Cost-Sensitive Boosting for Classification of Imbalanced Data

The classification of data with imbalanced class distributions has posed a significant drawback in the performance attainable by most well-developed classification systems, which assume relatively balanced class distributions. This problem is especially crucial in many application domains, such as medical diagnosis, fraud detection, network intrusion, etc., which are of great importance in machine learning and data mining. This thesis explores meta-techniques which are applicable to most classifier learning algorithms, with the aim to advance the classification of imbalanced data. Boosting is a powerful meta-technique to learn an ensemble of weak models with a promise of improving the classification accuracy. AdaBoost has been taken as the most successful boosting algorithm. This thesis starts with applying AdaBoost to an associative classifier for both learning time reduction and accuracy improvement. However, the promise of accuracy improvement is trivial in the context of the class imbalance problem, where accuracy is less meaningful. The insight gained from a comprehensive analysis on the boosting strategy of AdaBoost leads to the investigation of cost-sensitive boosting algorithms, which are developed by introducing cost items into the learning framework of AdaBoost. The cost items are used to denote the uneven identification importance among classes, such that the boosting strategies can intentionally bias the learning towards classes associated with higher identification importance and eventually improve the identification performance on them. Given an application domain, cost values with respect to different types of samples are usually unavailable for applying the proposed cost-sensitive boosting algorithms. To set up the effective cost values, empirical methods are used for bi-class applications and heuristic searching of the Genetic Algorithm is employed for multi-class applications. This thesis also covers the implementation of the proposed cost-sensitive boosting algorithms. It ends with a discussion on the experimental results of classification of real-world imbalanced data. Compared with existing algorithms, the new algorithms this thesis presents are superior in achieving better measurements regarding the learning objectives

Formulation and interpretation of the Chinese Guidelines for Surgical Treatment of Obesity and Type 2 Diabetes Mellitus

n/

Simultaneous Determination of Copper, Lead, and Cadmium at Hexagonal Mesoporous Silica Immobilized Quercetin Modified Carbon Paste Electrode

A new method was developed for simultaneous determination of copper, lead, and cadmium, based on their voltammetric response at a carbon paste electrode modified with hexagonal mesoporous silica (HMS) immobilized quercetin (HMS-Qu/CPE). Compared with quercetin modified carbon paste electrode (Qu/CPE) and quercetin ionic liquid modified carbon paste electrode (Qu-IL/CPE), the HMS-Qu/CPE exhibited improved selectivity and high sensitivity toward the detection of copper, lead, and cadmium. The properties of the HMS-Qu/CPE in 0.1 M HCOONa-HCl buffer solution (pH4.7) were investigated by adsorptive stripping voltammetry (ASV) and electrochemical impedance spectroscopy (EIS). The electrochemical behavior of copper, lead, and cadmium at the modified electrodes and factors affecting the preconcentration procedures were also investigated. Detection limits of 5.0, 0.8, 1.0 nM for copper, lead, and cadmium were obtained, respectively. The method is simple, fast, sensitive, and selective, and is successfully applied to soil sample

An Object SLAM Framework for Association, Mapping, and High-Level Tasks

Object SLAM is considered increasingly significant for robot high-level perception and decision-making. Existing studies fall short in terms of data association, object representation, and semantic mapping and frequently rely on additional assumptions, limiting their performance. In this paper, we present a comprehensive object SLAM framework that focuses on object-based perception and object-oriented robot tasks. First, we propose an ensemble data association approach for associating objects in complicated conditions by incorporating parametric and nonparametric statistic testing. In addition, we suggest an outlier-robust centroid and scale estimation algorithm for modeling objects based on the iForest and line alignment. Then a lightweight and object-oriented map is represented by estimated general object models. Taking into consideration the semantic invariance of objects, we convert the object map to a topological map to provide semantic descriptors to enable multi-map matching. Finally, we suggest an object-driven active exploration strategy to achieve autonomous mapping in the grasping scenario. A range of public datasets and real-world results in mapping, augmented reality, scene matching, relocalization, and robotic manipulation have been used to evaluate the proposed object SLAM framework for its efficient performance.Comment: Accepted by IEEE Transactions on Robotics(T-RO

CFD-Based Analysis of Wedges Water Entry under Impact Loads

1053-1056The impact on a falling wedge upon water entry is numerically investigated in this paper. After verified by experimental data, the numerical framework is applied for parametric studies on wedges of different drop heights and different deadrise angles to reveal the interaction behaviour between the wedge and water during impact. Pressure distribution on the wedge surface during the water entry shows that the pressure peak moves up along the surface as impact time increases. It is found that the force peak decrease with the increase of drop height and decrease of deadrise angle of the wedge. The peak positions move positively along the timeline as the increase of deadrise angle while the peak force appears just in a small impact time range for a wedge

4-Amino-13-(1-naphth­yl)-[2,2]paracyclo­phane

The title compound [systematic name: 12-amino-42-(1-naphth­yl)-1,4(1,4)-dibenzenacyclo­hexa­phane], C26H23N, was synthesized from 4-amino-13-bromo-[2,2]paracyclo­phane and 1-naphthalene­boronic acid in the presence of 1,4-dioxane. It is a new cyclo­phane-derived compound which can be regarded as a prospective ligand for asymmetric synthesis and catalysis. The benzene rings of the paracyclo­phane units are very slightly deformed from planarity as shallow boats

