STATISTICAL CAUSALITY AND EXTREMAL MEASURES

Petrovic, Ljiljana,Valjarevic, Dragana Korean Mathematical Society 2018 대한수학회보 Vol.55 No.2

In this paper we consider the concept of statistical causality in continuous time between flows of information, represented by filtrations. Then we relate the given concept of causality to the equivalent change of measure that plays an important role in mathematical finance. We give necessary and sufficient conditions, in terms of statistical causality, for extremality of measure in the set of martingale measures. Also, we have considered the extremality of measure which involves the stopping time and the stopped processes, and obtained similar results. Finally, we show that the concept of unique equivalent martingale measure is strongly connected to the given concept of causality and apply this result to the continuous market model.

Evaluation of the Composition and Morphology of a WTi/Si System Processed by a Picosecond Laser

Suzana Petrovic,D. Peruško,I. Radovi-Bogdanovic,G. Brankovic,M. Cˇekada,B. Gakovic,M. Jakšic,M. Trtica,Milosavljevic 대한금속·재료학회 2012 METALS AND MATERIALS International Vol.18 No.3

In this work we studied the influence of laser radiation on the composition, structure and morphology of WTi thin films deposited on n-type (100) silicon wafers. The films were deposited by d.c. sputtering from a 70:30 at% W-Ti target, using Ar ions, to a thickness of ~190 nm. Irradiation was performed with a pulsed Nd:YAG laser operating at 1064 nm, whereas the pulse duration was 150 ps. Laser fluences of 3.2and 5.9 J/cm2were found to be sufficient for modification of the WTi/silicon target system. The results show: (i) ablation of WTi thin film and a Si substrate in the central zone of spots, (ii) appearance of hydrodynamic features like resolidified material, (iii) partial ablation of the WTi thin film at the periphery and (iv) appearance of thin film cracks at the far periphery. On the non-ablated areas, the laser modifica-tion induced changes in composition, such as inter-mixing of components at the WTi/Si interface with for-mation of silicides in both metals. Surface oxidation was the dominant process in the ablated areas, which is demonstrated by the presence of a SiO2 phase.

Self assembly of biomimetic hydroxyapatite on the surface of different polymer thin films

M. Petrovic 한양대학교 세라믹연구소 2012 Journal of Ceramic Processing Research Vol.13 No.4

The role of the process of designing a scaffold in bone tissue engineering is to provide optimal conditions for new bone tissue growth. The primary concern of such engineering is to create an adequate nanotopology of the scaffold inner walls, which can initiate the growth and activity of bone cells. Here, we present a completely new scaffold designing process based on a biomimetic approach in order to improve the nanostructure of pore walls of previously-made calcium hydroxyapatite (CHA) porous scaffolds. CHA porous scaffolds were covered with different polymer thin films (alginate, cellulose and PLGA) and exposed to simulated body fluid (SBF) for 42 days. SBF induced in situ formation of “bone-like” apatite phases on the surface of CHA/polymer composites. Fourier Transformed Infrared (FTIR) spectroscopy showed that the biomimetically-assembled phase is CHA of slightly shifted stoichiometry. X-ray diffraction confirmed that CHA is self-assembled on the surface of all investigated thin films. The calculation of crystallite sizes showed small differences in the degree of crystallinity between different samples. Scanning electron microscopy revealed a dominant blow-ball morphology of CHA particles (size 1 - 5 µm) with nano-sized branches on their surfaces.

Statistical causality and extremal measures

Ljiljana Petrovic,Dragana Valjarevic 대한수학회 2018 대한수학회보 Vol.55 No.2

In this paper we consider the concept of statistical causality in continuous time between flows of information, represented by filtrations. Then we relate the given concept of causality to the equivalent change of measure that plays an important role in mathematical finance. We give necessary and sufficient conditions, in terms of statistical causali\-ty, for extremality of measure in the set of martingale measures. Also, we have considered the extremality of measure which involves the stopping time and the stopped processes, and obtained similar results. Finally, we show that the concept of unique equivalent martingale measure is strongly connected to the given concept of causality and apply this result to the continuous market model.

Application of Mixture Experimental Design in the Formulation and Optimization of Matrix Tablets Containing Carbomer and Hydroxypropylmethylcellulose

Aleksandra Petrovic,Nebojsa Cvetkovic,Dragica Popadic,Radmila Popovic,Svetlana Ibric,Svetlana Trajkovic,Zorica Djuric 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.12

Using mixture experimental design, the effect of carbomer (Carbopol® 971P NF) and hydroxypropylmethylcellulose (Methocel® K100M or Methocel® K4M) combination on the release profile and on the mechanism of drug liberation from matrix tablet was investigated. The numerical optimization procedure was also applied to establish and obtain formulation with desired drug release. The amount of TP released, release rate and mechanism varied with carbomer ratio in total matrix and HPMC viscosity. Increasing carbomer fractions led to a decrease in drug release. Anomalous diffusion was found in all matrices containing carbomer, while Case - II transport was predominant for tablet based on HPMC only. The predicted and obtained profiles for optimized formulations showed similarity. Those results indicate that Simplex Lattice Mixture experimental design and numerical optimization procedure can be applied during development to obtain sustained release matrix formulation with desired release profile.

