A burst mode digital communications system which is unique in that it modulates a sinusoidal carrier with discrete cosine segments. The discrete cosine segments may contain different time and amplitude values. The discrete cosine segments may be combined with each other or with zero slope level segments in order to effectively modulate the sinusoidal carrier. Rather than employing the use of filters for controlling instantaneous voltage changes, the present communications system forces the bit edges of the discrete cosine segments to occur at the zero slope points of a cosine wave, where no voltage changes occur. The communications system utilizes direct digital synthesis in order to create a carrier signal which closely represents sinusoidal carrier signal. The present communication system may be used in conjunction with various conventional methods such as phase-shift keying and amplitude-shift keying. A device is also disclosed for demodulating the carrier signal in order to recover the original base band signal. The burst mode digital communications system may also demodulate data by employing adaptive templates for more accurately determining received digital symbols.

1. Field of the Invention
The present invention relates to digital communications systems in which the carrier signal is varied in accordance with bursts of binary data being transmitted. More particularly, the present invention pertains to a burst mode data communications technique in which the carrier signal is optimized for bit synchronization and immunity to impairments arising from signal multi-path, in wireless applications, and reflections, due to impedance discontinuities in wire line applications.
2. Description of the Related Art
Digital modulation is the means by which a carrier, inherently, analog in nature, is made to carry digital information in a communications channel. This involves altering the amplitude of the carrier, the angular velocity of the carrier, or both. The objective is to create discrete phase/amplitude states in a manner that leaves little chance for ambiguity between the states. These discrete states, commonly designated as symbol states, correspond, to one or more binary bits of data. By regenerating the binary data at intervals along a transmission path, re-transmitting data that is determined to be corrupt and applying error correction, digital data can be transmitted over great distances with no degradation of quality, even in the presence of a significant level of background noise. This is in stark contrast to analog modulation in which noise effects accumulate through the transmission path, usually without remedy.
In digital communications channels, noise is only one problem which must be overcome. In wire line applications impairments in cables cause impedance discontinuities, whereby resultant distortion of the signal and recovery of the digital data at the receiver becomes much more difficult. In wireless applications, multi-path is a degrading factor, especially with antennas of low, directivity. The transmitted signal traverses the most direct and desirable path to the receiving antenna. However, the signal may traverse an indirect path as well, being reflected from a buildings or other object, and also arrive at the receiving antenna. Multi-path causes a summation of such reflected signals, delayed in time, with the main signal. This also makes recovery of the digital data more difficult.
The prior art uses techniques such as training sequences, which allow equalization to be gradually varied until the equalization settings are optimized. This approach works well with continuous data streams that last for seconds or more, but does not work very well for burst mode transmissions, which may originate from multiple points. The transmitter in this case bursts out data for short periods of time and then becomes quiet to allow other transmitters a chance to send data. For efficient use of the channel, each burst of data normally contains a preamble or header which is used for synchronization and for setting the receiver voltage thresholds. Then the payload data is sent followed by a trailer to gracefully end the transmission.
When channel impairments are present, the preamble is not always lengthy enough to allow an equalizer to train effectively. Each transmitter has its own unique path to a receiver, and associated impairments, which means the equalizer must be prepared to train on every burst or packet sequence of data. If additional header data and training time is allowed for data recovery, the effective data throughput can go down considerably. Some training sequences last for more than a second, which could translate into millions of throw away header bits at the beginning of every data burst. This is clearly undesirable when the goal is to get the maximum utilization of a communications channel.
Carrier signals for digital modulation are typically based on sinusoidal waveforms because such waveforms require the least amount of bandwidth. There exists three classical forms of digital sinusoidal modulation: amplitude shift keying (ASK), frequency shift keying (FSK) , and phase shift keying (PSK). Improvements have been made in digital sinusoidal modulation, however all of the improvements have been based on the three classical techniques previously mentioned. In ASK, the amplitude of the carrier signal is varied or shifted in response to changes in the digital data. In FSK, the frequency of the carrier signal is varied or shifted in response to changes in the digital data. In PSK, the phase of the carrier signal is varied or shifted in response to changes in the digital data.
There are also certain disadvantages associated with the classical modulation techniques. For example, ASK is especially susceptible to atmospheric noise and fading. FSK requires that an associated receiver detect two discrete frequencies before the frequency can be acquired and detected. This presents delays due to the additional time required to receive the several cycles of each frequency. PSK requires complex receiver circuitry in order to detect phase changes. Furthermore, elaborate filtering is necessary to control spurious outputs resulting from the discontinuities associated with the phase changes.
One disadvantage, however, is common to all of the classical modulation techniques and their derivative improvements. This is the use of fixed time slots for varying the characteristics of the carrier signal. When fixed time slots are used, variations in the carrier signal occur at random points along the sinusoidal waveform, thus resulting in spurious frequencies and expanding of the modulation bandwidth. Complex filtering becomes necessary in order to reduce the amplitude of these spurious frequencies. As the bit rate increases, the variations in the carrier signal occur more frequently, thus posing a challenging demodulation task.
It is well known that the amount of spurious output generated by the variation of a sinusoidal waveform is dependant upon the instantaneous value of the slope of the waveform when the changer occurs. Thus, a change which occurs at exactly the midpoint or highest kinetic energy point of the waveform generates the greatest amount of spurious output because the slope value is at its maximum. If the change occurs at exactly the peak of the waveform however, the least amount of spurious output is generated because the slope value is at its minimum, i.e., zero kinetic energy.
Representation of discrete states of digital data is accomplished through various base band encoding techniques. FIG. 2A illustrates various known base band encoding techniques. In non-return to zero level (NRZ-Level) encoding 28, digital code is produced by instantaneously shifting voltage levels at fixed bit time intervals so that two unique binary symbols are represented, a one and a zero. Thus, a one is represented by one level, while a zero is represented by the other level. The NRZ-Mark digital code 30 is produced by instantaneously shifting voltage levels at fixed bit intervals only when a one is transmitted and not changing levels when a zero is transmitted. The RZ digital code 32 is produced by instantaneously shifting voltage levels at half bit-time intervals when a one is transmitted and not changing levels when a zero is transmitted. A BI-PHASE-Level digital code 34 is produced by instantaneously shifting voltage levels at half bit-time intervals so that a one is a high level during the first half of the bit time and a zero is a high level during the second half of the bit time. The NRZ-4Level digital code 36 is produced by shifting voltage levels instantaneously after two, bit-time intervals. A one--one is transmitted by the top level, a one-zero is transmitted by the next lower level, a zero-one is transmitted by the next lower level, and a zero-zero is transmitted by the bottom level. By encoding two bit times into one symbol, NRZ-4Level encoding reduces the effective transitioning rate in half. Similarly, three bit times could be encoded into NRZ-8Level encoding to reduce the transitioning rate by one third. Multi-level encoding suffers from a drawback in that it necessitates a more complex receiver to detect and recover the transmitted symbol.
The prior art creates transitions at fixed bit times when encoding digital symbols. These transitions occur at the bit edges and remain steady until the next bit edge, thus requiring the transmission of a step function or rectangular pulse. The rectangular pulse or step function generates spurious energy components at frequencies from zero to infinity. Consequently, frequency multiplexing of data over a communications channel cannot be performed unless the instantaneous voltage transitions of the rectangular pulse are filtered to remove unwanted energy components throughout the frequency spectrum. The rectangular pulse and its corresponding bandwidth are shown in FIG. 3.
As an example, consider data transmitted at 1000 bits/second. The bit time T would be {fraction (1/1000)} of a second, or 1 millisecond. The first frequency null would occur at 1/T or 1000 Hz and energy components would extend from zero hertz to infinity. When the rectangular pulse is used to modulate a sinusoidal carrier, the negative frequency spectrum would also be translated up in frequency and the null to null bandwidth would be 2/T or 2000 Hz. However, energy outside of the main lobe is not required to recover the transmitted data. Furthermore, it is desirable to reduce the modulation bandwidth by eliminating frequency energy outside this primary lobe.
In order to transmit the maximum amount of data over a given digital communications channel, a small bandwidth and high bit rates are required. For example, more data can be transmitted over a frequency multiplexed communications channel, such as those used in satellite links, when data communication techniques are used that have narrow bandwidth requirements per carrier signal whiled still providing high data rates.
Much development work has gone into ways of minimizing the bandwidth of the rectangular pulse. In the prior art, the instantaneous transitions at the bit edges are smoothed by passing the rectangular pulse through filters. While the filtering process removes many of the unwanted frequencies outside of the main modulation lobe, it also removes some of the energy which helps in the symbol recovery process. Thus, a delicate balancing act must be made in choosing a filter suitable for reducing the bandwidth while not seriously degrading the modulation information contained within the symbol. It has been shown by Nyquist and others that the band limited rectangular pulse has an ideal shape after filtering which is called the sin x/x or sinc pulse.
A filtered rectangular pulse which closely approximates the ideal sinc pulse shape is commonly used to modulate a high frequency sinusoidal carrier, thus producing an upconverted frequency multiplexed communications channel which can transmit numerous messages simultaneously. Each digitally encoded base band signal is subsequently modulated with a carefully chosen local oscillator frequency in order to pack the greatest number of carrier signals within a given communications channel.
Recovery of individual carrier signals is accomplished through the use of a carefully created local oscillator capable of downconverting the carrier signal to the original digitally encoded base band signal. Due to the pulse filtering during the modulation process, the received base band signal has an xe2x80x9ceye patternxe2x80x9d associated with it. This eye pattern is the result of the vertical edges of the rectangular pulse being filtered and the shape of the xe2x80x9ceyexe2x80x9d opening is based on the sinc pulse shape.
Conventional demodulation of the data in the two symbol case is accomplished by using a zero voltage reference. A measurement is made at the center of the bit time in order to determine whether the received symbol is above or below this zero voltage level. It is important to base the decision of which bit was received precisely at the midpoint of the bit time because the least amount of ambiguity exists between symbols at the midpoint of the bit time. Furthermore, the decision of which symbol is received is complicated by interference and noise that is present to some degree in all communications channels. The interference and noise causes the eye opening to close, thus making it critical to choose the optimum point for symbol decision making.
