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When the high sound pressure at high frequencies is produced in the calculable pistonphone, for instance, in order to generate a sound field with a higher frequency such as not lower than 315 Hz and a sound pressure level reaching 174 dB Ref. 20 $\mu$Pa, the chamber is always designed small enough based on the sound pressure formula of the calculable pistonphone and the output capacity limitation of vibrators. Meanwhile, a balanced hole is always designed in the chamber to balance the inside and outside static pressure, which results in the offset of the piston equilibrium position and the large error of the calculated sound pressure. The mechanism of the piston offset is explained by the theory of fluid motion in circular pipes and thermal expansion. An eddy current sensor is thus introduced to measure the offset of piston of the calculable pistonphone and the primary calibration results were corrected. The experiment verified the phenomenon of the piston offset, and the effect of the correction method is confirmed in the primary calibration.

This paper reviews the work of Wu and Lin on the Union Jack lattice Ising model. This model is of interest as it one of the few to display re-entrant phase transitions. Specifically, we re-examine their result for the general anisotropic sublattice magnetizations, comparing these with the works of Vaks, Larkin and Ovchinnikov, and our own numerical simulations. We discuss the disagreements found in both sublattice predictions including non-zero antiferromagnetic results and a rotational variance. We will then suggest additional conditions and modified formulae that will allow valid results to be produced.

Sampling a signal at elevated sampling rates can be easily achieved by using time-interleaved analog-to-digital converters (TIADCs). TIADCs have more than one ADC in parallel. Each ADC samples the signal with a time gap of one sampling period and hence known as TIADC. The samples from all these ADCs are combined to reconstruct the signal. But the disadvantage of TIADCs is that they have mismatches like sampling time, gain and phase offset. The proposed work focuses on estimation and correction of these mismatches. For estimation of mismatches, teacher learner-based optimization (TLBO) algorithm was used and the estimated mismatches were used for correction by applying suitable operations. The proposed algorithm was applied for four-channel TIADCs. For estimation, a pilot signal is used which in this case is a monotonic sinusoidal signal. The estimation of mismatches was accurate and the correction was implemented for TIADCs with a sinusoidal input signal and the enhancement in signal quality was evaluated by finding signal-to-noise ratio (SNR) and signal-to-noise and distortion ratio (SNDR). There is a significant enhancement in SNR and SNDR. The average enhancements in SNR and SNDR are 50 and 46dB, respectively.

This study applies imperfect production processes to obtain in-control state by production correction and reorganization. Production processes are classified into two types of state: one is the type I state (out-of-control state) and the other is the type II state (in-control state). The type I state involves adjustment of the production mechanism. Production correction is either imperfect; worsening a production system, or perfect, returning it to "in-control" conditions. After N type I states, the operating system must be reorganized and returned to the beginning condition. At the beginning of the production of the each renewal cycle, the state of the process is not always to be restored to "in-control". The mean loss cost until "in-control" state, is determined. The existence of a unique and finite optimal N for an imperfect process under certain reasonable conditions is shown. A numerical example is presented.

Thirty-nine consecutive patients with little finger Dupuytren's contracture underwent open fasciectomy. Diseased abductor digiti minimi (ADM) pretendinous (PT) cords were identified. The mean pre-operative PIPJ contracture was 77° in the PT group and 66° in the ADM group. Mean residual deformity was 12° in the PT group and 9° in the ADM group. At six months, ten out of 27 patients had developed a recurrent deformity in the PT group (mean 24°) and seven out of 11 in the ADM group (mean 18°). There was no statistically significant difference between the two groups at any stage. Dupuytren's contracture of the little finger is as a result of an ADM cord in 29% of cases. In this series it led to an isolated contracture of the PIPJ in the majority of cases and rarely affected the MCPJ. Disease of the ADM cord was not associated with a difference in contracture or prognosis compared to a PT cord.

Changes in the curvature have not been reported in degenerative lumbar scoliosis (DLS) when the correction surgery was performed. The purpose of our study was to clarify the influence of the correction surgery of DLS. Twenty-one patients underwent corrective lumbar reconstruction surgery (1998–2003) only at the neurologically affected levels. The spinal curvature was retrospectively evaluated in these 21 patients with DLS using Cobb's methods. The mean preoperative Cobb's angle was 17.7° while the mean postoperative Cobb's angle was 6.1° (p < 0.0001) at 1 month after the surgery and 9.0° at the final follow-up. The correction rate was 65.2% at 1 month after the surgery and 50.2% at the final follow-up. Cobb's angle increased by 2.9°/43.4 months (mean, 0.80°/year) in these procedure. The surgical goals of DLS are the relief of neurological disorders and the cessation of the deterioration of spinal alignment. Strategies for DLS may include complete decompression, or correction of the spinal alignment in elderly patients with poor bone quality. Decompression and correction in the PLIF procedure only at neurologically affected levels may be one of the surgical procedures to challenge DLS.

In spinal tuberculosis, children bone is easily destroyed, and as a result spinal deformity complicates in higher rates in comparison with the adult tuberculous spine. However, the pediatric spine with tuberculosis is more flexible than those of the adult-spine, because spontaneous intercorporal fusion of the diseased segments in children never occur. Thus, prevention and/or correction of the tuberculous kyphosis is easier than those of the adults. Also in particular by posterior tethering instrumentation surgery the formed kyphosis can be corrected gradually during growth period. The key message is that in pediatric spinal tuberculosis, spontaneous intercorporal fusion of the diseased segment hardly takes place even under the posterior instrument-aided stabilization and the coverage of antituberculous chemotherapy. Therefore, tuberculous spine in children even after cure should be observed until growth maturity.

A novel dynamic brace for the treatment of idiopathic scoliosis based on parallel-actuated robotic system is proposed in this paper. The new brace can apply corrective forces on patients’ spine actively to correct the abnormal spine. However, the gravity of the dynamic system results in some adverse impacts, such as reducing comfort degree of patients, accuracy loss of rehabilitation force control, big error in direction and value of force. To overcome this problem, a new active force control strategy, proportional-derivative (PD) control with desired-gravity-compensation (DGC), is proposed to improve the effectiveness of scoliosis rehabilitation. Considering the electrically driven system and the environment contacting with the brace, the dynamic model of the active brace system is derived using Kane method. Based on the above mentioned, the force controller with DGC is designed for the brace system to compensate the impact of system gravity. The brace experiment system is built and various experiment tests are performed to verify the proposed control strategy. Experiment results demonstrate that the proposed control strategy, PD control with DGC, can distinctly reduce the influence of the brace system gravity and has more efficient control effectiveness compared with the classical PID controller.

In order to solve the previous problems of big paper-feeding errors and low positioning precision, a new correction positioning device for facial tissue has been proposed. Considering application of traditional mechanical correction devices during laminating and comparison on its advantages and disadvantages, it makes an electrification improvement in structure. Being controlled by motion control cards, utilize servo electromotor drives facial paper tissue correction to make sure that when the rate of paper is less than 12000 piece/h, the fitting error can be controlled within±0.5mm and when the rate is between 12000-15000 piece/h, the fitting error can be controlled within±1.0mm. The test results show that this device effectively improves the precision of adjusting and poisoning of facial tissue.