An artificial intelligent algorithm for tumor detection in screening mammogram

Cancerous tumor mass is one of the major types of breast cancer. When cancerous masses are embedded in and camouflaged by varying densities of parenchymal tissue structures, they are very difficult to be visually detected on mammograms. This paper presents an algorithm that combines several artificial intelligent techniques with the discrete wavelet transform (DWT) for detection of masses in mammograms. The AI techniques include fractal dimension analysis, multiresolution markov random field, dogs-and-rabbits algorithm, and others. The fractal dimension analysis serves as a preprocessor to determine the approximate locations of the regions suspicious for cancer in the mammogram. The dogs-and-rabbits clustering algorithm is used to initiate the segmentation at the LL subband of a three-level DWT decomposition of the mammogram. A tree-type classification strategy is applied at the end to determine whether a given region is suspicious for cancer. We have verified the algorithm with 322 mammograms in the Mammographic Image Analysis Society Database. The verification results show that the proposed algorithm has a sensitivity of 97.3% and the number of false positive per image is 3.92.     

采用自抗扰控制的三电机同步协调系统

自抗扰控制器自问世以来被用于多种应用场合,但其有着参数多,难整定的弊端,文中依据RBF神经网络结构简单、逼近能力强的优势提出了基于RBF神经网络的复合自抗扰参数调节器,利用RBF神经网络获得自抗扰参数的在线调整信息,且将其应用于三电机同步系统,经过实验验证,该调节器能实时调节自抗扰参数且能改善控制性能,具有实用性。     

红外立靶坐标测量系统的实现

提出了一种新型的红外立靶坐标测量系统的构想,借以改善目前靶场可见光立靶坐标测量系统工作受环境影响严重,不能全天时工作的缺点.对红外立靶坐标测量系统的关键技术问题红外探测器的波段选择进行了讨论,通过理论分析和试验验证,指出3-5μm的中波红外应作为红外立靶坐标测量系统的首选.在此基础上设计了一种可用于工程实践的红外立靶坐标测量系统,并对该系统的测量精度进行分析.     

Detection of spicules on mammogram based on skeleton analysis

Existence of spicules is one of important clues of malignant tumors. This paper presents a new image processing method for the detection of spicules on mammogram. Spicules can be recognized as line patterns radiating from the center of tumor. To detect such characteristic patterns, line skeletons and a modified Hough transform are proposed. Line skeleton processing is effective in enhancing spinal axes of spicules and in reducing the other skeletons. The modified Hough transform is applied to line skeletons and radiating line structures are obtained. Experiments were made to test the performance of the proposed method. The system was designed using 19 training images, for which one normal case was recognized to be star-shaped. The other case were recognized correctly. Another experiments using 34 test images were also performed. The correct classification rate was 74%. These results shows the effectiveness of the proposed method.     

A CAD system for the automatic detection of clustered microcalcifications in digitized mammogram films

Clusters of microcalcifications in mammograms are an important early sign of breast cancer. This paper presents a computer-aided diagnosis (CAD) system for the automatic detection of clustered microcalcifications in digitized mammograms. The proposed system consists of two main steps. First, potential microcalcification pixels in the mammograms are segmented out by using mixed features consisting of wavelet features and gray level statistical features, and labeled into potential individual microcalcification objects by their spatial connectivity. Second, individual microcalcifications are detected by using a set of 31 features extracted from the potential individual microcalcification objects. The discriminatory power of these features is analyzed using general regression neural networks via sequential forward and sequential backward selection methods. The classifiers used in these two steps are both multilayer feedforward neural networks. The method is applied to a database of 40 mammograms (Nijmegen database) containing 105 clusters of microcalcifications. A free-response operating characteristics (FROC) curve is used to evaluate the performance. Results show that the proposed system gives quite satisfactory detection performance. In particular, a 90% mean true positive detection rate is achieved at the cost of 0.5 false positive per image when mixed features are used in the first step and 15 features selected by the sequential backward selection method are used in the second step. However, we must be cautious when interpreting the results, since the 20 training samples are also used in the testing step.     

A comparison of methods for mammogram registration

Mammogram registration is an important technique to optimize the display of cases on a digital viewing station, and to find corresponding regions in temporal pairs of mammograms for computer-aided diagnosis algorithms. Four methods for mammogram registration were tested and results were compared. The performance of all registration methods was measured by comparing the distance between annotations of abnormalities in the previous and current view before and after registration. Registration by mutual information outperformed alignment based on nipple location, alignment based on center of mass of breast tissue, and warping.     

