A GPS receiver that acquires and tracks a split-C/A code separately aligns with the received signal the phases of a locally-generated 10.23 MHz square wave, which can be thought of as a 20.46 MHz square-wave code, and a locally-generated 1.023 MHz C/A code. The receiver first aligns the phase of the locally-generated square-wave code with the received signal, and tracks one of the multiple peaks of the split-C/A code autocorrelation function. It then shifts the phase of the locally-generated C/A code with respect to the phase of the locally-generated square-wave code, to align the local and the received C/A codes and position the correlators on the center peak of the split-C/A. The receiver then tracks the center peak directly, using a locally-generated split-C/A code.

A GPS receiver determines its global position based on the signals it receives from orbiting GPS or other satellites. The GPS satellites transmit signals using two carriers, namely, an L1 carrier at 1575.42 MHz and an L2 carrier at 1227.60 MHz. Each carrier is modulated by at least a binary pseudorandom (PRN) code, which consists of a to seemingly random sequence of ones and zeros that periodically repeat. The ones and zeros in the PRN code are referred to as "code chips," and the transitions in the code from one to zero or zero to one, which occur at "code chip times," are referred to as "bit transitions." Each satellite uses a unique PRN code, and thus, a GPS receiver can associate a received signal with a particular satellite by determining which PRN code is included in the signal.
The GPS receiver calculates the difference between the time a satellite transmits its signal and the time that the receiver receives the signal. The receiver then calculates its distance, or "pseudorange," from the satellite based on the associated time difference. Using the pseudoranges from at least four satellites, the receiver determines its global position.
To determine the time difference, the GPS receiver synchronizes a locally-generated PRN code with the PRN code in the received signal by aligning the code chips in each of the codes. It then determines how much the locally-generated PRN code is shifted, in time, from the known timing of the satellite PRN code at the time of transmission, and calculates the associated pseudorange. The more closely the GPS receiver aligns the locally-generated PRN code with the PRN code in the received signal, the more precisely the GPS receiver can determine the associated time difference and pseudorange and, in turn, its global position.
The code synchronization operations include acquisition of the satellite PRN code and tracking the code. To acquire the PRN code, the GPS receiver generally makes a series of correlation measurements that are separated in time by a code chip. After acquisition, the GPS receiver tracks the received code. It generally makes "early-minus-late" correlation measurements, i.e., measurements of the difference between (i) a correlation measurement associated with the PRN code in the received signal and an early version of the locally-generated PRN code, and (ii) a correlation measurement associated with the PRN code in the received signal and a late version of the local PRN code. The GPS receiver then uses the early-minus-late measurements in a delay lock loop (DLL), which produces an error signal that is proportional to the misalignment between the local and the received PRN codes. The error signal is used, in turn, to control the PRN code generator, which shifts the local PRN code essentially to minimize the DLL error signal.
The GPS receiver also typically aligns the satellite carrier with a local carrier using correlation measurements associated with a punctual version of the local PRN code. To do this the receiver uses a carrier tracking phase lock loop.
A GPS receiver receives not only line-of-sight, or direct path, satellite signals but also multipath signals, which are signals that travel along different paths and are reflected to the receiver from the ground, bodies of water, nearby buildings, etc. The multipath signals arrive at the GPS receiver after the direct-path signal and combine with the direct-path signal to produce a distorted received signal. This distortion of the received signal adversely affects code synchronization operations because the correlation measurements, which measure the correlation between the local PRN code and the received signal, are based on the entire received signal--including the multipath components thereof. The distortion may be such that the GPS receiver attempts to synchronize to a multipath signal instead of to the direct-path signal. This is particularly true for multipath signals that have code bit transitions that occur close to the times at which code bit transitions occur in the direct-path signal.
One way to more accurately synchronize the received and the locally-generated PRN codes is to use the "narrow correlators" discussed in U.S. Pat. Nos. 5,101,416; 5,390,207 and 5,495,499, all of which are assigned to a common assignee and incorporated herein by reference. It has been determined that narrowing the delay spacing between early and late correlation measurements substantially reduces the adverse effects of noise and multipath signal distortion on the early-minus-late measurements.
The delay spacing is narrowed such that the noise correlates in the early and late correlation measurements. Also, the narrow correlators are essentially spaced closer to a correlation peak that is associated with the punctual PRN code correlation measurements than the contributions of many of the multipath signals. Accordingly, the early-minus-late correlation measurements made by these correlators are significantly less distorted than they would be if they were made at a greater interval around the peak. The closer the correlators are placed to the correlation peak, the more the adverse effects of the multipath signals on the correlation measurements are minimized. The delay spacing can not, however, be made so narrow that the DLL can not lock to the satellite PRN code and then maintain code lock. Otherwise, the receiver cannot track the PRN code in the received signal without repeatedly taking the time to re-lock to the code.
With conventional GPS satellites, the L1 carrier is modulated by two PRN codes, namely, a 1.023 MHz C/A code, and a 10.23 MHz P-code that is encrypted with an encryption code that is known only to government-classified users, such as the military. The L2 carrier is modulated by the encrypted P-code. Generally, a GPS receiver constructed in accordance with the above-referenced patents acquires the satellite signal using a locally-generated C/A code and a locally-generated L1 carrier. After acquisition, the receiver synchronizes the locally-generated C/A code and L1 carrier with the C/A code and L1 carrier in the received signal, using the narrow correlators in a DLL and a punctual correlator in the carrier tracking loop. The receiver may then use the C/A code tracking information to track the L1 and/or L2 P-codes, which have known timing relationships with the C/A code, and with each other.
In a new generation of satellites, the L2 carrier is also modulated by a C/A code that is, in turn, modulated by a 10.23 MHz square wave. The square wave modulated C/A code, which we refer to hereinafter as the "split C/A code," has maximums in its power spectrum at offsets of .+-.10 MHz from the L2 carrier, or in the nulls of the power spectrum of the P-code. The split C/A code can thus be selectively jammed, as necessary, without jamming the L2 P-code.
The autocorrelation function associated with the split C/A code has an envelope that corresponds to the autocorrelation of the 1.023 MHz C/A code and multiple peaks within the envelope the correspond to the autocorrelation of the 10.23 MHz square wave. There are thus 20 peaks within a two chip C/A code envelope, or a square wave autocorrelation peak every 0.1 C/A code chips. The multiple peaks associated with the square wave are each relatively narrow, and thus, offer increased code tracking accuracy, assuming the DLL tracks the correct narrow peak.
It is our understanding that known GPS receivers acquire and track the split-C/A code in a conventional manner, using a locally-generated split-C/A code and L2 carrier. The receivers thus attempt to align the code chips of a receiver-generated split-C/A code with the code chips of the received split-C/A code, to track the center peak of the square-wave autocorrelation function. In the absence of multipath signals, the receivers track the center peak by tracking a peak that has the largest amplitude. If multipath signals are included in the received signal, however, the amplitude of the center peak of the square-wave autocorrelation function may not be discernibly greater than the amplitudes of nearby peaks. Accordingly, the DLL may track a peak that is 0.1 or 0.2 C/A code chips away from the center peak, and the receiver thus produce correspondingly inaccurate position measurements.


In a phase locked loop (PLL), phase shifters shift a phase of an input signal. Based on the phases of the input signal, the shifted signals, and a frequency division output signal, phase frequency detectors (PFDs) generate phase difference signals. In response to the phase difference signals, charge pumps (CPs) control output voltages thereof. Based on the output voltages of the CPs, a voltage controlled oscillator (VCO) outputs an output signal. A frequency divider divides the frequency of the output signal from the VCO to generate the frequency division output signal. A circulator outputs the frequency division output signal to one of the PFDs at a proper timing. A modulator reduces quantization errors of the frequency divider.

1. Field of Invention
The present invention relates to a phase locked loop (PLL). More particularly, the present invention relates to a PLL employing a plurality of phase frequency detectors (PFDs) and charge pumps (CPs) to accomplish fractional frequency division.
2. Description of Related Art
In communication systems or computer systems, a PLL generates output clock signals having synchronizing rising edges (or falling edges) with an input reference clock signal.
Conventionally, the PLL includes a phase frequency detector (PFD), a charge pump (CP), a low-pass filter (LPF), a voltage controlled oscillator (VCO), and a frequency divider. The PFD compares the phase of an input signal with the phase of a frequency division signal fed back from the frequency divider so as to generate a control signal and provide the same to the CP. In accordance with the control signal, the CP determines if an output voltage of the CP is increased or decreased. The LPF is capable of filtering high frequency spurs of the output voltage of the CP. The VCO receives the filtered output voltage from the CP so as to generate an output signal. The frequency divider divides the frequency of the output signal from the VCO to generate the frequency division signal and transmits the frequency division output signal to the PFD.
Quantization errors inevitably occur when a fractional frequency division is performed by an integer frequency divider. FIG. 1 is a schematic view illustrating errors occurring when the integer frequency divider (e.g. dividing by 4 or 5) is employed to perform the fractional frequency division (e.g. dividing by 4.5).
If the quantization error is pushed to high frequency side and then suppressed by the LPF, spur suppression can be desirably accomplished. However, a tradeoff is required between a bandwidth range and the capacity of spur suppression.
Currently, several conventional techniques using frequency multipliers and modulators (for example, a delta-sigma modulation (DSM)) have been developed to reduce the quantization errors. FIGS. 2a and 2b depict two conventional PLLs with use of the frequency multipliers and the modulators for error reduction.
Please refer to FIG. 2a. The first conventional PLL includes a frequency multiplier 201, a PFD 202, a CP 203, an LPF 204, a VCO 205, a frequency divider 206 and a modulator 207. Through the first conventional PLL, quantization errors are pushed to high frequency side, and a wider operation bandwidth is acquired, while the frequency resolution is reduced.
Please refer to FIG. 2b. The second conventional PLL includes a frequency multiplier 201′, a PFD 202′, a CP 203′, an LPF 204′, a VCO 205′, a frequency divider 206′, and a modulator 207′. A disadvantage of the second conventional PLL lies in that the output signal of the frequency divider 206′ does not have 50% duty cycles, and an additional duty cycle correction circuit is necessitated. Moreover, modulus errors may occur.

