#### 08. School of Science & Technology (2015-2019)

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Item Open Access Pairwise Overlap and Misclassification in Cluster Analysis(Nazarbayev University School of Science and Technology, 2015) Akynkozhayev, BirzhanShow more Separation of data into distinct groups is one of the most important tools of learning and means of obtaining valuable information from data. Cluster analysis studies the ways of distributing objects into groups with similar characteristics. Real-world examples of such applications are age separation of a population, loyalty grouping of customers, classification of living organisms into kingdoms, etc. In particular, cluster analysis is an important objective of data mining, which focuses on studying ways of extracting key information from data and converting it into some more understandable form. There is no single best algorithm for producing data partitions in cluster analysis, but many that perform well in various circumstances (Jain, 2008). Many popular clustering algorithms are based on an iterative partitioning method, where single items are moved step-by-step from one cluster to another based on optimization of some parameter. One of such algorithms, which will be mentioned in this paper is K-means algorithm, where data points are partitioned based on optimization of sum of squared distances within clusters (MacQueen, 1967). Another large class of algorithms are based on finite mixture model clustering methods. For example, stochastic emEMclustering method, which will also be covered in this article, is based on maximum likelihood estimation of statistical model parameters (Melnykov & Maitra). Misclassification of data is not a rare situation in cluster analysis. For instance, we can observe that several points have been misclassified on the previous figure (Figure 1) of true partition (a) versus the solution found by the K-means algorithm (b). Various factors lead to misclassification in clustering algorithms. The main goal of this paper is to analyze the effect of pairwise overlap, number of dimensions of data, and number of clusters on misclassification. The simplest case where misclassification can occur is when there are two clusters. The overlap is exact in this case, thus, we proceeded to use one of the simplest algorithms – K-means. At the higher number of clusters, when overlap is estimated, we considered more complex emEM algorithmShow more Item Open Access Multiple Point Compression on Elliptic Curves(Nazarbayev University School of Science and Technology, 2015) Otemissov, AdiletShow more The paper aims at developing new point compression algorithms which are useful in mobile communication systems where Elliptic Curve Cryptography is employed to achieve secure data storage and transmission. Compression algorithms allow elliptic curve points to be represented in the form that balances the usage of memory and computational power. The two- and three-point compression algorithms developed by Khabbazian, Gulliver and Bhargava [4] are reviewed and extended to generic cases of four and five points. The proposed methods use only basic operations (multiplication, division, etc.) and avoids square root finding. In addition, a new two-point compression method which is heavy in compression phase and light in decompression is developed.Show more Item Open Access Boundary Element Method for Stokes Flow in Incompressible Newtonian Fluids(Nazarbayev University School of Science and Technology, 2015-04) Tazhimbetov, Nurbek AkhmetulyShow more In this thesis, I present different discretization techniques for boundary integral method for Stokes flow in case of an incompressible Newtonian fluid. Boundary integral method (BIM) is one of many techniques that are used to solve Partial Differencial Equations (PDE) numerically. However, the basic advantage of the BIM is that it reduces the problem from n-dimensional domain to n - 1; for example, the two-dimensional square-box that contains viscous liquid can be solved by using the values of an unkown function at the boundary of square. Nevertheless, the BIM exhibits some challenges in finding the Green's function for a particular domain or differential operator, solving the integral equations and, especially, in computing the values of a complex domain. The latter one is quite diffcult because the flow diverges at corners (exhibits singularity). The goal of this work is to derive general analytical solution for Stokes equation (in integral equations form) and to compute the discretized integral equations using different quadrature rules for cavity problem.Show more Item Open Access Stable holomorphic polynomials on the half-plane and generalizations(Nazarbayev University School of Science and Technology, 2015-04) Kairzhan, AdilbekShow more The study of locations of zeroes of functions became popular among mathematicians many years ago. This investigation contributes a lot to wide range of theories and topics in Mathematics and Physics.Show more Item Restricted Morphometric characteristics of cancer cells grown in embryonic microenvironment and under antiviral treatment(Nazarbayev University School of Science and Technology, 2016) Shaimerdenova, MadinaShow more We describe here that both embryonic microenvironment treatment and antiviral treatment have the potential to serve as effective factors in changing morphometric characteristics of two highly aggressive cancer cell lines, with proven capability to decrease viability of cancer cells, reduce amount of colonies formed after treatment, alter intracellular features of cell such as nucleus and cytoskeleton and diminish aldehyde dehydrogenase activity after treatmentShow more Item Restricted Development of flow cytometry and microscopy techniques to monitor freshwater phytoplankton communities in Kazakhstani lakes(Nazarbayev University School of Science and Technology, 2016) Dashkova, VeronikaShow