Qos和NP模型化的一种面向对象方法

本文目的在于用ＯＯＰ方法描述ＱｏＳ和ＮＰ的模型，和其在层次状叠放的不同网络中的表示     

A registration framework for the comparison of mammogram sequences

In this paper, we present a two-stage algorithm for mammogram registration, the geometrical alignment of mammogram sequences. The rationale behind this paper stems from the intrinsic difficulties in comparing mammogram sequences. Mammogram comparison is a valuable tool in national breast screening programs as well as in frequent monitoring and hormone replacement therapy (HRT). The method presented in this paper aims to improve mammogram comparison by estimating the underlying geometric transformation for any mammogram sequence. It takes into consideration the various temporal changes that may occur between successive scans of the same woman and is designed to overcome the inconsistencies of mammogram image formation.     

GPON系统中面向业务的上行调度成帧算法

论证了传统成帧方式的弊端,然后在ITU-T G.984.3-200402-Ⅰ协议的基础上,提出了根据不同业务类型的优先级和等待时间调度的上行成帧算法,并且分析了算法的有效性,对算法进行了仿真,结果证明,改进型算法在负载较重的情况下,能够很好地保证高优先级数据优先成帧,同时也兼顾了低优先级数据,不至于堵塞.     

面向异步视频的嵌入式图像处理系统设计

在此设计出一种基于DSP-kFPGA技术的面向异步视频的嵌入式图像处理系统,以一种灵活的架构避免了帧间不同步方法对双口RAM显存的需求,既能够保证图像输出质量,又有利于提升图像处理的性能指标。系统以FPGA为核心,连接DSP和4片帧存,通过帧存的循环复用将缓存和显存融合起来,省略了数据搬运的环节。当输入帧频小于输出帧频时,从系统总体的角度分析帧存的状态转换规律;当输入帧频大于输出帧频时,从单个帧存的角度分析帧存的状态转换规律,并给出了可鳊程逻辑设计的源程序。该方案已在产品中应用,通过升级能够满足更高的技术要求。     

A clinically oriented video-based system for quantification of eyelid movements

A field-worthy system was developed to quantify the eyelid movements in clinical sites. The system consists of a home-use charge-coupled device video camera, a processing unit, and a personal computer. A white marker of 4-mm diameter and 30-mg weight is attached to the lower margin of the upper eyelid. The processing unit automatically detects the vertical displacement of the upper edge of the marker. One marker is attached to each eye so that the movements of the both eyelids are measured with one camera simultaneously. The measurement error of the system was evaluated in experiments on eight healthy subjects and eight patients with eyelid paralysis. The mean of the absolute error of peak amplitudes occurring in 2 min was 0.81 mm, with the worst error being +1.7 mm. The reproducibility of the mean peak amplitude measured on five consecutive days was within 1 mm. The mean peak amplitudes of both eyes were measured preoperatively and postoperatively for approximately three months for three patients who were operated on to remove vestibular schwannoma. The results demonstrated basic clinical utility of the system.     

An application oriented test procedure for designing microsteppingstep motor controllers

Describes an application oriented set-up for determining current references for a microstepping step motor controller. This eliminates the need for calculating these references from motor characteristics. Motor nonlinearities and asymmetries are taken into consideration and references for controllers can be obtained by an unattended test for any microstep size desired     

统一面向产品全生命周期的知识应用体系研究

提出统一知识应用体系的概念、性质和模型,以及知识应用体系的实现与实践。建立统一知识应用体系是梳通产品研制过程各业务信息系统之间知识获取与供应渠道、知识与研制过程结合渠道的系统性工程。通过统一的企业信息系统用户验证、业务系统检索服务、研制过程描述、知识与供应、知识应用门户等方式建立统一知识应用体系。     

The construction of an anatomically based model of the humanventricular conduction system

The ventricular conduction system is a complicated network of specialized muscle cells responsible for the transmission of electrical activity between the atria and the ventricles of the human heart. It has been the focus of numerous electrical and anatomical studies at both the microscopic and macroscopic levels. An understanding of its behavior at both levels is considered important, because it is primarily responsible for the spread of excitation in the ventricles. Previous computer models have been very simple ones that have been primarily adjuncts to models of the ventricles. This paper describes a strategy for the construction of conduction system models which is based on real microscopic and macroscopic features, although the model still is much simpler than reality. The model contains almost 35,000 individual cylindrical elements, each of whose physical dimensions approximate unit bundles of Purkinje and atrioventricular nodal cells. The model, whose physical appearance closely resembles that of the conduction system, was generated from limited anatomical data in less than 2 min CPU time on an IBM 3090 at the Cornell National Supercomputer Facility.     

