时域光学拓扑成像方法的模拟和实验研究

针对现有的以修正的朗伯-比尔定律(modified Lambert-Beer law,MLBL)为理论模型的光学拓扑方法存在量化度不准确的问题,提出了一种基于最小二乘拟合算法的时域光学拓扑成像方法.该方法利用时域扩散方程在半无限空间条件下的解析解和测量曲线实现最佳匹配以计算相邻的源点与探测点之间的待测组织吸收系数变化值.对该时域光学拓扑成像方法进行了一系列的模拟验证,并以基于时间相关单光子计数(time-correlated single photon counting,TCSPC)技术的多通道时间分辨测量系统为平台进行了实验验证.结果表明:所提出的最小二乘拟合算法总体上优于传统的基于经验值光程的MLBL方法.     

一种基于光子计数技术的时间分辨荧光免疫分析系统设计

以稀土荧光配合物作为标记物的时间分辨荧光免疫测定法在医学与生命科学的实践与研究中正发挥着越来越重要的作用.为此,设计了一种结构简单、成本低廉的基于FPGA的时间分辨光子计数器系统,改进了原有的Prony算法从而实现了对双组分五参数荧光信号的处理,并使用异氰酸苄基二乙烯三胺四乙酸络合铕(DTTA-Eu3+)和模拟的双组分荧光信号对系统和算法进行了实验验证.实验结果表明,系统对于DTTA-Eu3+的检测具有较高的准确度与线性度,相关系数r=0.996 2.对于双组分荧光信号,当两个荧光信号的差值在10倍以上时,使用改进后的Prony算法进行处理具有较高准确度,误差低于5%.     

A novel GEL-OHA/HAp bone substitute

Self-crosslinked gelatin-oxidized hyaluronic acid/ hydroxyapatite (GEL-OHA/HAp) composite bone substitute was successfully prepared with a novel in situ precipitation method without using any toxic chemical cross-linkers, and its characterizations, including elemental composition, surface morphology, crystallinity, and structure of crystalline phase, were carried out. In order to evaluate its corresponding performances, comparisons with glutaraldehyde crosslinked gelatin/hydroxyapatite (GEL-Glu/ HAp) composite were made in detail. The results indicate that nano-HAp crystallites are homogeneously dispersed in both GEL-OHA/HAp and GEL-Glu/HAp composites, and the HAp crystallites in the former take larger particle size than those in the latter. Mechanical property tests show the acceptable mechanical strength at high strain of GEL-OHA/HAp composite. Study of in vitro degradation and swelling demonstrate that the two composites have similar degradation rate and water absorption capability. By in vitro cell culture, it has been found out that the cells on the GEL-OHA/HAp composite show higher proliferative potential than the cells on the GEL-Glu/HAp composite. Compared with GEL-Glu/HAp composite, GEL-OHA/HAp composite provides an excellent strategy for preparation of non-toxic bone substitute with acceptable corresponding properties.     

Generalized inverse eigenvalue problem for (<Emphasis Type="Italic">P</Emphasis>,<Emphasis Type="Italic">Q</Emphasis>)-conjugate matrices and the associated approximation problem

In this paper, the generalized inverse eigenvalue problem for the (P,Q)-conjugate matrices and the associated approximation problem are discussed by using generalized singular value decomposition (GSVD). Moreover, the least residual problem of the above generalized inverse eigenvalue problem is studied by using the canonical correlation decomposition (CCD). The solutions to these problems are derived. Some numerical examples are given to illustrate the main results.     

A star-style trust model with the ability of data recovery for trusted computing platform

Varieties of trusted computing products usually follow the mechanism of liner-style chain of trust according to the specifications of TCG. The distinct advantage is that the compatibility with the existing computing platform is preferable, while the shortcomings are obvious simultaneously. A new star-style trust model with the ability of data recovery is proposed in this paper. The model can enhance the hardware-based root of trust in platform measurement, reduce the loss of trust during transfer process, extend the border of trust flexibly, and have the ability of data backup and recovery. The security and reliability of system is much more improved. It is proved that the star-style trust model is much better than the liner-style trust model in trust transfer and boundary extending etc. using formal methods in this paper. We illuminate the design and implementation of a kind of trusted PDA acting on star-style trust model.     

