A Hybrid Machine Learning Technique For Feature Optimization In Object-Based Classification of Debris-Covered Glaciers

Object-based features like spectral, topographic, and textural are supportive to determine debris-covered glacier classes. The original feature space includes relevant and irrelevant features. The inclusion of all these features increases the complexity and renders the classifier’s performance. Therefore, feature space optimization is requisite for the classification process. Previous studies have shown a rigorous exercise in manually selecting the best combination of features to define the target class and proven to be a time consuming task. The present study proposed a hybrid feature selection technique to automate the selection of the best suitable features. This study aimed to reduce the classifier’s complexity and enhance the performance of the classification model. Relief-F and Pearson Correlation filter-based feature selection methods ranked features according to the relevance and filtered out irrelevant or less important features based on the defined condition. Later, the hybrid model selected the common features to get an optimal feature set. The proposed hybrid model was tested on Landsat 8 images of debris-covered glaciers in Central Karakoram Range and validated with present glacier inventories. The results showed that the classification accuracy of the proposed hybrid feature selection model with a Decision Tree classifier is 99.82%, which is better than the classification results obtained using other mapping techniques. In addition, the hybrid feature selection technique has sped up the process of classification by reducing the number of features by 77% without compromising the classification accuracy

Sketch-Based Streaming Anomaly Detection in Dynamic Graphs

Given a stream of graph edges from a dynamic graph, how can we assign anomaly scores to edges and subgraphs in an online manner, for the purpose of detecting unusual behavior, using constant time and memory? For example, in intrusion detection, existing work seeks to detect either anomalous edges or anomalous subgraphs, but not both. In this paper, we first extend the count-min sketch data structure to a higher-order sketch. This higher-order sketch has the useful property of preserving the dense subgraph structure (dense subgraphs in the input turn into dense submatrices in the data structure). We then propose four online algorithms that utilize this enhanced data structure, which (a) detect both edge and graph anomalies; (b) process each edge and graph in constant memory and constant update time per newly arriving edge, and; (c) outperform state-of-the-art baselines on four real-world datasets. Our method is the first streaming approach that incorporates dense subgraph search to detect graph anomalies in constant memory and time

Enzyme and Reaction Engineering in Biocatalysis: Synthesis of (S)-Methoxyisopropylamine (= (S)-1-Methoxypropan-2-amine)

Methoxyisopropylamine is a chiral amine moiety common to the chemical structures of two important chloroacetamide herbicides, metolachlor and dimethenamid. The activity of both products lies predominantly in their (S)-enantiomeric forms. Celgro scientists have developed a high-productivity biocatalytic process to (S)-methoxyisopropylamine via transamination of methoxyacetone and isopropylamine. Biocatalyst and process optimization was achieved by integration of molecular biology, fermentation, enzymology, and engineering disciplines to identify and overcome kinetic, stability, and thermodynamic constraints on productivity. The result was a 50° vacuum reaction producing 2M (S)-methoxyisopropylamine (18 wt-%) at >99% ee, with 97% conversion of methoxyacetone in 7 h, meeting economic targets applicable to agrochemical manufacturing

Establishing Relationship between Pressure & Normal Shocks for Convergent-Divergent Nozzle-

Objective of the present study is to analyze experimentally the pressure variation in a varying area circular passage at different supply pressures and compare these with the theoretical solutions. It has been observed that flow of stream of the normal shock is always supersonic while in downstream is always sub-sonic thus shocks slow down the flow rates by sudden increase in pressure ratios. Shock strength is determined uniquely by the mach no. higher the mach no. of upstream of supersonic flow , greater is the shock strength & lower is downstream subsonic mach no. Theoretically minimum pressure is always present at the throat during subsonic condition. But experimentally the position of minimum pressure might be varied because of variation in the stagnation properties of the fluid. This project also includes flow phenomenon over the entire length of nozzle for varying back pressure

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Thermal Conversion of Carboxylate Salts and Catalytic Ketone Hydrogenation

Biomass as a source of energy and chemicals has gained importance due to the decreasing oil reserves, fluctuating oil prices and environmental concerns. Ethanol, a common fuel derived from biomass, is now used as a blend in conventional transportation fuels, however ethanol energy density (Higher Heating Value (HHV) = 29.84 MJ/Kg) is quite low compared to conventional gasoline (HHV = 46.53 MJ/Kg). This reduces overall energy density of the ethanol blended gasoline. Alcohols such as propanol (HHV = 33.6 MJ/Kg) and butanol (HHV = 37.3 MJ/Kg) have higher energy densities and can also be used as blends in conventional transportation fuels. Production of three to seven carbon alcohol fuels via acidogenic digestion and chemical upgrading of industrial biomass streams offers many advantages over sterile fermentation processes such as: lower capital cost, no need for sterility or genetically modified organisms, and the ability to produce a variety of chemicals such as carboxylic acids, ketones, esters, and alcohols. Carboxylate salts formed during acidogenic digestion of biomass can be thermally converted to ketones. The ketones can then be hydrogenated to form the desired longer-chain alcohols. In this thesis, two unit operations viz. thermal decomposition of carboxylate salts to ketones and hydrogenation of ketones to alcohols were studied. In the thermal decomposition unit operation, decomposition temperatures and decomposition products of various pure and biomass-derived carboxylate salts were determined. In the hydrogenation unit operation, the catalyst for ketone hydrogenation was identified. Further, the activity of ruthenium supported on activated carbon for hydrogenating ketones was explored using acetone as the model compound. A simple kinetic model accounting for the effects of temperature, H2 pressure, and acetone concentration was developed for acetone hydrogenation with the Ru/C catalyst

Ruptured liver abscess: Analysis of 50 cases

Background: Liver abscess (pyogenic and amebic) is frequently encountered clinical condition; however, it can result in lethal outcome if there is a delay in diagnosis and treatment. Despite modalities to diagnose the condition early, still ruptured liver abscess presents with a common cause of acute abdomen in surgical emergency. In developing countries, ruptured liver abscess is a common cause of mortality. For contained abscess, nonsurgical options are considered; however, for ruptured liver abscess, surgical intervention is considered necessary. Materials and Methods: This was a retrospective study carried in Safdarjung hospital, New Delhi, between 2015 and 2016. All patients with ruptured liver abscess (clear signs of peritonitis) were included in this study, and those patients having other causes of peritonitis were excluded. A preformed protocol for management was followed for all the patients, and various parameters contributing to the illness and its prognosis were evaluated and assessed. Results: Out of the fifty patients assessed, male patients were mainly affected (86%). The most affected age group was 31–40 years (64%) followed by 41–50 years (22%). Right hypochondrium pain was the most common presenting complaint. Nine patients (18%) had presented with signs of toxemia. Only right lobe of the liver was affected the most in 44 patients (88%). Escherichia coli was the most common organism isolated in our study in 19 patients (38%). A total of 19 patients (38%) had diabetes in our study and total of 13 patients had mortality in our study. Conclusion: Ruptured liver abscess most commonly involves the right lobe of the liver. Males are affected far higher than the females; probable cause believed to be higher alcohol consumption. Most common affected age group falls between 30 and 60 years of age. If prompt treatment is started in time, mortality involved with it is evitable