Object Detection using Dimensionality Reduction on Image Descriptors

The aim of object detection is to recognize objects in a visual scene. Performing reliable object detection is becoming increasingly important in the fields of computer vision and robotics. Various applications of object detection include video surveillance, traffic monitoring, digital libraries, navigation, human computer interaction, etc. The challenges involved with detecting real world objects include the multitude of colors, textures, sizes, and cluttered or complex backgrounds making objects difficult to detect. This thesis contributes to the exploration of various dimensionality reduction techniques on descriptors for establishing an object detection system that achieves the best trade-offs between performance and speed. Histogram of Oriented Gradients (HOG) and other histogram-based descriptors were used as an input to a Support Vector Machine (SVM) classifier to achieve good classification performance. Binary descriptors were considered as a computationally efficient alternative to HOG. It was determined that single local binary descriptors in combination with Support Vector Machine (SVM) classifier don\u27t work as well as histograms of features for object detection. Thus, histogram of binary descriptors features were explored as a viable alternative and the results were found to be comparable to those of the popular Histogram of Oriented Gradients descriptor. Histogram-based descriptors can be high dimensional and working with large amounts of data can be computationally expensive and slow. Thus, various dimensionality reduction techniques were considered, such as principal component analysis (PCA), which is the most widely used technique, random projections, which is data independent and fast to compute, unsupervised locality preserving projections (LPP), and supervised locality preserving projections (SLPP), which incorporate non-linear reduction techniques. The classification system was tested on eye detection as well as different object classes. The eye database was created using BioID and FERET databases. Additionally, the CalTech-101 data set, which has 101 object categories, was used to evaluate the system. The results showed that the reduced-dimensionality descriptors based on SLPP gave improved classification performance with fewer computations

Evaluation of fine needle aspiration cytology in the diagnosis of soft tissue tumors and its correlation with histopathological findings

Background: Fine Needle Aspiration Cytology (FNAC) is a useful, safe and cost effective tool that is used in the diagnosis of lesions in various organs. Even though the literature on FNAC of soft tissue masses is relatively scarce, a large amount of interest has developed in this area in the last few years due to the low cost of the procedure, low incidence of complications, feasibility and high therapeutic efficiency. So the present study was undertaken to study the nature of various soft tissue tumors by FNAC and to compare the cytological diagnosis with the results obtained by biopsy.  Methods: All cases 713 (Prospective-217 and Retrospective 496) included in present series were taken up for study. Aspiration of soft tissue lesions were performed following the technique of Zajicek et al. Smear was prepared, stained and examined. Histopathological details were available in 140 cases. Data was compiled in MS excel and checked for its completeness, correctness and then it was analyzed.Results: Total number of 11,560 FNAC was done in six and half year’s period from 1st April 2003 to 30th September 2009. Out of the total 713 cases of soft tissue tumors, 71.25% were reported as benign and 28.75% as malignant. Soft tissue tumors were more common in males in comparison to females, with M: F-1.63:1. Accuracy of FNAC for benign and malignant soft tissue tumours was 88.1% and 92.9% respectively.  Conclusion: The overall diagnostic accuracy of FNAC in the present study was found 90%. FNAC is a safe and reliable method of recognizing benign and malignant soft tissue tumors and in most instances histological sub typing is possible. Cytological diagnosis must be based on strict cytological criteria and well controlled ancillary techniques.

Pročišćavanje i karakterizacija bakteriocina proizvedenog s pomoću Bacillus subtilis R75, bakterije izolirane iz fermentiranoga zelenčića (Phaseolus radiatus)

Food-grade bacteria capable of producing bacteriocin with desirable preservation attributes have been isolated from traditional Indian fermented food dal vari, which has not been investigated so far. Among different isolates, Bacillus subtilis R75, isolated on MRS agar, exhibited antagonism against a wide range of foodborne pathogens that cause serious spoilage. Extracellularly produced bacteriocin was purified by single step gel exclusion column chromatography. The purity rate and molecular mass of 12 kDa of this compound were determined using SDS-PAGE. Activity units (AU) of bacteriocin were increased in each step of purification, reaching up to 5·10^6 AU/mL. The increase in the activity units directly affected the antimicrobial activity of purified bacteriocin, resulting in an increase up to 200, 333 and 175 % of the inhibition zones against indicator bacteria. Continuous decrease in the number of viable cells of microorganisms within 10 h after adding purified bacteriocin proved its bactericidal action. It withstood very high temperature, up to 121 °C, for 10 min, wider pH range, from 4.0 to 11.0, complete inactivation in the presence of proteolytic enzymes and storage stability up to 2.5 months.Iz dosada neispitanog tradicionalnog indijskog proizvoda dal vari, dobivenog fermentacijom zelenčića (graha mungo), izolirana je bakterija koja proizvodi bakteriocin što proizvod štiti od kvarenja. Od nekoliko ispitanih izolata, bakterija Bacillus subtilis R75, izolirana na MRS agaru, antagonistički je djelovala na različite patogene uzročnike kvarenja hrane. Ekstracelularno proizvedeni bakteriocin pročišćen je gel-filtracijom u jednom koraku. Čistoća i molekularna masa (12 kDa) spoja određeni su SDS-PAGE elektroforezom. Aktivnost bakteriocina povećala se svakom daljnjom fazom pročišćavanja, sve do 5·10^6 AU/mL. Povećanje aktivnosti izravno je utjecalo na antimikrobnu aktivnost pročišćenoga bakteriocina, pa se zona inhibicije rasta bakterija pokazatelja kvarenja povećala za 200, 333 i 175 %. Stalno smanjivanje broja živih stanica mikroorganizama i do 10 sati nakon dodatka pročišćenoga bakteriocina dokazuje njegovo baktericidno djelovanje. Bakteriocin je izdržao vrlo visoke temperature, čak i do 121 °C tijekom 10 min, širi raspon pH-vrijednosti (od 4,0 do 11,0) i potpunu inaktivaciju u prisutnosti proteolitičkih enzima, te je bio stabilan tijekom 2,5 mjeseca skladištenja proizvoda

