Real-time grasping strategies using event camera

Journal of Intelligent Manufacturing - Robotic vision plays a key role for perceiving the environment in grasping applications. However, the conventional framed-based robotic vision, suffering from...     

Success of electronic commerce Web sites: A comparative study in two countries

This study incorporated attitude toward a site (Ast) in the proposed model together with moderating factors like cultural effects and attitude toward online shopping (Ashop). The proposed model and hypotheses were partially supported in Taiwan's and Thailand's data. Information quality affected both user satisfaction and attitude toward the web site and was the dimension common across both countries. Ashop moderated the effects of system quality on user satisfaction in Taiwan, but moderated information quality in the Thailand. National identity moderated the effect of system quality on both user satisfaction and attitude toward the site in the Thai data.     

A proximity-aware load balancing in peer-to-peer-based volunteer computing systems

One of the main challenges in peer-to-peer-based volunteer computing systems is an efficient resource discovery algorithm. Load balancing is a part of resource discovery algorithm and aims to minimize the overall response time of the system. This paper introduces an analytical model based on distributed parallel queues to optimize the average response time of the system in a distributed manner. The proposed resource discovery algorithm consists of two phases. In the first phase, it selects peers in a load-balanced manner based on QoS constraints of request. In the second phase, a proximity-aware feature is applied to select the peer with minimum communication overhead among selected peers in the first phase. Two dispatching strategies are proposed for the load balancing based on stochastic analysis of routing in the distributed parallel queues. These policies adopt probabilistic and deterministic sequences to redirect requests to the capable peers in the system. Simulation results show that the proposed resource discovery algorithm improves the response time of user’s requests by a factor of 1.8 under a moderate load.     

Structural and Optical Studies on Sol-gel Composites of Nickel-Doped Nanocrystalline Zinc Oxide/Polyvinylidene Fluoride

Nickel-doped nanocrystalline ZnO with three different Ni concentrations was incorporated in polyvinylidene fluoride thin film for obtaining free-standing flexible film by sol-gel technique. The effect of Ni–ZnO loading on the optical and microstructural properties of the Ni–ZnO/polyvinylidene fluoride composite films was studied. X-ray photoelectron spectroscopy and Raman studies were performed to characterize the bonding environment. Fluorine-terminated surface showed a strong F1?s peak located at ～695?eV arising out of C–F bonds. Existence of β phase of polyvinylidene fluoride along with the presence of ZnO nanocrystals were indicated by Raman studies. Secondary ion mass spectrometry studies indicated the distribution of Ni–ZnO particles in the polyvinylidene fluoride matrix.     

Comparative evaluation of physical properties and aroma profile of carrot slices subjected to hot air and freeze drying

In the present study, carrots were subjected to hot air- and freeze-drying processes and their physical parameters and aromatic profile were compared. Water activity, shrinkage, hardness, springiness, cohesiveness, chewiness, rehydration ratio, and color measurements show that the convective drying of carrot slices lead to major changes in physical and aroma characteristics. The volatiles from air-drying of carrots contain terpenes, aldehydes, and alcohols which contribute to their aroma. The terpene, patchoulene imparting a spicy odor is reported for the first time in fresh carrots and it gets completely degraded during air dehydration. The key flavor components of fresh carrots were mostly retained during drying. The analytical results confirm that freeze-dried products had higher aroma retention.     