Attribute level lineage in uncertain data with dependencies

In uncertain data management, lineages are often used for probability computation of result tuples. However, most of existing works focus on tuple level lineage, which results in imprecise data derivation. Besides, correlations among attributes cannot be captured. In this paper, for base tuples with multiple uncertain attributes, we define attribute level annotation to annotate each attribute. Utilizing these annotations to generate lineages of result tuples can realize more precise derivation. Simultaneously, they can be used for dependency graph construction. Utilizing dependency graph, we can represent not only constraints on schemas but also correlations among attributes. Combining the dependency graph and attribute level lineage, we can correctly compute probabilities of result tuples and precisely derivate data. In experiments, comparing lineage on tuple level and attribute level, it shows that our method has advantages on derivation precision and storage cost.     

An anonymous authentication scheme withstanding the conspiracy attack

A novel anonymous authentication scheme is proposed based on the ring signature. In the scheme, the private key and the the freely chosen anonymity set are used to achieve anonymous authentication. In terms of the threshold sharing, a group of t members jointly implement threshold tracking. In order to improve the security of tracking, message recovery equation is used to verify and recover data leaked by the user. Compared with Liu et al’s scheme, the proposed scheme can resist conspiracy tracking and has less computational cost. On the premise of the discrete-logarithm-based assumption put forth by Lysyanskaya, Rivest, Sahai, and Wolf (LRSW) and Diffie-Hellman (DDH) assumption, the scheme is proved to meet the demands of anonymous authentication. The scheme has broad application prospects in many fields such as ad hoc network, electronic voting, and so on.     

A model-based calibration method of automotive electronic control unit

This paper presents a systematic method of designing the calibration toolbox of automotive electronic control unit (ECU) based on real-time workshop (RTW). To break the strong coupling of each functional layer, the hierarchical architecture of the calibration system is divided into the bottom driver layer, the intermediate interface layer and the top application layer. The driver functions meeting the specification of the automotive open system are sent and received in the intermediate interface layer. To reduce the development costs, the portable user codes are generated by RTW which provides a development environment from system simulation to hardware implementation. Specifically, the calibration codes yielded from the controller area network (CAN) calibration protocol (CCP) module are integrated into the control codes, called by a compiler in the daemons to build a corresponding project, and then downloaded into the object board to provide the A2L file. The experiments illustrate that the different drive modules are only needed to be replaced for the implementation of the calibration system applied in different hardware platforms.     

Generalized interior shock layer solution of nonlinear singularly perturbed elliptic equation for higher order

A class of singular perturbation boundary problem of elliptic equation for higher order is studied. Firstly, under suitable conditions, the generalized outer solution to reduced problems is considered. Then the generalized interior shock asymptotic solution to original problem is constructed by using the theory of generalized functions. Finally, using the fixed point theorem of functional analytic, the uniformly validity of the generalized asymptotic solution with interior shock and boundary layers is proved.     

Research and design of reconfigurable composite field multiplication in symmetric cipher algorithms

The composite field multiplication is an important and complex module in symmetric cipher algorithms, and its realization performance directly restricts the processing speed of symmetric cipher algorithms. Based on the characteristics of composite field multiplication in symmetric cipher algorithms and the realization principle of its reconfigurable architectures, this paper describes the reconfigurable composite field multiplication over GF((2~8)~k)(k=1,2,3,4) in RISC(reduced instruction set computer) processor and VLIW(very long instruction word) processor architecture, respectively. Through configuration, the architectures can realize the composite field multiplication over GF(2~8), GF((2~8)~2), GF((2~8)~3) and GF((2~8)~4) flexibly and efficiently. We simulated the function of circuits and synthesized the reconfigurable design based on the 0.18 μm CMOS(complementary metal oxide semiconductor) standard cell library and the comparison with other same kind designs. The result shows that the reconfigurable design proposed in the paper can provide higher efficiency under the premise of flexibility.