Further reductions in the bandwidth can be gained when more than two symbols are utilized. The number of symbols increases as a power of 2. For example, 2, 4, 8, 16, 32, 64, 128, 256, 512, and 1024 symbols are used in modern communications systems. To achieve a large number of unique and distinctive symbols, changes in carrier phase and amplitude are typically used. To go from 2 to 4 symbols gives a reduction of 2 in bandwidth. Eight symbols reduce bandwidth by one third, sixteen symbols reduces bandwidth by one fourth and so on. The penalty for increasing the number of symbols is the increased difficulty in determining which symbol was actually received.
When the binary case of two symbols is used, there is only one voltage reference needed to determine if the eye pattern is above or below the reference. However, when many symbols are used to reduce bandwidth, a corresponding increase in symbol amplitude and phase references are needed. This is further complicated by thee fact that interference and noise are always present in the channel, resulting in a greater possibility of making an incorrect symbol decision when an increased number of symbols are used.
The related art is represented by the following patents of interest.
U.S. Pat. No. 3,713,136, issued on Jan. 23, 1973 to John Nagy, Jr., describes an analog-to-digital converter of the dual slope integrating type that operates without counter reset or input gating circuitry to provide successive, accurate digital readouts representing the average magnitude of corresponding analog input signals. Nagy, Jr. does not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 3,980,826, issued on Sep. 14, 1976 to Albert X. Widmer, describes a bifrequency encoded binary data transmission system wherein the transmitted signal is predistorted to eliminate the need for equalization at the receiving end. Widmer does not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 4,395,642, issued on Jul. 26, 1983 to Stefan Traub, describes a sine-shaping circuit which is capable of generating a sinusoidal signal having low harmonic distortion, continuous slope and high accuracy. Traub does not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 4,435,824, issued on Mar. 6, 1984 to Brian W. Dellande et al., describes a communications system which generates an output signal of a selected primary frequency having digital data bits serially modulated thereon. The system utilizes a hybrid differential phase-shift keyed (DPSK) modulation. The improved DPSK modulation is frequency modulation of a phase encoded signal. A controller is used to control a frequency generator means which is used to shift the frequency of the output signal between primary and secondary frequencies. The controller and frequency generator means provide a modulated output signal which is D.C. balanced bit by bit and has substantially reduced harmonic energy. Dellande et al. do not suggest a burst mode digital communications system according to the claimed invention.
U.S. Pat. No. 4,472,747, issued on Sep. 18, 1984 to David M. Schwartz, describes a microcomputer system for converting an analog input signal into a digital form for storing in digital form in a highly condensed code and for reconstructing the analog signal from the coded digital form. Schwartz does not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 4,564,823, issued on Jan. 14, 1986 to John P. Stahler, describes a modulation system wherein a carrier signal is modulated by an input signal having a variable amplitude. The amplitude of the input signal is sampled every predetermined fractional cycle of the modulated signal. The carrier signal is modulated in response to the sampled amplitude of the input signal. This provides a modulated signal having an amplitude and duration which are inversely proportional to each other, but related to the sampled amplitude of the input signal, for each predetermined fractional cycle. The signal is subsequently demodulated by zero-crossing detection, peak-amplitude detection, or a combination of both. The system is self-clocking, does not produce discontinuous phase or amplitude changes, and does not introduce DC components. Stahler does not suggest a burst mode digital communications system according to the claimed invention.
U.S. Pat. No. 4,596,022, issued on Jun. 17, 1986 to Donald L. Stoner, describes a system for communicating digital data over a limited bandwidth transmission link. The system utilizes modulator means for receiving an input digital signal and generating a corresponding frequency shift keyed signal having high-frequency and low-frequency signals with in-phase signal transitions at frequency shifts. Demodulator means are provided for receiving-and demodulating the frequency shift signal in order to generate an output digital signal corresponding to the input digital signal. The demodulator means includes a zero crossing detector in order to recover the frequency shift keyed signal received. The system includes a transition detector for detecting transitions in the binary logic state on an input digital signal and generating a transition indicator signal in response thereto. A frequency shift key having an oscillator capable of generating high and low frequency signals is used to provide substantially in-phase signal shifts. Stoner does not suggest a burst mode digital communications system according to the claimed invention.
U.S. Pat. No. 4,745,628, issued on May 17, 1988 to William T. McDavid et al., describes a symbol generator for phase. modulated systems. The symbol modulator produces a filtered analog waveform for use in phase modulating a carrier. The symbol generator includes a memory for storing digital representations of analog waveform segments at predetermined addressable locations. Each segment corresponds to the cross-correlation of a predetermined filter function with a predetermined number of data bits in the data stream. The data stream is converted to an address for the memory to output a digital value to a digital to analog converter. The output of the digital to analog converter includes an in-phase and quadrature-phase components which are directed to a sample and hold circuit for generating the analog signals. The waveform segments are then sequentially assembled and directed to a vector modulator. McDavid et al. do not suggest a burst mode digital communications system according to the claimed invention.
U.S. Pat. No. 4,809,205, issued on Feb. 28, 1989 to Richard A. Freeman, describes a direct digital synthesizer which digitally generates a sinusoidal waveform by dividing the sine waves into a plurality of coarse phase angle intervals, which are in turn divided into a plurality of intermediate phase angle intervals. Freeman does not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 4,871,987, issued on Oct. 3, 1989 to Seiji Kawase, describes a binary signal modulator having a circuitry for sampling a binary signal at a predetermined sampling frequency. A modulating circuit responsive to the sampled binary signal is used for generating a modulated signal whose rising and decaying timings are respectively determined by the start end times of the binary signal. The rising and decaying timings of the modulated signal are defined as predetermined functions. Kawase does not suggest a burst mode digital communications system according to the claimed invention.
U.S. Pat. No. 4,897,620, issued on Jan. 30, 1990 to Ronald Y. Paradise, describes a continuous phase shift modulation system with improved spectrum control. The inventive method includes the step of determining, in advance, whether successive pulses are to have the same or different polarities for each of the in-phase and quadrature components. If successive components are to have the same polarity, then a continuous transition modulation signal between the successive pulses is provided in place of adjacent portions of the successive half-cosine pulses. The modulation of the other component is adjusted during the time of the continuous modulation signal so as to maintain a desirable constant amplitude characteristic. Paradise does not suggest a burst mode digital communications system according to the claimed invention.
U.S. Pat. No. 4,905,177, issued on Feb. 27, 1990 to Lindsay A. Weaver, Jr. et al., describes a method and apparatus for converting phase data into amplitude data. Weaver, Jr. et al. do not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 4,975,699, issued on Dec. 4, 1990 to Gary D. Frey, describes a circuit for generating an analog sine voltage from a digital phase input employing a memory storing sine and cosine values and a correction value for each phase and first and second digital-to-analog converters. Frey does not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 4,995,059, issued on Feb. 19, 1991 to Hisashi Ishikawa, describes a predictive coding device with an input terminal through which a sampled value is input, a predicting circuit for outputting a predicted value for the sampled value which has been input through the input terminal, and a look-up table arranged to receive, as a readout address, the sampled value input through the input terminal and the predicted value and then to output a predictive coded value. Ishikawa does not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 5,012,491, issued on Apr. 30, 1991 to Motoya Iwasaki, describes a burst mode digital communications system with a preamble detection circuit that requires a small amount of preamble information for establishing carrier and clock timing and controlling preamplifier gain by deriving error control signals simultaneously during the reception of a preamble. Iwasaki does not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 5,046,071, issued on Sep. 3, 1991 to Toshiyuki Tanoi, describes an encoding device for transforming a sequence of digital image signals into a sequence of transformed signals which is subjected to interframe predictive coding by the use of a subtractor and a local decoding loop. Tanoi does not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 5,237,324, issued on Aug. 17, 1993 to Alfredo R. Linz et al., describes a system for producing al modulation baseband analog signal responsive to serial bits of digital data. Linz et al. do not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 5,357,544, issued on Oct. 18, 1994 to Thomas G. Horner et al., describes a method of decoding a composite signal which includes receiving a composite signal including a pilot signal at a pilot signal frequency and first and second information modulated with a subcarrier at a harmonic of the pilot frequency. Horner et al. do not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 5,361,046, issued on Nov. 1, 1994 to John D. Kaewell, Jr. et al., describes a modulator capable of providing a fractional sample or symbol time. The modulator employs a decimation counter responsive to a clock having a frequency of M/N*symbol clock, where M is an interpolation factor and N is a decimation factor. The modulator uses this frequency to generate a data symbol clock to select frequency shift key (FSK) symbols from a sampled data array. A multiplier receives and multiplies the FSK symbols by a weighing factor which is determined by the decimation counter. The modulator allows digital modulations which consist of a non-integer number of samples per symbol time to be synthesized in an efficient manner. The modulator is also capable of producing fractional sample and symbol modulations in order to allow support of modulations with various symbol rates by hardware platforms which contain fixed digital to analog sampling clocks. Kaewell, Jr. et al. do not suggest a burst mode digital communications system according to the claimed invention.
U.S. Pat. No. 5,406,584, issued on Apr. 11, 1995 to David Erisman, describes a time shift keying digital communications system. The system utilizes a digital modulation technique which is unique in that fixed time slots are not used to vary the characteristics of the carrier signal. Instead, variations in the time slots are used to transfer the digital information. The modulation is created by synthesizing a carrier waveform capable of varying the time it takes for each peak to occur. The peaks of the carrier signal are tightly controlled to occur at exact discrete time slots corresponding to the base band digital signal. Erisman does not suggest a burst mode digital communications system according to the claimed invention.
