Older adults’ use of smart phones: an investigation of the factors influencing the acceptance of new functions

After adopting mobile phones, most older adults use them only for calling and SMS. The purpose of this study is to extend their usage of mobile phones to new functions. To understand older adults’ requirements of mobile phones, a questionnaire was constructed and 351 Chinese older adults were recruited to complete the questionnaires. Data collected through the questionnaires were analysed using explorative factor analysis. The results revealed that older adults’ requirements were composed of 10 factors: Find a Specific Function, Awareness and Attractiveness, Readability, Personal Concern, Soft Keys and Multi-tap, Hardware Capacity, Touch Screen, Concern of Learning, Connectivity, and Social Influence. Then, from the above 10 factors, the 6 most important factors were revealed using multiple linear regression analysis. The results imply that accepting new functions is different from accepting a product. Readability and Find a Specific Function, which are critical for older adults’ acceptance of feature phones, are not determinants of their acceptance of new functions in smart phones.     

Thermoplastic extrusion—the mechanism of the formation of extrudate structure and properties

Systems processed by thermoplastic extrusion can be regarded as heterophase polymer melts of incompatible water-plasticized biopolymers. In the process of thermoplastic extrusion, proteins and polysaccharides are melted at high pressure and temperature below the temperature region of their thermal decomposition. Dispersed particles of these systems can be deformed in flow. The mixed-melt anisotropic structure, formed in flow, is fixed by rapid conversion of the melt jet that lets the extruder die from a viscous state to a rubber-like state and then to a glassy state caused by cooling and drying. Incompatibility of proteins and polysaccharides in their water-plasticized melt mixtures impacts on structure formation and texturization during thermoplastic extrusion. Presented at the 20th ISF World Congress and 83rd AOCS Annual Meeting and Expo, May 10–14, 1992, Toronto, Ontario, Canada.     

A sum of squares approach to backstepping controller synthesis for piecewise affine and polynomial systems

This paper develops a backstepping controller synthesis methodology for piecewise polynomial (PWP) systems in strict form. The main contribution of the paper is to formulate sufficient conditions for controller design for PWP systems in strict form as a sum of squares feasibility problem under the assumption that an initial control Lyapunov function exists to start the iterative backstepping procedure. This problem can then be translated into a convex SDP problem and solved by available software packages. The controller synthesis problem for PWP systems in strict feedback form is divided into two cases. The first case consists of the construction of a sum of squares polynomial control Lyapunov function for PWP systems with discontinuous vector fields. The second case addresses the construction of a PWP control Lyapunov function for PWP systems with continuous vector fields. One major advantage of the proposed method is the fact that it can handle systems with discontinuous vector fields and sliding modes. The new synthesis method is applied to several numerical examples. One of these examples offers the first convex optimization solution to piecewise affine (PWA) control of a benchmark circuit system addressed before in the literature using non‐convex PWA control solutions. Copyright © 2013 John Wiley & Sons, Ltd.     

高维力学系统的能量方程

在低维系统中,能量方程因其明晰的物理意义而得到广泛的应用,而研究高维力学系统的能量方程也同样具有理论价值和实际意义,如位移对时间的导数是速度,速度对时间的导数是加速度,这些具有明显的物理意义,而加速度的导数其物理意义就不是很清晰了,但具有理论上的意义.本文应用广义经典力学中关于广义拉格朗日函数、广义动量和广义哈密顿函数等概念,推导了高维系统的能量方程,文中举了实例具体说明新方程的应用,为力学数学系统能量方程的推广提供了一种途经.     

Construction of highly nonlinear resilient Boolean functions satisfying strict avalanche criterion

Boolean functions with high nonlinearity, high resiliency and strict avalanche criterion （SAC） play an important role in the designs of conventional cryptographic systems. In this paper, a method is proposed to construct resilient Boolean functions on n variables （n even） satisfying SAC with nonlinearity 〉 2n-1 -2n/2. A large class of cryptographic Boolean functions that were not known earlier were obtained.     

