Digital processing of mechanical transient response signals—Digital filter approach

The primary aim of this paper is to bring to the attention of shock and vibration engineers the advantages of using digital filters for processing transient response signals. Specifically, the development of reliable high pass digital filters to remove the low frequency components in the acquired acceleration signals so as to obtain valid velocity and displacement-time records, is presented. It is concluded that the non-recursive filters are well suited for mechanical engineering transient response applications. The viability of the non-recursive digital filters for the intended application is established with the use of acceleration signals obtained from a laboratory shock test. Also as a part of this investigation, a set of user-friendly, computer programs for filter design and filtering are developed and implemented.     

New cation-deficient spinel oxides,Mn1−x□xV2−2xMo2xO4 (0⩽ x ⩽ 0.33)

New Mn_1?x□_xV_2?2xMo_2xO₄ (0 ? x ? 0.33) oxides have been prepared by hydrogen-reduction of the corresponding defect brannerite-type Mn_1?x□_xV_2?2xMo_2xO₆ oxide precursors. These solid solutions crystallize in a cation-deficient spinel structure. The cation distribution in these oxides has been determined by X-ray powder diffraction intensity analysis and the results indicate a cation distribution of (Mn_1?x□_x) _t[V_2?2xMo_2x]_oO₄.     

Effect of strain rate on the mode of fracture in elastoidin

The mechanical properties and fracture behaviour of dry and native elastoidin are studied as a function of strain rate, and the plastic set behaviour of the dry elastoidin is found to be sensitive to strain rate. The results are correlated with the scanning electron microscopy of the fractured ends of dry and native elastoidin. Broken ends of dry elastoidin, fractured at a strain rate of 10.0 min^–1, appear blunt and under the same conditions the native specimen's ends appear sharp.     

A vision-based approach to collision prediction at traffic intersections

Monitoring traffic intersections in real time and predicting possible collisions is an important first step towards building an early collision-warning system. We present a vision-based system addressing this problem and describe the practical adaptations necessary to achieve real-time performance. Innovative low-overhead collision-prediction algorithms (such as the one using the time-as-axis paradigm) are presented. The proposed system was able to perform successfully in real time on videos of quarter-video graphics array (VGA) (320 /spl times/ 240) resolution under various weather conditions. The errors in target position and dimension estimates in a test video sequence are quantified and several experimental results are presented.     

Mechanical properties of grafted casein films

Casein was grafted with mixtures of acrylonitrile (AN) and n-butyl methacrylate (n-BMA). The mole ratios of AN: n-BMA were 0.9:0.1 and 0.8:0.2. The mechanical properties of the grafted casein films were studied under uniaxial and biaxial stress conditions. A reduction in longitudinal stress and elongation at break was observed with the simultaneous application of lateral stress. Scanning electron micrographs of the stretched films (uniaxial and biaxial stress) are also presented.     

Genetic spider monkey‐based routing protocol to increase the lifetime of the network and energy management in WSN

Wireless sensor networks (WSNs) include large distributed nodes in the sensing field. However, the sensor nodes may die due to energy deficiency as they are situated in a hostile environment. Therefore, an energy‐efficient WSN routing protocol is necessary in order to better accommodate the various environmental conditions. In this paper, we have proposed a new Energy‐Efficient Genetic Spider Monkey‐based Routing Protocol (EGSMRP) to improve the stability and lifetime of sensor nodes. The operation of EGSMRP is classified into two stages: (i) setup phase and (ii) steady‐state phase. In the setup phase, GSMO‐based cluster head selection procedure is done. In this phase, the base station utilizes the GSMO algorithm as a device to generate energy‐efficient clusters. Followed with this, the steady‐state phase solves the load balancing issue by utilizing the intracluster data broadcast and dual‐hop intercluster broadcasting algorithm. Thereby, the proposed EGSMRP protocol has shown the energy‐based opportunistic broadcasting with reduced control overhead. Simulation is performed in various conditions to evaluate the effectiveness of the proposed EGSMRP protocol using different metrics such as throughput, control overhead, energy consumption, end‐to‐end delay, and network lifetime. From the simulation results, it was evident that EGSMRP has achieved a higher performance compared to other traditional approaches such as EBAR, MCTRP, IEEMARP, HMCEER, and EFTETRP.     

On the use of secret sharing as a secure multi-use pad

Secret sharing (SS) is a cryptographic method proposed independently by Adi Shamir and George Blakley in 1979 to encode the keys of public-key cryptography by splitting them into maximally entropic shares that are distributed to participants, only revealing the secret when combined. Each new sharing instance, even of the same key, produces a different set of shares to distribute anew. This paper investigates SS as an independent cipher to secure confidential messages between a limited set of trusted participants by eliminating the need to redistribute shares. A participant’s master share is permanently fixed and unlimited temporary shares are created and combined with it to reveal new messages. Security is argued against specific and general attacks.     

Fracture behaviour of cross-linked collagen fibres

Mechanical properties such as stress - strain, fracture behaviour and thermal behaviour were studied for cross-linked collagen fibres. The shrinkage temperature of cross-linked fibres shows increase in temperature when compared to the control. The results on measurements of breaking strength and strain show significant change when compared with that of the control. The morphological features of the fractured ends of cross-linked fibres were indicative of certain specific patterns. A critical observation of these patterns indicate the role played by the nature of cross-linking agents on the mechanism of failure of these fibres.