Phase locked loop with phase shifted input


Disclosed is a shadow mask having a fine slit that can improve precision and resolution of a pattern by reducing side etching during an etching process of a mask substrate, and a manufacturing method thereof. The shadow mask includes a mask substrate, a slit region formed by penetrating through the mask substrate, the slit region having a plurality of undercut portions at respective sides thereof, each undercut portion having a unit thickness, and a shadow region provided in the mask substrate, the shadow region corresponding to a region other than the slit region.

1. Field of the Invention
The present invention relates to a shadow mask, and a manufacturing method thereof.
2. Discussion of the Related Art
FIGS. 1 to 3 are cross sectional views for sequentially illustrating a method of manufacturing a shadow mask according to the related art. The shadow mask is applied to a liquid crystal display apparatus (LCD apparatus) or an organic light-emitting diode (OLED) in order to form printed patterns. According to the shadow mask manufacturing method in the related art, a photoresist pattern PR is formed on a mask substrate 10 as shown in FIG. 1. The mask substrate 10 is then wet etched using the photoresist pattern PR as an etching mask as shown in FIG. 2. The photoresist pattern PR on the mask substrate 10 is finally removed as shown in FIG. 3, thereby completing the manufacturing process of the shadow mask. FIG. 4 is a plan view illustrating a part of a shadow mask according to the related art. FIG. 5 is a cross sectional view illustrating the shadow mask shown in FIG. 4, the cross sectional view taken along the line I-I′. As shown in FIG. 4 and FIG. 5, the related art shadow mask is characterized by thickness R1, size of the shadow region R2, size of the slit region R3 in which slits corresponding to final printed patterns are formed, length R4 of the upper part of the mask, and the pitch R5. Generally, the thickness R1 of a shadow mask is 40 micrometers to 50 micrometers. The size of the shadow region R2 is 100 micrometers or 120 micrometers. The size of slit region R3 is 40 micrometers, and the length R4 of upper part of the mask is about 20 micrometers.
When manufacturing the shadow mask according to the above described method, a large amount of side etching occurs beneath the photoresist pattern PR. Therefore, it is difficult to manufacture a shadow mask having slits or slots with precise sizes. Further, it is difficult to manufacture a shadow mask having slits or slots with substantially uniform sizes along the vertical direction of the mask. Generally the size of the side etching is about 40 micrometers or more when the thickness of the mask is 40 micrometers. Since it is impossible to have the pitch R5 be smaller than the sum of half the thickness of the mask (0.5*R1) and the length of the slit region R3, the pitch R5 must be 140 micrometers or more if the length of the slit region R3 is 40 micrometers. In this case, if the side etching occurs by 2 micrometers at respective sides of the slit region, the length of the slit region R3 must be 44 micrometers or more. Further, since there can be severe process errors in the shadow mask manufacturing method according to the related art, it is difficult to design a shadow mask with fine pitches or patterns using the conventional manufacturing technologies.

Shadow mask and manufacturing method thereof


The present invention discloses a method and an apparatus for channel calibration among multiple RRUs, and pertains to the field of communications technologies. The method includes self-calibrating two RRUs to obtain two self-calibration coefficient, exchanging calibration sequences between the two RRUs through an air interface, returning, by one RRU, the calibration sequence received from another RRU to the another RRU in the air interface, and acquiring a calibration coefficient of the another RRU according to the calibration sequences and the self-calibration coefficients.

In a TDD (time division duplex) system, a base station performs estimation on an uplink channel by detecting an SRS (sounding reference signal) signal sent by a UE (user equipment) and uses an estimated uplink channel as a downlink channel to perform beamforming according to reciprocity of an uplink and a downlink of the TDD system. Theoretically, an uplink and a downlink in the TDD system are reciprocal; however, in an actual system, different intermediate radio frequency transceiving channel responses in the base station are respectively introduced to uplink and downlink channel responses. By means of theoretical analysis, it is found that if ratios of transmit channel responses to receive channel responses of any two intermediate radio frequency channels are different, an effect of coherent transmission is affected. Therefore, compensation needs to be performed on each intermediate radio frequency transceiving channel, which is referred to as channel calibration. Currently, there is a mature method for channel calibration for a single cell.
CoMP (Coordinated Multi-Point, coordinated multi-point transmission) is a key feature of an LTE (Long Term Evolution) system. A problem of interference on an edge of an LTE cell may be effectively resolved by using a CoMP technology. A base station side in the LTE system may include a BBU (baseband unit), and each BBU may be connected to multiple RRUs (remote radio unit). As one type of CoMP technology, a JT (joint transmission) technology may significantly increase cell edge throughput and average throughput. To implement a gain brought by the JT technology in the TDD system, channel calibration needs to be performed as well in the TDD system. Different from a single-cell beamforming technology, the JT technology requires that ratios of uplink radio frequency channel responses to downlink radio frequency channel responses are the same, where the uplink and downlink radio frequency channel responses are corresponding to various antennas of multiple cells. Even though channel calibration is performed on each cell, if calibration among cells is not performed, the JT technology still cannot achieve expected performance. Currently, a channel calibration technology for a single RRU is relatively mature; however, joint calibration among multiple RRU channels is still a difficult problem in the industry.

Method and apparatus for channel calibration among multiple RRUs


In a drive arrangement for wheels of a motor vehicle which are driven by means of an electric machine via a differential, the electric machine includes a rotor and a stator and drives a drive element of the differential whose output shafts output to the wheels of the motor vehicle. In order to achieve a structurally compact construction which enables favorable transmission ratios the rotor outputs to the drive element of the differential and that by interposing a gear mechanism, the drive element and/or the output shafts are supported offset to the rotation axis of the rotor.

The present invention relates to a drive arrangement for wheels of a motor vehicle.
The following discussion of related art is provided to assist the reader in understanding the advantages of the invention, and is not to be construed as an admission that this related art is prior art to this invention.
In electrically driven motor vehicles or hybrid drives, it is know to drive an axle of the motor vehicle by means of an electromotor or an electric machine (also shiftable to function as generator during braking) via a customary differential. If the electric machine is to have a high torque or respectively a high driving power, the accommodation in the motor vehicle can pose problems.
It would be desirable and advantageous to provide an improved drive arrangement with which relatively large size electric motors or electric machines can be built in a structurally favorable manner and with higher constructive degrees of freedom


The invention provides compositions and methods for holding systems, devices, apparatuses, or portions thereof in a retracted, extended, or intermediate configuration. In particular, the invention provides permanent magnets and/or magnetizable materials configured to hold systems, devices, apparatuses, or portions thereof in retracted, extended, and/or intermediate configurations.

A variety of installed lighting applications involve lights which are extendable and retractable. Lighting may be installed in furniture, seating, seating arrangements, cars, boats, medical equipment, etc. Various mechanical mechanisms exist for positioning lights at various degrees of extension (e.g., springs, friction elements, locking assemblies, etc.). Unfortunately, these mechanisms can be cumbersome, and due to their reliance on mechanical devices, they wear out or become non-functional over time. Further, mechanical hold devices tend to be limited in the number, or variety of positions in which they can hold an extendable light.


A manually or automatically controlled adjusting bed-chair combination for persons suffering limited mobility due to accident, disease, or age who thus require intensive caregiving efforts by others. This portable body supporting device provides a patient with greater mobility and self-care even if he/she is confined therein for weeks, months, or longer. The bed-chair includes an upper frame for supporting the invalid's body in a large number of postures ranging from side, supine, sitting, reclining or standing. In turn, this upper frame is articulated by lower supporting frames powered by linear actuators, or the equivalent, and controlled by the patient control or the caregiver's override and automatically preset control to provide a timed regimen of turning or tilting according to the occupant's needs. Whether in bed or chair mode, the support frame consists of an upper body, middle and leg-foot segment. The mid-section provides a base to which the other two sections are pivotally mounted. Turning the middle section up to 20.degree. right or left relieves the local pressure on skin and other tissue yielding comfort and avoiding ulceration, cramping and discomfort. The optional accessories further increase the freedom of choice of more positions, actions, and controls, even to sensing difficulty and aiding excretion along with the option of using vibration and other therapeutic stimulations. The bed-chair's diverse positions enable easier entrance and exit. Ready disassembly into three or more sections facilitates transport. A mattress with special foam distributes the body weight over maximum area while cervical and lumbar supports plus adjustable edge tubes give security and comfort choice to abet healing.

