Medical image contrast enhancement based on improved sparrow search algorithm

The collection or transmission of medical images is often disturbed by various factors, such as insufficient brightness and noise pollution, which will result in the deterioration of image quality and significantly affect the clinical diagnosis. To improve the quality of medical images, a contrast enhancement method based on improved sparrow search algorithm is proposed in this paper. The method is divided into two steps to enhance the medical images. First, a new transform function is introduced to improve the brightness or contrast of medical images, and two parameters in the transform function are optimized by the improved sparrow search algorithm. Second, adaptive histogram equalization method with contrast limited is used to equalize the result image of the previous step to make the pixel distribution of the image more uniform. Finally, a large number of experiments and qualitative and quantitative analyses were conducted on the common data sets. The analysis results demonstrate that the presented approach outperforms some existing medical image processing approaches.     

新一代动三轴仪计算机数据采集与处理系统

在８０年代研制的动三轴仪基础上,采用现代计算机技术,实现了对动三轴试验全过程动应力、动应变和动孔压发展变化的实时采集、显示和数据文件在线存盘。不仅使数据处理过程全部自动化,且成功地解决了滞回圈等非规则曲线面积及莫尔圆公切线求解等一系列难题。     

8098单片机控制的直流调速系统

介绍８０９８单片机控制的直流调速系统。该系统采用Ｍ／Ｔ法测速;全数字晶闸管触发方式;速度、电注双闭环ＰＩ调节器和逻辑无环流控制方案,发挥了８０９８单片机的优势,系统性能较高。     

聚丙烯酰胺澄清果汁工艺研究——澄清过程主要成分的变化

本文研究了聚丙烯酰胺澄清苹果汁时的主要成分变化。结果表明:澄清后果汁的透光率在98％以上;主要果汁成分的保存率均在95％以上。这一结果与果胶酶澄清法和超滤澄清法有所不同。这种差异是由于澄清机理不同所致。     

更新观念,加强企业内部管理之我见

企业要适应市场、摆脱亏损局面,必须更新观念,加强内部管理:要牢固树立“用户第一、销售第二、生产第三”的观念;狠抓管理,苦练内功,增强企业竞争力。     

Analysis of spatial-temporal converters for all-optical communication links

We analyze parallel-to-serial transmitters and serial-to-parallel receivers that use ultrashort optical pulses to increase the bandwidth of a fiber-optic communication link. This method relies on real-time holographic material for conversion of information between spatial and temporal frequencies. The analysis reveals that the temporal output of the pulses will consist of chirped pulses, which has been verified experimentally. When the signal pulses are transmitted along with a reference pulse, the distortions of the received signal, caused by dispersion and other factors in the fiber, are canceled because of the phase-conjugation property of the receiver. This self-referencing scheme simplifies the receiver structure and ensures perfect timing for the serial-to-parallel conversion.     

Defense frontier analysis of quantum cryptographic systems

When a quantum cryptographic system operates in the presence of background noise, security of the key can be recovered by a procedure called key distillation. A key-distillation scheme effective against so-called individual (bitwise-independent) eavesdropping attacks involves sacrifice of some of the data through privacy amplification. We derive the amount of data sacrifice sufficient to defend against individual eavesdropping attacks in both BB84 and B92 protocols and show in what sense the communication becomes secure as a result. We also compare the secrecy capacity of various quantum cryptosystems, taking into account data sacrifice during key distillation, and conclude that the BB84 protocol may offer better performance characteristics than the B92.     

Generalized spin filtering and an improved derivative-sign binary image method for the extraction of fringe skeletons

Generalized spin filters, including several directional filters such as the directional median filter and the directional binary filter, are proposed for removal of the noise of fringe patterns and the extraction of fringe skeletons with the help of fringe-orientation maps (FOM's). The generalized spin filters can filter off noise on fringe patterns and binary fringe patterns efficiently, without distortion of fringe features. A quadrantal angle filter is developed to filter off the FOM. With these new filters, the derivative-sign binary image (DSBI) method for extraction of fringe skeletons is improved considerably. The improved DSBI method can extract high-density skeletons as well as common density skeletons.     

多分支平行双线输电线故障定位算法的研究

本文针对多分支平行双线输电线提出了一种新的故障定位方法。应用相同的算法对全部分支进行逐条搜索,故障分支和故障点位置可以一并被确定。经仿真证明,该方法是有效的。