U.S. Pat. No. 5,430,764, issued on Jul. 4, 1995 to William A. Chren, Jr., describes a direct digital frequency synthesizer that employs residue number system based processors to generate output waveforms of desired frequencies. Chren, Jr. does not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 5,467,294, issued on Nov. 14, 1995 to Vince Hu et al., describes a method and apparatus suitable for generating programmable digital sine waves which involves converting the output of a direct digital synthesizer or numerically controlled digital oscillator to a higher frequency with a multiplier-less structure that takes advantage of the. properties of trigonometric identifiers for sine and cosine. Hu et al. do not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 5,479,168, issued on Dec. 26, 1995 to Keith O. Johnson et al., describes digital encoding/decoding methods and apparatus for ultra low distortion reproduction of analog signals which are also compatible with industry standardized signal playback apparatus. Johnson et al. do not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 5,479,451, issued on Dec. 26, 1995 to Charles Eldering et al., describes a method for data recovery in burst mode communications systems that include a data signal having a burst preamble with a defined sequence of m bits, by sampling in a first sampling step the burst preamble with n samples per bit carried out by n bit clocks with different phases, and providing a sampled burst preamble. Eldering et al. do not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 5,481,230, issued on Jan. 2, 1996 to Paul Chang et al., describes a phase modulator circuit and a method for generating an output signal having individually positionable edges. The phase modulator includes a programmable pulse generator for producing an output signal and a control value source for delivering a sequence of control values to the generator. The control values determine the time between successive output pulses. Succeeding control values are provided in response to the edges of the output signal and each next control value in the sequence is made available to the programmable pulse generator within the time between successive edges of the output. Chang et al. do not suggest a burst mode digital communications system according to the claimed invention.
U.S. Pat. No. 5,513,219, issued on Apr. 30, 1996 to Ronald E. Ham, describes a method and apparatus for transmitting information at a high rate by using an undermodulated frequency shift keyed signal. The transmission rate is independent of the data content and the system requires no zero crossing detectors. The apparatus also includes a demodulator which combines non-linear processing circuitry with a conventional demodulator. Ham does not suggest a burst mode digital communications system according to the claimed invention.
U.S. Pat. No. 5,621,766, issued on Apr. 15, 1997 to Bradley B. Bakke et al., describes a signal receiver using a burst detector to detect the occurrence of a burst. Bakke et al. do not suggest a burst mode digital communications system in accordance with the claimed invention.
U.S. Pat. No. 5,642,386, issued on Jun. 24, 1997 to A. Gregory Rocco, Jr., describes an all-digital data sampling circuit and related sampling method for a burst mode data communications system. Rocco, Jr. does not suggest a burst mode digital communications system in accordance with the claimed invention.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed.
The present invention is a burst mode digital communications system which provides a method for digitally modulating a sinusoidal carrier. The method utilizes direct digital synthesis techniques to create discrete carrier segments having zero slope edges. The discrete carrier segments may contain different time, phase, or amplitude values and can be combined with other discrete carrier segments having zero slope edges or zero slope level segments to modulate the sinusoidal carrier. A table of phase amplitude values is first created using direct digital synthesis, techniques and subsequently stored in a read only memory (ROM) look-up table. A plurality of digital data blocks are then sent to an associated transmitter and modulated. The modulation is performed such that the bit edges of each of the digital data blocks occur at zero slope points where no voltage step changes take place. The stored phase amplitude values for each digital data block are then passed through a digital-to-analog converter, thereby producing an analog waveform. A microprocessor and a phase accumulator may be utilized to accurately control reception and, modulation of the digital data blocks. In preferred embodiments off the invention, the output of the digital-to-analog converter may be filtered in order to remove sampling artifacts and produce a low distortion waveform.
The present invention also provides a method for demodulating data which has been modulated by discrete carrier segments having zero slope edges. The data received is in the form of a carrier signal which is composed of carrier segments. The carrier segments are filtered in order to remove unwanted noise. The carrier segments of the modulated data may then be recovered by detecting the presence or absence of the carrier segments within a predetermined bit time or symbol duration. In preferred embodiments of the invention, the frequency of the carrier symbol is downconverted to the lowest possible value and filtered.
The present invention also provides a carrier segment communications system which includes means for receiving a plurality of digital data blocks. The digital data blocks are received in a sequential manner. Furthermore, each digital data block has a discrete value associated therewith which is selected from a predetermined number of possibly assigned discrete values. In certain preferred embodiments of the invention, the predetermined number of possibly assigned discrete values is two Thus, each block of digital data is a binary digit. The system also includes means for modulating the data blocks in order to construct a carrier signal having carrier segments of predetermined shapes. The predetermined shapes are selected from a predetermined set of shapes consisting of cosine segments, sine segments, zero slope level segments, and combinations thereof. The edges of each carrier segment have a slope equal to zero. In preferred embodiments of the invention, the carrier segments are pi radians in length, so that they begin at a zero slope point and terminate at a zero slope point.
The system monitors the completion of each successive carrier segment being used to construct the carrier signal and a controller produces a control signal which indicates the correct carrier segment to be used. The controller accomplishes this task by examining the discrete value associated with the incoming digital data blocks and determining which carrier segment is representative of the digital data block being examined. It is preferred that the system further include means for transmitting the resulting carrier signal to a remote location. Furthermore, the remote location should be capable of receiving the carrier signal and demodulating it so that the base band digital signal is recovered.
When a digital signal is summed with a delayed version of itself as would happen in a multi-path condition, a complex waveform results from the destructive and constructive interaction of the amplitudes and phases that represent each digital symbol In the proposed burst mode communications technique of the present invention, simple sine waves are sampled, facilitating symbol bit edge synchronization in the preamble, and then special symbol combinations are sampled to enable optimum recognition of subsequent symbols. Special receiving techniques are then utilized to eliminate long training and equalization delays in order to maximize multi-point burst mode digital data communications.
At the beginning of the data burst or packet, determining the symbol bit edges is critical for proper synchronization. If the symbol bit edges are incorrectly detected, the entire packet can be lost, so the present invention utilizes specially created symbols for this purpose. After synchronization, the symbols must be detected with the least amount of ambiguity possible. The receiver detection process in the present invention utilizes the impaired symbol directly and does not require an equalizer to compensate for the effects of the impairment. This technique allows the synchronization and detection set up processes to occur in the first few bits of the packet.
Conventional techniques require a coherent phase reference local oscillator to phase lock onto the incoming carrier. This phase locked local oscillator is then heterodyned with the incoming data carrier to determine the phase and amplitude constellation used for demodulation. When impairments are present, equalization is necessary to keep the received signal constellation tightly grouped for optimum symbol recognition. Both ends of the communications link may even send training sequences to each other to further adapt to the communications link impairments. All of these conventional techniques require significant time delays, which reduce throughput and are very undesirable in burst mode communications systems.
In the proposed burst mode digital communications system, carrier segments and special symbols are initially transmitted at the beginning of the burst. These are designed to provide symbol edge synchronization which can be used for a long series of data symbols to follow. The amplitudes of the symbols are used as a standard from which voltage thresholds are derived. After the synchronization symbols are transmitted, the data symbols can be changed to convey the maximum amount of detectable information between digital states so as to reduce ambiguity in the detection process. This technique can be especially useful in the presence of impairments such as signal interferers, multi-path reflections, or reflections caused by non-terminated wire or cable links. When two ends of a communications link have systems based on precision high speed system clocks, the small inherent frequency differences between the two systems can be ignored if the data bursts are small or interspersed with synchronization symbols during the data bursts.
For the reception and demodulation of data symbols in the proposed system, the receiver is based on digital techniques where analog-to-digital sampling of the received waveform first takes place. These data samples are first compared against an expected pattern or template to find the symbol edge synchronization. A known transmitted sequence of special preamble symbols, digitally sampled, allows the receiver to store these samples to be used as templates, uniquely defining the pattern for each digital state Each subsequent received bit has its associated digital values compared against the stored templates to determine how many digital values matched the stored template values. The template with the highest number of matches then determines the decision as to which symbol was received. This technique is adaptive since the templates incorporate sampled digital values that already account for channel impairments. These templates are constantly updated for each data burst, which allows for increased immunity from multi-path or reflective impairments. This technique also allows very rapid acquisition of the data burst, which translates into higher data throughputs.
Accordingly, it is a principal object of the invention to provide a burst mode digital communications system which digitally creates a sinusoidal carrier by utilizing discrete carrier segments which can be added together or added with zero slope level segments.
It is another object of the invention to provide a burst mode digital communications system which digitally modulates a sinusoidal carrier using direct digital synthesis techniques to produce data symbols that are unambiguous and resistant to channel impairments.
It is yet another object of the invention to provide a burst mode digital communications system which controls the instantaneous voltage changes occurring at the bit edges without the use of filters.
It is a further object of the invention to provide a burst mode digital communications system which minimizes the amount of spurious output associated with the digital modulation of a sinusoidal carrier.
It is yet a further object of the invention to provide a burst mode digital communications system which demodulates digital data which has been modulated by carrier segments having zero slope edges.
Still another object of the invention is to provide a burst mode digital communications system which digitally demodulates the data by utilizing digital data template values captured from the incoming carrier with impairments that are compared continuously with new symbols to determine the digital symbol data.
Still a further object of the invention is to provide a burst mode digital communications system which employs a data channel with high bit rates and a narrow bandwidth that is immune to noise and signal interference.
Still a further object of the invention is to provide a burst mode digital communications system which enables multi-symbol communications using amplitude modulation in combination with frequency diversity.
It is an object of the invention to provide improved elements and arrangements thereof in a burst mode digital communications system for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.