1. Field of the Invention
The invention relates generally to an apparatus permitting either the patient or a caregiver to adjust the positions of a segmented bed-chair combination to facilitate comfort and relief from discomfort along with ease of patient transfer from the bed to a wheel chair, toilet, walker or other apparatus associated with treatment, change of bed clothing and hygienic maintenance.
2. Description of the Related Art
Immobility and prolonged confinement present both psychological and physically evident pathological problems to patients, ranging from malaise, depression, feelings of helplessness and loss of motivation on the one hand to decubitus ulcers, loss of local circulation and unsanitary dermatologic insult from waste products, or edema of extremities and gangrene on the other. Not only are patients affected by these conditions but so too are the responsible caregivers who must lift, turn, wash, change bed and clothing, arrange for food and dispose of waste. Such operations often require that attendants have a high level of strength and skill to move and reposition the patient, regardless of the patient's size or weight.
To address various aspects of these problems, a number of devices have been developed. Among these is the cradling and articulated bed disclosed in U.S. Pat. No. 3,875,598, held by one of the inventors of the instant device. The subject bed is capable of widening and narrowing to create either a flat bed surface or a cradle bed surface. In addition, the supporting surface is capable of powered rotation either to one side or the other allowing the patient to be rolled easily and it is further capable of elevating a head portion, a thigh portion and a calf portion to permit the patient to be moved to a multitude of reclining and seated positions. The disclosure of this patent is incorporated by reference herein.
U.S Pat. Nos. 4,085,471 and 4,190,913, to DiMatteo et al, are directed to invalid bed arrangements which allow a patient to use a toilet without leaving the bed or, alternatively, for placing a patient in a wheel chair. The bed is divided into three sections comprised of head, central and foot sections. The bed can be manipulated to elevate a patient from a supine to an upright seated position for using a toilet or movement into a wheel chair.
U.S. Pat. No. 4,199,829, to Watanabe et al, discloses a patient carrier that transfers a patient from cooperating bed systems to cooperating wheel chairs. The apparatus comprises a carrier with three groups of forks that are insertable into slots in the bed mat or seat and back rests of a wheel chair thereby permitting the patient to be moved from one to the other.
U.S. Pat. No. 4,225,988, to Cary et al, discloses a bed assembly that has a plurality of mattress support members that can be moved to provide a variety of patient positions from fully reclining to various seated positions with legs angled and supported. Alternatively, the apparatus facilitates turning of the patient by permitting elevation of one side or the other of the mattress support
U.S. Pat. Nos. 4,432,353 and 4,763,643, both to Vrzalik, disclose a kinetic treatment table for a therapeutic insulating bed. The bed is capable of being lifted or lowered, tilted at an angle, and is further capable of raising a portion of the bed to prop a patient into an upright position.
U.S. Pat. No. 4,760,615, to Furniss, discloses a device for raising and transporting patients involving a tiltable platform and hinged head and foot platforms. U.S. Pat. No. 276,756, to Persson, shows an apparatus for turning a person confined to a bed and U.S. Pat. No. 4,357,722, to Thompson, discloses a bed with an adjustably tensionable patient supporting net. The bed has a cradle-like frame supported for pivotable movement by a base frame.
In the foregoing, various aspects of patient movement have been addressed. However, none of the systems address the multitude of other problems encountered by either the caregiver or the patient. In particular, none gives the patient the ability to adjust his/her body position and thus take control over somatic movement which action yields many important psychological benefits. Moreover, each is focused on a particular patient problem to the exclusion of related issues, some of them created by the attempt to solve the problem at hand. Furthermore as a group they are cumbersome and most are needlessly arcane in their approach to solving a problem.

Multiple position adjustable day night patient bed chair


A sintered alloy is produced from mixed powder containing first hard particles, second hard particles, graphite particles, and iron particles. The first hard particles are Fe—Mo—Ni—Co—Mn—Si—C-based alloy particles, the second hard particles are Fe—Mo—Si-based alloy particles, the mixed powder contains 5 to 50 mass % of the first hard particles, 1 to 8 mass % of the second hard particles, and 0.5 to 1.5 mass % of the graphite particles, when total mass of the first hard particles, the second hard particles, the graphite particles, and the iron particles is set as 100 mass %.

1. Technical Field
The present disclosure relates to a production method of a sintered alloy, a sintered-alloy compact, and a sintered alloy.
2. Description of Related Art
A sintered alloy containing iron as the base may be applied to a valve seat or the like of an internal combustion engine. In order to further improve wear resistance, hard particles may be included in a sintered alloy. In a case where hard particles are included, graphite particles and iron particles are mixed with the hard particles into a powder, and the mixed powder is compacted into a sintered-alloy compact. Thereafter, by heating the sintered-alloy compact and sintering the resultant, a sintered alloy is generally obtained.
As a production method of such a sintered alloy, a production method of a wear-resistant iron-based sintered alloy, in which mixed powder obtained by mixing hard particles, graphite particles, and iron particles together is compacted into a sintered-alloy compact, and the sintered-alloy compact is sintered while causing carbon (C) of the graphite particles of the sintered-alloy compact to diffuse into the hard particles and the iron particles, is suggested (for example, refer to Japanese Patent Application Publication No. 2004-156101 (JP 2004-156101 A)).
Here, the hard particles contains 20 to 70 mass % of Mo, C: 0.2 to 3 mass %, Mn: 1 to 15 mass %, and the remainder including unavoidable impurities and Co, and the mixed powder contains, when the total amount of the hard particles, the graphite particles, and the iron particles is assumed to be 100 mass %, 10 to 60 mass % of the hard particles and 0.2 to 2 mass % of the graphite particles. Since the hard particles are dispersed in the sintered alloy, abrasive wear can be suppressed.

Production method of sintered alloy, sintered-alloy compact, and sintered alloy


A phased antenna arrangement and a method for estimating the calibration ratio of an active phased antenna having a plurality of phased array antenna elements are described. The phased antenna arrangement includes a plurality of antenna elements, a plurality of receiving channels, an injection unit for injection of calibrating signals into the receiving channels, a point RF-source, located in a far field zone, a distance measurement unit, an amplitude and phase measurement unit and a data processing unit. The method comprises injecting an internal calibrating signal having a known amplitude and phase to each antenna element. An external calibration signal from a stationary RF-source is sequentially injected to all of the phased array antenna elements so that different phases of the external calibration signal arrive at each of the antenna elements. The differences in phases of the external calibration signal reaching the antenna elements are compensated so as compute an effective signal amplitude that would reach all of the antenna elements at zero phase difference. Calibration ratio is calculated as the ratio between the amplitude of the internal calibrating signal to the effective signal amplitude of the external calibration signal.

The antenna of an active phased array system must be able to steer its beam so that the system can obtain information about the surroundings in different directions. It is also desirable that the antenna suppress signals from other directions than the direction in which the system is currently transmitting and receiving. A phased array antenna comprises a number transmitting/receiving elements, usually arranged in a planar configuration. Each element, or a group of elements, is driven by a transmit/-receive (T/R) module which controls the phase and the amplitude of the corresponding antenna element.
On transmission of a signal from a phased array antenna, the signal is divided into a number of sub-signals, and each sub-signal is fed to one of the modules. The modules comprise signal channels guiding the sub-signals to the antenna elements. Each signal channel comprises controllable attenuators or amplifiers and controllable phase-shifting devices for controlling the amplification and the phase shift of the modules. The signals transmitted through the antenna elements interfere with each other. By selecting suitable values of the relative amplification and the relative phase-shifting between the modules and by utilizing the interference of the transmitted signals, the directional sensitivity of the antenna can be controlled.
During reception in a phased array antenna, the opposite procedure takes place compared to transmission. Each antenna element receives a sub-signal. The modules comprise signal channels for reception and through these signal channels the sub-signals are collected in a single point in which all sub-signals are added to form a single composite signal. The signal channels for reception also comprise amplifiers and phase shifters, and the directional sensitivity of the antenna for reception can be controlled in a corresponding way as for transmission, by varying the amplification and phase-shifting of the modules.
In order to obtain the desired directional properties of the antenna, it is necessary to minimize the side lobe levels of the antenna. To enable low side lobe levels with an electrically controlled phased array antenna, high accuracy of the amplification and the phase shift in the modules is required. In practice, this is achieved by introducing a calibration function in the antenna system. Central to the calibration concept is the compensation of the various contributions of cables, attenuators, phase shifters, regulators and other parts in the transmit/receive channels which respond differently at different temperatures, for each antenna element and at each radio frequency. The calibration procedure is required to determine what controls should be applied to the transmit/receive modules in order to obtain the desired current distribution on the antenna aperture.
For example, if it is required that the phase of the signal fed to all antenna elements be identical, but it is found during calibration that, owing to mismatches in the phase shifters coupled to first and second antenna element, there is a phase difference between the signals output by a first antenna element and a second antenna element of +15°, then the phase shift signal that is fed to the second antenna element must have a phase offset of −15° relative to the phase shift signal fed to the first antenna in order to compensate for the mismatch in the two phase shifters. Differences between the amplitudes of signals that are output by different antenna elements caused by mismatches in the gains of the amplifiers coupled to the antenna elements are compensated for in a similar manner by applying different gain offsets to the antenna elements relative to a given reference antenna element.
Phased array antenna architectures typically include a calibration network, whose purpose is to provide injection of a predetermined calibration signal to each antenna element and to the T/R module connected to it. Such a calibration network is shown in U.S. Pat. No. 7,068,218 (Göttl et al.) which describes a calibration device for an antenna array, or an improved antenna array, that can be viewed as a set of RF-couplers (one coupler per antenna element) interconnected and driven by a passive network having a common feed point. The passive network splits the drive signal in a predetermined manner so that the signal fed to each antenna element is known in advance and the phase and gain offsets are known and predetermined.
During use, one or more antenna elements may become out of calibration. This can occur, for example, owing to one or more antenna elements being replaced. Since the replacement antenna elements will inevitably have slightly different properties to the original antenna elements, the original offsets will not compensate for slight differences in the phase and gain characteristics of the phase shifters and amplifiers used to feed steering signals to the replacement antenna elements. This typically requires that the complete phase antenna array be returned to the factory for re-calibration in order to establish the new offsets. It is also known to perform the re-calibration procedure in the field, but this then requires a calibration network for which the required offsets are known for each phase shifter and amplifier. Such calibration networks are available but they require sophisticated electronics and are expensive.
U.S. Pat. No. 7,068,218 Göttl et al. discloses a calibration procedure that utilizes, in addition to the operational transmit/receive channels, also an auxiliary injection network, whose contribution must be known in advance. This is determined using the concept of the calibration ratio, which measures the ratio between signals injected externally (in principle from infinity) to those injected internally.
Some antennas are factory calibrated. When deployed, the quality of the calibration is tested by one means or another and if the test fails the antenna is sent back to the factory for recalibration. Other antennas have field calibration capability. A number of approaches for calibration of such antennas have been proposed in prior art.
There is a vast literature of prior art relating to phased antenna calibration and the determination of calibration ratio. Of the many different approaches that are known in the art, all presently fall into one of two categories. Some methods use an external calibration signal that is disposed at infinity so that the respective amplitudes and phases of the external calibration signals injected into each antenna element are the same. This, of course, greatly simplifies the determination of calibration ratio, but is not feasible when there is insufficient space between the external calibration source and the phased array antenna, such as when a phased array antenna is recalibrated in the field.
The other approach disposes the external calibration source proximate each antenna element in turn, while ensuring that the distance from the external calibration source to each antenna element is the same and that the external calibration source is exactly aligned to the optical center of each antenna element. This also ensures that the respective amplitudes and phases of the external calibration signals injected into each antenna element are the same, but requires critical and consequently complex alignment and is both time-consuming and expensive.
Replacement of a failed T/R module during antenna maintenance is a routine procedure, which requires recalibration of the antenna system. The amplification and phase shift of the T/R modules are obtained by considering the change in amplitude and phase of the test signal when it passes the T/R module. The control signals controlling the attenuators and the phase shifters in the T/R modules can now be corrected so that the amplification and the phase-shift are made to coincide with the desired amplification and phase-shift.
In accordance with the calibration procedure of plane array antennas in a production environment as taught by above-mentioned U.S. Pat. No. 7,068,218 (Göttl et al.), for example, a plane wave RF-source is used to simulate a point RF-source at infinity. If the propagation direction of the plane wave is parallel to the bore sight axis of the plane array, all array antenna elements are in the same phase conditions. This means that ideally measured phase values of the signal received by all array antenna elements are identical since each pair of array antenna elements and T/R module is assumed to be identical. The calibration procedure enables amplitude and phase characteristics of each pair of antenna element and T/R module to be determined.
When the calibration reference signal is derived from a distant source such as a satellite, the signal emanates from infinity so that its wavefront is effectively equidistant from all the antenna elements. It therefore arrives in the same phase at all the antenna elements. But it is not always practical to use a distant source for the calibration source, particularly when space is at a premium as is often the case in field calibration. Prior art approaches that employ so-called near field calibration are known to feed a planar calibration signal successively to the antenna elements. For example, U.S. Pat. No. 6,084,545 (Lier et al.) discloses a near-field calibration arrangement for a phased-array antenna that determines the phase shifts or attenuation of the elemental control elements of the array. The calibration system includes a probe located in the near field, and a calibration tone generator. According to the concept of reciprocity, the near field calibration procedure can be applied to transmit or receive modes as well. In case of receive calibration mode, a probe sequentially moves from one antenna element to another, keeping the same coupling conditions (distance from antenna plane, polarization, orientation etc.) and transmitting the same test signal. A receive antenna array has a switching arrangement, providing appropriate RF-module/antenna element connection to the measurement unit via controllable phase shifter/attenuator. The near-field calibration goal achieves the same signal parameters (phase and amplitude) coming from each RF-module (and appropriate probe locations) by applying control signals to the appropriate phase shifters and attenuators.
It should also be noted that regardless of whether near field or far filed calibration is performed, when a calibration network is factory-calibrated, sets of calibration values must be pre-assigned to each antenna. These values cannot be determined in the field and are apt to be inapplicable to a replacement antenna element, so that if an antenna element is replaced in the field, such an approach is fraught with difficulty.
In summary, far field calibration allows the calibration signal to be fed simultaneously to all the antenna elements from a common source and ensures that it will arrive at the same phase at all the antenna elements; but is not suitable for use in confined spaces, such as when re-calibrating antenna elements in the field. On the other hand, near field calibration requires that in order for the external calibration signal to arrive at the same phase at all the antenna elements, it must be fed to each antenna element sequentially and this requires precise alignment which is time-consuming and expensive.
It would therefore be desirable to combine the advantages of both approaches so as to calibrate the antenna elements using an external calibration signal that is fed from a common source that is proximate the antenna elements so as to reach all the antenna elements simultaneously, while nevertheless correcting for the fact that the external calibration signal arrives at different phases to each of the antenna elements.