America’s Nationalist Turn and Territorial Revisionism in the Asia-Pacific

Bojan PETROVIC 동북아역사재단 2017 Journal of Northeast Asian History Vol.14 No.2

Parametric Model Variability of the Proximal Femoral Sculptural Shape

Suzana Petrovic Savic,Branko Ristic,Zoran Jovanovic,Aleksandar Matic,Nikola Prodanovic,Nabil Anwer,Lihong Qiao,Goran Devedzic 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.7

In this paper, a method of parameterisation of a proximal femur model is presented. The created model retains all the anatomical and morphological features of a realistic model. The parametric model of the femur, the so-called master model, is defined by establishing a relation between appropriate femoral regions which extend along the parametrically described axis of the femur. An initial 3D model of the femur is segmented from the CT image and further parameterized to a master model with the potential for customization, i.e. for adaptation to patient-specific values using X-ray images, still maintaining precise anatomical consistency. The first step towards the femur customization is the contour extraction of different types of tissues represented in X-ray images. As medical images can be blurry, image processing was carried out and a Canny edge detector operator was applied. The numerical values of the parameters were determined by manual measuring of defined regions on an X-ray image. The variability testing was performed on 12 femurs. The proposed model can greatly contribute to preoperative planning, implant selection, as well as to the overall shortening of intervention time.

European Coaching Council (ECC)

Ladislav Petrovic 한국코칭능력개발원 2008 Coach Vol.24 No.2

The European Coaching Council is acting as a specialist group working under the umbrella of the European Network of Sport Science, Education and Employment (ENSSEE) and it is formally playing the role of the continental body for Europe of the International Council for Coach Education (ICCE). The mission of the ECC is to promote the development of coaching across Europe by providing clear reference points for the education, development, qualification and employment of coaches. Reference points have been be developed with and made available for use by EU member states, international federations, higher education and other agencies. One of the main recent projects of ECC is an international study on the Recognition of Coaching Competence and Qualifications. This document describes the review process that has been carried out on the EU 5-level structure for the recognition of coaching qualifications. The need for the review was identified by the members of the European Coaching Council, given that the initial structure for the recognition of coaching qualifications was first developed in 1999. It was also felt that there was a need to more fully engage with the International Federations on the issue of coach education, competence and qualifications. In a wider, global context the International Council for Coach Education has also indicated the need for a framework to guide the recognition of coaching qualifications between different countries. In addition, there have been several wider developments within vocational education and training in the European Union that have significant implications for the way in which coaches are educated and their competence and qualifications recognised. A European Coaching Convention had been proposed and accepted which identifies this review document on the recognition of coaching competence and qualifications as the European recognised reference point for the period 2008-11.

Early growth response protein 1 acts as an activator of SOX18 promoter

Isidora Petrovic,Natasa Kovacevic-Grujicic,Milena Stevanovic 생화학분자생물학회 2010 Experimental and molecular medicine Vol.42 No.2

Sex-determining region Y box 18 (Sox18/SOX18) gene is an important regulator of vascular development playing a role in endothelial cell specification or differentiation,angiogenesis and atherogenesis. The aim of this study was to perform comprehensive functional characterization of the human SOX18 promoter, including determination of transcription start point (tsp)and identification of control elements involved in the regulation of SOX18 gene expression, with an emphasis on angiogenesis-related transcription factors. Analyses were performed in HeLa cells, representing a tumor cell line, and in EA.hy926 cells used as an endothelial model system. We have determined unique tsp of SOX18 gene, located 172 nucleotides upstream from ATG codon. Further, we have shown that SOX18 promoter region, -726 to -89 bp relative to tsp, contains positive cis-regulatory element(s) that stimulates SOX18 promoter activity, while region -89 to + 166 represents the minimal promoter. Within this region we have recognized the presence of essential element(s),positioned from -89 to +29, which harbors cluster of three putative early growth response 1 (EGR1) binding sites. By in vitro binding assays and functional analyses we have shown that these three putative binding sites are functionally relevant and sufficient for EGR1-induced SOX18 transcription. Mutations of these binding sites significantly impaired activity of the SOX18 promoter, particularly in EA.hy926 cells, indicating the importance of these regulatory elements for SOX18 promoter activity in endothelial setting. By data presented in this study, we have established SOX18 as a novel target gene regulated by EGR1 transcription factor, thus providing the first functional link between two transcription factors previously shown to be involved in the control of angiogenesis.

Special issue dedicated to Professor Cae-One Kim : How Far and Soon to the East? The Prospects for Future EU Enlargement

( Milenko Petrovic ) 한국EU학회 2004 Asia-Pacific Journal of EU Studies Vol.2 No.2