Broader HIV-1 neutralizing antibody responses induced by envelope glycoprotein mutants based on the EIAV attenuated vaccine

<p>Abstract</p> <p>Background</p> <p>In order to induce a potent and cross-reactive neutralizing antibody (nAb), an effective envelope immunogen is crucial for many viral vaccines, including the vaccine for the human immunodeficiency virus (HIV). The Chinese equine infectious anemia virus (EIAV) attenuated vaccine has controlled the epidemic of this virus after its vaccination in over 70 million equine animals during the last 3 decades in China. Data from our past studies demonstrate that the Env protein of this vaccine plays a pivotal role in protecting horses from both homologous and heterogeneous EIAV challenges. Therefore, the amino acid sequence information from the Chinese EIAV attenuated vaccine, in comparison with the parental wild-type EIAV strains, was applied to modify the corresponding region of the envelope glycoprotein of HIV-1 CN54. The direction of the mutations was made towards the amino acids conserved in the two EIAV vaccine strains, distinguishing them from the two wild-type strains. The purpose of the modification was to enhance the immunogenicity of the HIV Env.</p> <p>Results</p> <p>The induced nAb by the modified HIV Env neutralized HIV-1 B and B'/C viruses at the highest titer of 1:270. Further studies showed that a single amino acid change in the C1 region accounts for the substantial enhancement in induction of anti-HIV-1 neutralizing antibodies.</p> <p>Conclusions</p> <p>This study shows that an HIV envelope modified by the information of another lentivirus vaccine induces effective broadly neutralizing antibodies. A single amino acid mutation was found to increase the immunogenicity of the HIV Env.</p

Increased Expression and Altered Methylation of HERVWE1 in the Human Placentas of Smaller Fetuses from Monozygotic, Dichorionic, Discordant Twins

<div><h3>Background</h3><p>The human endogenous retroviral family W, Env(C7), member 1 gene (<em>HERVWE1</em>) is thought to participate in trophoblast cell fusion, and its expression is diminished in the placentas of singleton intrauterine growth-retarded pregnancies. However, there is limited information about the role of <em>HERVWE1</em> in discordant fetal growth in twins. This study was to compare <em>HERVWE1</em> gene expression between the placentas of discordant monozygotic twins and to identify its regulation by methylation.</p> <h3>Methodology/Principal Findings</h3><p>Fetuses from twenty-one pairs of monozygotic, dichorionic, discordant twins were marked as “smaller” or “larger” according to birth weight. Placental <em>HERVWE1</em> mRNA and protein expression profiles were analyzed using quantitative RT-PCR and immunohistochemistry (IHC) staining. Methylation profiles of the <em>HERVWE1</em> promoter region were analyzed using a pyrosequencing assay. DNA methyltransferase (<em>DNMT</em>) transcript levels were analyzed by RT-PCR. 5-methyl cytosine (5-MC) was stained using an immunohistochemical assay. There was a significant negative correlation between <em>HERVWE1</em> mRNA levels and birth weight in twins (<em>P</em><0.01). Whereas the mean methylation level of the <em>HERVWE1</em> promoter region was diminished in the smaller group in discordant twins(<em>P</em><0.01), increased mRNA and protein levels of <em>HERVWE1</em> were found in smaller fetuses compared with larger fetuses in discordant twins(<em>P</em><0.01). There was no significant difference in 5-MC staining intensity between discordant twins (<em>P</em>>0.05). The <em>DNMT3b3</em> mRNA levels in the smaller group were significantly downregulated compared with the larger group in discordant twins(<em>P</em><0.05), whereas the <em>DNMT3b7</em> mRNA levels in the smaller group were significantly upregulated compared with the larger group in discordant twins(<em>P</em><0.05).</p> <h3>Conclusions/Significance</h3><p>In discordant, monozygotic, dichorionic twins, <em>HERVWE1</em> expression was higher in smaller fetuses and lower in larger fetuses. Methylation of the <em>HERVWE1</em> gene promoter region may participate in the regulation of <em>HERVWE1</em> gene expression in discordant twin pregnancies.</p> </div

Study on Calculation Method of Soluble Aerosol Removal Efficiency Under High Humidity Condition

Pool scrubbing is a potential method to remove aerosol particles under accident conditions of nuclear power plants. The relative humidity of aerosol laden gas will increase significantly when passing through the water pool, which will most likely induce hygroscopic growth of soluble aerosol. The hygroscopic growth of soluble aerosol can lead to the deviation of the size distribution of aerosol at the outlet of the water pool, resulting in a large evaluation error of the removal efficiency. In order to solve this problem, the size distributions of sodium chloride at the upstream and downstream of bubble column were measured at a gas flow rate of 4 lpm and a liquid height of 80 cm, respectively. Two methods of calculating aerosol actual size-dependency removal efficiency were proposed and compared. One method is directly calculating the removal efficiency by adding a diffusion drying tube installed at the upstream of Scanning Mobility Particle Sizer (SMPS) to reduce the relative humidity of sample gas below the efflorescence point. Another method is modifying the aerosol size distribution and concentration curve by using the hygroscopic growth theory of soluble aerosols. The experiment results obtained by the two methods are in good agreement