Burst mode digital communications system


The present invention provides a buffing machine for lens, which comprises chuck shafts for chucking a lens of eyeglasses and for rotatably supporting the lens of eyeglasses and a buff wheel for lens for buffing end surface of the lens of eyeglasses, wherein a rotation axis of the buff wheel is tilted with respect to the chuck shafts, and a buffing surface of the buff wheel is a conical curved surface.

The present invention relates to a buffing machine for lens, and in particular to a buffing machine for lens used to polish end surfaces of lenses of eyeglasses.
Among eyeglasses currently in practical use, frameless eyeglasses have no frame to accommodate lenses and the eyeglasses are used with end surfaces of the lenses exposed to outside. In this respect, end surfaces of the lenses are polished by buffing to finish them as mirror surfaces.
Now, description will be given on a conventional type buffing machine for lens, referring to FIG. 11 and FIG. 12.
In the figure, reference numeral 1 represents a lens of eyeglasses, and the lens 1 of eyeglasses is held by lens chuck shafts 2 of the buffing machine for lens and 2 via lens chucks 3 and 3, and there is provided a buff wheel 4, which has a rotation axis in parallel to an axis of the lens chuck shaft 2. The buff wheel 4 is produced by sewing a buff cloth 5 together. The lens chuck shaft 2 is rotatably mounted on a tiltable frame (not shown) and is rotated by a motor (not shown) installed on the frame.
In case end surface of the lens 1 of eyeglasses is to be buffed, it is chucked by the lens chuck shafts 2 and 2. Then, the frame not shown in the figure is laid down, and the end surface of the lens 1 of eyeglasses is brought into contact with the rotating buff wheel 4 while the lens 1 of eyeglasses is being rotated.
In the buffing machine for lens as described above, the surface of the buff cloth 5 is fluffy. As seen in FIG. 12, fluffs 6 on the surface of the buff cloth 5 are raised perpendicularly with respect to the peripheral end surface of the buff wheel 4 due to centrifugal force caused by the rotation of the buff wheel 4. The front surface of the lens is usually curved toward +side (i.e. convex side), and the fluffs 6 buff or polish peripheral edges of front surface of the lens 1 of eyeglasses. Various types of coating 7 are coated on the lens to protect the lens body or to increase transmittance of light. There have been problems in that the coating 7 on peripheral edges of the lens is damaged by the fluffs 6. In the conventional type buffing machine, buff having high rigidity such as hard buff, felt buff, etc. has been used so that the end of the lens is not buried in the buff. Therefore, it is easy to buff end surface of the lens when end surface is flat, but if end surface is V-shaped, only tips of the end surface of the lens touch the surface of the buff, and it is difficult to buff the entire end surface of the lens.


An exercise apparatus for performing an armless push-up allows a user to engage in gravity-driven, resistance exercise with improved pectoral isolation and range of motion as compared to known push-up devices. The exercise motion is performed using a yoga-inspired, bent-elbow plank position by a prone (face-down) user. The user places each forearm on a trolley mounted at the top of opposed rails that are inclined toward an elevated centerline. As the trolleys move down the opposed inclined rails, the user's chest descends down; and as the user pinches his elbows together using the pectoralis muscles, the trolleys move up the inclined rails again. Gravity imparts a centered user balance, and the resistance can be varied, such as by changing the incline of the rail assemblies, changing the weight associated with the user, or by adding resistance to the trolley movement.

Resistance exercise is any exercise where muscles contract against an external resistance, the objective being to increase strength, tone, mass, or muscular endurance. Lifting weights using dumbbells or weight machines is an example of resistance exercise. Resistance can also come from elastic tubing or bands, cinder blocks, one's own body weight (for example, as with conventional push-ups), or any other object that forces one's muscles to contract. Broadly speaking, exercise involving resistance training develops the strength and endurance of large muscle groups.
Conventional push-ups are a time-honored and effective exercise predominantly used to develop upper body strength. They are considered a body weight exercise because it is one's own body weight that provides the resistance. Body weight exercises such as push-ups require the individual to stabilize and balance the weight in order to lift the body. This need for balance requires that numerous muscle groups be incorporated, and therefore push-ups and other body weight exercises provide strengthening beyond just those muscles primarily involved in actually displacing the body weight.
The muscles predominantly involved in traditional push-ups are the arms (particularly the triceps), the shoulders (particularly anterior deltoids) and the chest (pectoralis major and pectoralis minor). Although the chest muscles are one of the primary groups of muscles exercised and strengthened by performing push-ups, the effectiveness of push-ups for strengthening the pectoralis muscles is limited. The arms (triceps) are smaller muscles that move through a larger range of motion during a push-up, and therefore fatigue more quickly. This is a critical limiting factor in the duration and intensity of exercise that the chest muscles endure. Often, the fatigued arm muscles reach the point of failure before the pectoralis muscles, and at this point the push-up exercise is no longer effective.
Typically, pectoralis muscle strengthening and development is achieved through weight-lifting. This frequently requires expensive equipment to isolate and maximize the benefit. Unfortunately the "anytime, anywhere" usefulness of body weight exercise is lost. Bench press, chest butterfly, and cross-over pulls are common weight-lifting exercises that target the pectoralis muscles. To some extent, these exercises (particularly bench press) require significant muscle input from the arms, and therefore suffer from the same fatigue-limiting effect seen with standard push-ups. To overcome this, so-called pec decks were created. To a significant extent, these machines isolate their resistance effects to the chest and overcome the limitation for pectoral exertion associated with arm fatigue. These machines are effective for chest development but are commonly large, heavy, not portable, and expensive.
There are some devices available to enhance the effectiveness and comfort of traditional push-ups; however, a continuing and unmet need exists for new and improved exercise equipment that addresses the foregoing arm-fatigue limitations.

Exercise apparatus for performing a bent-elbow plank position push-up and method of using same


The present invention provides a mobile network for handling multiple subscribers having the same calling line identity. Each multiple subscriber has an individual mobile subscriber number and a common mobile subscriber number that can be used to replace the individual mobile subscriber number. One mobile subscriber has an identical individual and common mobile subscriber number, and the mobile network receives a mobile subscriber number from a multiple subscriber. The mobile network has a terminal management server that determines whether the mobile subscriber number is either the individual mobile subscriber number or the common mobile subscriber number. Each individual mobile subscriber number and common mobile subscriber number is a Mobile Subscriber Integrated Services Digital Network (MSISDN) number. The mobile subscriber number is used during a location update procedure.

