Transport study of Berry's phase, the resistivity rule, and quantum Hall effect in graphite

Transport measurements indicate strong oscillations in the Hall-,$R_{xy}$, and the diagonal-, $R_{xx}$, resistances and exhibit Hall plateaus at the lowest temperatures, in three-dimensional Highly Oriented Pyrolytic Graphite (HOPG). At the same time, a comparative Shubnikov-de Haas-oscillations-based Berry's phase analysis indicates that graphite is unlike the GaAs/AlGaAs 2D electron system, the 3D n-GaAs epilayer, semiconducting $Hg_{0.8}Cd_{0.2}Te$, and some other systems. Finally, we observe the transport data to follow $B\times dR_{xy}/dB \approx - \Delta R_{xx}$. This feature is consistent with the observed relative phases of the oscillatory $R_{xx}$ and $R_{xy}$.Comment: 5 pages, 4 figure

Magnetotransport in Two Dimensional Electron Systems Under Microwave Excitation and in Highly Oriented Pyrolytic Graphite

This thesis consists of two parts. The first part considers the effect of microwave radiation on magnetotransport in high quality GaAs/AlGaAs heterostructure two dimensional electron systems. The effect of microwave (MW) radiation on electron temperature was studied by investigating the amplitude of the Shubnikov de Haas (SdH) oscillations in a regime where the cyclotron frequency $\omega_{c}$ and the MW angular frequency $\omega$ satisfy $2\omega \leq \omega_{c} \leq 3.5\omega$. The results indicate negligible electron heating under modest MW photoexcitation, in agreement with theoretical predictions. Next, the effect of the polarization direction of the linearly polarized MWs on the MW induced magnetoresistance oscillation amplitude was investigated. The results demonstrate the first indications of polarization dependence of MW induced magnetoresistance oscillations. In the second part, experiments on the magnetotransport of three dimensional highly oriented pyrolytic graphite (HOPG) reveal a non-zero Berry phase for HOPG. Furthermore, a novel phase relation between oscillatory magneto- and Hall- resistances was discovered from the studies of the HOPG specimen

Comparison of Candidate Itemset Generation and Non Candidate Itemset Generation Algorithms in Mining Frequent Patterns

Association rule mining is one of the important techniques of data mining used for exploring fruitful patterns from huge collection of data. Generally, the finding of frequent itemsets is the most significant step in association rules mining, and most of the research will be centered on it. Numerous algorithms have been discovered to find effective frequent itemsets. This paper compares the frequent pattern mining algorithms that use candidate itemset generation and the algorithms without candidate itemset generation. In order to have on field simulation for comparison, a case study algorithm from both types was chosen such as ECLAT and FP-growth algorithms. Equivalence class clustering and bottom up lattice traversal (ECLAT) algorithm accommodates ?Depth First Search? approach and requires the generation of candidate itemset. The FP-growth algorithm follows the ?Divide and Conquer? method and does not require candidate itemset generation. In this paper, the benchmark databases considered for comparison are Breast Cancer, Customer Data, and German Data etc. The performances of both the algorithms have been experimentally evaluated in terms of runtime and memory usage. From the result it is analyzed that the FP-tree algorithm is more advantageous as it does away with the need of generation of candidate patterns

Clustering of Images from Social Media Websites using Combination of Histogram and SIFT Features

In recent years, the rapid growth of high dimensional datasets has created an emergent need to extract the knowledge. With the tremendous growth of social network, there has been a development in the amount of new data that is being created every minute on the networking sites. This work presents an efficient analysis of SIFT and color histogram features with spectral clustering algorithm. In this work the images from social media websites are downloaded. The downloaded images are stored in the database. The proposed feature extraction technique is based on combination of both SIFT descriptor and color Histogram to increase the efficiency. The extracted features are then clustered using spectral clustering algorithm. The spectral clustering method is a clustering area which achieves the clustering goal in high dimension by allowing clusters to be formed with their own correlated dimension

EXPERIMENTAL STUDY ON BEHAVIOUR OF COLD FORMED STEEL LIPPED ANGLE COLUMNS

This article reports the experimental work on the behavior of cold formed steel lipped angle columns performed with pinned end conditions under axial compression. In this work three different types of equal and unequal plain and lipped angle sections were chosen with a total of 12 specimens. The column lengths were taken as 1200 mm. The material properties of these sections were found by conducting Tensile Coupon test. The section geometries were selected in order to take account of all types of buckling modes. The column strengths determined from the experiment was examined with the design strength attained from Direct Strength Method in North American Specification and with the Numerical results (ABAQUS) for Cold formed steel structures. Finally, an appropriate design proposal was suggested for DSM to forecast the ultimate strength of cold formed steel columns

Acculturation and oral health status among Tibetan immigrants residing in Bangalore City, India

Background: This study is the first of its kind conducted among Tibetans immigrants to Bangalore City, India to study the effects of acculturation on the oral health outcomes of less established group of individuals. Objectives: To determine the Acculturation and oral health status among Tibetan immigrants in Bangalore city and to assess the relationship between them. Materials and Methods: A random sample of 560 immigrants aged 18 years and above from different Tibetan centre of Bangalore city were included for the study. Acculturation was measured using modified Psychological-behavioral acculturation scale. Dental caries experience and periodontal status were recorded. Results: 49.1% of females and 50.9% of males were in highly accultured group. Bivariate analysis using Chi-square test was performed using 5% significance level. Logistic regression analysis demonstrated a strong association between DMFT and Ethnic factors, and periodontal status with language barrier and utilization of health care. Discussion: Reducing disparities in oral health status and in the use of dental services among Tibetan immigrants require attention to cultural factors such as language barrier and age at migration and immigrant’s degree of acculturation