Electrochemical dithiothreitol assay for large-scale particulate matter studies

Particulate matter (PM) air pollution is associated with human morbidity and mortality. Measuring PM oxidative potential has been shown to provide a predictive measurement between PM exposure and adverse health impacts. The dithiothreitol (DTT) assay is commonly used to measure the oxidative potential of PM_2.5 (PM less than 2.5?µm aerodynamic diameter). In the common, kinetic form of this assay, the decay of DTT is quantified over time (indirectly) using 5,5′-dithiobis(2-nitrobenzoic acid) (DTNB, Ellman’s reagent) via UV/vis absorbance spectroscopy. The loss of DTT can also be quantified directly using electrochemical detection. The objectives of this work were (1) to evaluate the electrochemical assay, using commercially available equipment, relative to the UV/vis absorbance assay and (2) to apply the electrochemical method to a large (>100) number of PM_2.5 filter samples. Also presented here is the comparison of an endpoint assay to the kinetic assay, in an attempt to reduce the time, labor, and materials necessary to quantify PM oxidative potential. The endpoint, electrochemical assay gave comparable results to the UV/vis absorbance assay for PM_2.5 filter sample analysis. Finally, high filter mass loadings (higher than about 0.5?µg PM per mm² filter) lead to suboptimal DTT assay performance, which suggests future studies should limit particle mass loadings on filters.

Copyright © 2019 American Association for Aerosol Research     

Performance Analysis of Optimum Combining Technique in OFDM Based Full Duplex Multiantenna DF Relay Network with Narrowband Interference

In this paper, optimum combining technique is applied to minimize the effect of Narrowband Interference (NBI) in Orthogonal Frequency Division Multiplexing based full duplex relay network. The NBI signal is assumed to be quasi-static over the duration of a transmitted signal. Multiple antennas are employed at Decode and Forward relay and destination nodes. The Probability Density Function of Signal to Interference Ratio at relay and destination nodes is derived using Hotelling’s T ² distribution. Analytical expression for the end-to-end outage probability of the proposed network is derived using the hypergeometric functions. As the weight vector of the optimal combiner is determined using the statistics of the interference channels, the performance of the proposed network becomes better than the network with maximal ratio combining.     

Regulation of promoter-CAT stress genes in HepG2 cells by suspensions of particles from ambient air

Whole-cell patch recording techniques were used to analyze spontaneous electrical activity in cerebellar Purkinje cells acutely isolated from postnatal rats. Spontaneous activity was present in 65% of the cells examined, and it included simple and complex firing patterns which persisted under conditions that eliminated residual or reformed synaptic contacts. Under voltage clamp, both spontaneous and quiescent cells displayed similar voltage-dependent conductances. Inward current was carried by Na+ through tetrodotoxin (TTX)-sensitive channels and by Ca2+ through P-type and T-type Ca channels. P-type current was present in all cells examined. T-type current was found in <50%, and it did not correlate with spontaneous activity. We found no evidence of a transient (A-type) potassium current or hyperpolarization-activated cationic current in either spontaneous or quiescent cells. Spontaneous activity did correlate with a lower activation threshold of the Na current, resulting in substantial overlap of the activation and inactivation curves. TTX reduced the holding current of spontaneous cells clamped between -50 and -30 mV, consistent with the presence of a Na "window" current. We were unable, however, to measure a persistent component of the Na current using voltage steps, a result which may reflect the complex gating properties of Na channels. An Na window current could provide the driving force underlying spontaneous activity, as well as plateau potentials, in Purkinje cells.     

3D text segmentation and recognition using leap motion

In this paper, we present a method of Human-Computer-Interaction (HCI) through 3D air-writing. Our proposed method includes a natural way of interaction without pen and paper. The online texts are drawn on air by 3D gestures using fingertip within the field of view of a Leap motion sensor. The texts consist of single stroke only. Hence gaps between adjacent words are usually absent. This makes the system different as compared to the conventional 2D writing using pen and paper. We have collected a dataset that comprises with 320 Latin sentences. We have used a heuristic to segment 3D words from sentences. Subsequently, we present a methodology to segment continuous 3D strokes into lines of texts by finding large gaps between the end and start of the lines. This is followed by segmentation of the text lines into words. In the next phase, a Hidden Markov Model (HMM) based classifier is used to recognize 3D sequences of segmented words. We have used dynamic as well as simple features for classification. We have recorded an overall accuracy of 80.3 % in word segmentation. Recognition accuracies of 92.73 % and 90.24 % have been recorded when tested with dynamic and simple features, respectively. The results show that the Leap motion device can be a low-cost but useful solution for inputting text naturally as compared to conventional systems. In future, this may be extended such that the system can successfully work on cluttered gestures.