1. Field of Invention
The present invention relates to a mobile network; and more particularly relates to a mobile network for handling multiple subscribers having the same calling line identity.
2. Description of Related Art
FIGS. 1A and 1B respectively show the basic elements of a high-level system architecture of a known Universal Mobile Telecommunications System (UTMS) generally indicated as 10 and a known Public Land Mobile Network (PLMN) generally indicated as 20 that together provide a backdrop for understanding the subject matter of the present invention.
In FIG. 1A, the UTMS has User Equipment (UE) 12, a UMTS Terrestrial Radio Access Network (UTRAN) 14 and a Core Network 16 coupled by known interfaces Uu and lu. In FIG. 1B, the PLMN 20 includes the UE 12, the UTRAN 14 and the CN 16 shown in FIG. 1A coupled to external networks generally indicated as 18, including either another PLMN, Public Switched Telephone Network (PSTN), Integrated Digital Services Network (ISDN) etc., all generally indicated as 18a, as well as the Internet generally indicated as 18b. The UE 12 is known in the art and contains a Universal Subscriber Identity Module (USIM) 12a and Mobile Equipment (ME) 12b. The USIM 12a is a known smart card that is arranged in the ME 12b, holds the subscriber identity, performs authentication algorithms and stores authentication and encryption keys and other information that is need by the ME 12b to interact with the PLMN 20. The ME 12b is also known as a mobile station (MS), which may include many different types of mobile electronic devices such as a mobile phone, a personal digital device (PDA), a laptop computer, etc. The UMTS Terrestrial Radio Access Network (UTRAN) 14 is also known in the art and contains one or more nodes B (i.e. base stations) 14a in combination with one or more Radio Network Controllers (RNC) 14b, that combined to provide a known radio interface between the UE 12 and the CN 16. The CN 16 is a combination of high-capacity switches and transmission facilities that form the backbone of the PLMN 20 in FIG. 1B. The CN 16 includes a Mobile Services Switching Center/Visitor Register Location (MSC/VLR) 16a, a Home Register Location (HLR) 16b, a Gateway Mobile Services Switching Center 16c, a Serving GPRS Support Node 16d, and a Gateway GPRS Support Node (GGSN) 16e, which are all known in the art.
Recently, some networks, such as the PLMN shown in FIG. 1B, have introduced new features providing Same Calling Line Identity (CLI) for multiple subscribers (MS1, MS2, MS3 in FIGS. 2A and B) and allowing incoming calls and SMS arriving with this same CLI to be sent to an appropriate MS. This is part of a Multi-SIM subscription concept. The principle is that the user (subscriber) may have multiple mobile stations (MS) (e.g. one handheld and one in the car) and they will all use the same identity when they originate calls or short messages. In addition, incoming calls and SMS reach the right MS. Calls could for example use sequential ringing (if a first MS does not answer, the call is transferred to second MS and so on) or simultaneous ringing. An SMS is typically sent only to the primary phone. This solution is based on the fact that a respective SIM card, like the SIM card 12a (FIG. 1B), is inserted in each MS, and that this SIM card 12a has its own or individual International Mobile Subscriber Identifier (IMSI) and its own or individual Mobile Subscriber ISDN Number (MSISDN). The IMSI is understood to represent the SIM card number, while the MSISDN is understood to represent the phone number of the MS. The MS also has an individual International Mobile Equipment Identity (IMEI) associate with it, which is understood to be a unique manufacturer number assigned by the manufacturer of the MS. As shown in FIGS. 2A and B, the individual IMSI number (IMSI1, IMSI2, IMSI3) and MSISDN number (MSISDN 1, MSISDN 2, MSISDN 3) are registered in the HLR 16b, 16b′ under a subscription profile of the PLMN 20. Additionally, each of these subscription profiles (subscriber profile 1, subscriber profile 2, subscriber profile 3) also has a so-called common MSISDN number, which can be used to replace the individual MSISDN. This way the PLMN 20 that is visited by a MS can receive the common MSISDN of the visiting MS instead of the individual MSISDN during a location updated procedure related to the visiting MS. There are two alternatives for storing the subscriber profiles in the HLR:                One of the subscriber profiles in the HLR 16b also has an identical individual and common MSISDN numbers, such as subscriber profile 3 in FIG. 2A, and this subscriber is referred to as a so-called primary subscriber, while the mobile phone, which contains that SIM card (IMSI), is referred to as a so-called primary phone.        Another implementation alternative is none of the profiles have identical individual and common MSISDN number as shown in FIG. 2B. The common MSISDN number identifies a list of members, so called group. One member of the group can be selected as a primary member. In this case, the terminated transactions with the common MSISDN number can be routed further from the group to the primary member with the help of a stored individual identifier of the primary member. The primary member of the group is referred to as a so-called primary subscriber, while the mobile phone, which contains that SIM card (IMSI), is referred to as a so-called primary phone.
The way this feature presently handles a Short Message Service (SMS) message is noted. For example, the SMS message sent to the common MSISDN is only provided to the primary phone. In comparison, the non-primary phone will receive the SMS message only if sent to its individual MSISDN. A common MSISDN and/or individual MSISDN may be sent from the HLR 16b to the VLR 16a, or the SGSN 16d, depending if the VLR 16a or SGSN 16d supports the feature. It should be noted that the feature is described regarding MSC/VLR but is also applicable to SGSN because an SGSN sends and receives SMS exactly like the MSC/VLR. As shown, the VLR also stores the IMEI of the MS.
One problem with this new CLI feature is that it conflicts with the remote MS configuration performed by a Terminal Management Server (TMS) 30 shown FIGS. 2A and B in the PLMN 20 when the MS visits a new PLMN.
Currently, in operation when the MS visits the new PLMN, the MS provides its IMSI number to the MSC/VLR 16a of the visited PLMN. In addition, the MS also provides an IMEI to the MSC/VLR. For example, FIGS. 2A and B shows three mobile stations MS1, MS2, MS3 providing their respective IMEI numbers, IMEI1, IMEI2, IMEI3, to the MSC/VLR 16a upon visiting the PLMN 20. In this case, the MSC/VLR 16a informs the TMS 30 of the new IMSI/MSISDN/IMEI combination. When the TMS 30 detects that a new MSISDN is not yet configured, it will derive from the IMEI the mobile type of the MS, and send the proper configuration to the visiting MS through the SMS message.
In operation, if the MSC/VLR 16a uses the Same CLI for the multiple subscribers feature, the TMS 30 may receive the common MSISDN and a non-primary MS IMEI. The TMS 30 will then attempt to configure this IMEI, but the SMS message addressed to the common MSISDN will reach the primary MS (subscriber profile 3). In view of this, the primary MS will then be misconfigured, and the non-primary MS will not be configured at all.
If the MSC Same CLI feature for multiple subscribers is used, the TMS 30 has no mechanism to determine if the received MSISDN is the individual MSISDN of the MS or the common MSISDN of the MS, and so it cannot use it for remote configuration of the visiting MS.

Method and apparatus for determining individual or common mobile subscriber number in mobile network for handling multiple subscribers having the same calling line identity


A non-metallic laboratory jack comprises two oppositely disposed reinforcing elements having I-beam cross-sectional configuration disposed in the central elevational region of the jack; a base position below the reinforcing elements and a load-bearing platform positioned above the reinforcing elements and a plurality of pairs of cross links. A rotatable threaded shaft associated with the reinforcing elements.

1. Field of the Invention
The present invention relates to devices for lifting and lowering objects, and more particularly to light-weight jacks adaptable for use in a laboratory environment.
2. Description of the Prior Art
Prior art discloses many devices and mechanisms for raising and lowering heavy objects. Many such devices are constructed of metal, however, utilization of metallic jacks in the laboratory environment has substantial drawbacks. It is known that metal can be expensive because of the fabrication and assembly expense. Significantly, metals, particularly relatively inexpensive metals, have a tendency to corrode. This is unacceptable in the laboratory environment, where corrosion might affect the results of the conducted experiments. Furthermore, corrosion might affect the mechanisms of the jacks by interfering with relative movement between working parts. Still further, metallic jacks are known to be heavy and relatively difficult to operate, especially in limited confinement areas of many laboratories.
Low weight jacks made of non-metallic materials are also known in the art. However, such lifting devices have not been very successful for a number of reasons. Typically, their structural elements have not been developed in a manner to utilize plastic materials, while being strong enough to lift heavy objects and maintaining a small size. A great majority of non-metallic jacks are replicas of their traditional metallic counterparts. One drawback in adapting existing metallic structures to plastic construction is that the standard metal jacks are better able to withstand the gravitational, bending and torsion forces and momentums to which the jacks are exposed. Many non-metallic jacks of the prior art do not contain strengthening or reinforcing elements especially provided to resist such forces and momentums.
The prior art non-metallic jacks typically suffer from such major drawbacks as a limited collapse of their structure due to applying loads or pressures in a substantially vertical directions and undesirable movement or wobbling and/or dislocation of the structural element as a result of off-center forces applied to the jack. The latter drawback often causes the inability to maintain scissor sub-assemblies parallel to each other and maintaining the load-bearing platform to be oriented in a plane parallel to the base throughout the operation of the jack.
Another drawback of non-metallic jacks of prior art made of plastic materials is the relative complexity of structures as they contain many parts. In this manner, an expensive mold is often required for production of each and every part of the assembly, ultimately increasing the cost of manufacturing of the non-metallic jack.
Thus, there has been a long-felt unsolved need to provide a non-metallic laboratory jack which is relatively inexpensive, non-corrosive, and does not alter results of laboratory experiments. There is also a need for an inexpensive jack which is made by utilizing a limited number of standardized parts. Furthermore, there has been a need for such a laboratory jack of non-metallic construction which is specifically adapted to withstand bending, torsion, and momentums found during regular use.


An ice bank of an ice-making device for a refrigerator is disclosed, for smooth crush and discharge of ice, which includes a housing for storing ice made in an icemaker, and provided rotatably to apply the power to the stored ice at a rotation direction; an ice discharger having at least one hole through which the ice is discharge to the external; a crusher provided in the inside of the housing, the crusher guiding the stored ice to the hole of the ice discharge and crushing the ice as a predetermined size before discharging the ice to the hole according to a user's select; and rotating means for rotating the housing. Also, the crusher includes fixed crushing means fixed to the inside of the housing, and rotation crushing means rotated for being synchronized with the housing so as to crush the ice before discharging the ice to the external according to a user's select.