Phased array antenna having integral calibration network and method for measuring calibration ratio thereof


The present invention provides a method and apparatus for achieving conformal step coverage of one or more materials on a substrate using sputtered ionized material. In one embodiment, a chamber having one or more current return plates, a support member, an electromagnetic field generator and a support member is provided. The target provides a source of material to be sputtered by a plasma and then ionized by an inductive coil, thereby producing electrons and ions. During processing, a bias is applied to the support member by an RF power source. The return plates are selectively energized to provide a return path for the RF currents, thereby affecting the orientation of an electric field in the chamber.

1. Field of the Invention
The present invention relates to an apparatus and method for processing substrates. Specifically, the invention relates to a method for depositing a conformal layer of material on a substrate in an ionized metal plasma process.
2. Background of the Related Art
Sub-quarter micron multi-level metallization represents one of the key technologies for the next generation of ultra large-scale integration (ULSI) for integrated circuits (IC). In the fabrication of semiconductor and other electronic devices, directionality of particles being deposited on a substrate is important to improve in filling of electric features. As circuit densities increase, the widths of vias, contacts and other features, as well as the dielectric materials between them, decrease to 0.25 xcexcm or less, whereas the thickness of the dielectric layer remains substantially constant. Thus, the aspect ratios for the features, i.e., the ratio of the depth to the minimum lateral dimension, increases, thereby pushing the aspect ratios of the contacts and vias to 5:1 and above. As the dimensions of the features decrease, it becomes even more important to get directionality in order to achieve conformal coverage of the feature sidewalls and bottoms.
Conventionally, physical vapor deposition (PVD) systems have been used to deposit materials in device features formed on a substrate. PVD systems are well known in the field of semiconductor processing for forming metal films. Generally, a power supply connected to a processing chamber creates an electrical potential between a target and a substrate support member within the chamber and generates a plasma of a processing gas in the region between the target and substrate support member. Ions from the plasma bombard the negatively biased target and sputter material from the target which then deposits onto a substrate positioned on the substrate support member. However, while such processes have achieved good results for lower aspect ratios, conformal coverage becomes difficult to achieve with increasing aspect ratios. In particular, it has been shown that coverage of the bottoms of the vias decreases with increasing aspect ratios.
One process capable of providing greater directionality to particles is ionized metal plasma-physical vapor deposition (IMP-PVD), also known as high density physical vapor deposition (HDP-PVD). Initially, a plasma is generated by introducing a gas, such as helium or argon, into the chamber and then coupling energy into the chamber via a biased target to ionize the gas. A coil positioned proximate the processing region of the chamber produces an electromagnetic field which induces currents in the plasma resulting in an inductively-coupled medium/high density plasma between a target and a susceptor on which a substrate is placed for processing. The ions and electrons in the plasma are accelerated toward the target by a bias applied to the target causing the sputtering of material from the target by momentum transfer. A portion of the sputtered metal flux is then ionized by the plasma to produce metal ions in the case where the target comprises a metal. An electric field due to an applied or self-bias, develops in the boundary layer, or sheath, between the plasma and the substrate that accelerates the metal ions towards the substrate in a vector parallel to the electric field and perpendicular to the substrate surface. The bias energy is preferably controlled by the application of power, such as RF or DC power, to the susceptor to attract the sputtered target ions in a highly directionalized manner to the surface of the substrate to fill the features formed on the substrate.
One of the problems with HDP-PVD processes is the inability to achieve conformal step coverage in the increasingly smaller device features. Conformal coverage of the bottom and sidewalls of the features is needed to optimize subsequent processes such as electroplating. Electroplating requires conformal barrier and seed layers within the device features in order to ensure uniform filling of the feature. While conventional HDP-PVD achieves good bottom coverage due to the directionality of the ions provided by the bias on the substrate, the sidewall coverage can be less than conformal. This result is caused in part by the induced high directionality of ions towards the bottom of the features with little directionality toward the sidewalls.
The effects of a bias on a substrate can be described with reference to FIGS. 1-2 which illustrate the direction of metal ions 14 entering a via 16 formed on a substrate 10. FIG. 1 illustrates a PVD processing environment wherein no bias is supplied to the substrate 10. As a result, the directionality of the ions 14 is determined primarily by the ejection profile of material (usually atoms) from the target and by the inelastic collisions with other particles in the chamber, such as Ar ions which are provided in a plasma. The angular distribution 22 of the ions 14 in FIG. 1 typically results in little deposition on the bottom 18 of the via 16 due to a large proportion of the ions 14 striking the substrate 10 at oblique angles.
FIG. 2 illustrates the processing environment in a HDP-PVD process wherein the angular distribution of the ions 14 is influenced by the electrical field E due to the applied or self-bias at the surface of the substrate. The electric field E is oriented perpendicular to the substrate 10 and the positively charged ions 14 travel along a trajectory parallel to the electric field E toward the bottom 18 of the via 16. The angular distribution 24 of the ions 14 in FIG. 2 is typically results in moderate to low deposition on the sidewalls 20 and high to moderate deposition on the bottom 18 than is possible without the bias. As compared to the angular distribution 22 of FIG. 1, the distribution 24 exhibits a tighter pattern indicating more directionality parallel to the electric field E.
One of the reasons for poor sidewall coverage of device features in HDP-PVD processes is the orientation of the electric field E shown in FIG. 2. The electric field E extends between the substrate and a chamber component that provides a return path for the RF currents supplied to the support member during processing. Typically, the chamber component is an annular conductive member, such as a metal process shield, disposed proximate to the substrate. Additionally, the chamber component is grounded to support the flow of current to ground.
A schematic representation of a chamber 25 having a substrate support 26, a coil 30 and grounded conductive process shield 27 is shown in FIG. 3. A substrate 28 is disposed on the substrate support 26 for processing and a plasma 29 is maintained in the chamber 25 near the substrate 28. Due to the annular shape of the process shield 27, the field lines of the electric field E between the plasma 29 and the substrate 28 are uniformly distributed with a substantial vertical component relative to the substrate 28. As a result, during processing, ions experience a force due to the electric field E causing the ions to be accelerated down toward the bottoms of the device features formed in the substrate 28 with little direction toward the sidewalls of the features.
Therefore, there is a need to provide a technique for depositing a layer conformally over the surface of features, particularly sub-half micron and higher aspect ratio features.
The present invention generally provides an apparatus and method for depositing a conformal layer on device features in a plasma chamber using sputtered ionized material. In one embodiment, a chamber having a target, a substrate support member and a magnetic field generator to ionize the target material is provided. The target comprises the material to be sputtered by a plasma formed adjacent to the target during processing. The magnetic field generator may be one or more single-turn or multi-turn coils adapted to ionize the sputtered material. The invention provides methods and apparatus adapted to affect the angular distribution of ions present in the chamber.
In one aspect of the invention, a method of modulating the orientation of an electric field between the support member and one or more current return plates is provided. The electric field is generated by applying a reference signal to the support member and providing a current return path through one or more of the return plates. A phase shifted reference signal provided to one or more of the return plates determines the return path of the currents. Preferably, the electric field is rotated about a central axis of the processing chamber at a desired frequency. Additionally, the electric field strength may be modulated by varying the signal power supplied to the support member. A reference signal is provided to the support member to supply a bias to a substrate disposed thereon.
In another aspect of the invention, an apparatus is provided having one or more return plates disposed in the chamber. The return plates and the support member are each coupled to a signal source adapted to produce a reference signal and a phase shifted reference signal. Preferably, the apparatus includes a phase shift network disposed between the signal source and the return plates wherein the phase shift network is adapted to further split an input signal.

