We study the dynamics of an adaptive coupled array of phase oscillators. The adaptive law is designed in such a way that the coupling grows stronger for the pairs which have larger phase incoherence. The proposed scheme enhances the synchronization and achieves a more reasonable coupling dynamics for the network of oscillators with different intrinsic frequencies. The synchronization speed and the steady-state phase difference can be adjusted by the parameters of the adaptive law. Besides global coupling, nearest-neighbor ring coupling is also considered to demonstrate the generality of the method.

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The purpose of the present study was to determine the location of the mental foramen (MF) based on soft- and hard-tissue landmarks, to facilitate prediction of the location of this structure during facial and dental surgery. Forty-two hemispheres of 21 adult cadavers (16 men and 5 women; aged 30-75 years) were dissected to expose the MF. The locations of the MFs were evaluated with direct and photographic measurements. Most of the MFs presented a single foramen (95%), except for only 2 cases with double foramina (5%). The MFs localized 23.38 +/- 2.00 mm inferior and 3.55 +/- 1.70 mm medial to the cheilion in the front view while 23.59 +/- 2.11 mm inferior and 7.19 +/- 3.03 mm posterior to the cheilion in the lateral view. Based on the hard-tissue landmarks, we found that most of the MFs localized inferior the second premolar in most of the cases (73.8%), and the MFs localized 23.34 +/- 2.39 mm below the cusp tip of the second premolar, 16.56 +/- 2.53 mm below the inferior alveoli, and 15.56 +/- 1.74 mm superior the bottom of the mandible. The position of the MF varied from 8.7 degrees medial to 15.5 degrees posterior in the vertical angle with the change of surgical body position from supine to lay-side position. Our results may provide a more detailed information to predict the location of the MFs.

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The high-precision distribution of optical pulse trains via fibre links has had a considerable impact in many fields. In most published work, the accuracy is still fundamentally limited by unavoidable noise sources, such as thermal and shot noise from conventional photodiodes and thermal noise from mixers. Here, we demonstrate a new high-precision timing distribution system that uses a highly precise phase detector to obviously reduce the effect of these limitations. Instead of using photodiodes and microwave mixers, we use several fibre Sagnac-loop-based optical-microwave phase detectors (OM-PDs) to achieve optical-electrical conversion and phase measurements, thereby suppressing the sources of noise and achieving ultra-high accuracy. The results of a distribution experiment using a 10-km fibre link indicate that our system exhibits a residual instability of 2.0 × 10−15 at1 s and8.8 × 10−19 at 40,000 s and an integrated timing jitter as low as 3.8 fs in a bandwidth of 1 Hz to 100 kHz. This low instability and timing jitter make it possible for our system to be used in the distribution of optical-clock signals or in applications that require extremely accurate frequency/time synchronisation.

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