more In this project, we tested an approach based on separating fluorescent viability and metabolic dyes between different excitation lasers in order to reach minimal spectral overlap with the autofluorescent signal using flow and imaging cytometryShow more Item Restricted Application of advanced molecular techniques for analyzing phytoplankton population in Burabay National Nature Park Resort(Nazarbayev University School of Science and Technology, 2016) Sarsembekova, AsselShow more In this work, the molecular techniques as DNA extraction, DNA quantification, PCR analysis were optimized and subsequent sequencing was performed on MiSeq platform (Illumina, USA). We aimed to apply molecular methods to analyse phytoplankton population inhabiting Lake Shortan and Lake BurabayShow more Item Restricted Co-expression of FVIII with human IGG FC Fragment or mouse IL-10 in encapsulated G8 myoblast cells as a potential treatment of hemophilia A(Nazarbayev University School of Science and Technology, 2016) Kanketayeva, ZhansayaShow more In this master thesis study we have shown that recombination G8 myoblasts, encapsulated in alginate-PLL microcapsules can successfully secrete detectable levels of both Fc and IL-10 out of the capsules and sustain good viability, showing the potential of co-delivering FVIII by encapsulated cells.Show more Item Restricted Concentration dependent mitostatic effect and inhibition of cell motibility by different tubulin binding drugs-comparative study(Nazarbayev University School of Science and Technology, 2016) Balabiyev, ArnatShow more Here, we demonstrate the comparative effects of nocodazole, taxol and vinorelbine on mitotic progression and cell motility using mouse fibroblasts and three cancer cell linesShow more Item Restricted Role of astrocyte aging in the pathogenesis of Alzheimer`s disease(Nazarbayev University School of Science and Technology, 2016) Imangali, NurgulShow more In this study we presented in vitro model for replicative senescence of primary human astrocytes isolated from fetal brainsShow more Item Restricted Oral administration of chitosan/DNA nanoparticles containing DNA coding for FVIII and FC IgG fragment or IL-10 for the modulation of immune responses to FVIII in hemophilia mice(Nazarbayev University School of Science and Technology, 2016) Yerkesh, ZhadyraShow more Hemophilia A is an X-linked bleeding disorder, which occurs due to deficiency of clotting protein FVIII. Current treatment involves regular lifelong infusion of recombinant or plasma-derived FVIII protein, which is suboptimal, invasive and very expensive. One of the biggest challenges of the current therapy is the recognition of FVIII by immune system as a foreign substance, leading to the development of neutralizing antibodies, which makes further administration of FVIII ineffective. Therefore, an alternative cost effective and safe treatment to Hemophilia A is highly desirable. We propose chitosan-mediated oral non-viral gene therapy as a safe and costeffective strategy for immune modulation in severe hemophilia A cases. Having a strong affinity for DNA and forming nanoparticles, chitosan-DNA complexes protect plasmid DNA fi-om degradation by the low pH envu-onment of the stomach and from nucleases in the GI tract; further, safe re-administration of nanoparticles is possible. We also propose to include in the plasmid DNA coding for the Fc fragment of IgG heavy chain region, which contains Tregitope sequences, T cell epitopes that specifically activate regulatory T cells or anti-inflammatory cytokine IL-10 that may modulate the immune response against FVIII protein. Therefore, it is hypothesized that orally administered chitosan/DNA nanoparticles will lead to clinically relevant amount of FVIII in the host without an immune response, providing long term, cost-effective and safe treatment for hemophilia A. For this study we aimed to: I) optimize nanoparticles in terms of effective gene expression in vitro; 2) treat hemophilic mice orally with chitosan nanoparticles containing DNA coding for FVIII and for immunomodulatory elements (Fc fragment of IgG and IL-10) to induce tolerance to FVIII. We found that the key factors contributing to the effectiveness of gene expression in chitosan/DNA nanoparticles are the type of chitosan, the charge ratio (N/P) and the DNA concentration. In vivo, the optimized nanoparticles containing FVIII+Fc DNA significantly decreased antibody formation specific to F V I I I in prophylactic group of mice, and in 4/6 mice receiving nanoparticles containing FVIII+IL-10. It is tempting to hypothesize that this strategy might also be extended to modulate immune responses to other antigens.Show more Item Restricted Migration characteristics of cancer cells grown in embryonic microenvironment and under antiviral agents(Nazarbayev University School of Science and Technology, 2016) Karapina, OrynbassarShow more This study describes a method for investigating reprogramming of cancer cells using chicken embryo extract and dimishing cancer cell progressing with acyclovir and it was used as innovative approach to address whether aggressive cancer cells with high potential to proliferate and migrate to distant organs could respond to the treatments, which could control cell fate determinationShow more Item Open Access Statistical Morphological Disambiguation for Kazakh Language(Nazarbayev University School of Science and Technology, 2016) Azamat, DaianaShow more This paper presents the results of developing a statistical model for morphological disambiguation of Kazakh text. Starting with basic assumptions we tried to cope with the complex morphology of Kazakh language by breaking up lexical forms across their derivational boundaries into inflectional groups and modeling their behavior with statistical methods. We also provide maximum likelihood estimates for the parameters and an effective way to perform disambiguation