Vijay, Vivek

Instrumented versions of functional geriatric screening tests have been developed to improve clinical precision. Several different instrumented versions of the Sit-to-Stand (iSTS) test have been developed using a range of sensors such as accelerometers and cameras. An instrumented chair equipped with load cells and an ultrasound sensor was developed to detect phases of the STS (Sit to Stand). The chair was designed to be able to detect all the phases of the STS, including when the person was not in contact with the chair. Performance of the iSTS chair was compared between an RGB camera approach, and a data-fusion approach using the load-cell and ultrasound equipped chair. Ten adult subjects were tested performing the 5STS at two self-selected speeds. The accuracy of the load cell equipped chair was 70%, while the RGB camera achieved 76% accuracy. The ultrasound version of the chair and the fusion of the RGB and load cells technique both achieved significantly better accuracy at 86% and 89%, respectively. The new version of the instrumented chair obtained a high degree of accuracy in detecting the different phases of the STS and is suitable to detect STS phases without requiring additional sensors. Future work will test older subjects and aim to develop new parameters based on the phases of the STS as indicators of physical performance.

Thermal emittance is an important parameter for the solar thermal collectors as thermal radiative losses from the solar thermal collector increase to the fourth power of temperature. This should be minimized using infrared reflectors in designing spectrally selective absorber coatings for solar thermal applications. The thermal emittance of zirconium (Zr) film as an infrared reflector has been investigated for the use in the spectrally selective absorber. The Zr metallic films are deposited using DC magnetron sputtering process on stainless steel and glass substrates and the deposition process has been optimized to achieve the minimum thermal emittance. The effect of structural, microstructural and surface morphological properties of Zr films is investigated on the emittance of fabricated structures. The X-ray diffraction analysis revealed that the Zr film coatings consist of both cubic and hexagonal Zr crystallographic phase. The optimized deposition time and temperature showed 0.12 and 0.14 emittance values for Zr film coatings on stainless steel and glass substrates respectively.

Zirconium carbide-nitride absorber (ZrC-ZrN) and zirconium reflector tandem structures were prepared on glass and aluminum substrate, in conjunction with zirconium oxide (ZrOx) anti-reflection coatings, using DC/RF magnetron sputtering system. The solar absorption properties of zirconium carbide-nitride absorber layers were optimized by controlling nitrogen flow during synthesis process for optimal solar thermal response. X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements were carried out on fabricated absorber-reflector tandem structures to understand the structure-property correlation. We absorbed strong dependence of zirconium nitride fraction on solar thermal performance. We observed enhanced solar absorptance α ∼ 0.86 and thermal emittance ϵ ∼ 0.05 at room temperature for structures fabricated with optimized synthesis parameters. The optimized structures are stable up to 150 °C in the air without any significant degradation in their solar performance.

The proper analysis of PV power plant is one of the most crucial requirement for the development of technology, proper distribution and maintainance. This paper presents analysis and comparision of performance of two grid-connected photovoltaic plants which are situated at the same place but based on different module technologies. the monitored plants are 43 kW grid-connected amorphous-silicon system and 58 kW multicrystelline-silicon grid-connected PV system. The performance indices that are used for comparative study of systems are performance ratio, specific yield, reference yield, capture loss, system loss, system efficiency, PVUSA rating, and performance indicator based on ratio of ac power at PTC to dc power at STC. Three year monitored data from July 2011 to July 2014 since plant commissioned are used for the analysis. Major operation and maintainance issues that have occured during this period are also discussed.

We will discuss a small novel hexagonal shaped geometry for ultra wideband (UWB) monopole antenna with notch characteristics. The self-similar nature of this fractal like geometry provides higher effective antenna length and wide operating bandwidth because of the onset of multiple resonances. Notch characteristics are introduced using a rectangular slot in the ground plane, which enhances the reflection coefficient over the entire UWB frequency operating range for the proposed device. The optimized 19 mm × 15 mm dimensions, for the proposed antenna are the smallest among such geometries, exhibiting a large bandwidth from 3.1 GHz to 11.7 GHz with VSWR < 2 over the entire frequency range. The proposed antenna demonstrates nearly omnidirectional radiation pattern, proper impedance matching, and good return loss over the entire UWB frequency range.

