Image edge detection based on multi-fractal spectrum analysis

In this paper, an image edge detection method based on multi-fractal spectrum analysis is presented. The coarse grain H?lder exponent of the image pixels is first computed. then, its multi-fractal spectrum is estimated by the kernel estimation method. Finally, the image edge detection is done by means of different multi-fractal spectrum values. Simulation results show that this method is efficient and has better locality compared with the traditional edge detection methods such as the Sobel method. __________ Translated from Journal of Hunan University (Natural Sciences), 2004, 31(4): 28–33     

Study of hybrid optical burst networks

We propose the hybrid optical burst switching (HOBS), and investigate the HOBS-based ring topology with numerical simulation. Results indicate that the packet loss ratio in HOBS is much less than that in optical burst switching(OBS) and its performance depends on some parameters such as the packet proportion, the electronic buffer size and the processing speed in the node. __________ Translated from Journal on Communications, 2005, 26(11): 7–11 (in Chinese)     

Adaptive equality prediction of batch processes based on PLS model

There are usually no on-line product quality measurements in batch and semi-batch processes, which make the process control task very difficult. In this paper, a model for predicting the end-product quality from the available on-line process variables at the early stage of a batch is developed using partial least squares (PLS) method. Furthermore, some available mid-course quality measurements are used to rectify the final prediction results. To deal with the problem that the process may change with time, recursive PLS (RPLS) algorithm is used to update the model based on the new batch data and the old model parameters after each batch. An application to a simulated batch MMA polymerization process demonstrates the effectiveness of the proposed method. __________ Translated from Jorunal of Tsinghua Science and Technology(Natural Science Edition), 2004, 44(10): 1360–1363 (in Chinese)     

零电压零电流开关全桥PWM变换器的研究

文本通过分析全桥ZVZCS PWM变换器的工作原理,得出其与传统的全桥ZVZCS PWM变换器的不同之处,然后具体分析对于变化的负载电流,电路环流是如何自我调节以实现ZCS的,并给出了一些影响实现ZVZCS的关键元器件的参数设计公式。最后样机的试验波形证了本文的分析研究。     

单片机双机并行通信中所遇问题及解决方法

本文主要介绍由单片机组成双机系统在并行通信中所遇到的问题以及采用ATF1504AS的原因及实现的方法。详细介绍系统的设计目的、结构、采取的抗干扰性措施、软硬件实现的方法等。     

Energy transfer mechanism of GdPO4: RE3+ (RE = Tb, Tm) under VUV-UV excitation

Polycrystal of GdPO₄:RE³⁺ (RE=Tb, Tm) phosphors were prepared by solid-state method. Vacuum ultraviolet excitation and emission spectrum and the energy transfer mechanism between the host and dopants of Tb³⁺ and Tm³⁺ were investigated respectively. The emission of Gd³⁺ at 313 nm was enhanced by the strong absorption of CTS of Tm³⁺ at 180 nm in GdPO₄: Tm. It has also been concluded that the excitation of Gd³⁺ is transferred to Tb³⁺ and then emission peaks of ⁵D_J→⁷F_J of Tb³⁺ were observed.     

DTM320／580型磨煤机传动齿轮轴断裂原因分析及防范措施

介绍了DTM580/320型磨煤机传动齿轮轴断裂的情况,并进行了分析;找到了断裂的原因,提出了防范措施。     

Complete stability of cellular neural networks with time-varying delays

In this paper, the complete stability of cellular neural networks with time-varying delays is analyzed using the induction method and the contraction mapping principle. Delay-dependent and delay-independent conditions are obtained for locally stable equilibrium points to be located anywhere, which differ from the existing results on complete stability where the existence of equilibrium points in the saturation region is necessary for complete stability and locally stable equilibrium points can be in the saturation region only. In addition, some existing stability results in the literature are special cases of a new result herein. Simulation results are also discussed by use of two illustrative examples.     

Clustering for Processing Rate Optimization

Clustering (or partitioning) is a crucial step between logic synthesis and physical design in the layout of a large scale design. A design verified at the logic synthesis level may have timing closure problems at post-layout stages due to the emergence of multiple-clock-period interconnects. Consequently, a tradeoff between clock frequency and throughput may be needed to meet the design requirements. In this paper, we find that the processing rate, defined as the product of frequency and throughput, of a sequential system is upper bounded by the reciprocal of its maximum cycle ratio, which is only dependent on the clustering. We formulate the problem of processing rate optimization as seeking an optimal clustering with the minimal maximum-cycle-ratio in a general graph, and present an iterative algorithm to solve it. Experimental results validate the efficiency of our algorithm     

Image segmentation via self-organising fusion

A method called self-organising fusion (SOF) for performing fast image segmentation is presented. The input image is divided into a set of small regions, each associated with a working feature. First, all regions are simultaneously updated and then a statistical process is applied to merge the qualified regions. The contours of objects are obtained by alternating the two processes of updating and merging until convergence. The concurrent updating creates a SOF behaviour that facilitates the identification of regions presumably comprising the same object. The method can save computation cost as both updating and merging are conducted in parallel fashion, and as parameter selection is done for local regions, it is able to deal with fairly complex images