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Security is an essential service for wired and wireless network communications. The success of mobile ad hoc networks (MANET) strongly depends on people’s confidence in its security. However, the characteristics of MANET pose both challenges and opportunities in achieving security goals, such as confidentiality, authentication, integrity, availability,(More)
By itself, the absolute distance of an object cannot be accurately judged beyond 2-3 m (refs 1-3). Yet, when it is viewed with reference to a flat terrain, humans accurately judge the absolute distance of the object up to 20 m, an ability that is important for various actions. Here we provide evidence that this is accomplished by integrating local patches(More)
egacy information systems are typically the backbone of an organization’s information flow and the main vehicle for consolidating business information. They are thus mission critical, and their failure can have a serious impact on business.1 In fact, a LIS can be defined as “any information system that significantly resists modification and evolution.”2(More)
Image phase from gradient echo MRI provides a unique contrast that reflects brain tissue composition variations, such as iron and myelin distribution. Phase imaging is emerging as a powerful tool for the investigation of functional brain anatomy and disease diagnosis. However, the quantitative value of phase is compromised by its nonlocal and orientation(More)
The multilayered myelin sheath wrapping around nerve axons is essential for proper functioning of the central nervous system. Abnormal myelination leads to a wide range of neurological diseases and developmental disorders. Non-invasive imaging of myelin content is of great clinical importance. The present work demonstrated that loss of myelin in the central(More)
As indicated by several recent studies, magnetic susceptibility of the brain is influenced mainly by myelin in the white matter and by iron deposits in the deep nuclei. Myelination and iron deposition in the brain evolve both spatially and temporally. This evolution reflects an important characteristic of normal brain development and ageing. In this study,(More)
In mobile ad hoc networks, due to unreliable wireless media, host mobility and lack of infrastructure, providing secure communications is a big challenge in this unique network environment. Usually cryptography techniques are used for secure communications in wired and wireless networks. The asymmetric cryptography is widely used because of its(More)
Frequency shift of gradient-echo MRI provides valuable information for assessing brain tissues. Recent studies suggest that the frequency and susceptibility contrast depend on white matter fiber orientation. However, the molecular underpinning of the orientation dependence is unclear. In this study, we investigated the orientation dependence of(More)
The derivation of susceptibility from image phase is hampered by the ill-conditioned filter inversion in certain k-space regions. In this article, compressed sensing is used to compensate for the k-space regions where direct filter inversion is unstable. A significantly lower level of streaking artifacts is produced in the resulting susceptibility maps for(More)
BACKGROUND In the spring of 2008, an EV71-caused hand, foot, and mouth disease (HFMD) outbreak occurred in Fuyang city, Anhui Province, China. Jiangsu Province that borders Auhui to the east is presumed as a key station for the spread of EV71 to other regions of the Yangtze River Delta. OBJECTIVES To investigate the HFMD prevalence in Zhenjiang city of(More)