Abstract: The present invention provides methods and systems for keeping the ephemeris in a navigational receiver current to achieve fast TTFF without the need for connecting to an aiding network or remote server. In an embodiment, the receiver keeps the ephemeris current by downloading the ephemeris in the background. In the preferred embodiment, the receiver uses a background sleep/wake up process to download current ephemeris with minimal power drain. In this embodiment, the receiver alternates between a sleep mode and a wake up mode. During the wake up mode, the receiver attempts to download current ephemeris. The receiver then goes back to the sleep mode until the next wake up to conserve power. The receiver may wake up from the sleep mode to download the ephemeris when the stored ephemeris is no longer current or the ephemeris broadcasted from a satellite has been updated or based on receiver usage patterns.

Abstract: The present invention provides methods and systems that enable a mobile navigation receiver to accurately determine its trajectory with non-current ephemeris in stand-alone mode. In an embodiment, the receiver computes the position for the same location using non-current ephemeris and current ephemeris at different time instances. The receiver then determines a position correction by finding the difference between these two computed positions, and applies this correction to the trajectory generated with non-current ephemeris to obtain a more accurate trajectory. In another embodiment, the receiver computes an initial position of the receiver using non-current ephemeris and finds the difference between the computed initial position and an accurate approximation of the initial position. The receiver then shifts the subsequent receiver trajectory computed using non-current ephemeris by the difference to obtain a more accurate trajectory.

Abstract: A driving head for an air wrench, connected at the front end of a main body of an air wrench and formed with four equal side surfaces, includes a quadrate stage with a preset length and a front end stage having a neck at its rear end connected with the quadrate stage. Each side surface of the front-end stage is formed as an arc starting from the top to the neck to keep its diagonal distance just fit with the quadrate groove of the working sleeve. Therefore, the driving head can drive the working sleeve to work by either fitting the front end stage and the quadrate stage in the quadrate groove completely or fitting only the front end stage in the quadrate groove with an inclined angle.

Abstract: The present invention provides systems and methods for enabling a navigation signal receiver to perform both data assisted and non-data assisted integration to provide better integration during signal acquisition, reacquisition and tracking. In data assisted integration mode, a receiver uses known or predicted data bits to remove the modulated data bits of a received signal prior to integration. In non data assisted integration mode, when the data bits are not known or predictable, the receiver uses an optimal estimation or maximum likelihood algorithm to determine the polarities of the modulated data bits of the received signal. This may be done by determining which of various possible bit pattern yields the maximum integrated power. When the modulated data bits are not known or predictable over a limited range, the receiver carries out data assisted integration over the known or predictable data bits and additional non data assisted integration.

Abstract: The present invention provides a method and apparatus for a satellite navigation receiver to lock onto satellite signals in the cold start mode with no information on the receiver position, the satellite position, or time estimates stored in the receiver's memory. All satellites in a positioning system are divided into groups based on the satellite constellation structure. In an embodiment, the positioning system is the Global Positioning System (GPS) and all GPS satellites are divided into three groups. During initialization of the receiver, the satellites are searched per group to lock onto at least one satellite signal. Other satellites are then searched in a given order based on their respective distance or proximity to the first satellite acquired. This method reduces the Time-to-First-Fix (TTFF) ordinarily required by conventional receivers in the cold start mode.

Abstract: Indolestyryl compounds and use thereof for a high density recording media and method for fabricating the same. The indolestyryl compounds exhibit strong absorbance in the visible light region (400˜700 nm) of the spectrum, resistance to heat and light, high light sensitivity, and excellent solubility, resulting from their special chemical configuration. Furthermore, the indolestyryl compounds can be used as recording layer materials in high density recording media for matching a reading laser wavelength and enhancing the reflective index and carrier-to-noise ratio (CNR) of the high density recording media. Accordingly, the recording sensitivity and the readout characteristics of high density recording media comprising the indolestyryl compound according to the present invention can be improved.

Abstract: A method for increasing transmission efficiency of an electronic device using a serial peripheral interface includes receiving data from a first pin of the serial peripheral interface of the electronic device during a first duration according to a clock signal received from a clock pin of the serial peripheral interface of the electronic device, and outputting data from the first pin during a second duration according to the clock signal.

Abstract: Fast Fourier Transform (FFT) based Phase Lock Loops (PLLs) are provided for use in navigational signal receivers. In an embodiment, a navigation receiver correlates a received navigational signal with a locally generated signal into correlation samples, e.g., one-millisecond correlation samples. The navigation receiver includes a FFT based PLL that corrects phase shifts in the correlation samples due to the Doppler frequency by considering both the Doppler frequency and its rate of change, which are obtained from a FFT computation with interpolation. The phase corrected correlation samples are then integrated over a length of a navigation data bit, e.g., 20 milliseconds, to determine the sign of the data bit of the received signal. In another embodiment, a soft decision feedback technique involving integration extending over the present data bit and several prior data bits is used to determine the sign of a present data bit of the received signal.

Abstract: A method to determine the polarity of navigation data from weak satellite signals is disclosed. After bit edge is detected, a method in frequency domain is used to determine the present bit polarity with the help of several prior data bits which are already known, is disclosed. The impact of residual frequency can be mitigated by frequency transform. This method is especially useful in removing the data modulation in the weak signal for subsequent long coherent integrations.

