Anomaly detection from log files using unsupervised deep learning

Computer systems have grown in complexity to the point where manual inspection of system behaviour for purposes of malfunction detection have become unfeasible. As these systems output voluminous logs of their activity, machine led analysis of them is a growing need with already several existing solutions. These largely depend on having hand-crafted features, require raw log preprocessing and feature extraction or use supervised learning necessitating having a labeled log dataset not always easily procurable. We propose a two part deep autoencoder model with LSTM units that requires no hand-crafted features, no preprocessing of data as it works on raw text and outputs an anomaly score for each log entry. This anomaly score represents the rarity of a log event both in terms of its content and temporal context. The model was trained and tested on a dataset of HDFS logs containing 2 million raw lines of which half was used for training and half for testing. While this model cannot match the performance of a supervised binary classifier, it could be a useful tool as a coarse filter for manual inspection of log files where a labeled dataset is unavailable

Trends of Dithiocarbamate Residues in Raspberries in the Republic of Serbia over the Period 2007/2010

Dithiocarbamates (DTC) are among the most commonly used in the world. In the Republic of Serbia almost 300 active substances are registered including five dithiocarbamate fungicides (ziram, mancozeb, metiram, propineb and tiram). For raspberry protection from fungal diseases, only mancozeb combined with metalaxylM (Ridomil Gold MZ 68-WG; mankozeb 640 g/kg + metalaxyl-M 40 g/kg), of all dithiocarbamates, is authorized for use in the Republic of Serbia. Dithiocarbamates present in food can be of health concern. They have at least three modes of toxic action. These include: (a) the capacity to generate carbon disulfide (CS2), (b) biotransformation into ethylenethiourea (ETU), (c) the ability to chelate physiologically important ions (e. g., copper). The Serbian government authorities adapted the maximum residue levels (MRLs) to the MRLs set by the European Union in 2010 (The Official gazette 27/2010) but dithiocarbamate levels were not set for all agricultural products. The MRLs for dithiocarbamates in raspberries (dithiocarbamates expressed as CS2, including maneb, mancozeb, metiram, propineb, thiram and ziram) in the EU and the Republic of Serbia is 0.05 mg/kg. The paper presents the method validation results and the results of dithiocarbamate monitoring study. Our study comprised the determination of the dithiocarbamate residues content in 103 raspberry samples from the market of the Republic of Serbia taken during 2007/2010. Over 20% of samples were above the MRLs (0.05 mg/kg), with the highest detected concentration of 0.8 mg/kg. The headspace GC/MS multi-residue method, based on the analysis of carbon disulphide obtained after the treatment of analytes with hydrochloric acid in the presence of tin (II) chloride was used. The averaged recovery from raspberries was spiked in the range of 0.05 - 1.25 mg/kg, is 91.35%. The limits of detection (LOD = 3 x sigma baseline noise) and quantification (LOQ = 10 x sigma baseline noise) were approximately 0.01 and 0.03 mg/kg, respectively. The linearity obtained without matrix was R-2=0.992, and with matrix was R-2=0.999. The matrices did not have interfering peaks in the time of CS2 elution

Influence of different tetracycline antimicrobial therapy of mycoplasma (mycoplasma synoviae) in laying hens compared to tea tree essential oil on table egg quality and antibiotic residues

The food of animal origin that is the most consumed is the table egg, but laying hens treated with antibiotics can produce eggs contaminated with antibiotic residues. Residues of antibiotics may present a risk for consumer health. Keeping in mind that laying hens almost always suffer from Mycoplasma (Mycoplasma synoviae), for which they are treated with antibiotics, high-quality egg production is even harder. Our research aimed to investigate the influence of three different antibiotics compared to the tea tree (Melaleuca alternifolia) essential oil administered to naturally infected laying hens with M. synoviae, on antibiotic residues in eggs as well as the egg nutritive and sensory qualities. A total of 20,000 laying hens, housed in one facility and divided into four lines each consisting of 5000 hens naturally infected with M. synoviae, was used. For the antimicrobial therapy, tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) were used, respectively. As a control, tea tree essential oil (TT) was used. Based on the gained results all tetracyclines treatment residue values were significantly (p < 0.05) higher compared to the control treatment (TT), but without any significant differences (p > 0.05) between themselves. The results showed no differences in the nutritive and the sensory qualities of eggs between the control and the experimental treatments (p > 0.05). Keeping in mind the obtained results from this study, it can be concluded that tea tree essential oil could be successfully used as a natural antibiotic in the treatment of M. synoviae, without any adverse effects on table egg quality

Electronic Nose: A First Sensors Array Optimization for Pesticides Detection Based on Wilks' A-Statistic

This paper describes an E-Nose aimed to Pesticide Detection which uses an array of different commercial gas sensors. In order to optimize the array reducing the redundancies due to similar sensors answers, Wilks’ A-statistic has been used