Method and apparatus for bias deposition in a modulating electric field


A method, system and apparatus for applying and synchronizing filter information with a multimedia presentation, such as a movie provided in a video-on-demand context, to suppress objectionable content. In one example, filter information, which includes an indicia of a portion of the multimedia presentation including objectionable content and a type of suppression action, is provided on either a set-top-box or a video-on-demand server. A user selects a particular video-on-demand presentation, and the selection is transmitted to the set-top-box. Filtering may take place at the set-top-box side such that the complete video-on-demand movie is transmitted to the set-top box and then content suppression, such as skipping, muting, cropping, and blurring, takes place at the set-top-box. Alternatively, some or all suppression may take place at the server such that some or all of the objectionable content is not transmitted to the set-top-box. Additionally, whether in a video-on-demand, DVD, or other environment it may be necessary to synchronize filter with the multimedia content so that the proper objectionable content is suppressed.

Video-on-demand, pay-per-view and other movies and multimedia content presentations that are transmitted to a client device, such as a cable or satellite set-top-box, a personal computer or the like or read from a removable storage media, such as a CD, DVD or the like, often contain some content, whether audio, video, embedded links, etc., that is inappropriate for some audiences or simply undesirable for some audiences. For example, it is well known that some multimedia presentations, whether music on a CD, a movie on DVD, various television channels, etc., can contain language and explicit content not suitable for children. Thus, it would be useful for a parent to be able to suppress the unsuitable content, while still allowing their children to view the non-objectionable portions of the presentation. It would also be useful for others to be able to suppress certain content they may personally find undesirable, but still be able to view and/or listen to certain multimedia content presentations. Such usefulness would be particularly beneficial in video-on-demand and other similar content provisions platforms where suitable filtering applications are not presently widely available. Such usefulness would also be particularly beneficial if the suppression is accurately synchronized with the presentations to minimize the suppression of non-objectionable content.

Synchronizing filter metadata with a multimedia presentation


Disclosed is a positive active material for a lithium secondary battery having high capacity and long durability properties, and particularly to a powder of LiaNi1xe2x88x92xxe2x88x92yCoxMyO2xe2x88x92zFz and LiaNi1xe2x88x92xxe2x88x92yCoxMyO2xe2x88x92zSz (where M is a metal selected from the group consisting of Al, Mg, Sr, La, Ce, V, and Ti, and wherein 0xe2x89xa6x less than 0.99, 0.01xe2x89xa6yxe2x89xa60.1, 0.01xe2x89xa6zxe2x89xa60.1, and 1.00xe2x89xa6axe2x89xa61.1) an oxygen in LiaNi1xe2x88x92xxe2x88x92yCoxMyO2 is substituted with F or S whereby the durability, capacity and structural safety of the positive active material is increased.

This application is based on application No. 99-22764, filed in the Korean Industrial Property Office on Jun. 17, 1999, the content of which is incorporated hereinto by reference.
(a) Field of the Invention
The present invention relates to an active material for a lithium secondary battery and a method of preparing the same, more particularly, to an active material for a lithium secondary battery in which an oxygen (O) in a LiaNi1xe2x88x92xxe2x88x92yCoxMyO2 is substituted with F or S, and a method of preparing the same.
(b) Description of the Related Art
Due to technological advances in appliance miniaturization and weight reduction, and increased functionality of cordless portable appliances such as video cameras, personal phones, and personal computers, there are escalating requirements for the sources of electric power used to driving these appliances. Particularly, there have been advances in developing and studying rechargeable lithium secondary batteries around the world, anticipating the need for a battery with a high energy density.
A lithium secondary battery uses as an anode and a cathode materials which can intercalate and deintercalate lithium ions, and is prepared by filling organic or polymer electrolyte between the cathode and the anode to move the lithium ions. The battery generates electric energy by a redox reaction when lithium ions intercalate and deintercalate in the cathode and in the anode.
Lithium secondary batteries use carbon materials or lithium metals as anodes and intercalatable/deintercalatable chalcogenide compounds as cathodes. Carbon materials are substituted for lithium metals because the latter, when used as an anode, has the disadvantage of educing dendrites with the associated danger of explosion and a reduction in recharging efficiency.
On the other hand, complex metal oxides such as LiCoO2, LiMn2O4, LiNi1xe2x88x92xCoxO2 (0 less than X less than 1), and LiMnO2 are now being studied for a cathode use because chrome oxide, MnO2, etc. that were initially used have problems with low recharge efficiency and safety.
Manganic positive active materials such as LiMn2O4, LiMnO2, etc, or cobaltic positive active materials such as LiCoO2, etc, had been developed, but they have the limits of capacity of 120 mAh/g and 160 mAh/g respectively when recharged at 4.3 V. Also, LiCoO2 has been widely used due to having the high voltage capacity, excellent electrode properties, and an electro-conductivity of 10xe2x88x922 to 1 S/cm at ambient temperature, but it has low stability when recharged and discharged at a high current rate.
There have been developments in the study of nickelic positive active materials that show a discharge capacity more than 20% greater than cobaltic positive active materials.
Lithium secondary batteries using nickelic positive active materials have the potential to make high capacity batteries due to their high discharge capacity, but more development of nickelic active materials is needed in order to overcome defects associated with their low durability and the structural instability of LiNi1xe2x88x92xCoxO2 (0 less than x less than 1).
Synthesizing methods employing solid state processes, co-precipitation methods, polymer chelating agents, etc, have been developed and researched thus far on LiNi1xe2x88x92xMxO2 (0 less than x less than 1) powder with some Ni substituted with Co, Mn, etc, for improving structural safety features, discharge capacities, and life span properties of the basic nickel based cathode compound, LiNiO2.
LiNiO2 has disadvantages in that it is difficult to synthesize, is not practical to use in a battery because of poor durability, and its capacity decreases suddenly during continuous discharge-recharge cycles due to instabilities caused by its repeated structural change from monoclinic to hexagonal and back, in spite of having a discharge capacity of 200 mAh/g at 1.0 C.
To solve these problems, Co is added to LiNiO2 in order to stabilize the structure, but this causes the problem that the capacity of LiNiO2 decreases relative to the amount of Co added, and this quantity must be more than 30 mole %.
To improve the structural stability, LiNi1xe2x88x92xMxO2 (M is a metal such as Co or Mn, etc, 0 less than x less than 1) and LiNi1xe2x88x92xCoxMyO2 (M is a metal such as Al, Mg, Sr, La, Ce, etc, 0 less than x less than 1, 0.01 less than y less than 0.1) were developed. However, these nikelic positive active materials also have defects of structural instabilities, and this defect causes the stability of the system of lithium secondary battery to decrease.
It is an object of the present invention to provide a positive active material for a Li secondary battery, wherein LiaNi1xe2x88x92xxe2x88x92yCoxMyO2xe2x88x92zFz and LiaNi1xe2x88x92xxe2x88x92yCoxMyO2xe2x88x92zSz (where M is a metal selected from the group consisting of Al, Mg, Sr, La, Ce, V, and Ti, and wherein 0xe2x89xa6x less than 0.99, 0.01xe2x89xa6yxe2x89xa60.1, 0.01xe2x89xa6zxe2x89xa60.1, and 1.00xe2x89xa6axe2x89xa61.1) powders in which an oxygen (O) in LiaNi1xe2x88x92xxe2x88x92yCoxMyO2 is substituted with F or S are synthesized to improve the durability, capacity, and structural stability of the battery.
It is another object to provide a method of preparation of the positive active material for a Li secondary battery.
In order to achieve these other objects, the present invention provides positive active materials for Li secondary battery in which an oxygen (O) in LiaNi1xe2x88x92xxe2x88x92yCoxMyO2 (where M is a metal selected from the group consisting of Al, Mg, Sr, La, Ce, V, and Ti, and wherein 0xe2x89xa6x less than 0.99, 0.01xe2x89xa6yxe2x89xa60.1, 0.01xe2x89xa6zxe2x89xa60.1, and 1.00xe2x89xa6axe2x89xa61.1) is substituted with F or S, that is, positive active materials selected from the group consisting of the following formulae 1 and 2:
LiaNi1xe2x88x92xxe2x88x92yCoxMyO2xe2x88x92zFzxe2x80x83xe2x80x83[Formula 1],
LiaNi1xe2x88x92xxe2x88x92yCoxMyO2xe2x88x92zSzxe2x80x83xe2x80x83[Formula 2],
and
where M is a metal selected from the group consisting of Al, Mg, Sr, La, Ce, V, and Ti, and wherein 0xe2x89xa6x less than 0.99, 0.01xe2x89xa6yxe2x89xa60.1, 0.01xe2x89xa6zxe2x89xa60.1, and 1.00xe2x89xa6axe2x89xa61.1.
Also, the present invention further provides a method of preparation the positive active material selected from the group consisting of the formulae 1 and 2.
The method comprises a step of synthesizing Ni1xe2x88x92xxe2x88x92yCoxMy(OH)2 by a coprecipitation method; a step of mixing the material with LiOH, and LiF or NaS powder; and a step of producing the positive active compound of the formulae 1 and 2 by heating and cooling the mixture.