Analysis of a large dimensional contingency table is quite involved. Models corresponding to layers of a contingency table are easier to analyze than the ful model. Relationships between the interaction parameters of the full log-linear model and that of its corresponding layer models are obtained. These relationships are not only useful to reduce the analysis but also useful to interpret various hierarchical models. We obtain these relationships for layers of one variable, and extend the results for the case when layers of more than one variable are considered. We also establish, under conditional independence, relationships between the interaction parameters of the full model and that of the corresponding marginal models. We discuss the concept of merging of factor levels based on these interaction parameters. Finally, we use the relationships between layer models and full model to obtain conditions for level merging based on layer interaction parameters. Several examples are discussed to illustrate the results. © Taylor & Francis Group, LLC.

The aim of this study was to investigate whether parameters from an instrumented one-leg stance (OLS) on a force plate could provide relevant information related to fall risk in older people. Forty-two community dwelling older people including 17 fallers and 25 nonfallers, and 25 young subjects performed a OLS while standing on a force plate, with parameters related to transferring weight onto one leg and postural sway in singe-leg stance evaluated. No differences were observed between older fallers and nonfallers and the younger participants for any of the weight transfer parameters. The younger participants were able to reduce their postural sway during the OLS test after the first 0-2 s period, unlike older participants who swayed the same amount throughout the test. The older fallers swayed significantly more than both nonfallers and younger participants throughout the 10-s of OLS evaluated. When the tests were used to classify older participants as fallers, the instrumented OLS achieved 100% accuracy, compared to 69.0% classification accuracy for the five times sit-to-stand test, 61.9% for the standard OLS, and 47.6% for the timed-up-and-go test. These findings suggest that the standard OLS test might not be suitable to detect fall risk. In contrast, an instrumented version of the OLS could provide valuable additional information that could identify older fallers. Future work will include a prospective study of the instrumented OLS in a larger population of older people.

The evaluation of risk factors for falls (RFF) is a key point in fall prevention for the elderly. Since the information of the main actionable RFF can not always be regularly re-evaluated by medical factors, their automatic prediction would allow providing useful recommendations to reduce the risk of falls. This article explores the advantages of three oversampling methods to improve the quality of the prediction of 12 target RFF on the basis of a real imbalanced data set. We first present the data set, together with the selection of 45 variables and 12 target variables and other pre-processing steps. Second, we present the three oversampling methods, SMOTE, SMOTE-SVM, and ADASYN, the classifiers (Logistic Regression, Random Forest, Bayesian Network, Artificial Neural Network, and Naive Bayes), and the quality measures that we use in this study (balanced accuracy, area under ROC curve, area under Precision-Recall curve, F1 and F2 score). Each target is successively evaluated from all other variables. Results are presented by the classifier (averaging over targets) and by target (averaging over classifiers), for each oversampling method and quality measure. Finally, statistical tests validate the interest of using oversampling methods. The three methods demonstrate a clear advantage in comparison with the imbalanced data set, and SVM-SMOTE provides the best increment.

The Indian Institute of Technology, Jodhpur (IITJ) has been monitoring and recording all the parameter of 101 kW (43.30 kW A-Si PV system located in Block 1 and 58.08 kW C-Si PV system in Block 2) grid tied solar photovoltaic system over the 4 year. The paper present the operational data 43.30 kW amorphous silicon (A-Si) based PV system located at Block 1 and 58.08 kW crystalline silicon based PV system at Block 2 of IIT Jodhpur. This paper helps in a study of the performance and consistency of this system. This paper will estimate the theoretical and actual Power output, Energy yield of the both PV systems. During the year, the PV systems in Jodhpur, India have generated a 74922 kWh by C-Si PV and 55910 kWh solar energy by A-Si PV system. As a whole, the location of Solar PV system is the primary reason of energy variability and system production.

Automated clinical tests that assess quality of geriatric screening tests such as the Five-Times-Sit- To-Stand (5STS) and the Timed-Up-and-Go (TUG) are being designed to assess the decline in functional ability of elderly. The existing techniques to assess the quality of these physical activities include sensor-based techniques including body mounted sensors, force sensors and, vision and imaging sensors. These sensors have their own advantages and disadvantages towards the task of clinical assessment. In this work, we introduce a fusion- based technique to combine multiple sensors leveraging advantages of individual sensors, in such a way that the resulting assessment is more accurate. We evaluate our technique for 5STS test using a fusion of a chair and RGB sensors. In a test of 15 older people, there was no significant difference in performance between the two sensors, obtaining 76% and 73% for the RGB and chair, respectively. However, a significant improvement was obtained for the fusion technique, with 90% accuracy for all the phases of the STS test. The proposed fusion technique was observed to be better than the individual sensor assessment.