1. Field of the Invention
The present invention relates to a refrigerator, and more particularly, to an ice bank of an ice-making device, having an improved structure for discharging ice smoothly.
2. Discussion of the Related Art
In general, a refrigerator is provided with a cooling chamber and a freezer. At this time, the cooling chamber keeps a temperature at about 3° C.–4° C. for keeping food and vegetables fresh for a long time, and the freezer keeps a temperature at a sub-zero temperature for keeping and storing food frozen for a long time.
Recently, the refrigerator has been developed for performing various additional functions besides a typical function thereof. For example, an icemaker may be provided in the refrigerator. FIG. 1 is a schematic view illustrating a general ice-making device for a refrigerator, and FIG. 2 is a schematic view illustrating a general icemaker of an ice-making device for a refrigerator. Referring to FIG. 1 and FIG. 2, the icemaker 1 is provided and fixed in an upper inside part of a freezer of the refrigerator. The icemaker 1 freezes up water and discharges ice automatically.
Hereinafter, the icemaker 1 is provided with an ice-making part 11 making ice, a water-supplying part 12 provided at one side of the ice-making part 11 so as to supply water to the ice-making part 11, a controller 13 provided at the other side of the ice-making part 11 and having a motor (not shown) therein, and an ejector 14 connected with the motor to discharge the ice made in the ice-making part 11 to an ice bank 5. Also, a connector 15 is provided at the rear side of the icemaker 1 to connect the icemaker 1 with the freezer of the refrigerator.
At this time, the ice-making part 11 is formed in a semi-cylindrical shape, and a plurality of ribs 16 are provided at fixed intervals so as to divide an interior space of the ice-making part 11 into sections. Then, the ejector 14 has a shaft crossing the center of the ice-making part 11, and a plurality of fins 14a are provided at a side portion of the shaft of the ejector 14 so as to discharge the made ice to the ice bank 5.
Also, a slide bar 17 is provided at a side of the fin 14a to guide the ice to the ice bank 5. More specifically, the ice guided by the fin 14a of the ejector 14 is dropped onto the slide bar 17, and then the ice slide along the surface of the slide bar 17 for being moved to the inside of the ice bank 5 provided at a lower part of the icemaker 1.
A heater (not shown) is provided on a lower surface of the ice-making part 11. In order to transfer the made ice, it is required to separate the ice from the surface of the ice-making part 11. For this, a temperature on the lower surface of the ice-making part 11 is increased with the heater, whereby the surface of the ice is melted, and the ice having the melted surface is smoothly transferred.
In a door 2 of the freezer for the refrigerator, there are the ice bank 5 and a dispenser 21 besides the icemaker 1. The ice bank 5 stores the ice made in the icemaker 1, and discharges the ice to the dispenser 21 at a user's need. At this time, the ice bank 5 is provided in a cylindrical shape having a hollow interior space, and the ice bank 5 is provided with a container for storing the ice, an ice transfer 3, and a crusher 4. The ice transfer 3 is means for transferring the stored ice to the dispenser 21, which is provided with a motor 31 and an auger 33. In this case, as the auger 33 is rotated according to the motor 31, the ice stored in an upper part of the ice bank 5 is moved to a lower part. Also, the crusher 4 is provided in the auger 33. In case the ice is made as a large-size piece, the piece of ice is crushed for being suitable to make cool drink and food with the ice.
However, the ice bank 5 having the aforementioned structure according to the related art has the following disadvantages.
First, the auger has a function for rotating the ice by the motor. If the dispenser is not used for a long time period, the ice may be caught and fixed in the auger, whereby it is impossible to move the ice smoothly, and the auger may be distorted. That is, the ice stored in the center of the container is moved smoothly. However, it is hard to move the ice stored in side portions of the container 21 with the auger 22. Accordingly, the driving motor 25 for driving the auger 22 may be damaged.
Furthermore, the driving motor 25 is provided in the lower part of the dispenser 30. Thus, it is required to provide an additional connection shaft 24 for transferring rotation power of the driving motor 25 to the auger 22, so that the structure of the inner wall of the door 2, in which the connection shaft 24 is provided, is complicated.
In order to overcome these problems, it is required to develop the ice bank of the ice-making device and the refrigerator using the same, having the structure to made the piece of ice in a size corresponding to a user's desire without changes and damages of the inside structure in the ice bank, to discharge the ice stored and fixed in the container smoothly.

Ice bank of ice-making device for refrigerator


A strut runner includes a member extending lengthwise in a first direction, where the member includes an underlying panel and one or more walls that extend from the panel. The member may be configured to at least partially support the panel array while being integrated or directly connected to the underlying structure. Additionally, the strut runner may include one or more peripheral extensions that extend a distance outward from the body.

A popular and existing method of mounting equipment such as solar panels to a roof is by the use of posts called stanchions. These stanchions are usually fastened to structural members (e.g. rafters or trusses) located just below the top roof surface called the decking. Before the stanchions are fastened to the structural members, the difficult task of locating the exact position of these members must be undertaken. The method for finding the structural members varies from using a proximity sensor (e.g. commercially available stud finder), to taking an educated guess and drilling or hammering a nail into the structural member, to very carefully measuring inside and outside of the structure. After the structural member has been located, a pilot hole must be drilled through the decking and into the structural member. The stanchion can then be fastened to the roof by means of a lag screw. Afterward, to prevent water from penetrating into the structure, the stanchion must be flashed into the roofing with a conical-shaped sheet metal part, such as a flashing boot. Roof sealant, like mastic, may be applied between the stanchion and the roof surface and between the flashing and the stanchion to further ensure weatherproofing.
The entire process of locating the structural member, drilling a pilot hole, fastening the stanchion, sealing, and flashing is time-consuming and labor-intensive. To add to the cost of the labor required, the cost to purchase and stock the stanchions, associated hardware, sealant, and flashings are also expensive. In addition to stanchion style products such as TILE-TRAC and the FASTJACK series from PROFESSIONAL SOLAR PRODUCTS of Camarillo Calif., commercial hangar bolts and other structural stanchions are employed with similar labor requirements and results.
The use of stanchions is popular because the roof penetrations for the stanchions can be reliably sealed using existing roofing methods with a standard flashing. However, the use of stanchions typically raises the mounted equipment off the roof by 4-8″, which is not aesthetically pleasing.

Strut runner member and assembly using same for mounting arrays on rooftops and other structures


Described are methods, systems, and computer-program product embodiments for selecting a face image based on a name. In some embodiments, a method includes receiving the name. Based on the name, a name vector is selected from a plurality of name vectors in a dataset that maps a plurality of names to a plurality of corresponding name vectors in a vector space, where each name vector includes representations associated with a plurality of words associated with each name. A plurality of face vectors corresponding to a plurality of face images is received. A face vector is selected from the plurality of face vectors based on a plurality of similarity scores calculated for the plurality of corresponding face vectors, where for each name vector, a similarity score is calculated based on the name vector and each face vector. The face image is output based on the selected face vector.

Current facial recognition systems rely on comparisons between an unknown face image with a collection of known face images corresponding to known persons to identify the person in the unknown face image. For example, DeepFace, a deep learning facial recognition system developed by Facebook, is capable of determining whether two images contain the same face with 97% accuracy. Such facial recognition systems, however, require that the person shown in the unknown face image be known to the system and whose face is stored in the collection of known face images.
In 2017, researchers from the Hebrew University of Jerusalem have discovered that a person's name may be reflected in his facial appearance, a phenomenon dubbed 'The Dorian Gray' effect, after Oscar Wilde's eponymous hero. In their experiments, they found that participants were able to correctly select the correct names to match corresponding face images at a rate better than random chance. In further experiments, the researchers trained deep convolutional neural networks (i.e., an example of a machine-learning algorithm) on a set of almost 100,000 portrait images to achieve an average matching accuracy of 59% compared to the expected accuracy of 50% based on random guess. Therefore, current facial recognition systems may be further improved by matching faces with names using the 'Dorian Gray' effect, which does not require that the person in a face image be known to the system before selecting a likely name for that person. The 59% accuracy achieved by the researches, however, is far too low to be useful and needs to be improved.


A printing press can securely supply a printing plate while bringing a printing plate into alignment with a plate cylinder in an axial direction of the plate cylinder, as well as omitting the necessity to return the plate registration of the plate cylinder to the original point. The printing press includes a printing plate guide plate that is pivotally movably mounted in an opening of a body cover that covers the plate cylinder, a sucker for holding a printing plate by suction so as to pull the same towards the printing plate guide plate. The sucker is disposed so as to be movable towards a clamping gripper disposed on the plate cylinder and in a direction parallel to an axis of the plate cylinder.

1. Field of the Invention
The present invention relates to a printing press and more particularly a structure of a printing section disposed between a sheet feeding section and a sheet discharge section so as to supply a printing plate to a clamping gripper that is disposed on a plate cylinder and to mount the supplied printing plate on the plate cylinder.
2. Related Art
A sheet-fed printing press (hereinafter referred simply to a printing press) generally includes a printing section between a sheet feeding section and a sheet discharge section. This printing section is to print on sheets by a printing plate mounted on a plate cylinder. There is a necessity to mount a printing plate on the plate cylinder with accurate alignment. For mounting a printing plate on the plate cylinder, the printing press is generally equipped with a printing plate mounting device that automatically mounts a printing plate, which has been manually inserted into a clamping gripper disposed in the plate cylinder. According to a recently proposed printing press, an automatic supply mechanism is employed to automatically supply a printing plate (a new plate), which has been once set at a predetermined position by an operator, to a clamping gripper. For example, Japanese Patent No. 2844231 proposes an automatic plate supply device that has a sucker arranged on a printing plate guide plate disposed on the front side of a body cover of the printing section for sucking a printing plate (plate rear side). According to a technique of this Patent, the printing plate guide plate with the printing plate held by the sucker is inclined towards the clamping gripper of the plate cylinder and the sucker is linearly moved towards the clamping gripper so as to supply the printing plate to the clamping gripper.
Meanwhile, in supplying each printing plate to the clamping gripper, the printing plate is brought into alignment with the clamping gripper (plate cylinder) by the engagement between a pair of axially spaced apart protrusions as an engaging means formed on the clamping gripper and cutouts as an engaged means formed in each printing plate. In this arrangement, the sucker holds by suction a printing plate which has been laid down on the printing plate guide plate and moves towards the clamping gripper while holding the printing plate. If the printing plate on the printing plate guide plate is axially displaced relative to a given position, the engaged means of the printing plate is unlikely to be in alignment with the engaging means so that, with the printing press of this type, which automatically drives the clamping gripper, a signal generated upon the alignment of a printing plate with the plate cylinder is not output, and hence the clamping gripper cannot be controlledly driven. This makes it impossible to mount the printing plate on the plate cylinder. In order to address this problem, for example, Japanese Utility Model Application Laid-open No. Hei-05-26374 proposes a technique in which a guide piece is arranged on the printing plate guide plate for guiding a printing plate along a lateral side edge thereof so as to bring the engaged means of the printing plate into alignment with the engaging means of the clamping gripper. For achieving this alignment in the printing press of this type, the plate cylinder must be previously returned to a given axial position (original point) proper for a printing plate to be newly supplied, as described in for example Japanese Patent No. 3066614. The returning of a plate registration (the axial position) of the plate cylinder to the original point (position) is required for the reason that if the plate registration (the axial position) of the plate cylinder has been displaced from a proper position after the use of the printing plate for the last printing operation, a newly supplied printing plate for the subsequent printing operation may not match the plate registration (the axial position of the plate cylinder), and as a result, it is not possible to bring the cutouts as the engaged means of the printing plate into engagement with the protrusions as the engaging means of the clamping gripper.
The above conventional printing press is provided with a guide piece arranged on the printing plate guide plate so as to guide a lateral edge of the supplied printing plate. This guide piece is fixed in position on the printing plate guide plate and therefore, if the mounting position of the printing plate guide plate relative to the body cover is not accurate, the alignment of the engaged means with the engaging means may not be possible. Also, as another disadvantage associated with the prior art, it is necessary to perform an additional step of returning the plate registration (axial position) of the plate cylinder to the original point (position) in order to make the cutouts as the engaged means match with the protrusions as the engaging means of the clamping gripper of the plate cylinder.
It is an object of the present invention to provide a printing press that is capable of accurately bringing a printing plate into alignment with the plate cylinder by securely making the engaged means of the printing plate match in position with the engaging means provided on the side of the plate cylinder in supplying the printing plate to the plate cylinder, as well as omitting the necessity to return the plate registration of the plate cylinder to the original point.