离心铸造大口径球铁管用复合功能型脱硫剂的研制

为使硫量波动的高炉铁液能适应大型离心铸造球铁铸管生产,研制了一种成本较低廉、添加操作简单的复合功能型脱硫剂。其主要组分包括强脱[S]去[O]材料钝化镁粒、碳化钙,增加石墨核心元素Zn和膨胀集渣材料珍珠岩,以及能抑制反球化作用和净化铁液的材料等。采用冲入法进行球化处理,这种脱硫剂覆盖在球化剂和孕育剂上,使用方法简单,效果良好。     

Computer-aided thermodynamic study of solid Co---Pd alloys by Knudsen cell mass spectrometry, and calculation of the phase diagram

F.c.c. solid Co---Pd alloys have been investigated thermodynamically by means of computer-aided Knudsen cell mass spectrometry. Thermodynamic evaluation has been performed by applying the “digital intensity ratio” method. The thermodynamic excess properties can be described algebraically by means of thermodynamically adapted power series with two adjustable parameters, i.e. C₁^G (−20 810 + 9.608T) J mol⁻¹) and C₂^G (−30 720 + 6.78T) J mol⁻¹). At 1470 K, f.c.c. solid Co---Pd alloys are characterized by negative molar excess Gibbs energies G^E, exothermic molar heats of mixing (H^E) and small negative molar excess entropies S^E. At 1470 K, the minimum G^E value is −4600 J mol⁻¹ (61.9 at.% Pd), the minimum H^E value is −9400 J mol⁻¹ (59.5 at.% Pd) and the minimum S^E value is −3.3 J mol⁻¹ K⁻¹ (55.9 at.% Pd). The thermodynamic activities of Co show small positive deviations from the ideal case for the Co-rich alloys (x_Pd < 0.34), and negative deviations from Raoults' law for alloys with higher Pd contents. The Pd activities a_Pd show negative deviations from the ideal case for all compositions. The phase diagram has been computed by means of a generally applicable procedure for the calculation of the equilibrium compositions of coexisting phases. This was achieved using the results of this work, thermodynamic data from earlier mass spectrometric studies on the liquid phase, and literature data for the heat capacities and enthalpies of Co and Pd.     

A pseudo-spectral scheme for the approximate solution of a time-fractional diffusion equation

We consider an initial-boundary-value problem for a time-fractional diffusion equation with initial condition u₀(x) and homogeneous Dirichlet boundary conditions in a bounded interval [0, L]. We study a semidiscrete approximation scheme based on the pseudo-spectral method on Chebyshev–Gauss–Lobatto nodes. In order to preserve the high accuracy of the spectral approximation we use an approach based on the evaluation of the Mittag-Leffler function on matrix arguments for the integration along the time variable. Some examples are presented and numerical experiments illustrate the effectiveness of the proposed approach.     

CAS wavelet method for solving the fractional integro-differential equation with a weakly singular kernel

In this paper, a computational method for numerical solution of a class of integro-differential equations with a weakly singular kernel of fractional order which is based on Cos and Sin (CAS) wavelets and block pulse functions is introduced. Approximation of the arbitrary order weakly singular integral is also obtained. The fractional integro-differential equations with weakly singular kernel are transformed into a system of algebraic equations by using the operational matrix of fractional integration of CAS wavelets. The error analysis of CAS wavelets is given. Finally, the results of some numerical examples support the validity and applicability of the approach.     

飞腾平台中硬件数据压缩的驱动设计与实现

数据压缩是有效处理大数据的关键技术,在飞腾处理器平台上基于zlib库的数据压缩通常采用软件的方式实现,在数据处理量大而且实时性要求较高的情况下,已经难以满足需求。针对这个问题,通过研究zlib编程函数库,结合飞腾处理器的特性,完成了飞腾平台中硬件数据压缩的驱动设计与实现,其中提出了双向DMA传输技术和基于一致性内存的命令环机制,从而进一步提高了基于硬件的数据压缩的效率。通过实验证实了飞腾平台中采用硬件数据压缩改进的有效性。