Positive active material for lithium secondary batteries and method of preparing the same


The present invention relates to microbial compositions useful in treating swimming pool water to reduce water evaporation.

Evaporation is a significant contributor to water loss, and a major contributor to maintenance costs, in residential and commercial swimming pools and spas. For example, the evaporative loss from an unoccupied 10,000 sq ft pool with a water temperature of 80° F., an air temperature of 78° F., and relative humidity of 50 percent is about 132 liters/hour or nearly 35 gallons/hour. See M. M. Shah, HPAC Engineering, Oct. 1, 2011. Over a 12 hour period at these conditions water loss can exceed 400 gallons. This volume can nearly double if the pool is fully occupied. It is, therefore, desirable to reduce or eliminate evaporation, especially in drought stricken areas such as the southwestern United States where water resources are limited.
Traditional pool covers consist of a physical barrier that is fitted over the pool surface when the pool is not in use. A properly fitted cover can reduce evaporative water loss up to 97% (See World Wide Web at daisypoolcovers.com.au/daisy-saves/evaporation/). However, physical covers are only effective when the pool or spa is not in use.
Recently, so called "liquid" covers have become available. These products spread a thin layer of surface active material over the surface of the pool creating a monomolecular film that suppresses water and heat loss. "Liquid" covers can provide some benefit even when the pool or spa is in use since the film is fluid and reforms after disruption by swimmers. The film-forming materials used in these products range from surface active polymers, such as modified polysiloxanes (Aquatain™) to simple fatty alcohols (waterSavr™).
A number of surface active materials are commonly introduced to pools and spas during use. Sunscreens and suntan lotions contain several different surface active ingredients including emollients such as isopropyl isostearate, caprylic/capric triglyceride, C12-C15 alkyl benzoate, and diisopropyl sebacate. Additionally, wax esters, cholesterol esters, and free fatty acids are present from human sebum. This collection of oily, greasy materials (typically referred to as FOG for Fats, Oils, Grease) represents a significant soil load, causing pool water to grow cloudy over time and forming a scum ring around the edge of the pool.
There is an opportunity to use these FOG materials as precursors to liquid films to aid in reducing water evaporation and retaining heat while simultaneously clarifying the water, reducing filter head pressure and pump run times by breaking the FOG components down into constituent fatty acids and fatty alcohols.

Methods for reducing evaporative loss from swimming pools


According to examples, an apparatus may include a processor and a memory on which is stored machine readable instructions that are to cause the processor to receive, from a first node, a client request and a response corresponding to the processed client request, in which the first node is configured to generate the response by processing the client request on a service and processed client request is configured to change a state of the service. The instructions are also to cause the processor to receive, from the first node, a response corresponding to the received request, generate an entry including the received request and response, commit the generated entry into a journal, and send an acknowledgement of the received request and response to the first node after the generated entry is committed into the journal.

A distributed system, such as a cluster of computing nodes, hosts a number of services that are available to clients. The hosting of services across a cluster of computing nodes enables performance of dynamic load-balancing as demand on the computing nodes varies, as computing node failures occur, as well as for changes in computing node scale. In order for the computing nodes in the cluster to provide reliable fault tolerance, a backup computing node provides the same service states as a primary computing node in the event of a primary computing node failure.


A drill includes: a drill housing having a chuck collar of the drill made as a polygonal prism or a cylindrical collar having at least a secant flat surface formed thereon, a central drilling tool axially mounted in the drill housing, and a sleeve member having a hollow bore portion centrally formed through the sleeve member, having a coupling adapter formed on a proximal end of the sleeve member concentrically detachably secured to the chuck collar of the drill housing and having a screw driver member detachably mounted on a distal end of the sleeve member, whereby upon coupling of the sleeve member secured with the screw driver member onto the chuck collar of the drill, the hollow sleeve member on the drill will encase the central drilling tool previously axially mounted in the drill housing without first dismantling the central drilling tool for convenient replaceable uses of the drill.

When it is intended to electrically operate a screw driver by a conventional electric or hand drill, a drilling tool or bit should be first dismantled from a chuck of the drill and the screw driver is then clamped on the chuck of the drill housing for screw driving purpose. It is quite inconvenient for such a replacing operation by detachably and replaceably mounting the drilling tool or the screw driver on the drill housing. If two hand tools, namely one for the drill and the other for the screw driver, are simultaneously prepared for their parallel uses, their equipment cost and handling inconvenience may be increased.


A detection and processing circuitry of a magnetostriction type torque sensor is disclosed. An alternating current voltage signal Vo is generated and output from an oscillator. A shift circuit shifts a phase of the AC voltage waveform of the oscillator by 1/4 period and outputs the phase shifted voltage to a detector. The detector modulates the inverted voltage signal Va on the basis of the phase shifted voltage signal and an integrator integrates the detector output voltage in a time range from (.alpha.-.pi./2) to (.alpha.-3.pi./2). Thus, the output voltage signal Vd from the integrator indicates a resistance value of an imaginary part, i.e., inductance of the impedance of the detection coil of a magnetostrictive shaft of the torque sensor which is not dependent on the change in a temperature.

The present invention relates generally to a processing circuit for processing an output signal from a sensing device such as a magnetostriction type torque sensor.
A U.S. patent application Ser. No. 7/969,056 (which corresponds to German Patent Application filing No. P 42 374 16. 2 filed on Oct. 23, 1992) exemplifies a previously proposed detecting and processing circuitry for a sensing device such as a magnetostriction type torque sensor applicable to the detection of a torque of, for example, an output shaft of an internal combustion engine.
In the previously proposed processing circuitry of the torque sensor, a detection of the torque is taken in the form of a change in impedance of detection coils installed on an outer periphery of a magnetostrictive shaft of the torque sensor. However, each impedance in the two detection coils is divided into real parts of the impedances, i.e., iron losses r1, r2 and imaginary parts thereof, i.e., resistances 2.pi.fL1 and 2.pi.fL2 due to inductances of the detection coils. These resistances are temperature dependent not only when the torque is applied about the magnetostrictive shaft but also when the surrounding temperature is changed.
That is to say, since the magnetic characteristic on the magnetrostrictive shaft is changed according to the surrounding temperature, this change being detected in the form of the impedances consisting of the self-inductances and iron losses of the detection coils, a voltage output from a rectifier is deviated from a real value of the torque and is dependent on the temperature, so that an accurate detection of the torque cannot be made.
In addition, the magnetic characteristic described above is different according to a thermal processing of the magnetrostrictive shaft during its manufacture and its magnetic permeability .mu. is different. Consequently, a different magnetic permeability causes an ill effect on a magnetic path resistance (so called, magnetic resistance) which is constituted by the iron losses r1, r2 so that deviations in the sensitivity of each magnetrostrictive shaft occur.

Detecting and processing circuitry for magnetostriction type torque sensor


An endoscope has a removable suction tube to facilitate cleaning and reduce the risk of patient infection. The endoscope includes an elongated flexible probe with a housing at its proximal end to control the direction and operation of the probe and for viewing images carried by optical fibers from the distal end of the probe. A recess or slot extending along either the suction tube or probe enables the suction tube to be removably secured to the probe. A suction tube connector at the proximal end of the suction tube allows the suction tube to be removably secured to the housing and also provides a connector for removable attachment to an external suction line. In the preferred embodiment, the suction tube connector includes means for regulating suction through the suction tube, such as a vent opening that can be manually sealed by a healthcare provider.

