to provide an improved shoring adapter which enables to reduce at least some of the above shortcomings.