Printing press having plate supply device with axially movable sucker


A sleeve (4) is fitted on a supporting table (3) to be positioned in front of a storage device (42) which carries a plurality of rolls (27) of first ribbon-like manufactured articles (25) contained in respective boxes (43). Each box has a transferable film (30) bearing identification inscriptions thereon, applied to a paper substrate (29). One of said manufactured articles (25) is unfolded and longitudinally extended on the sleeve (4) by a first grasping member (55) in order to be then cut by a cutting member (68) acting close to the box. A heated presser roller (32) longitudinally movable on the ribbon-like-manufactured article (25) causes the transferring of the film (30) to the sleeve (4). Simultaneously, the application of the film (30) belonging to a second ribbon-like manufactured article (26) is carried out, said second manufactured article (26) being supported by a main carriage (33) carrying the presser roller (32) and engaging with a positioning roller ( 73) unfolding the manufactured article on the sleeve (4) before the presser roller (32).

The present invention relates to a process and an apparatus to apply identification inscriptions on sleeves made of elastomeric material in the production of driving belts.
It is known that in the production of driving belts in general the formation of an axially elongated substantially cylindrical sleeve of elastomeric material incorporating textile reinforcement structures is first provided. This sleeve will be subsequently circumferentially slit at a plurality of axially spaced cuts so as to obtain a number of belts of predetermined width.
However, before said slitting operation the sleeve will be submitted to a marking step in which wordings and inscriptions designed to appear on each of the finished belts are applied to the outer surface thereof, so that said belts may be easily distinguishable from the different types of produced and marketed belts.
In greater detail, usually inscriptions printed on the sleeve give indications relative for example to the brand, model and sizes of the belt, as well as the production date or period of the belt itself.
It will be easily understood that indications relative to the belt brand and type, as well as to size features, are indispensable so that the different types of belt produced may be distinguished from one another in an easy and sure manner.
Indications relative to the production date and period can instead be useful for example when a given lot of belt needs to be withdrawn from the market for example due to defects found out in use, in the belts produced in a particular period.
Currently known methods adapted to apply inscriptions on sleeves are fundamentally based on silk-screen processes.
These processes are necessarily carried out in a substantially manual manner and involve an important waste of time and man-power.
Actually the operator must suitably position a serigraphy stencil on the sleeve being worked in order to subsequently coat a paint layer on the stencil itself. This paint, passing through suitably arranged pervious areas on the serigraphy stencil, will deposit on the sleeve thereby forming the desired inscriptions.
It is to be noted that not only the above silk-screen methods involve important working costs, but also bring about problems related to ecology and health. In fact the unavoidably ejected amounts of paints and solvents are highly polluting.
In addition, these paints and solvents release important amounts of volatile substances which can be injurious to the health of workers carrying out the operation.

Process to apply identification inscriptions on sleeves made of elastomeric material in the manufacture of driving belts


An elongated shut apparatus includes a primary plate and a follower plate with the inner sides thereof facing to each other. Both the primary and the follower plate are made of soft high molecular material and have a concave shaped cross section with a thick central part getting thinner toward two lateral ends thereof.

1. Field of the Invention
The present invention relates to a kind of shut apparatus and particularly to a shut apparatus, which provides two engaging elements, being possible to be separated by foreign forces so as to actuate the operations of opening and shut.
2. Description of Related Art
The shut apparatus traditionally such as buttons, adhesive buckle belt or zippers is widely used in our daily lives and each of the preceding shut apparatus has its own specific feature.
In fact, the purpose and function of the shut apparatus pursued are easy to be operated and accurate to be opened and closed. Of course, the cost is one of factors has to be considered too. For some special fields, which are required to have the function such as water resistance, if the function of airtight and water resistance can be met effectively, the shut apparatus would become much more useful. Taking the conventional zipper as an example, it is really needed to meet the requirement of airtight and water resistance.


A length compensator for pipelines, preferably plastic pipelines, containing two connecting components, preferably made from plastic, a compensating element made from an elastic material, preferably a thermoplastic elastomer (TPE), and a supporting pipe, wherein the compensating element is arranged between the two connecting components and the compensating element ends are connected to the connecting components, wherein the outer lateral surface of the compensating element is suitably encompassed by the inner lateral surface of the supporting pipe around its entire circumference, wherein the supporting pipe has a circular cross-sectional area and the compensating element expands and contracts exclusively in the axial direction.

Length compensators serve for accommodating or compensating the change in length of an installed pipeline, which is caused, for example, by temperature changes or external influences such as forces caused by earthquakes, pump strokes etc. The length of a pipeline changes depending on the temperature, be this as a result of the external temperature or the medium temperature of the medium transported in the pipeline. This change in length, be it an expansion or a contraction, needs to be accommodated. From the prior art, for example, pipe loops are known which permit or accommodate a certain change in length due to their deflections of the pipeline. Bellows or rubber sleeves are furthermore also known from the prior art, as are pipes which are axially displaceable inside one another.
The German utility model 7325208 discloses an expansion compensator for pipelines, wherein the expansion body is arranged in a housing which has an oval cross-sectional shape in which the expansion body can accordingly also move horizontally.
The solutions described above are disadvantageous in that they require a large amount of space, have only a small compensation distance and/or do not permit a high internal pressure or do not permit the same internal pressure as the pipeline itself.


PEHAM dendrimers of the formula:

Dendrimers are highly branched, often spherical molecules in which branches may terminate at charged amino groups that radiate from a central core molecule. Amine-terminated dendrimers have a high density of positively charged amine groups on the surface, such as with PAMAM dendrimers. Due to controlled chemical synthesis, dendrimers have a very precise size and defined shape.
PEHAM dendrimers are related to PAMAM dendrimers but differ in at least one or more of the following characteristics: PEHAM dendrimers show increased thermal stability, more rapid building of surface functionality with increased molecular weight at lower generations thereby reducing costs to make, narrow polydispersity, increased interior void volume, have interior functionality and/or extender groups in the branch arms. These PEHAM dendrimers are described in U.S. Ser. No. 10/594,776, filed 20 Apr. 2005 (published as US 2007/0244296 on Oct. 18, 2007) and U.S. Ser. No. 11/630,044, filed Dec. 21, 2005 (published as US 2007/0298006 on Dec. 27, 2007). Although agricultural use is mentioned generally, there are no specific examples to such use.
It is known that various desired active moieties that are used in agriculture lose effectiveness or require repeated application due to various environmental conditions. The following references discuss some of these issues. When a plant is treated with an active moiety in a carrier, such as spraying it on the plant leaves, the problems observed are uptake and translocation of the desired active moiety or photodegradation of the active. Various attempts have been used to minimize such results such as by adding a surfactant such as Ethylan™ TU [Baker, Edward A., et al., Pestic. Sci. 34, 167-182 (1992)], or an organosilicone surfactant [Stevens, Peter J. G., et al. Pestic. Sci. 38, 237-245 (1993)], or Tinopal™ [Reddy, N. P., et al., Pest Manag. Sci. 64, 909-915 (2008)]. Other approaches concern improving retention on the leaves by adding cuprous oxide and copper oxychloride with a dispersing agent [Large, E. C. et al., Annals of Applied Biol., 33(1), 54-63 (1945), improving local distribution on the leaves by water [Hislop, E. C. et al., Ann. Appl. Biol. 66, 89-101 (1970)], penetration of intact leaf cuticles by various herbicides was measured and found low for several actives [Baker, Edward A., Pestic. Sci. 29, 187-196 (1990)], and imazaquin spray retention, foliar washoff and runoff losses under rainfall conditions was determined which was quite high [Reddy, Krishna N., et al., Pestic. Sci. 48, 179-187 (1996)].
Additionally, UV light causing photodegradation of the active has been studied to try to minimize this effect on loss of active efficacy by several groups, such as to protect amphotericin B [Tufteland, Megan L. et al., Pest Manag. Sci. 65, 624-628 (2009)], rimsulfuron [Scrano, Laura et al., Pestic. Sci. 55, 995-961 (1999)], fenarimol [Sur, Nivedita et al., Pest Manag. Sci. 56, 289-292 (2000)], flucythrinate [Chattopadhyhya S. et al., Pestic. Sci. 31, 163-173 (1991)], phosalone [Walia, S. et al., Pestic. Sci. 25, 1-9 (1989)], fluchloralin [Saha, Tapas et al., Pest Manag. Sci. 58, 179-182 (2001)], flumioxazin [Kwon, Jeong-Wook, et al., Pest Manag. Sci. 60, 939-943 (2004)], bensulfuron-methyl [Si, You-Bin, et al., Pest Manag. Sci. 60, 286-290 (2003)], benzoylphenylurea [Marsella, Adam, et al., Pest Manag. Sci. 56, 789-794 (2000)], and vinclozolin [Schick, Bernhard et al., Pestic. Sci. 55, 1116-1122 (1999)]. A method is to shield the active from UV such as by nanoparticle carriers of hollow silica nanoparticles [Li, Zhu-Zhu et al., Pest Manag. Sci. 63, 241-246 (2007)], using absorber compounds [Hussain, Manzoor et al., Pestic. Sci. 28, 345-355 (1990)], glufosinate [Kocher, Helmut et al., Pestic. Sci. 37, 155-158 (1993)], and 2-propanol and methyl 12-hydroxystearate [Schwack, Wolfgang et al., Pestic. Sci. 40, 279-284 (1994)].
U.S. Pat. No. 6,939,831 describes the use of dendrimers having 2-20,000 phosphorous to nitrogen bonds with active moieties in agriculture. This composition is always a gel composition, which limits its method of application.
These known decreases in the usefulness of an agricultural active moiety cause the requirement for repeated application of the active moiety to the plant, which adds costs for these repeated applications and environmental issues for the runoff or soil retention of the agricultural active moiety.
Clearly, a way to deliver active moieties to plants, while increasing the solubility and penetration of the active moiety, reducing the amount of active to apply or avoiding repeated applications to lower the environmental impact, is desired.
Any feature or combination of features described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification, and the knowledge of one of ordinary skill in the art. Additional advantages and aspects of the present invention are apparent in the following detailed description and claims.

