Some Novel Methods of Ordered Dither

Various authors have contributed their original works in the field of digital halftoning during past two to three decades. Still this field has not lost its glory. The goal of the study was to investigate novel methods in digital halftoning specially, in ordered dithering. This paper is concerned with two novel methods of ordered dither. In the first method dithering is done first by pre-embedding a pattern image generated from a matrix pattern with the original image. In the second method dithering is done by thresholding the original image with respect to a threshold matrix pattern constructed using a character writing pattern. The two methods may be applied in digital halftone reproduction and as special effect imaging

Treatment of benign bone tumors: judicious use of adjuvants result in better functional outcomes

Background: While curettage has been a common treatment option for low grade benign lytic bone lesions, a careful extension of curettage enhances it’s efficacy without compromising the integrity of surrounding normal bone. Many adjuvants are used for extension of curettage, but all are not universally available, and each has it’s own drawbacks. We report outcome of extended curettage of benign lytic bone lesions using high-speed burr, electrocautery, hydrogen-peroxide, and pulsatile lavage. Methods: The study was conducted on 25 patients,10 to 40 years in age, with lytic bone lesions proven benign. Tumors belonged to Campanacci Grade 1 and 2 of varying histological types. High-speed burr, electrocautery, hydrogen-peroxide, and pulsatile lavgage were extensively used after curetting the lesions with sharp curettes. Defects were filled with bone graft or substitute where needed, if the cavity size was more than 1/3rd of the width of the bone on radiographic assessment. Patients were reviewed for minimum 18months. Results: All defects reverted to near-normal radiological appearance with excellent functional outcome recorded in most cases. Eighty percent patients recovered uneventfully. Mild limited complications were noted as prolonged period of pain in 12% and superficial infection in 8%. No local recurrence was observed. Conclusions: This study demonstrates the efficacy of extended curettage in treatment of benign tumors and tumor like lesions of bone using simple cheap modalities which are  universally available. In properly selected cases of benign bone tumors, a meticulously performed extended curettage provides an effective treatment option that safeguards functionality without compromising on safety

Prediction of Remaining Useful Life of anAircraft Engine under Unknown Initial Wear

Abstract Effectiveness of Condition Based Maintenance (CBM) strategy depends on accuracy in prediction of Remaining Useful Life (RUL).Data driven prognosisapproaches are generally used to estimate the RUL of the system. Presence of noise in the system monitored data may affect the accuracy of prediction. One of the sources of data noise is the presence of unknown initial wear in the samples. Present paper illustrates the effect of such initial wear on prediction accuracy and presents the guidelines to handle such initial wears. Two Artificial Neural Network (ANN)models are developed. First model is developed with the help of completedata; while the second model is developed after removing samples with abnormal initial wear.‫̅ݔ‬ and R control chart is used to screen the samples with abnormal initial wear. It is found that the presence of initial wear significantly affects the prediction accuracy. Also, it is found that RUL estimation for a unit with short history tends to produce great uncertainty.Hence, it is recommended that RUL prediction should be continuously updated with age of the unit to increase the effectiveness of CBM policy

A novel current sensor indicator enabled WAFTR model for tool wear prediction under variable operating conditions

The health indicators (HIs) were extracted from the current sensor to represent the tool wear progression. The extracted HIs were found poorly correlated with the progression of tool wear as the raw current sensor signal was susceptible to the influence of other parts and structures in the machine tool. Hence, this paper proposed a novel current sensor-based HI that utilised the mean of inverse hyperbolic cosine function fitted to an envelope of the current signal to improve the correlation. Using the extracted HIs, many bespoke machine learning (ML) models have been developed by researchers. However, these models have many hyperparameters, difficult to interpret and especially poor prediction accuracy has been observed under variable operating conditions. This study overcame these issues by proposing a Weibull Accelerated Failure Time Regression (WAFTR) model, which combines process parameters data with HI for improving the prediction accuracy under variable operating conditions. This model mapped a functional relationship with tool wear in the form of probability density function to identify best HIs and acceleration/deacceleration factors which makes it interpretable. The acceleration/deacceleration factors are useful to deaccelerate the tool wear evolution by controlling the specific values of the machining parameters

Limited Laminectomy and Restorative Spinoplasty in Spinal Canal Stenosis

Study DesignProspective cohort study.PurposeEvaluation of the clinico-radiological outcome and complications of limited laminectomy and restorative spinoplasty in spinal canal stenosis.Overview of LiteratureIt is critical to achieve adequate spinal decompression, while maintaining spinal stability.MethodsForty-four patients with degenerative lumbar canal stenosis underwent limited laminectomy and restorative spinoplasty at our centre from July 2008 to December 2010. Four patients were lost to follow-up leaving a total of 40 patients at an average final follow-up of 32 months (range, 24-41 months). There were 26 females and 14 males. The mean±standard deviation (SD) of the age was 64.7±7.6 years (range, 55-88 years). The final outcome was assessed using the Japanese Orthopaedic Association (JOA) score.ResultsAt the time of the final follow-up, all patients recorded marked improvement in their symptoms, with only 2 patients complaining of occasional mild back pain and 1 patient complaining of occasional mild leg pain. The mean±SD for the preoperative claudication distance was 95.2±62.5 m, which improved to 582±147.7 m after the operation, and the preoperative anterio-posterior canal diameter as measured on the computed tomography scan was 8.3±2.1 mm, which improved to 13.2±1.8 mm postoperatively. The JOA score improved from a mean±SD of 13.3±4.1 to 22.9±4.1 at the time of the final follow-up. As for complications, dural tears occurred in 2 patients, for which repair was performed with no additional treatment needed.ConclusionsLimited laminectomy and restorative spinoplasty is an efficient surgical procedure which relieves neurogenic claudication by achieving sufficient decompression of the cord with maintenance of spinal stability

25th annual computational neuroscience meeting: CNS-2016

The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong