In the article are presented results from historic research and a new interpretation of historical material. The planetary orbits are closed curves; this is the main cause of the stability of our system, and this important circumstance stems from the law of attraction which, whatever the initial circumstances, makes each celestial body which is not expelled from our system follow the circumference of an ellipse. Until now it was not observed that the Newtonian law of attraction is the only one that fulfills this condition. In 1873, Joseph Louis Bertrand published a short but important paper in which he proved that there are two central fields only for which all bounded orbits are closed, namely, the isotropic harmonic oscillator law and Newton’s universal gravitation law. Bertrand offers the following problem: If you know that the planets describe conics without suggesting anything more, to find the expression of the components of the force from which they depend as a function of the coordinates of the application point.\n Another solution to this problem is given, which is based on the works of Darboux. Only two laws satisfy the necessary conditions: First law where force varies inversely with the square of the distance, and this is the law of Newton and second law where the attraction is proportional to the distance. The hypothesis is that the natural laws of the Universe depend on the scale of the phenomena. Within a galaxy is probably the only valid law of Newton. However, in the extra-galactic space of colossally longer distances, the other law is probably valid, where the attracting power is proportional to the distance. This may explain the \"escape of galaxies\" and the observed \"red shift\".
In this paper, we investigate divisor graphs with four triangles and establish a forbidden sub-graph characterization for all divisor graphs containing four triangles.
In this paper, we introduce a new flexible generator of continuous\ndistributions called the transmuted Burr X-G (TBX-G) family to extend and increase the flexibility of the Burr X generator. Two special sub-models namely, TBX-exponential and TBX-log-logistic distributions are introduced. Statistical properties of the TBX-G family are calculated. We discuss five estimation approaches to estimate the TBX-G parameters and numerical simulations are conducted to compare between the suggested approaches. Using two skewed engineering data sets, we illustrate the importance and flexibility of two sub-models of the TBX-G class as compared with other existing competing distributions.
Normalization appears to be an essential step for data analysis and MCDM methods. In this study, it is aimed to reveal the positive and negative features of the normalization techniques that can be used in the context of MCDM problems. For this purpose, fourteen sets reflecting different scenarios of decision problems were used to compare normalization techniques. Applied comparison results showed that the properties of problems and MCDM methods should be taken into account in the selection of the normalization technique. If the decision-maker decides to choose the one with the highest (or lowest) performance value in the criteria among the alternatives and to avoid the one with the lowest (or highest) performance value, it will be correct to use the normalization techniques depending on optimization aspect. On the other hand, if there are ideal/utopian values determined by the decision-maker for each criterion, it will be sensible to use reference-based normalization techniques. If the decision-maker has the opinion that the values in the criteria do not represent the monotonous increasing / decreasing benefit, then the usage of non-linear normalization techniques can be helpful. Also, it would be correct to choose mixed normalization techniques if the mentioned condition changes within the context of the criteria. However, some data structures, such as having zero and negative values in the decision matrix, can prevent the use of some normalization techniques. Besides, the problem of rank reversal, the range of normalized values, obtaining the same optimization aspect for all criteria, the robustness, and the validity of the results will affect the choice of the normalization technique.
Given that the motivational factors’ identification regarding the online purchasing is critical to the online retailers’ success, the research on the antecedents of the online customer experience (cognitive and affective experiential states) has attracted widespread attention. This research covers an extensive survey of the major discrepancies in the buyer of online products’ behavior according to the age of the respondents and synthesized their findings into an econometric model able to explain the impact of the cultural, social, personal and psychological traits on the online purchasing. The survey in this paper reveals that a myriad of factors have been examined in the context of online buyer\'s psychological perception in relation to the motivational factors. The results on these factors have been reported. The proposed econometric model helps decision makers from online retailers to better understand the motivational factors of online customers, to discover recent trends in this stream of the research, and to shed light on the future research.
The current study includes the assessment of physicochemical characteristics along with the microbial diversity of water samples collected from three important sacred hot water springs of the Uttarakhand state in India near to the world-famous Hindu shrine Yamunotri temple. Hot water samples were collected for two continuous years 2015-2016 in two sampling operations each year and overall fifteen physicochemical attributes were observed and recorded. However, the microbial diversity was explored by using morphological, biochemical and MALDI-TOF-MS. A total of twenty-two microbial strains were identified from Surya Kund with water temperature ranged between 86°C and 89°C; twenty-two microbial strains were identified from Draupadi Kund with water temperature ranged between 65°C and 69°C and twenty-one microbial strains were identified from Yamunotri Tapt Kund with water temperature ranged between 45°C and 48°C during the study period. This maiden study on the assessment of physicochemical characteristics and thermophilic microbial diversity of all three hot water springs can be a good reference for further studies on similar aspects. The available data will also help to understand the reason behind the curative properties of these hot water springs. It also helps the government and local administration to take preventive measures for the conservation and management of these hot water springs.
E0 algorithm is the most popular which used for data transmission Bluetooth communication among devices. E0 is having a 128-bit of symmetric stream cipher key length. Many types of attacks at Bluetooth protocol and cryptanalysis of E0 has proved that it would be broken by using 264 operations. In this work, we have proposed hybrid encryption based on blowfish and md5 algorithms to improve the security of transferring data between two computers connected using Bluetooth technique. Because of the advantages of key management of the MD5 algorithm, we used it to encrypt the secret key of BlowFish algorithm which used for encryption of plaintext. Therefore, the proposed hybrid encryption (BlowFish and MD5) will positively improve the security of data during transmission in Bluetooth media.