Abstract: An indolestyryl compound. The indolestyryl compound has formula (I): wherein Z1 comprises benzene, naphthalene, or heterocyclic ring containing O, S, or N, R2 comprises H, halogen atoms, C1-5 alkyl, nitro, ester, carboxyl, sulfo, sulfonamide, sulfuric ester, amide, C1-3 alkoxy, amino, alkylamino, cyano, C1-6 alkylsulfonyl, or C2-7 alkoxy carbonyl, R3, R4, R5, and R6 comprise H, alkyl, aralkyl, or heterocyclic ring containing O, S, or N, R7 and R8 comprise H or alkyl, R10 comprises H, alkyl, halogen atoms, nitro, hydroxyl, amino, ester, or substituted or non-substituted sulfonyl, W comprises carbon or nitrogen, Y comprises carbon, oxygen, sulfur, selenium, —NR, or —C(CH3)2, m is 1˜3, and X1 comprises an anionic group or an anionic organometallic complex, wherein R3 and R4 are joined to a nitrogen atom or R5 and R6 are joined together to form a ring, and R bonded to nitrogen is C1-5 alkyl.

Abstract: The present invention provides GPS receivers with clock calibration for fast reacquisition of GPS signals after waking up from a sleep state or coming out of signal blockage. In a preferred embodiment, a GPS receiver comprises a local clock based on an oscillator, e.g., crystal oscillator. The GPS receiver calculates a clock calibration value based on a computed oscillator count for the period during which the GPS receiver is in the sleep state or the signal is blocked. This clock calibration value is used to calibrate the local clock after the GPS receiver wakes up or comes out of signal blockage for fast reacquisition of GPS signals.

Abstract: The present invention provides GPS receivers capable of tracking very weak GPS signals particularly in an indoor environment without assistance from an external server or a network. In a preferred embodiment, a GPS receiver initially acquires and locks onto GPS satellite signals to compute receiver position outdoors. The GPS receiver then tracks at least one satellite signal indoors to maintain acquisition parameters for quick acquisition of GPS signals. To save power, the receiver automatically goes to the sleep state and periodically wakes up, i.e., powers up, to maintain the at least one satellite signal tracking. During the wakeup state, the receiver collects ephemeris data from the at least one satellite signal when the ephemeris data needs to be updated for quick acquisition of GPS signals.

Abstract: The techniques to detect and mitigate the false reacquisition in a global satellite navigation receiver are disclosed. The false reacquisition due to frequency side-lobes and code autocorrelation secondary lobes are considered for mitigation. A set of two threshold values is used to detect correct reacquisition and reject false reacquisition. While the reacquisition of the signal is straight forward when the correlation is clear with the power above the first threshold, it is not so clear when the power is between two thresholds. So a further search for the maximum power among the retained dwells results in correct reacquisition. The search range depends upon the signal blockage interval and receiver dynamics. The feedback from navigational solution may be used to determine the search range both in frequency and code phase. In the case of frequency side-lobes, which occur only at specified frequency components, these frequencies are tested for maximum power response.

Abstract: The present invention discloses an auto-assembling system for assembling the frames and the covers of devices, completely. The auto-assembling system configured on a platform includes a transportation device, a lateral assembling power module, a buffer, a control circuit and a power source. The above-mentioned transportation device has a fillister for receiving the frames and the covers of the devices. The frames that are combined with the covers in the transportation device are driven by the horizontal assembling power module. The buffer is used as a cushion for the lateral assembling power module. When the lateral assembling power module moves to the buffer, it causes the frames and the covers to be assembled. The control circuit connects to the lateral assembling power module for controlling the activating timing of the foregoing lateral assembling power module. The power source connects to the lateral assembling power module and the control circuit to provide the power for them.

Abstract: The present invention discloses an auto-assembling system for small shell devices. The system includes a first transportation component, a second transportation component, a first driving module, a second driving module, a power assembling module and a control circuit. The first transportation component having a first transportation belt and the second transportation component having a second transportation belt are used to transport the frames or the covers of the devices. The first driving module configured on the first transportation component is used to move the frames or the covers transported by the first transportation component to an assembling area downstream a slide. The second driving module configured on the second transportation component is used to move the frames or the covers transported by the second transportation component to the assembling area along a track.

Abstract: Methods to achieve data bit synchronization from weak navigational satellite signals are based on a maximum likelihood criterion. The bit synchronization technique may be implemented by calculating a normalized dot product of two consecutive one-millisecond correlation values. Similar normalized dot products are calculated at intervals separated by one bit duration, and these dot products are summed and compared with pre-computed thresholds to declare bit edge detection. In another implementation, the normalized dot product of adjacent correlation values is replaced by a coherent integration powers of adjacent correlation values.

Abstract: A method and device to track navigational satellite signals, are claimed. In this invention, a combination of down-sampling and frequency domain transformation are used to track the navigational satellite signals under dynamic environment. A Fast Fourier Transform (FFT) with long coherent integration has been employed to determine the varying frequency components with high resolution. By representing a number of correlation values with their average value, it is possible to represent a long sequence of input values by a smaller number of values and a relatively short length FFT can reveal the low frequency components that are present in the signal during tracking operation. A large reduction in the computational load may be achieved using this down-sampling method without compromising on the frequency resolution.

Abstract: A method and device to acquire navigational satellite signals combines non-coherent and coherent integrations and can efficiently acquire both strong and weak signals. Successive steps eliminate lower powered and less likely combinations of code offsets and carrier frequencies or dwells of a given satellite signal. Only remaining dwells then are correlated and integrated over larger time duration to obtain the most probable dwell or dwells, which results in reduced computational load. The selection of most likely dwells is based on Parseval's theorem on equivalence of power in time and frequency domains. An optimal estimator algorithm efficiently estimates the probable navigation data bits embedded in the received signal. In case of an ambiguity due to several possible dwells, the steps are repeated with a new set of signal samples.

Abstract: A switching signal input device for use with an electronic apparatus is provided. The switching signal input device includes a switch part, an operating part and a resilience element, and is capable of performing four-directional switch control actions in response to the elastic forces generated from the resilience element on two planes perpendicular to each other.