An integrated system for prediction and analysis of solderinterconnection shapes

In this paper, an integrated system [predicting solder interconnection shapes (PSIS)] is built to predict and analyze the shape of solder interconnections in electronic packaging. The purposes are to numerically simulate the formation of solder joints, analyze the shape of solder joints and its influential factors and provide an efficient tool for design and manufacturing engineers to improve the integrity of solder interconnections. The formation of solder joints is numerically simulated through a surface evolver program and the calculation is automated with an additional controller. A datafile generator is developed in which the potential energies, geometry of the conjunction and boundary conditions of the initial solder joint can be generated visually and transferred into evolver syntax automatically. A post processor is built to analyze the global three-dimensional (3-D) shape and cross section profiles of solder fillets. Also, the applications for solder interconnection shape prediction of chip component (RC3216) are conducted with this system     

Constructing Internet coordinate system based on delay measurement

In this paper, we consider the problem of how to represent the locations of Internet hosts in a Cartesian coordinate system to facilitate estimation of network distances among arbitrary Internet hosts. We envision an infrastructure that consists of beacon nodes and provides the service of estimating network distance between pairs of hosts without direct delay measurement. We show that the principal component analysis (PCA) technique can effectively extract topological information from delay measurements between beacon hosts. Based on PCA, we devise a transformation method that projects the raw distance space into a new coordinate system of (much) smaller dimensions. The transformation retains as much topological information as possible and yet enables end hosts to determine their coordinates in the coordinate system. The resulting new coordinate system is termed as the Internet Coordinate System (ICS). As compared to existing work (e.g., IDMaps and GNP), ICS incurs smaller computation overhead in calculating the coordinates of hosts and smaller measurement overhead (required for end hosts to measure their distances to beacon hosts). Finally, we show via experiments with both real-life and synthetic data sets that ICS makes robust and accurate estimates of network distances, incurs little computational overhead, and its performance is not susceptible to the number of beacon nodes (as long as it exceeds a certain threshold) and the network topology.     

面向数字电视环境的业务运营支撑系统

针对我国数字电视业务运营的特点，从业务和技术上分别分析了对业务运营支撑系统的要求，提出了系统的体系结构和功能结构，并介绍了其中的关键技术。     

An approach for handling the nonlinearities of HVDC system forstability analysis

An approach for linearizing the nonlinearities of the high voltage direct current (HVDC) system for analyzing the system stability over wide range of operation is presented. The nonlinearities can be linearized with ±5% error over a wide range of system operation. It is shown that the nonlinearities introduced by the converter, real power, and reactive power equations can be linearized over a wide range by using the integral square error (ISE) method. The results are compared with standard techniques called small signal analysis. It is shown that the stability margin of the system predicted by the new technique is relatively smaller than what is predicted by small signal analysis. The system stability boundaries are determined by the AC voltage and the reactive current control. These two control schemes may provide the same stability margin, provided appropriate controller gains are selected. The power factor control modeling is discussed     

面向司法大数据的文本主题OLAP系统

随着大数据技术的发展,加强司法大数据应用成为推进司法现代化建设的重要手段,如何处理司法大数据中的非结构化数据亟待解决.为此,本文提出了面向司法大数据的文本主题OLAP系统.在离线数据处理模块中,设计了Span数据模型,并定义了多种针对该模型的操作符;设计了基于规则的文本行政区划归类方法,并构建了主题立方体.在线上查询模块中,实现了基于倒排索引的关键词搜索方法和最大独特主题范围查询,提供了上卷、下钻、切片等功能.通过在大规模的真实数据集上对系统进行测试,实验结果证明了该系统的合理性和实用性.     

An intelligent data mining system for drop test analysis ofelectronic products

Drop testing is one common method for systematically determining the reliability of portable electronic products under actual usage conditions. The process of drop testing, interpreting results, and implementing design improvements is knowledge-intensive and time-consuming, and requires a great many decisions and judgments on the part of the human designer. To decrease design cycles and, thereby, the time to market for new products, it is important to have a method for quickly and efficiently analyzing drop test results, predicting the effects of design changes, and determining the best design parameters. Recent advances in data mining have provided techniques for automatically discovering underlying knowledge from large amounts of experimental data. In this paper, an intelligent data mining system named decision tree expert (DTE) is presented and applied to drop testing analysis. The rule induction method in DTE is based on the C4.5 algorithm. In our preliminary experiments, concise and accurate conceptual design rules were successfully generated from drop test data after incorporation of domain knowledge from human experts. The data mining approach is a flexible one that can be applied to a number of complex design and manufacturing processes to reduce costs and improve productivity