1. Field of the Invention
The present invention relates generally to the field of endoscopes. More specifically, the present invention discloses an endoscope with a removable suction tube.
2. Statement of the Problem
Endoscopes have been used for many years in the medical field for viewing within a desired region of the patient""s body through the patient""s airway, other natural orifices, or a surgical incision. An endoscope typically has an elongated flexible probe with a housing at its proximal end. Optical fibers extending the length of the endoscopic probe carry an image from the distal end of the probe to the housing, where it can be viewed through an eye piece by the physician. The housing also includes one or more controls allowing the physician to direct the distal tip of the probe in a desired direction. The probe can also be equipped with one or more instrument channels for surgical implements. A suction channel extends the length of the endoscopic probe to facilitate removal of mucus, blood, or secretions that can obstruct the physician""s view or interfere with endoscopic surgery.
The problem is that these channels are difficult to clean and sterilize because only the ends of the channels are open. A conventional autoclave can be used to sterilize an endoscope probe with heat and pressure. But, this tends to be harmful to the polymer components of the endoscope probe and can substantially shorten its useful life. Alternatively, the endoscope probe can be sterilized by immersion in a liquid chemical bath. Unfortunately, the efficacy of this approaches depends on the ability of the liquid to fully penetrate into all regions of the endoscope probe, which is often not possible if the suction channel contains mucus, coagulated blood, or the like. In addition, neither autoclave sterilization nor chemical bath sterilization can ensure complete removal of biological materials that may become trapped within the channels of an endoscope probe.
One approach has been to manually clean the channels in the endoscope probe with a cleaning rod or brush. However, this approach is relatively labor intensive, costly, and may expose the worker to contamination. There is also a risk that the cleaning process is not 100% effective since it is very difficult to visually inspect the interior length of the channels in the endoscope probe.
3. Prior Art
A variety of endoscopes with removable tubes or sheaths have been disclosed in the prior, including the following:
The Takahashi ""631 patent discloses a removable tube that can be inserted into a slot in an endoscopic probe.
U.S. Pat. No. 4,646,722 to Silverstein et al. discloses an endoscope with a protective sheath having a transparent window at its distal end. Channels for taking biopsies, or injecting air or water to wash the window of the sheath may extend along the endoscope either inside or outside the sheath. If the channels are positioned inside the sheath, they may be inserted in a longitudinal groove formed in the endoscope core.
The Takahashi ""585 and ""617 patents disclose a sheathed endoscope with a channel tube that is removably insertable into the main body of the endoscopic probe.
U.S. Pat. No. 5,193,525 to Silverstein et al. discloses an endoscope with an antiglare tip at its distal end.
The Adair ""940 patent discloses a device for assisting in insertion of an endotracheal tube. The assist device includes a handle, a malleable elongated insertion section, and an endoscope assembly. The handle may also include a suction port for attaching a suction tube for evacuation of the trachea during the intubation process.
Hori discloses an endoscope with a removable cover and an U-shaped viewing channel.
The Adair ""256 patent discloses an endoscope with a separable disposable tube assembly.
Jones discloses an endoscope with a collapsible access that allows insertion of functional instruments such as a biopsy device or tubes for supplying air, water, suction, and irrigation.
The Harhen patents disclose an endoscope with an elastomeric sheath.
The patents to Wilk et al. disclose a biopsy channel liner for use with an endoscope.
Crawford discloses an endoscope with a replaceable irrigation channel that is held in a groove extending along the exterior surface of the endoscope.
4. Solution to the Problem
Nothing in the prior art discussed above shows an endoscope with a suction tube that can be removably inserted into a slot extending the length of the endoscope, and having a connector at its proximal end to secure the suction tube to the housing of the endoscope. The suction tube connector can be equipped with a vent hole to allow the physician to regulate suction through the suction tube. The distal end of the suction tube can also be removably attached to a connector within the slot at the distal tip of the endoscope probe.
The present invention overcomes many of the shortcomings of conventional endoscopes by allowing the suction tube to be easily removed and discarded after use. The connectors at either end of the suction tube hold the suction tube securely in place to the remainder of the endoscope. The suction tube tends to prevent biological material from collecting in the slot. However, if cleaning is necessary, the slot is open from the endoscope housing to its distal tip for easy access.
This invention provides an endoscope having a removable suction tube to facilitate cleaning and reduce the risk of patient infection. The endoscope includes an elongated flexible probe with a housing at its proximal end to control the direction and operation of the probe and for viewing images carried by optical fibers from the distal end of the probe. A recess or slot extending along either the suction tube or probe enables the suction tube to be removably secured to the probe. A suction tube connector at the proximal end of the suction tube allows the suction tube to be removably secured to the housing and also provides a connector for removable attachment to an external suction line. In the preferred embodiment, the suction tube connector includes means for regulating suction through the suction tube, such as a vent opening that can be manually sealed by a healthcare provider.
A primary object of the present invention is to provide an endoscope that is easier to clean and sterilize.
Another object of the present invention is to provide an endoscope that reduces the risk of patient infection.
Yet another object of the present invention is to provide an endoscope that can be quickly and easily assembled and used by healthcare providers.
These and other advantages, features, and objects of the present invention will be more readily understood in view of the following detailed description and the drawings.


Disclosed herein are a method for operating machines and a system using the method, which can manage relations required in order to execute commands. The method includes generating a capability set required to execute the command by analyzing the command, and determining whether to participate in a machine group to execute the commands based on the generated capability set and capability parameters and status parameters of the machine.

1. Technical Field
Embodiments based on the concept of the present invention generally relate to a method for operating machines and a system using the method and, more particularly, to a method for operating machines and a system using the method, which manage relations between machines that are required in order to execute externally received commands.
2. Description of the Related Art
Recently, systems for connecting machines through a network and sharing information between the machines have been applied to various fields, such as health care, telemetry, smart homes, and smart cars, as well as household appliances and electronic devices.
Therefore, when various machines form collaborative relations, methods for managing the relations between the machines are required.

Method for operating machines and system using the same

ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE


A method for fabricating a semiconductor device includes forming a hard mask pattern over a substrate, forming a protection layer by transforming a portion of a sidewall of the hard mask pattern, forming a trench by etching the substrate using the hard mask pattern and the protection layer as an etch barrier, forming an isolation layer by filling the trench with an insulation material, removing the hard mask pattern, and performing a cleaning process. By forming the protection layer, it is possible to prevent the isolation layer from being lost during the removing of the hard mask pattern and the cleaning process and thus prevent generation of a moat.

The present invention relates to a method for fabricating a semiconductor device, and more particularly, to a method for forming an isolation layer, which is able to prevent generation of a moat, and a method for fabricating a nonvolatile memory device using the same.
Recently, researches for a so-called charge trap device (CTD) such as a charge trap type nonvolatile memory device are actively in progress to implement a large-scaled nonvolatile memory device of sub-40 nm dimensions. The charge trap type nonvolatile memory device has a stacked structure where a tunnel insulation layer, a charge trap layer, a dielectric layer and a gate electrode are sequentially stacked over a substrate and stores data by trapping or capturing charge in a trap site within the charge trap layer, wherein the trap site has a significant depth.
Meanwhile, since the charge trap type nonvolatile memory device is constructed of the combination of a plurality of unit memory devices, it requires an isolation layer to electrically isolate the unit memory devices from each other. In general, the isolation layer is formed by a shallow trench isolation (STI) method employing a trench structure.
FIGS. 1A to 1C illustrate a method for fabricating a charge trap type nonvolatile memory device in the prior art.
Referring to FIG. 1A, a tunnel insulation layer 12, a charge trap layer 13, a buffer oxide layer 14 and a hard mask nitride pattern 15 are sequentially formed over a substrate 11.
Then, after forming a trench 16 for the device isolation by etching the buffer oxide layer 14, the charge trap layer 13, the tunnel insulation layer 12 and the substrate 11 using the hard mask nitride pattern 15 as an etch barrier, an isolation layer 17 is formed by filling the trench 16 with an insulation material. Herein, the isolation layer 17 is formed using an oxide layer having a relatively superior filling characteristic, e.g., a spin on dielectric (SOD) layer, to prevent the generation of defects such as seams within the layer.
Referring to FIG. 1B, a wet etch process is performed to remove the hard mask nitride pattern 15. The hard mask nitride pattern 15 is removed using a phosphoric acid solution.
Subsequently, a cleaning process is performed to remove residue and the buffer oxide layer 14, thereby exposing the top surface of the charge trap layer 13. The cleaning process is performed using a hydro fluoric acid solution.
Referring to FIG. 1C, after forming a dielectric layer 18 along the entire surface of a resultant structure including the isolation layer 17, a gate electrode 19 is formed on the dielectric layer 18.
However, in the prior art, as the edge of the isolation layer 17 may be damaged during the process of removing the hard mask nitride pattern 15, moat (M) is generated. This is because the SOD layer used as the isolation layer 17 may contain impurities such as carbon and a lot of minute defects such as voids formed therein and thus may be comparatively easily etched by the phosphoric acid solution. Furthermore, the moat (M) becomes more serious concern in the cleaning process since the isolation layer 17 and the buffer oxide layer 14 are formed of the same oxide layer and thus the isolation layer 17 is also etched by the hydro fluoric acid solution used in the cleaning process.
Moreover, it is preferable to form the dielectric layer 18 having uniform thickness over the resultant structure so that the unit memory devices of the nonvolatile memory device have uniform performance characteristics. However, since the moat (M) has a horn shape and the dielectric layer 18 has relatively small thickness around the moat (M), it is difficult to form the dielectric layer 18 having the uniform thickness over the resultant structure, as shown in a portion indicated by a reference numeral B in FIG. 1C.
In addition, it is preferable that the charge trap layer 13 and the gate electrode 19 are electrically separated from each other by the dielectric layer 18 to enable a normal operation of the nonvolatile memory device. However, there is a concern that a coupling ratio of the charge trap layer 13 and the gate electrode 19 is changed by an electrical short through an opening in the dielectric layer 18 in the area of the moat (M), as shown in a portion indicated by a reference numeral A in FIG. 1C.

Method for forming isolation layer and method for fabricating nonvolatile memory device using the same


One connector housing includes a resilient locking arm having a through-hole provided at its tip, a pair of detection terminals attached to said resilient locking arm and opposed to the through-hole, a first spring portion provided on the side of a warping space of the resilient locking arm and inserted between the resilient locking arm and the pair of detection terminals, the first spring portion having a protrusion to be engaged in said through-hole so as to force the locking arm in an anti-warping direction, and a second spring portion always forcing said resilient locking arm in the anti-warping direction. Another connector housing includes an engagement protrusion which is to be engaged in the through-hole to push the protrusion, thereby warping the first spring portion in an anti-forcing direction to be brought into contact with the pair of detection terminals. Thus, connector fitting of one and another connector housings can be surely detected electrically. The fitting detection connector can have a buffer spring member which is arranged between the contact portion and intrusion protrusion of the first spring portion.

