Public key encryption with filtered equality test revisited

Designs, Codes and Cryptography - Without revealing data in the plain, public key encryption with equality test can achieve the basic cryptographic functionalities required. However, the extended...     

Stress-concentration factors for semielliptical notches in beams under pure bending

Elliptical notches in rectangular beams under pure bending are examined photoelastically. Stress-concentration factors due to a single elliptical notch are obtained for wide ranges of 2a/h andd/h, where 2a, d, andh are the width of notch, depth of notch, and depth of beam, respectively. In particular, the geometries of the optimum elliptical notches producing the least stress concentrations are obtained. Almost the whole elliptical boundary of these notches are stressed to the same peak, which indicates that these notches will probably produce the least stress concentrations among all notches, elliptical or nonelliptical. The graphs herein will enable the designers to find the stress-concentration factors of elliptical notches and to pick out the geometry of the optimum notch which will give the least stress concentration for any given values of 2a/h andd/h. Stresses and the stress-concentration factors at the bottom of the beam opposite the notch are also obtained. These stresses, though smaller in magnitude, are of an opposite sign to the peak stress at the notch. For brittle materials, a smaller tensile stress may be more critical than a large compressive stress; therefore, these stress-concentration factors are also given.     

Enhanced mechanical performance and biological evaluation of a PLGA coated β-TCP composite scaffold for load-bearing applications

Porous β-tricalcium phosphate (β-TCP) has been used for bone repair and replacement in clinics due to its excellent biocompatibility, osteoconductivity, and biodegradability. However, the application of β-TCP has been limited by its brittleness. Here, we demonstrated that an interconnected porous β-TCP scaffold infiltrated with a thin layer of poly(lactic-co-glycolic acid) (PLGA) polymer showed improved mechanical performance compared to an uncoated β-TCP scaffold while retaining its excellent interconnectivity and biocompatibility. The infiltration of PLGA significantly increased the compressive strength of β-TCP scaffolds from 2.90 to 4.19 MPa, bending strength from 1.46 to 2.41 MPa, and toughness from 0.17 to 1.44 MPa, while retaining an interconnected porous structure with a porosity of 80.65%. These remarkable improvements in the mechanical properties of PLGA-coated β-TCP scaffolds are due to the combination of the systematic coating of struts, interpenetrating structural characteristics, and crack bridging. The in vitro biological evaluation demonstrated that rat bone marrow stromal cells (rBMSCs) adhered well, proliferated, and expressed alkaline phosphatase (ALP) activity on both the PLGA-coated β-TCP and the β-TCP. These results suggest a new strategy for fabricating interconnected macroporous scaffolds with significantly enhanced mechanical strength for potential load-bearing bone tissue regeneration.     

Managing a retail-competition distribution channel with incentive policies

In reality, the multi-retailer channel of distribution has occurred in many industries, such as electronics, appliances, and apparel. The practice of the supplier providing incentives to retailers to promote sales is also quite prevalent in today’s business. This paper considers a two-retailer supply chain in which the supplier provides a cash discount to a specific retailer (a senior company owning more market share and having less pressure on the utilization of capital investment) and a credit period to another (a junior company owning less market share and having more pressure on the utilization of capital investment). The end demand for each channel has a substitute effect in terms of retail prices. The research problem originates from operations of dual-retailer channels in the automotive parts and accessories industry. The objective of the supplier is to determine the cash discount and credit period to maximize his profit. Both retailers determine pricing and ordering policies to maximize profits. This paper applies a Supplier Stackelberg framework to obtain equilibrium solutions for every entity. Numerical analysis is conducted to discuss the influence retailer competition has on the decision behaviors of the supplier and retailers.     

SYNTHESIS OF MELEZITOSE DERIVATIVES

The reactivity of melezitose hydroxyls is studied during tritylation in pyridine. Some novel derivatives of melezitose are prepared. An acetyl is transferred from the 4- to the 6-position after detritylation of 3 and 4. The structures of the products are proved by elemental analysis; ¹ H, ¹³ C, and ¹ H- ¹ H COSY NMR spectra;IR spectra; and fast-atom bombardment mass spectrometry.     

A novel 1 × 2 optical power splitter with PBG structures on SOI substrate

A novel 1 × 2 optical power splitter in size of 8.0 μm × 4.2 μm is presented in this paper, by using photonic bandgap (PBG) structures on silicon-on-insulator (SOI) substrate. The splitting ratio can be adjusted by changing the air hole position to get wide tuning range. The design is examined by the commercial finite-difference-time-domain (FDTD) software for various splitting ratios. Some approximated formulas are obtained through curve-fitting to facilitate design process.     

Mass spectrometric studies of heterocyclic organophosphorus compounds: 1,3,2-benzodioxaphospholes

The mass spectral behaviour of a new type of organophosphorus compound, 1,3,2-benzodioxaphospholes, under 70 eV electron impact has been studied by means of high and low resolution mass spectrometry as well as by B/E and B²/E linked scans. The influence of different substituents in the molecule (O, S or N) on the mass spectra is investigated. The reason for isomerization between oxygen and sulphur within a molecule studied by mass spectrometry is discussed.     

Translation drag coefficient of a self-similar assembly of spheres immersed in an incompressible fluid.

On the basis of deterministic fractals and the Rotne-Prager hydrodynamic interaction tensor, we confirm the asymptotic as well as the finite size scaling of the friction coefficient lambda of a self-similar structure. The fractal assembly is made of N spheres with its dimension varying from D < 1 to D = 3. The number of spheres can be as high as N approximately O(10(4)). The asymptotic scaling behavior of the friction coefficient per sphere is lambda approximately N(1/D-1) for D > 1, lambda approximately (lnN)(-1) for D = 1, and lambda approximately N(0) for D < 1. The crossover behavior indicates that while in the regime of D > 1 the hydrodynamic screening effect grows with the size, for D<1 it is limited in a finite range, which decays with decreasing D.