Abstract: PEHAM dendrimers of the formula:

Abstract: Specific PEHAM dendrimers are used in a formulation with an active agent for agricultural purposes. In particular, the PEHAM dendrimers may be used for increasing the efficacy of the active agent in various ways, such as by improving solubility of the active agent in the formulation, by improving adhesion and penetration of the active agent to plant surfaces, or by improving the water-fastness of the active agent to the plant or seed. The PEHAM dendrimers may also increase the efficacy of the active agent by increasing soil penetration of the active agent to reach the plant roots or under soil parts, by reducing soil adhesion of the active agent to reach the plant roots or under soil parts, or by reducing enzymatic degradation of the active agent by the plant or seed or microorganisms in the soil.


A chemically adsorbed multilayer film is formed through the process of replacing a halogen atom on the surface of a chemically adsorbed film with an alkaline metal or changing the halogen atom to a Grignard group by Grignard reaction. This manufacturing method does not disrupt the molecules of the chemically adsorbed film, is easy to perform, low in cost and is safe. After replacing the halogen (for example, Br) on the surface of the film with an alkaline metal such as Li, a condensation reaction including a dealkalihalide reaction is promoted by contacting the chemically adsorbed film with an adsorbent, such as a chemical adsorbent--containing a halosilane group at one end of a molecule--dissolved in a nonaqueous solvent. A chemically adsorbed multilayer film is then formed by reacting the chemically adsorbed film with chemical absorption composition and with water after removing unreacted adsorbents using a nonaqueous solution.

Current methods used for manufacturing a chemically adsorbed multilayer film include cumulation (built-up) methods, mentioned, for example, in page 851 of the sixth volume of Langmuir (K. Ogawa et al., Langmuir, 6, 851 (1990)) and page 201 of the one hundred first volume of Journal of Colloid Interface Science (J. Gun et al., Journal of Colloid Interface Science, 101, 201 (1984)). The cumulation (built-up) methods include repetitions of the following process:
forming a monomolecular film by a dehydrochlorination reaction between a chlorosilyl group of a chemical adsorbent, which is a linear molecule having the chlorosilyl group at one end and a double bond at the other end, with a group on the surface of the substrate such as a hydroxyl group; PA1 creating reactive hydrogen atoms by modifying the double bond either by treating it with oxidizing agents such as potassium permanganate or irradiating it with an electron beam. PA1 forming a chemically adsorbed film by contacting a substrate surface with a chemical adsorbent which has one or more halogen atoms and functional groups selected from the groups in the following Formulas 1!-5! and a cyano group on the substrate surface; EQU --A.sub.1 X.sub.m Formula 1! PA1 reacting the alkaline metal composition with a chemical adsorption composition that includes a functional group, selected from the groups shown in the above formulas 1!-5!, a carbonyl, aldehyde, carboxyl, acyl, amide, or ester group.
Reactive hydrogen atoms also can be made by replacing the double bond with an amino group by irradiating a polymer film having the double bond with an electron beam in a nitrogen atmosphere, thereby forming a multilayer film.
However, the above-noted method of using an electron beam is problematic in that it requires an expensive large-scale apparatus. Also, a film is likely to be disrupted due to the subtle changes in radiation intensity of an electron beam. Moreover, severe risks are involved in the operation.
The method of treating with oxidizing agents, on the other hand, has a problem in that an unsaturated bond is not likely to be oxidized when the unsaturated bond is located on the surface of the monomolecular film (that is, the end of a monomolecular chemical adsorbent). Due to the usage of strong oxidizing agents, moreover, there is a problem in that the Si--C bond is likely to be broken.

Method of manufacturing a chemically adsorbed multilayer film

Matsushita Electric Industrial Co., Ltd.


In a process for the coating of boards (4) with a poured material (L), especially for the coating of printed circuit boards with, for example, solder resist, the boards (4) to be coated are transported through and beneath a curtain of poured material descending transversely to the transport direction and the poured material descending in the form of a pouring curtain (LV) thus falls onto the boards (4). The descending pouring curtain (LV) falls onto a planar deflector surface (20) before falling onto the board (4), with an acute angle (.alpha.) being formed between the deflector surface (20) and the plane of the pouring curtain (LV), which deflector surface (20) has a cut-off edge (21) at its lower end. After falling onto the deflector surface (20), the poured material runs along that deflector surface (20) downwards towards the cut-off edge (21) and then descends onto the board (4).

The efficient and fast coating of boards with a poured material is becoming increasingly important, especially with regard to the one-sided or two-sided coating of printed circuit boards, for example with solder resist. For that purpose, for example, the widely known curtain pouring process is used, the basic mode of operation of which is described in EP-A-0 002 040 and also in numerous other protective rights. The curtain pouring process essentially operates by transporting a board to be coated (e.g. the aforementioned printed circuit board) beneath a pouring head. The pouring head is arranged transversely to the transport direction of the board being coated. The poured material (e.g. the solder resist) descends from the pouring head in the form of a pouring curtain and falls onto the board located below the pouring head, while the board is being transported, essentially along a line running transversely to the transport direction. The continuous transportation of the board through and beneath the pouring curtain results in the whole board's being coated with poured material.
That process works perfectly well and it, as well as several variants thereof, is used in the printed circuit board-manufacturing industry for the coating of printed circuit boards. Because there is a clear prevailing trend towards ever smaller finished articles and also, as a result, towards ever fewer and smaller printed circuit boards in each finished article, circuit boards that are printed on both sides are now already used in very large numbers and, in many cases, are even the standard. Such circuit boards that are printed on both sides often also have so-called through-platings.
When such printed circuit boards are being coated, the pouring curtain and, as a result, the poured material naturally falls also onto the regions of the board where such through-platings are provided. Consequently, on the other side of the board and in the through-platings themselves there are formed so-called "blobs of coating", which have to be removed by means of correspondingly lengthy and, as a result, troublesome washing-out. Furthermore, it has emerged that, when the board is coated using the conventional curtain pouring process, the distribution of the poured material along the line of impact of the pouring curtain on the board and, as a result, over the width of the whole board is not always sufficiently homogeneous.

Curtain coating apparatus having a planar deflector surface and method for using the same


Embodiments of the present disclosure provide a travel plan recommendation method, an apparatus, a device and a computer readable storage medium. In the method according to the embodiments of the present disclosure, the travel plan classification model is obtained by training with the comprehensive consideration of the diversity of users, the diversity of the travel environment in time and space and dynamics of the user's travel preference, and the travel feature vector is generated according to the user persona information and the travel mode distribution information of the user, the current travel environment feature information and the feature information of the starting point and the destination point of the current travel, the travel feature vector is inputted into the travel plan classification model to calculate the scores of the candidate travel plans, and the travel plan recommended to the user according to the scores of the candidate travel plans.

With the continuous development of the electronic map technology, people become more and more dependent upon the navigation function of the electronic map, a client of the electronic map can recommend various travel plans for a user based on a starting point and a destination point provided by the user, such as various travel plans for different trip modes.
Currently, in the recommendation of a travel plan to the user, generally, the "fastest" travel plan is recommended to the user according to total durations of the travel plans, or the travel plan with the "lowest cost" is recommended according to total costs of the travel plans. However, due to the diversity of users and travel environments, existing travel plan recommendation methods have low recommendation accuracy and poor stability, thus they cannot meet user requirements.

Travel plan recommendation method, apparatus, device and computer readable storage medium