1. Field of the Invention
The present invention relates to a fitting detection connector which can electrically detect whether female and male connector housings have been fit into each other. The present invention also relates to a detection contact spring structure and a detection terminal deformation preventing structure which are used for the above fitting detection connector.
2. Description of the Prior Art
FIGS. 17 and 18 show a conventional fitting detection connector disclosed in Japanese Utility Model Publication No. Hei 4-3419.
This connector 28 includes one connector housing 29 with a connector fitting detection portion 30 provided on its outside. A sub-housing 33 of insulating resin composed of a terminal chamber 31 and a contact member insertion portion 32 is attached to the exterior wall of the housing 29. A pair of detection terminals 34, 34 are incorporated in the chamber 31 so that the respective tip male tabs 35, 35 are projected in parallel from the sub-housing 33. A contact member 36 having an shape is inserted and locked in the insertion portion 32 and its contact springs 37, 38 having different heights are opposed to the respective male tabs 35, 35. As seen from FIG. 18, the tip 41 of a resilient locking arm 40 of the other connector housing 39 presses a non-contact side contact spring piece 37 as shown in a dotted line so that the above pair of male tabs 35, 35 are brought into contact with the pair of contact spring pieces 37, 38. Thus, the fitting in the connector 28 can be detected.
The above connector structure has a disadvantage that the connector 28 itself becomes large because the fitting detection portion 30 is projected from the outside of the connector housing 29. Further, when the resilient locking arm 40 sits on and is engaged with the protrusion 42 of the one housing 29, the restitutive force of the locking arm 40 is weakened so that the pressing force of the contact piece 37 becomes insufficient. For this reason, the detection of fitting may become uncertain.
JP-A (Laid-Open) Sho 61-186180 also discloses a conventional fitting detection connector, particularly a detection terminal deformation preventing structure. This structure has the same disadvantage as in the conventional fitting detection connector disclosed in JU-Publication No. Hei 4-3419.


Disclosed herein are a sealant composition for use with tires, a tire having at least one component with at least one surface at least partially coated with the sealant composition, and related methods for applying the sealant composition to tires. The sealant composition comprises biorubber and a softener comprising at least one of plant oil or plant resin and has a non-petroleum content of at least 70% by weight.

Sealant compositions may be used in pneumatic tires to improve an installed tire's durability when the vehicle upon which the tire is installed is operated. Use of the sealant composition may enable the pneumatic tire to withstand a puncture from a sharp object such as a nail. By incorporating a sealant composition into an interior portion of a pneumatic tire, one or more punctures which could otherwise render the vehicle inoperable or require repair can be plugged by flow or movement of the sealant composition into the hole created by the puncture.

Bridgestone Americas Tire Operations, LLC


The present invention relates to a complex comprising nerve growth factor (NGF) and trk-proto-oncogene protein. The present invention also relates to methods for detecting the presence of NGF and trk-proto-oncogene receptor. The present invention further relates to methods that may be used in diagnostics and therapeutics for neurodegenerative diseases such as Alzheimer's and Huntington's by detecting NGF-trk receptor pairs.

The development of the vertebrate nervous system is characterized by a series of complex events beginning with an apparently homogeneous neuroepithelium in the early embryo and leading to formation of diverse, highly ordered, and interconnected neural cell types in the adult. Considerable descriptive and experimental evidence has been amassed which points to the existence of limiting diffusible factors that are required for the targeting, survival, and proper synaptic arrangement of neurons (R. W. Oppenheim, In: Studies in Developmental Neurobiology. (Cowan, W. M. ed.), Oxford Univerity Press, pp. 74-133, 1981; W. D. Snider and E. M. Johnson, Ann. Neurol. 26:489-506 (1989)). Functional neuronal circuits are sculpted from an initially overabundant production of neurons during development. In the mid term embryo, a process of programmed cell death eliminates a major proportion of the neuron population, leaving behind the appropriate number of neurons required for innervation of target tissues (V. Hamburger and R. Levi-Montalcini, J. Exp. Zool. 111:457-502 (1949); Y.-A. Barde, Neuron 2:1525-1535 (1989)).
The discovery of Nerve Growth Factor (NGF) provided the first direct evidence for the existence of neurotrophic, polypeptide factors (R. Levi-Montalcini and V. Hamburger, J. Exp. Zool. 116:321-362 (1951); R. Levi-Montalcini and P. U. Angeletti, Physiol. Rev. 48:534-569(1968)). This has been followed by the more recent description of additional neurotrophic factors: BDNF, CTNF, and NT-3, (for review see W. D. Snider and E. M. Johnson, Ann. Neurol. 26:489-506 (1989); G. Barbin et al., J. Neurochem. 43:1468-1478 (1984); P. C. Maisonpierre et al., Science 247:1446-1451 (1990)). The physiological consequences elicited by NGF in vitro and in vivo have been at the center of research in neurobiology for several decades. Consequently, considerable information is now available about the cell types that respond to NGF in the peripheral and central nervous systems.
NGF is known to play a role in the targeting and survival of sympathetic and neural crest-derived sensory neurons as well as in selected populations of cholinergic neurons in the brain (L. A. Greene and E. M. Shooter, Annu. Rev. Neurosci. 3:353-402 (1980); H. Thoenen and Y.-A. Barde, Physiol. Rev. 60:1284-1335 (1980); H. Gnahn et al., Dev. Brain. Res. 9:45-52 (1983)). It appears that the NGF dependent cholinergic neurons in the basal forebrain correspond to the population of cells that undergo attrition of Alzheimer's disease (F. Hefti, Annals of neurology, 13:109-110 (1983); Hefti and Wemer, 1986; Johnson and Tanuchi, 1987; P. J. Whitehouse et al., Science 215:1237-1239 (1982)). In vivo studies, in which NGF was injected in the periphery of the mouse embryo trunk, result in enhanced survival of sensory ganglia that are normally targeted for cell death (V. Hamburger et al., J. Neurosci. 1:60-71 (1981); I. B. Black et al., In: Growth Factors and Development, Current Topics in Developmental Biology, vol. 24 (Nilsen-Hamilton, ed.), pp. 161-192 (1990)).
Exposure of embryos to NGF antibodies results in reduced survival of dorsal root ganglion neurons while injection of NGF antibodies into neonate mice has the principal effect of inhibiting the survival of sympathetic neurons (R. Levi-Montalcini and B. Booker, Proc. Natl. Acad. Sci. USA, 46:373-384 or 384-391 (1960); S. Cohen, Proc. Natl. Acad. Sic. USA, 46:302-311 (1960); E. M. Johnson et al., Science 210:916-918 (1980)).
In vitro, some tumor cell lines of neural origin respond to the presence of NGF by undergoing differentiation along neuronal pathways. PC12 cells, derived from a rat pheochromocytoma, are the best characterized of these cell lines and represent a widely accepted model for NGF-mediated response and for neuronal differentiation (L. A. Greene and A. S. Tischler, Proc. Natl. Acad. Sci. USA 73:2424-2428 (1976)).
Although much is understood about the biology of NGF outside the cell, the mechanisms by which NGF elicits neurotrophic effects within the cell have not been fully resolved. Interaction of NGF with a cell receptor is a requisite step in the transmission of neurotrophic signals within the cell (for review see M. V. Chao, In: Handbook of Experimental Pharmacology, vol. 95/II Peptide Growth Factors and Their Receptors II (Sporn, M. B. and Roberts, A. B. eds.), Springer-Verlag, Heidelberg, pp. 135-165 (1990)). A major advance in understanding NGF interactions with the cells was the identification and cloning of a 75kDa receptor (75kNGF-R) that binds NGF, and is present in NGF-responsive cells. The clones of the gene encoding 75kNG-R have been characterized from several species (M. V. Chao et al., Science 232:418-421 (1986); M. J. Radeke et al., Nature 325:593-597 (1987)). Unfortunately, the structural and biological properties of 75kNGF-R have provided limited clues about the nature of the NGF signal trandsuction pathway inside the cell. 75kNGF-R displays the binding properties of a low affinity NGF receptor (Kd.apprxeq.10.sup.-9 M) when expressed in exogenous cell lines and analysis of the intracellular domain has not revealed putative domains of catalytic action (M. V. Caho, In: Handbook of Experimental Pharmacology, Vol. 95/II Peptide Growth Factors and Their Receptors II (Sporn, M. B. and Roberts, A. B. eds.), Springer-Verlag, Heidelberg, pp. 135-165 (1990)).
The biological responsiveness to NGF, however, is widely held to depend upon interactions with a high affinity binding component implying that other receptor or receptor subunits may be involved in NGF responses. The search for potential second messengers that might transmit NGF signals in PC12 cells has led to recent evidence indicating that activation of tyrosine kinases may represent an early response to the presence of NGF (Maher 1988). These data implicate tyrosine kinases as candidates in the composition of a high affinity receptor.
The trk proto-oncogene encodes a tyrosine kinase (TK) receptor with a tightly regulated neural pattern of expression during murine development (D. Martin-Zanca et al., Genes Dev. 4:683-694 (1990); D. Martin-Zanca et al., In: The Avian Model in Developmental Biology: From Organism to Genes, Editions du CNRS - 1990, pp. 291-302 (1990)). In vivo, transcripts for this gene were observed only in neural crest-derived sensory neurons of the peripheral nervous system through E17 of mouse development. Several lines of evidence have led applicants to investigate the possible involvement of trk in pC12 cell NGF-mediated events.
The need exists in the field to determine whether trk proto-oncogene tyrosine kinase receptor is activated via direct interaction with NGF. The present invention provides a complex comprising NGF ligand and trk-proto-oncogene receptor. The direct binding of NGF to the trk receptor leads to tyrosine phosphorylation and tyrosine kinase activity in response to NGF exposure in trk expressing cells. Knowledge of the trk physiological receptor and cognate NGF complex may allow a detailed study of nerve growth and regeneration. Furthermore, the demonstration of NGF-trk receptor complexes demonstrates methods for identifying related tyrosine kinase receptors providing additional neurotropic-factor pairs.

TRK tyrosine kinase receptor is the physiological receptor for nerve growth factor

The United States of America as represented by the Department of Health and Human Services