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On New Substances of Urea Derivatives Obtained by the Quantum-mechanical Method ab Initio, Their Structural-geometric, Charge and Energy Properties
Yury Mikhailovich Petrenko
Issue:
Volume 7, Issue 3, September 2021
Pages:
40-53
Received:
12 July 2021
Accepted:
24 July 2021
Published:
13 August 2021
Abstract: The body of humans and animals contains large quantities of urea, which is believed to serve as an excretory agent for removing excess protein in it. With regard to the toxicity of this substance in the body there is no clarity, whether it is a uremic toxin, or whether this substance is not toxic. It is possible that the role of urea in the body is connected with its metabolites. It is known that there are substances that are derivatives of urea, which exhibit high biological activity. Instance, the well-known carbamide derivative, hydroxycarbamide has gained recognition as an important anticancer drug and an effective promising therapeutic agent for sickle cell anemia. The discovery of new substances and the establishment of their properties is an important task of science, both theoretical and practical. Urea can be a source of new substances, urea derivatives with interesting properties. The aim of the work was, on the basis of quantum mechanical studies, to find out the fundamental possibility of the existence of other urea-derived substances and some other substances of a similar nature and to carry out a comparative analysis of their properties in terms of the interaction of their molecules with water molecules and with each other. In this work, the possibility of the existence of many substances that are derivatives of urea was discovered. Regarding the new urea-derived substances discovered by us, they can be divided into two groups of substances, substances containing a carbohydroxyl group in their composition and substances not containing it. Among the discovered new substances containing a karbohydroxyl group, a substance was found that is an isomer of urea. Based on the quantum mechanical approach, a comparative analysis of the structure, charge and energy properties of carbamide, hydroxycarbamide, and a number of new virtually synthesized carbamide derivatives is carried out. The work shows how the molecules of these substances interact with each other and with water molecules. Numerical values of geometric, charge and energy characteristics of new substances are given and the results obtained are discussed.
Abstract: The body of humans and animals contains large quantities of urea, which is believed to serve as an excretory agent for removing excess protein in it. With regard to the toxicity of this substance in the body there is no clarity, whether it is a uremic toxin, or whether this substance is not toxic. It is possible that the role of urea in the body is...
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Morphological Similarity Clustering and Its Applications in Anomaly Detection of Time Series
Hu Shaolin,
Huang Xiaomin,
Su Naiqian,
Wang Shihua
Issue:
Volume 7, Issue 3, September 2021
Pages:
54-61
Received:
1 August 2021
Accepted:
16 August 2021
Published:
27 August 2021
Abstract: Time series data clustering is an important branch and difficult topic in the field of data clustering. In this paper, the definition of temporal data morphological similarity is proposed, a set of affine invariant morphological similarity measurement methods of time series data is established, and a morphological clustering algorithm based on morphological similarity measurement is developed. Using morphological similarity measurement of time series data, two groups of abnormal change detection algorithms for time series data are established, which can be used to detect the morphological consistency of different periodical sampling series in the same time series and the morphological consistency among several time series in the same period. Based on these algorithms stated above, the multiple monitoring algorithms are proposed, which can be used to monitor states of many kinds of industry process. The effectiveness of the methods and algorithms is verified with theoretical deduction and simulation results. Simulation results show that these algorithms are very valuable for mining, clustering, modeling, statistical learning of multi-source time series data, as well as the detection and diagnosis of abnormal process changes.
Abstract: Time series data clustering is an important branch and difficult topic in the field of data clustering. In this paper, the definition of temporal data morphological similarity is proposed, a set of affine invariant morphological similarity measurement methods of time series data is established, and a morphological clustering algorithm based on morp...
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Modelling the Volatility of Central Bank of Kenya Currency Exchange Rates
Oganga Caneble,
Anthony Wanjoya,
Anthony Ngunyi
Issue:
Volume 7, Issue 3, September 2021
Pages:
62-68
Received:
15 August 2021
Accepted:
25 August 2021
Published:
4 September 2021
Abstract: In emerging countries, such as Kenya, the foreign exchange market is an important aspect in the economic development of a country. The currency exchange rate market, like the rest of the world's financial markets, has been marked by considerable instabilities over the last decade. The objective of this paper is to model the volatility of the KSH/USD exchange rate prices using and calculate the VaR using the GARCH-EVT model. In particular, this article uses the two-stage GARCH-EVT approach to estimate the value at risk of the Kenyan Shilling against the US dollar., particularly the one-day ahead Value-at-Risk forecast in risk control. The conditional and unconditional coverage test are used to back test the model. We compare the performance of the GARCH-EVT with the daily log returns of key currency in addition to modelling the value at risk in the Kenyan Foreign Exchange market (US dollar) foreign currencies from the period November 2004 – June 2021 for trading days with the exception of holidays and weekends. The mean equation that was best fitting for the data was ARMA (4,2). The optimal GARCH model for the returns of the KSH/USD exchange rate is the GARCH (1,3) with student-t innovations. The results of the backtesting show that GARCH-EVT can be utilized to estimate and forecast VaR at both 5% and 1% level of significance.
Abstract: In emerging countries, such as Kenya, the foreign exchange market is an important aspect in the economic development of a country. The currency exchange rate market, like the rest of the world's financial markets, has been marked by considerable instabilities over the last decade. The objective of this paper is to model the volatility of the KSH/US...
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