Hidden Symmetries in Classical Mechanics and Related Number Theory Dynamical System

Classical Mechanics consists of three parts: Newtonian, Lagrangian and Hamiltonian Mechanics, where each part is a special extension of the previous part. Each part has explicit symmetries (the explicit Laws of Motion), which, in turn, generate implicit or hidden symmetries (like the Law of Conservation of Energy, etc). In this Master\u27s Thesis, different types of hidden symmetries are considered; they are reflected in the Noether Theorem and the Poincare Recurrence Theorem applied to Lagrangian and Hamiltonian Systems respectively. The Poincare Recurrence Theorem is also applicable to some number theory problems, which can be considered as dynamical systems. In this thesis, we study the problem The first digits of the powers of integers . A dynamical system interpretation for this problem allows to apply the Poincare Recurrence Theorem to find several unexpected hidden symmetries like rotations on the circle and on the torus, as well as hidden arithmetic progressions in the set of all the exponents

Tribological behavior of dual and triple particle size SiC reinforced Al0MMCs: a comparative study

Purpose- The aim is to study the tribological behavior of dual particle size (DPS)and triple particle size (TPS) SiC reinforced aluminium allloy based metal matrix composites - MMCs (Al/SiCp MMC)SiCp/Al-MMC). Design /methodology /approach- Al-MMCs were prepared using 20 vol% SiC reinforcement into aluminum metal matrix and developed using a stir casting process. Stir casting is a primary process of composite production whereby the reinforcement ingredient material is incorporated into the molten metal by stirring. The triple particle size (TPS) composite consist of SiC of three different sizes viz., coarse, intermediate and fine. The solution heat treatment was done on as cast (AC) composite at 540 0C for four hours followed by precipitation treatment. The wear test was carried out using a pin-on-disc type tribo-test machine under dry sliding condition. A mathematical analysis was also done for power factor values based on wear and friction results. The wear morphology of the damaged surface was also studied using optical microscope and scanning electron microscope (SEM) in this investigation. Findings- The test results showed that heat treated composite exhibited better wear resistance properties compared to as cast composite. It is anticipated that heat treatment could be an effective method of optimizing the wear resistance properties of the developed Al-MMC material

Wear behavior of as-cast and heat treated triple particle size SiC reinforced aluminium metal matrix composites

Purpose – The purpose of this paper is to study the wear behavior of as-cast (AC) and heat treated (HT) triple particle size (TPS) silicon carbide (SiC) reinforced aluminum alloy-based metal matrix composites (SiCp/Al-MMC). Design/methodology/approach – Al-MMCs were prepared using 20?vol.% SiC reinforcement into aluminum metal matrix and developed using a stir casting process. Stir casting is a primary process of composite production whereby the reinforcement ingredient material is incorporated into the molten metal by stirring. The TPS composite consist of SiC of three different sizes viz., coarse, intermediate, and fine. The solution heat treatment was done on AC composite at 540°C for 4?h followed by precipitation treatment. The wear test was carried out using a pin-on-disc type tribo-test machine under dry sliding condition. A mathematical analysis was also done for power factor values based on wear and friction results. The wear morphology of the damaged surface was also studied using optical microscope and scanning electron microscope (SEM) in this investigation. Findings – The test results showed that HT composite exhibited better wear resistance properties compared to AC composite. It is anticipated that heat treatment could be an effective method of optimizing the wear resistance properties of the developed Al-MMC material. Practical implications – This paper provides a way to enhance the wear behavior of automotive tribo-components such as brake rotor (disc and drum), brake pad, piston cylinder, etc. Originality/value – This paper compares the wear behavior of AC and HT TPS reinforced Al-MMC material under dry sliding condition

Monetary policy and inflation targeting in a small open-economy

This paper investigates the transmission mechanism of monetary policy and inflation targeting in a small open-economy by using backward-looking of aggregate supply (AS) and aggregate demand (AD) framework. Since September 1998 until July 2005, Malaysia has implemented a currency pegged to the U.S dollar in responding to the Asian financial crisis. However, since the 21st of July 2005 until at present, the Central Bank of Malaysia (CBM) has eliminated pegging with the U.S dollar and moved to the floating exchange rate with basket currencies framework. This new regime has an essential role to be a primary objective of policy in stabilizing exchange rate against its major trading partners, particularly the regional countries. Nevertheless, maintaining the soundness of interest rate is also important to perceive inflation targeting in increasing economic growth. Therefore, by using a quarterly data from 1991:1 to 2006:1, this study has adopted a traditional structural econometrics model (SEM) to examine the role of inflation targeting in monetary policy transmission in a small-open economy, i.e. Malaysia. The findings indicated that output gap is an important variable in forecasting a domestic inflation rate and interest-rates policy is statistically significant in influencing the output gap. Therefore, the choosing of interest-rates as a policy target is vital in controlling the domestic inflation rate.monetary policy transmission; inflation targeting; interest rate; exchange rate; fiscal policy

Analysis on Factors that Affect Stock Prices: A Study on Listed Cement Companies at Dhaka Stock Exchange

