R&D manpower forecasting for chemical industries in India

The results of a study conducted in India to determine the R&D manpower requirements toward the end of the century in for the country's chemical industries are presented. For 1981-1987 data, projections are made for short-term and long-term manpower requirements. To account for environmental changes, variable parameter regression is used for ten years and exponential smoothing is used for subsequent years. The explanatory variables for the manpower requirements are established and are partitioned into time-dependent and time-independent variables     

Evaluation and selection of hedging policies using stochastic reservoir simulation

A hedging policy is characterized by three parameters, namely, starting water availability (SWA), ending water availability (EWA) and hedging factor (HF). The effects of these three parameters on the reservoir performance indicators have been evaluated and discussed for a southwest monsoon-dependent within-year reservoir system in southern India. For the performance evaluation, synthetically generated periodic inflow sequences from a periodic autoregressive model have been used. Quite a number of the 1800 hedging policies considered for the reservoir system, yield a better overall performance compared to the standard operating policy (SOP). Reliability, Resilience and vulnerability are found to increase with SWA for a specified EWA. On the other hand, all these performance indicators are found to decrease with EWA for a specified SWA. Hence, it is desirable to start the hedging at reasonably high SWA. All performance indicators remain practically constant at higher ranges of EWA for a given SWA. If hedging is started when there is enough water in storage, reliability, resilience and average deficit increase with degree of hedging, whereas vulnerability decreases significantly up to a hedging factor of 0.3. An interactive computer program has been developed for the selection of compromising hedging policies, and its usefulness has been discussed.     

Defect studies of ZnSe nanowires

During the synthesis of ZnSe nanowires various point and extended defects can form, leading to observed stacking faults and twinning defects, and strong defect related emission in photoluminescence spectra. In this paper, we report on the development of a simple thermodynamic model for estimating the defect concentration in ZnSe nanowires grown under varying Se vapour pressure and for explaining the results of our experimental findings. Positron annihilation spectroscopy was used successfully for the first time for nanowires and the results support predictions from the defect model as well as agreeing well with our structural and optical characterization results. Under very high Se vapour pressure, Se nodules were observed to form on the sidewalls of the nanowire, indicating that beyond a limit, excess Se will begin to precipitate out of the liquid alloy droplet in the vapour-liquid-solid growth of nanowires.     

Unobtrusive long-range detection of passive RFID tag motion

This paper presents a novel method for detecting the motion of passive radio-frequency-identification (RFID) tags within the field of a detecting antenna. The method allows the unobtrusive detection of human interactions with RFID-tagged objects without requiring any modifications to existing communications protocols or RFID hardware. We use the response rate (a metric in lieu of the true received RF-signal intensity) at the reader to study the impact of tag translation, rotation, and coupling, as well as environmental effects. Performance is improved by introducing the idea of multiple tags/readers. Movement-detection algorithms are developed and integrated into the RFID monitoring system, and verified by experiments that demonstrate excellent results.     

Battery-free wireless identification and sensing

The Wireless Identification and Sensing Platform (WISP) project explores an approach to provide power for sensor networks, based on passive radio-frequency-identification technology. In traditional passive RFID systems, ambient high-power readers interrogate battery-free devices, called tags, that modulate the interrogating signal to communicate a unique identifier to the reader. The WISP project aims to augment RFID tags with sensors so that tags can also send sensed data to the readers. We call these augmented tags wisps. Basing wisps on RFID has some immediate advantages. RFID tags communicate to ambient readers over distances of up to eight meters. Solutions compatible with RFID standards might therefore find quicker acceptance and see faster improvement than other solutions.     

Reliability Optimisation of FMS with Spare Tooling

Tool reliability plays an important role in the performance and justification of flexible manufacturing systems (FMS). Failure of a single tool can cause downtimes over the entire system. This results in missing due dates, and inferior products. Therefore, in order to justify the large capital investment associated with FMS, the system must perform in a reliable manner to give an acceptable or expected rate of return on capital. FMS reliability should be studied at the planning and design stages, as tool failures pose a major obstacle to achieving this objective. In this paper, a mathematical model has been developed to determine the spares requirement of the tooling system in an FMS, so that the desired system reliability is achieved and the cost is minimised. The influence of tool sharing on cost, reliability, spares requirement, and tool magazine capacity of the FMS are analysed. The tools and tool transporter are subject to general failure distributions.     

Planar defects and phase transformation in ZnSe nanosaws

ZnSe nanostructures were grown on Si substrates by Au catalyzed vapor phase growth at 725°C. Three different types of ZnSe nanosaws have been observed using transmission electron microscopy (TEM). Detailed structural and microstructural investigation has been carried out using electron diffraction and high-resolution TEM (HRTEM). It has been found that stacking faults and phase transformation are important features of the nanosaw formation. The controlled formation of these ZnSe nanosaws could have very important device applications.     

Effect of Hedging on Over-Year Reservoir Performance

Based on a detailed Monte-Carlo simulation, the effects of hedging parameters namely, starting water availability (SWA), ending water availability (EWA) and hedging factor (HF) on reservoir storage performance indicators have been investigated within the storage-yield plane of over-year reservoirs. Also, trade-off relationships between the various storage performance indicators are developed and selection of reasonable compromising hedging policies based on performance criteria is attempted for over-year reservoirs. Regions within the storage-yield plane of over-year reservoirs where hedging would be effective are identified. This would help the reservoir managers in mitigating the severity during long stretched critical drought periods.     

Energy Scavenging for Inductively Coupled Passive RFID Systems

Deployment of passive radio-frequency identification (RFID) systems or RFID-enhanced sensor networks requires good understanding of the energy scavenging principles. This paper focuses on the energy scavenging design considerations of inductively coupled passive HF RFID systems. The theoretical estimation of the power by a loop antenna is derived, and the effect of the design parameters on the harvested power is investigated. It is shown that the power delivery performance is largely affected by the tag load at the reader. An adaptive matching circuit at the reader is proposed for achieving optimum power delivery performance when the reader has a variable load. Experimental studies confirm analytical derivations     

Challenges for Event Queries over Markovian Streams

Building applications on top of sensor data streams is challenging because sensor data is noisy. A model-based view can reduce noise by transforming raw sensor streams into streams of probabilistic state estimates, which smooth out errors and gaps. The authors propose a novel model-based view, the Markovian stream, to represent correlated probabilistic sequences. Applications interested in evaluating event queries — extracting sophisticated state sequences — can improve robustness by querying a Markovian stream view instead of querying raw data directly. The primary challenge is to properly handle the Markovian stream's correlations.