with the Viterbi algorithm.Show more Item Open Access On a stochastic interacting particle system with pushing dynamics(Nazarbayev University School of Science and Technology, 2016) Abdukadyrov, NurlanShow more In this paper we study a stochastic two-particle system on Z where particles interact each other by pushing dynamics. We derive the explicit formulas of the transition probability and of the probability distributions of each particle's position at time t. Finally, we discuss about the generalization of our works to N-particle system.Show more Item Open Access Optimization of convex geometries: component quadratic and general(Nazarbayev University School of Science and Technology, 2016) Myrzakul, ZhanbotaShow more In this Capstone Project, we worked with a class of closure systems called convex geometries, which are closure systems with a closure operator that satisfies the anti-exchange property. We first looked at the result of optimization algorithm of component quadratic systems, which are discussed in [4], and reproved it for the case of convex geometries. We then investigated the following question: if a convex geometry is given by a set of implications, is it possible to find its optimum basis in polynomial time when the convex geometry does not have particular properties (for instance, not component quadratic)?Show more Item Open Access On logistic-normal distribution(Nazarbayev University School of Science and Technology, 2016-04) Almagambetova, Ayanna; Zakiyeva, NazgulShow more Existing distributions do not always provide an adequate fit to the complex real world data. Hence, the interest in developing more flexible statistical distributions remains strong in statistics profession. In this project, we present a family of generalized normal distributions, the T-normal family. We study in some details a member of the proposed family namely, the logistic-normal (LN) distribution. Some properties of the LN distribution including moments, tail behavior, and modes are examined. The distribution is symmetric and can be unimodal or bimodal. The tail of the LN distribution can be heavier or lighter than the tail of the normal distribution. The performance of the maximum likelihood estimators is evaluated through small simulation study. Two bimodal data sets are used to show the applicability of the LN distributionShow more Item Open Access Stability Analysis of SEIS model with spatial variations(Nazarbayev University School of Science and Technology, 2016-05) Baki, ZhuldyzayShow more In this report we present an SEIS model for infectious diseases with latent period and no immune response for spatially heterogeneous environment. Spatial heterogeneity is designed by several metapopulations. It was shown that global dynamics of an epidemics completely depends on basic reproduction number R0. By fxing the number of patches to two, we use next generation matrix method to obtain basic reproduction number and make further analysis on it. Migration rates of individuals are considered as one of the main factors that influence R0. Moreover, some numerical simulations for the dynamics of the system with different initial conditions is presented.Show more Item Open Access Finite Element Solution of Thermal Gee-Lyon Flows in a Circular Tube(Nazarbayev University School of Science and Technology, 2016-05) Aimambet, NarkenShow more The goal of this project is to calculate the temperature distribu- tion of certain pressure-driven non-Newtonian ows inside a circular tube. The rheology under consideration is the type in which the shear stress is an implicit function of the shear rate de ned as the inverse function of an odd function. The uid velocity in the tube is approximated by the steady state velocity pro le along the tube length and the viscosity is assumed to be independent of the temperature. The velocity pro le is computed by using Mathematica's build-in ODE solver semi-analytically. The corresponding steady state temperature pro le at tube length is then calculated taking into account of heat source generated by shear rate from the uid ow by solving an ODE. The temperature distribution from the entrance to the fully developed region is then approximated numerically by using the axisymmet- ric linear triangular nite elements. Material and geometric constants and data for extrusion of chemical Lucite through the tube in literature are used for the numerical example. Comparison of the numerical result with the industrial experimental result is made at a point along the central axis of the tube.Show more Item Open Access Modeling of corneal deformation under air-puff by nonlinear differential equations(Nazarbayev University School of Science and Technology, 2016-05) Jangabylova, Aliya; Zhalgas, AidanaShow more Intraocular Pressure (IOP) is a main factor for the diagnosis of glaucoma. In this report, the kinematic viscoelastic corneal models, specifcally the Maxwell and the Kelvin-Voight models, of human eye ball will be proposed for determining the displacement of the cornea during the air-puff tonometry simulations and its relationship to IOP. The purpose of project is to study the in uence of elasticity and viscosity to the corneal deformations under an air puff.Show more Item Open Access Representation of Convex Geometries by Convex Structures on a Plane(Nazarbayev University School of Science and Technology, 2016-05) Bolat, MadinaShow more Convex geometries are closure systems satisfying anti-exchange axiom with combinatorial properties. Every convex geometry is represented by a convex geometry of points in n-dimensional space with a special closure operator. Some convex geometries are represented by circles on a plane. This paper proves that not all convex geometries are represented by circles on a plane by providing a counterexample. We introduce Weak n-Carousel rule and prove that it holds for confgurations of circles on a plane.Show more