This study investigates on identifying the main forces that affect share prices in the capital market of Bangladesh. For this, the study considers a panel data set of 7 companies of cement industry listed in the Dhaka Stock Exchange (DSE) for the period 2006-2015.The investigation approach is designed with Ordinary Least Square (OLS) regression with fixed effects and random effects models. Six fundamental and technical issues namely Earning Per Share (EPS), Net Asset Value Per Share (NAVPS), Price Earnings (P/E), Gross Domestic Production (GDP), Consumer Price Index (CPI) and Interest Rate Spread (IRS) have been brought in light as the major determinants of prices in cement industry. The findings claim that these variables are instrumental in affecting the share prices in the Bangladesh market as far as the cement industry is concerned. Among these factors EPS, NAVPS, P/E and CPI have been found significantly instrumental for cement industry in Bangladesh contexts while other variables were not found noticeably significant. A moderate R square (0.1142-.4567) found in both the Fixed and Random models justify the considerable impact of these variables on the market price of shares. Hence, the study recommends present and potential investors to consider these factors prior to trade and inject funds on securities as the study witnessed volatility in share prices by the fluctuations of these factors. Key Words: Capital Market, Share Price, Dhaka Stock Exchange

Job Satisfaction of Employees in Banking Sector: A Case Study on Janata Bank Limited

The aim of this study is to evaluate the level of job satisfaction of the employees of state owned commercial bank (SCB) named as Janata Bank Limited. Data was collected for this study by questionnaire method. The study shows that Job preference, Cooperation among Co-workers, Working Environment, Working Facilities, Salary Satisfaction, Increment Satisfaction, Welfare Facilities, other facilities, Performance Appraisal System, Behavior of boss, Career Development organism, and Promotion system significantly influence job satisfaction of  employees. The study indicates a positive sign regarding overall job satisfaction of employees of the bank. In such situation, job satisfaction of bank officers becomes an important issue that has to be taken care of in order to achieve ultimate goals of the banking sector in Bangladesh. Keywords: Job satisfaction, SCB (state owned commercial bank), Bank Employees and Satisfaction Leve

Identifying Important Features For Exoplanet Detection: A Machine Learning Approach

The study and discovery of exoplanets (planets outside the solar system) have been a major focus in astronomy. Many efforts have been made to discover exoplanets using ground based and space based observatory, NASA’s Exoplanet Exploration Program being one of them. It has developed modern satellites like Kepler which are capable of collecting large array of data to help researchers with these objects. With the increasing number of exoplanet candidates, identifying and verifying their existence becomes a challenging task. In this research, we propose a statistical and machine learning approach to identify important features for exoplanet identification. For this purpose, we use the Kepler Cumulative Object of Interest (KCOI) dataset. After pre-processing the data we utilize statistical methods namely ANOVA F-test, Mutual Information Gain (MIG), Recursive Feature Elimination (RFE) to select the most significant features and have trained 10 state-of-the-art classifiers on them recursively to identify the features that leads to best performance. According to the results of our investigation, classifiers trained on features chosen by Recursive Feature Elimination with Random Forest as estimator produces superior results, with CatBoost classifier being the best with an accuracy of 99.61%. Our findings demonstrate the potential of machine learning in helping astronomers to efficiently and accurately verify exoplanet candidates in large astronomical datasets

Impak hasil berasaskan petroleum terhadap perbelanjaan awam di Malaysia

Kajian ini bertujuan untuk menilai sumbangan hasil cukai dan bukan cukai daripada sumber asli petroleum terhadap perbelanjaan kerajaan persekutuan (perbelanjaan awam). Kaedah ekonometrik siri masa iaitu pendekatan Autoregressive Distributed Lag (ARDL) digunakan untuk mengkaji impak hasil petroleum tersebut terhadap perbelanjaan awam. Dapatan kajian menunjukkan cukai pendapatan petroleum, hasil daripada dividen PETRONAS dan hasil cukai bukan petroleum signifikan mempengaruhi belanja awam secara positif dalam jangka panjang. Penemuan kajian ini mencerminkan wujudnya keperluan kepada kerajaan persekutuan di Malaysia untuk memperkukuhkan lagi asas kutipan cukai terutama daripada hasil cukai yang bukan berasaskan sumber asli bagi mengurangkan kebergantungan pembiayaan perbelanjaan awam menerusi hutang awam

Evaluation of Novel Bio-friendly Two-step Process in the Removal of Heavy Metals from the Wastewater

Two-step treatment technique was developed for the treatment of water by Pseudomonas aeroginosa in a bioreactor in a first phase and then the bacterial treated water was treated with the vetiver grass, cattails and water hyacinth in second phase. Two-step process of bioremediation of 13 days was found to be satisfactory for As, Ba, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn in compared to the direct treatments with vetiver grass, cattails and water hyacinth in 20 days. As the plants cannot work or tolerate the higher concentrations of heavy metals, so with the first step on an average 52.48% reduction of heavy metals were done within 5 days. It was observed that 100% removal of Pb was found by two-step process of Pseudomas aeroginosa with cattails and water hyacinth, respectively in 13 days, while 98.16% removal of Pb was found by direct plant treatment of water hyacinth in 20 days. It was clear that the two-step treatment for vetiver grass, cattails and water hyacinth were found as the most effective treatments