Improved perioperative seroma and complication rates following the application of a 2-layer negative pressure wound therapy system after inguinal lymphadenectomy for metastatic cutaneous melanoma

Background: Perioperative complications following inguinal lymphadenectomy, including seroma formation, are frequent. We have employed a 2-layer negative pressure wound therapy (2-LNPWT) as a method to reduce seroma rate and perioperative complications. We present the outcome of our initial experience with 2-LNPWT and compare the outcomes of its use with traditional closed suction drains (CSDs).  Materials and methods: A non-randomised retrospective case–control series was analysed. Surgeons performing inguinal lymphadenectomy for metastatic cutaneous melanoma utilised either the 2-LNPWT therapy or traditional CSDs according to their practice preference.  Results: The study included 111 patients. The cohorts were well matched for gender, disease burden, body mass index and comorbidities. The 2-LNPWT technique was associated with significantly better postoperative outcomes than CSD, in terms of incidence of seroma formation (26.9% vs 49.4%; p < 0.03), period of drainage (15 days vs 20 days; p = 0.005) and return to theatre rate (0% vs 15.3%; p = 0.03). The overall seroma rate was 44.1%. The only significant association with seroma initiation was the type of drainage system used (2-LNPWT 31.2% vs CSD 58.3%; p < 0.03; OR 3.0). The method of drainage did not alter the course of an established seroma. There was no significant difference in overall or disease-specific survival detected between the 2 groups.  Conclusion: This retrospective non-randomised case control study has demonstrated the safe use of a novel application of negative pressure wound therapy that significantly reduced the incidence of seroma formation and postoperative complication rate for inguinal lymphadenectomy for melanoma

Search for top squarks in the four-body decay mode with single lepton final states in proton-proton collisions at s \sqrt{s} = 13 TeV

A search for the pair production of the lightest supersymmetric partner of the top quark, the top squark (t∼1), is presented. The search targets the four-body decay of the t∼1, which is preferred when the mass difference between the top squark and the lightest supersymmetric particle is smaller than the mass of the W boson. This decay mode consists of a bottom quark, two other fermions, and the lightest neutralino (χ∼01), which is assumed to be the lightest supersymmetric particle. The data correspond to an integrated luminosity of 138 fb−1 of proton-proton collisions at a center-of-mass energy of 13 TeV collected by the CMS experiment at the CERN LHC. Events are selected using the presence of a high-momentum jet, an electron or muon with low transverse momentum, and a significant missing transverse momentum. The signal is selected based on a multivariate approach that is optimized for the difference between m(t∼1) and m(χ∼01). The contribution from leading background processes is estimated from data. No significant excess is observed above the expectation from standard model processes. The results of this search exclude top squarks at 95% confidence level for masses up to 480 and 700 GeV for m(t∼1) − m(χ∼01) = 10 and 80 GeV, respectively

Measurement of the cross section of top quark-antiquark pair production in association with a W boson in proton-proton collisions at s \sqrt{s} = 13 TeV

The production of a top quark-antiquark pair in association with a W boson $(t\bar{t}W)$ is measured in proton-proton collisions at a center-of-mass energy of 13 TeV. The analyzed data was recorded by the CMS experiment at the CERN LHC and corresponds to an integrated luminosity of 138 fb$^{−1}$. Events with two or three leptons (electrons and muons) and additional jets are selected. In events with two leptons, a multiclass neural network is used to distinguish between the signal and background processes. Events with three leptons are categorized based on the number of jets and of jets originating from b quark hadronization, and the lepton charges. The inclusive $(t\bar{t}W)$ production cross section in the full phase space is measured to be 868 ± 40(stat) ± 51(syst) fb. The $(t\bar{t}W)+$ and $(t\bar{t}W)−$ cross sections are also measured as 553 ± 30(stat) ± 30(syst) and 343 ± 26(stat) ± 25(syst) fb, respectively, and the corresponding ratio of the two cross sections is found to be 1.61±0.15(stat)$^{+0.07}_{−0.05}$(syst). The measured cross sections are larger than but consistent with the standard model predictions within two standard deviations, and represent the most precise measurement of these cross sections to date

Measurement of the Dependence of the Hadron Production Fraction Ratios fs/fuf_s / f_u and fd/fuf_d / f_u on BB Meson Kinematic Variables in Proton-Proton Collisions at s=13TeV\sqrt{s} = 13 TeV

The dependence of the ratio between the $B^0_s$ and $B^+$ hadron production fractions, $f_s/f_u$, on the transverse momentum $(p_T)$ and rapidity of the $B$ mesons is studied using the decay channels $B^0_s→J/ψϕ$ and $B^+→J/ψK^+$. The analysis uses a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment in 2018 and corresponding to an integrated luminosity of $61.6  fb^{−1}$. The $f_s/f_u$ ratio is observed to depend on the $B$ $p_T$ and to be consistent with becoming asymptotically constant at large $p_T$. No rapidity dependence is observed. The ratio of the $B^0$ to $B^+$ meson production fractions, $f_d/f_u$, is also measured, for the first time in proton-proton collisions, using the $B^0→J/ψK^{*0}$ decay channel. The result is found to be within 1 standard deviation of unity and independent of $pT$ and rapidity, as expected from isospin invariance