In a typical conventional narrowband active noise control (ANC) system, each reference (cosine or sine) wave is filtered by an FIR secondary-path estimate called x-filtering block. The number of x-filtering blocks is twice of the number of targeted frequencies (q), which may pose a bottleneck in system implementation. In this paper, we propose new efficient and robust narrowband ANC systems. An IIR-type feedforward secondary-path compensator is newly introduced in front of the loudspeaker, whose inverse is an FIR minimum phase part of the secondary-path estimate. The remaining FIR nonminimum phase part is used as the x-filtering block whose length may be much shorter. To further reduce the complexity, we use a special bandpass filter bank to decrease the number of x-filtering blocks. As a result, the new systems only require, regardless of q, two (2) x-filtering blocks whose order may be significantly smaller than that of the secondary-path estimate. Modification to the new systems is also made to achieve robustness with respect to the frequency mismatch (FM) between the reference and primary signal frequencies. Extensive simulations reveal that the new systems and their modified versions work almost as well as the conventional system does, and are capable of mitigating the influence of the FM, while enjoy tremendous computational advantage.
This paper compares batch and continuous technologies in terms of product quality and process performance in pharmaceutical tablet manufacturing using ethenzamide as the active pharmaceutical ingredient. Batch and continuous processes using wet granulation were investigated by performing experiments on the scale of 5 and up to 100 kg/lot, using the same raw materials. Three technologies were tested and compared: (i) batch technology using fluidized bed granulation, (ii) batch technology using high shear granulation, (iii) continuous technology using high shear granulation. In the full-scale experiment, in all three technologies including continuous technology, the quality of the tablets fulfilled the target values regarding hardness, active pharmaceutical ingredient content, and dissolution. The granules produced by different technologies, however, presented varying attributes regarding granule size distribution, loose bulk density, or scanning electron microscope images. The process performance, more specifically the yield, was slightly better for batch technologies than for the continuous technology, mainly due to losses in the start-up operation. Notably, this study has shown that continuous technology, which is generally believed to not entail scale-up procedures, could in fact, require parameter adjustment for prolonged operation. The results provided suggestions for improvements to implement large-scale continuous technologies in the pharmaceutical industry.
A new class of wireless aided GPS requirements for CDMA and IDEN handsets has resulted from the FCC’s E911 mandate. This mandate requires wireless carriers such as Verizon, Sprint, and Nextel to support E911 calling from all mobile devices. Location of the caller needs to be known to the emergency service with 50 meters 2DRMS accuracy at least 67% of the time. Sony has modified the baseband signal processing of two generations of GPS IC’s to comply with this mandate. Software solutions for this mandate were developed for the CXD2932 and CXD2951 GPS devices that communicate with Sony Ericsson’s CM42 CDMA cellular phone module. This paper describes Sony’s solution as implemented in the CXD2932/51. Verification and test procedures are also presented, with descriptions of in-house test equipment and the Sony Ericsson phone modules. In addition to lab testing, performance results from field tests using the Verizon network are also presented and show a consistently high level of accuracy and availability, demonstrating the superior performance achieved.
Most of aluminum circular tubes were formed by extrusion processes. The circular tube has high flexural rigidity and torsional rigidity as compared with its weight. Therefore, tube consumption is increasing for reducing industrial parts' weight in many products. The shape of tube cross section must be changed and manufactured in proportion to the magnitude of moment, which will act on them. Therefore, we have invented and made a new prototype extrusion machine which can control the inside diameter of circular tubes, and this study is the one of the extrusions with changing cross section shape. The possibility and characteristics of the extrusion using tapered mandrel were experimentally made clear in this study.
We have studied the derailment and overturning of railway vehicles during earthquakes. Numerical simulation clarified dynamic behaviors and running safety limits of a vehicle on a vibrating track. The results of the simulation are now effectively used for the design of railway structures. And vibration tests using a half-body car mounted on a shinkansen bogie were performed, that confirmed the validity of the numerical analysis. These results were premised on the sin wave vibration. This paper shows behaviors of vehicle on an observed vibration during an earthquake based on numerical simulation. And we suggest running safety limits for seismic motions that can be used in seismic design of railway structures.
Rotating machines such as diesel engines, cutting machines, fans, motors, etc., generate sinusoidal noise signals that may be effectively reduced by narrowband active noise control (ANC) systems. In this paper, a typical filtered-X LMS (FXLMS) based narrowband ANC system equipped with an online secondary-path modeling subsystem is analyzed in detail. First, difference equations governing the dynamics of the FXLMS algorithm for secondary source synthesis and the LMS algorithm for secondary-path estimation are derived in terms of convergence in both mean and mean square. Steady-state expressions for mean-square error (MSE) as well as the residual noise power are then developed in closed form. Extensive simulations are performed to demonstrate the validity of the analytical results.
This paper addresses proposal and verification of a wire type steering system for an All Terrain Vehicle. The final purpose is to develop the automatic traveling robot that investigates the environment. Generally, the investigators occasionally wastes time and hangs the hands through they investigation because the land is vast. Therefore, development of the automatic traveling vehicles are required. In this research, as the former step, mechanical property on steering is studied to develop of the steer control device.
