数据源特性对序列模式挖掘结果的影响

用IBM数据生成工具生成数据考察了客户序列数、平均序列长度、平均事务长度、项目数等数据特性对挖掘结果序列模式个数的影响,得到了单项特性对挖掘结果序列模式个数的影响模型,用以在进行正式挖掘之前,通过数据特性对挖掘结果进行初步判断。     

Effects of Visfatin on Intracellular Mechanics and Catabolism in Human Primary Chondrocytes through Glycogen Synthase Kinase 3β Inactivation

Osteoarthritis (OA) is still a recalcitrant musculoskeletal disease on account of its complex biochemistry and mechanical stimulations. Apart from stimulation by external mechanical forces, the regulation of intracellular mechanics in chondrocytes has also been linked to OA development. Recently, visfatin has received significant attention because of the clinical finding of the positive correlation between its serum/synovial level and OA progression. However, the precise mechanism involved is still unclear. This study determined the effect of visfatin on intracellular mechanics and catabolism in human primary chondrocytes isolated from patients. The intracellular stiffness of chondrocytes was analyzed by the particle-tracking microrheology method. It was shown that visfatin damages the microtubule and microfilament networks to influence intracellular mechanics to decrease the intracellular elasticity and viscosity via glycogen synthase kinase 3β (GSK3β) inactivation induced by p38 signaling. Further, microtubule network destruction in human primary chondrocytes is predominantly responsible for the catabolic effect of visfatin on the cyclooxygenase 2 upregulation. The present study shows a more comprehensive interpretation of OA development induced by visfatin through biochemical and biophysical perspectives. Finally, the role of GSK3β inactivation, and subsequent regulation of intracellular mechanics, might be considered as theranostic targets for future drug development for OA.     

Visual people counting using gender features and LRU updating scheme

Multimedia Tools and Applications - The general public spends a significant amount of time in front of digital signage seeking information from many venues such as exhibition halls and shopping...     

Generalized inverse spectral problem for pseudo-Jacobi matrices with mixed eigendata

In this paper, we investigate a generalized inverse eigenproblem for pseudo-Jacobi matrices with mixed eigendata. These matrices appear in non-Hermitian Quantum Mechanics and extend the well-known concept of Jacobi matrices. It is shown that a unique pseudo-Jacobi matrix may be recovered from certain prescribed mixed eigendata, i.e. its leading principal submatrix, two distinct real eigenvalues, and part of the corresponding eigenvectors. An algorithm is provided for the reconstruction of such a matrix, and illustrative numerical experiments are presented to test the algorithm. The recurrence relation involving leading principal minors is crucial for the problem solution.     

A new random walk model for PCS networks

This paper proposes a new approach to simplify the two-dimensional random walk models capturing the movement of mobile users in personal communications services (PCS) networks. Analytical models are proposed for the new random walks. For a PCS network with hexagonal configuration, our approach reduces the states of the two-dimensional random walk from (3n²+3n-5) to n(n+1)/2, where n is the layers of a cluster. For a mesh configuration, our approach reduces the states from (2n2-2n+1) to (n²+2n+4)/4 if n is even and to (n ²+2n+5)/4 if n is odd. Simulation experiments are conducted to validate the analytical models. The results indicate that the errors between the analytical and simulation models are within 1%. Three applications (i.e., microcell/macrocell configuration, distance-based location update, and GPRS mobility management for data routing) are used to show how our new model can be used to investigate the performance of PCS networks     

Effects of mesomorphic β nanograins on crystallization and photoexcited emission of poly(9,9-di-n-hexyl-2,7-fluorene)

Structural evolution processes of solution-cast and melt-quenched poly(9,9-di-n-hexyl- 2,7-fluorene) (PFH) were quantitatively examined using small/wide-angle X-ray scattering (SAXS/WAXS) and differential scanning calorimetry. SAXS/WAXS profiles of solution-cast PFH indicated presence of nanograins (radius of gyration R_g ≈ 5 nm) of 2D-ordered β phase. Upon heating above T_g, perfected packing order and growth of β nanograins up to R_g ≈ 10 nm result in suppressed formation of α crystallites up to 190 °C, beyond which extensive melting accompanied by significant (albeit partial) transformation of β nanograins into α nanocrystals of R_g ≈ 13 nm can be observed in a narrow temperature range of 190–200 °C. Thus transformed α crystallites remained stable in size before melting above 235 °C. The nanograin structures observed are correlated to phase-dependent optical absorption and photoexcited emission. Results suggest sensitive influences of the size/spatial distribution of β nanograins (particularly in the layering direction of the 2D-ordered chain packing) on photoexcited emission of the polyfluorene film.     

Effects of cache mechanism on wireless data access

In wireless data transmission, the capacity of wireless links is typically limited. Since many applications exhibit temporal locality for data access, the cache mechanism can be built in a wireless terminal to effectively reduce the data access time. This paper studies the cache performance of the wireless terminal by considering a business-card application. We investigate the least-recently used replacement policy and two strongly consistent data access algorithms called poll-each-read and callback. An analytic model is proposed to derive the effective hit ratio of data access, which is used to validate against simulation experiments. Our study reports how the data access rate and the data update distribution affect the cache performance in a wireless terminal.     

高温透波陶瓷材料研究进展

透波陶瓷材料已成为高超声速飞行器天线罩、天线窗等部件的关键候选材料。因此,如何有效提升透波陶瓷材料的耐温、透波、承载等特性是发展高超声速飞行器的关键技术之一。本文针对高超声速飞行器对透波陶瓷材料的技术要求,阐述了透波陶瓷材料的发展历史,着重对现有透波陶瓷材料体系及其透波特性测试方法和原理的研究历史和现状进行了全面回顾,并提出今后的发展方向。本文旨在为未来新一代高超声速飞行器的设计提供参考。     

Estimation of reliability and cost relationship for architecture-based software

In this paper, we propose a new method to estimate the relationship between software reliability and software development cost taking into account the complexity for developing the software system and the size of software intended to develop during the implementation phase of the software development life cycle. On the basis of estimated relationship, a set of empirical data has been used to validate the correctness of the proposed model by comparing the result with the other existing models. The outcome of this work shows that the method proposed here is a relatively straightforward one in formulating the relationship between reliability and cost during implementation phase.     

Critical Influence of Organic A′-Site Ligand Structure on 2D Perovskite Crystallization

Organic A′-site ligand structure plays a crucial role in the crystal growth of 2D perovskites, but the underlying mechanism has not been adequately understood. This problem is tackled by studying the influence of two isomeric A′-site ligands, linear-shaped n-butylammonium (n-BA⁺) and branched iso-butylammonium (iso-BA⁺), on 2D perovskites from precursor to device, with a combination of in situ grazing-incidence wide-angle X-ray scattering and density functional theory. It is found that branched iso-BA⁺, due to the lower aggregation enthalpies, tends to form large-size clusters in the precursor solution, which can act as pre-nucleation sites to expedite the crystallization of vertically oriented 2D perovskites. Furthermore, iso-BA⁺ is less likely to be incorporated into the MAPbI₃ lattice than n-BA⁺, suppressing the formation of unwanted multi-oriented perovskites. These findings well explain the better device performance of 2D perovskite solar cells based on iso-BA⁺ and elucidate the fundamental mechanism of ligand structural impact on 2D perovskite crystallization.