基于3D可视化GIS的前视参考图生成方法

基于匹配识别的导航系统不能缺少匹配参考图的支持,制备前视匹配参考图更是前视目标匹配识别的一个关键环节。为了利用航空航天图象信息制备出有效的前视匹配识别所需的参考图,提出了基于3D可视化GIS的前视参考图生成方法,介绍了该方法总体思路,分析了其中的三维数据制备、目标区三维场景生成和前视匹配序列参考图生成等关键环节,给出了部分制备的参考图与实时图的匹配实验结果。实验结果表明,利用这种方法制备的前视参考图可以满足前视匹配识别的需求。     

基于TMS320F2812的液晶显示模块接口设计

为适应工业应用现场以及智能化仪器仪表前端显示的需要,阐述了TMS320F2812DSP和QH2001液晶显示模块的原理及特性,提出了一种基于高速DSP处理器控制低速液晶显示模块的接口设计方案,并对该方案的硬件接口电路和软件驱动程序进行了设计,同时给出了软、硬件实现的相应电路图、程序流程图以及具体程序段;实验调试表明,设计方案结构简单、成本低、抗干扰能力强、显示性能稳定可靠,达到设计要求,能够有效解决高速DSP对低速LCD的驱动及显示问题,并取得了良好的显示效果,对其它便携式系统显示终端的设计也具有一定参考价值。     

Herfindahl index applied to Fourier analysis

Since the harmonic components in the signal to be analyzed are uncertain and diverse, it is difficult to make the sampling frequency and the signal length be harmonically related to the component frequencies included in the signal, and the leakage is produced in the discrete Fourier transform. Based on the definition of the Herfindahl index in economics, the spectrum concentration can be defined and computed. The appropriate number of points can be decided according to the peak location of the spectrum concentration. The method and the examples are specified in detail in the paper.     

Delay‐dependent stability and stabilization of neutral time‐delay systems

This paper is concerned with the problem of stability and stabilization of neutral time‐delay systems. A new delay‐dependent stability condition is derived in terms of linear matrix inequality by constructing a new Lyapunov functional and using some integral inequalities without introducing any free‐weighting matrices. On the basis of the obtained stability condition, a stabilizing method is also proposed. Using an iterative algorithm, the state feedback controller can be obtained. Numerical examples illustrate that the proposed methods are effective and lead to less conservative results. Copyright © 2008 John Wiley & Sons, Ltd.     

Using QuickBird imagery and a production efficiency model to improve crop yield estimation in the semi-arid hilly Loess Plateau,China

Crop yield is a key element in rural development and an indicator of national food security. A method that could estimate crop yield over large hilly areas would be highly desirable. Methods including high spatial resolution satellite imagery have the potential to achieve this objective. This paper describes a method of integrating QuickBird imagery with a production efficiency model (PEM) to estimate crop yield in Zhonglianchuan, a hilly area on Loess Plateau, China. In the PEM model, crop yield is a function of the photosynthetic active radiation (PAR), fraction of absorbed photosynthetically active radiation (f_APAR) and light-use efficiency (LUE). Based on the high spatial resolution QuickBird imagery, a land cover classification is used to attribute a class-specific LUE. The f_APAR is related to spectral vegetation indices (SVI), which can be derived from the satellite images. The LUE, f_APAR and incident PAR data were combined to estimate the crop yield. Farmer-reported crop yield data in 80 representative plots were used to validate the model output. The results indicated QuickBird imagery can improve the accuracy of predicted results relative to the Landsat TM image. The predicted yield approximated well with the data reported by the farmers (r² = 0.86; n = 80). The spatial distributions of crop yield derived here also offers valuable information to manage agricultural production and understand ecosystem functioning.     

A New Discriminant Principal Component Analysis Method with Partial Supervision

Principal component analysis (PCA) is one of the most widely used unsupervised dimensionality reduction methods in pattern recognition. It preserves the global covariance structure of data when labels of data are not available. However, in many practical applications, besides the large amount of unlabeled data, it is also possible to obtain partial supervision such as a few labeled data and pairwise constraints, which contain much more valuable information for discrimination than unlabeled data. Unfortunately, PCA cannot utilize that useful discriminant information effectively. On the other hand, traditional supervised dimensionality reduction methods such as linear discriminant analysis perform on only labeled data. When labeled data are insufficient, their performances will deteriorate. In this paper, we propose a novel discriminant PCA (DPCA) model to boost the discriminant power of PCA when both unlabeled and labeled data as well as pairwise constraints are available. The derived DPCA algorithm is efficient and has a closed form solution. Experimental results on several UCI and face data sets show that DPCA is superior to several established dimensionality reduction methods.     

