IP restoration vs. optical protection: Which one has the least bandwidth requirements?

Survivability in IP-over-WDM networks has already been extensively discussed in a series of studies. While many studies assume an IP restoration scheme and focus on network connectivity in order to ensure proper recovery, few studies deal with optical protection. We investigate this question with the objective of estimating the respective bandwidth requirements of both recovery schemes, subject to single or multiple failures. We also design a mixed recovery scenario where the recovery is taken care at a different layer depending on the type of failures.Results shows that optical protection is by far the most economical recovery scheme in terms of bandwidth requirements.     

Determination of the Metastable Zone Width by a Simple Optical Probe

The metastable zone width (MSZW) defines an operating boundary for a crystallization process; thus, it is important to determine the MSZW for a given crystallization process. The application of a simple optical probe consisting of a line laser source, a light‐dependent resistor, and a simple processing circuit in the determination of the MSZW of an anti‐solvent crystallization process is presented. The optical probe detects the point of nucleation as a sharp change in output voltage upon the onset of nucleation. The isothermal crystallization of glycine from a glycine/water solution using ethanol as anti‐solvent was used here to assess the performance of the proposed measurement system. The effects of various operating parameters on the MSZW of glycine were also investigated. The kinetic parameters of nucleation were estimated from the data obtained.     

High-energy radiation-resistant vulcanizates. II. EPDM

In this article, Part II of the series, we report a detail study on stabilization of EPDM vulcanizates in γ-radiation environment. The special additives (antirads), namely pyrene (Py), brominated acenaphthene (BrAc), poly(acenaphthene sulfide) (PAcSu) and poly(pyrene sulfide) (PPySu) were used for the stabilization studies. The efficiency of these antirads for EPDM had been monitored by the means of electrical resistivity, wide-angle X-ray diffraction, and mechanical properties. The stabilization of EPDM to withstand 200 Mrads of γ radiation in air environment is achieved. © 1994 John Wiley & Sons, Inc.     

Ecological compensation: an evaluation of regulatory compliance in New Zealand

Ecological compensation is an example of a trade-off whereby loss of natural values is remedied or offset by a corresponding compensatory action on the same site or elsewhere, determined through the process of Environmental Impact Assessment (EIA). Ecological compensation actions are often criticised for having low levels of compliance: meaning that they are achieved only partially or not at all, while development activity proceeds with much greater certainty. Our research investigated compliance with 245 conditions relating to ecological compensation across 81 case studies across New Zealand under the Resource Management Act 1991. Our results show that present tools and practice in New Zealand are not adequately securing the necessary benefits from ecological compensation requirements, with 35.2% of requirements not being achieved. Significant variation in non-compliance with ecological compensation occurs between different activities, applicant types and condition types, while critical variables within the planning process influence levels of compliance. Our research demonstrates the importance of understanding the nature of non-compliance and of providing a consistent and robust decision-making framework for the consideration of ecological compensation in practice.     

Reflexive transitive invariant relations: A basis for computing loop functions

Invariant assertions play an important role in the analysis and verification of iterative programs. In this paper, we introduce a related but distinct concept, namely that of invariant relation. While invariant assertions are useful to prove the correctness of a loop with respect to a specification (represented by a precondition/ postcondition pair) in Hoare’s logic, invariant relations are useful to derive the function of the loop in Mills’ logic.     

Processing of PLA/sisal fiber biocomposites using direct- and extrusion-injection molding

The processing strategy adopted to develop biocomposites plays a significant role in determining their characteristics. The present experimental investigation explores the feasibility of using direct-injection molding (D-IM) process for processing of sisal fiber (3?mm and 8?mm) reinforced poly-lactic acid biocomposites with a fiber weight fraction of 30%. For a comparative analysis, mechanical and morphological behavior of biocomposites developed using D-IM process is compared with biocomposites developed using extrusion-injection molding (E-IM) process. The mechanical behavior in terms of tensile, flexural and impact properties is compared and discussed in relation to extracted fiber morphology and fiber orientation as well as dispersion within the developed biocomposites. Morphological investigation of extracted fibers revealed severe fiber attrition and fiber length variation during E-IM process as compared with D-IM process. However, short sisal fiber (3?mm) reinforced biocomposites developed using both the processes exhibit uniform fiber dispersion and orientation, resulting in comparable mechanical properties. The tensile and flexural strength of D-IM-SF biocomposites increased remarkably by 34.7% and 15.9%, respectively, as compared with D-IM-LF biocomposites. Similarly, the tensile and flexural modulus of D-IM-SF biocomposites increased significantly by 92.5% and 56.7%, respectively, as compared with D-IM-LF biocomposites. However, D-IM process incorporating long fibers exhibit better impact properties.     

A robust authentication scheme for telecare medical information systems

Multimedia Tools and Applications - With the speedy progress in technology, the Internet has become a non-separable part of human life. It is obvious to use the Internet in all fields and medical...