CoBTx-Net: A model for business collaboration reliability verification

Collaborative business process can become unreliable when business partners collaborate in a peer- based fashion without central control. Therefore, reliability checking becomes an important issue that needs to be dealt with for any generic solution in managing business collaboration. In this paper, we propose a novel Choreographical Business Transaction Net (CoBTx-Net) to model collaborative business process and to manage the collaboration by individual participants. Furthermore three reliability properties named Time-embedded dead marking freeness, Inter-organizational dead marking freeness, and Collaborative soundness are defined based on CoBTx-Net to verify (1) the violation of time constraint, (2) collaborative logic conflicts, and (3) the improper termination from individual organizations.

An Efficient Authentication Scheme for Access Control in Mobile Pay-TV Systems

In a mobile pay-TV system, a large number of messages are exchanged for mutual authentication purposes. In traditional authentication schemes, with one-to-one delivery, one authentication message per request is delivered from a head end system to subscribers. This results in the delivery of a large quantity of messages and therefore is inefficient and costly. Moreover, since most traditional schemes use an RSA-based signature for identity validation and nonrepudiation of communication, they suffer from high communication costs. Due to its wireless nature, mobile pay-TV is vulnerable to attacks during hand-off. As traditional schemes do not support hand-off authentication, they are insecure during hand-off. With these shortcomings, they are not suitable for mobile pay-TV. In this paper, we propose an innovative authentication scheme, in which, by providing one-to-many facility, only one authentication message for multiple requests is broadcasted from the head end system to subscribers. By employing bilinear property of pairing and elliptic curve cryptography, our scheme provides one-to-many facility in the case of multiple requests for the same service in a short period of time. This new scheme achieves better broadcast efficiency and performance on communication costs than traditional ones. Additionally, this scheme provides a hand-off authentication mechanism to protect the access of services while preventing attacks during hand-off; therefore, the scheme is more secure to support access control. Moreover, to provide anonymous authentication for protecting identity privacy, the scheme adopts an identity-based scheme while traditional schemes do not apply. The scheme inherits advantages of the identity-based scheme that a public key does not need to be certificated, the certification authority mechanism will not be needed and the key exchange overhead can be reduced. With these advantages of our scheme, it is well suited for mobile pay-TV system.     

Granular Rough Theory: A representation semantics oriented theory of roughness

The present work is an archival paper for a series of contributions proposed in last few years on building a theory of roughness over pure mereological relations among information granules. There are five major efforts taken in the present paper: (1) emphasizing on the representational semantics of theory of roughness: to approximately represent a class of entities characterized by some aspects in terms of entity collections described at other aspects; (2) defining a representation model Granular Representation Calculus (GrRC) to synthesize complex information systems from information granules; (3) establishing notion of Granular Rough Theory (GrRT) over information granules operated in terms of GrRC; (4) extending GrRC/GrRT to various computational environments such as multi-agent systems and ontological computing environments; (5) exploring pragmatic aspects of GrRC/GrRT in implementing prototypes with data model and object programming orientations, and proposing an Ontology-Driven Web Information System as a granular-rough computational Web intelligence framework over GrRC/GrRT.     

Impulsive controller design for singular networked control systems with packet dropouts

This paper considers the problem of impulsive time-delay control for singular networked impulsive control systems(SNICSs) and uncertain SNICSs both with network-induced delay and packet dropouts. The parameter uncertainty is assumed to be norm bounded. The problem to be addressed is the design of robust impulsive time-delay feedback controllers such that the exponential stability of the resulting closed-loop system is guaranteed for admissible uncertainties. By applying Lyapunov function theory and Halanay Lemma, impulsive time-delay controller is derived through solving LMIs. Numerical examples are provided to demonstrate the application of the proposed method.