Curve25519 based lightweight end-to-end encryption in resource constrained autonomous 8-bit IoT devices

Robust encryption techniques require heavy computational capability and consume large amount of memory which are unaffordable for resource constrained IoT devices and Cyber-Physical Systems with an inclusion of general-purpose data manipulation tasks. Many encryption techniques have been introduced to address the inability of such devices, lacking in robust security provision at low cost. This article presents an encryption technique, implemented on a resource constrained IoT device (AVR ATmega2560) through utilizing fast execution and less memory consumption properties of curve25519 in a novel and efficient lightweight hash function. The hash function utilizes GMP library for multi-precision arithmetic calculations and pre-calculated curve points to devise a good cipher block using ECDH based key exchange protocols and large random prime number generator function.

Approximation by pseudo-linear discrete operators

<p style='text-indent:20px;'>In this note, we construct a pseudo-linear kind discrete operator based on the continuous and nondecreasing generator function. Then, we obtain an approximation to uniformly continuous functions through this new operator. Furthermore, we calculate the error estimation of this approach with a modulus of continuity based on a generator function. The obtained results are supported by visualizing with an explicit example. Finally, we investigate the relation between discrete operators and generalized sampling series.</p>

A new bivariate Archimedean copula with application to the evaluation of VaR

In this paper, a new generator function is proposed and based on this function a new Archimedean copula is introduced. The new Archimedean copula along with three representatives of Archimedean copula family which are Clayton, Gumbel and Frank copulas are considered as models for the dependence structure between the returns of two stocks. These copula models are used to simulate daily log-returns based on Monte Carlo (MC) method for calculating value at risk (VaR) of the financial portfolio which consists of two market indices, Ford and General Motor Company. The results are compared with the traditional MC simulation method with the bivariate normal assumption as a model of the returns. Based on the backtesting results, describing the dependence structure between the returns by the proposed Archimedean copula provides more reliable results over the considered models in calculating VaR of the studied portfolio.

METHODS OF GENERATING TASKS FOR KNOWLEDGE ASSESSMENT

The article considers different methods of generation of test assignments . Their characteristics and their shortcomings were provided. Based on the shortcomings of other methods, the optimal method of the tests’ generation is chosen in the form of an online exam system with a test generator function. The article describes various requirements for the test assignments including possible types of tests, questions and tasks. The high relevance of the online exam systems is identified, as well as an analysis of its advantages and disadvantages. A comparison of characteristics of the existing systems of online examination is carried out, the basic parameters of these systems and differences between them are defined. Based on this comparison, the essential components of the system and the stages of its creation were identified. The article provides description of each component/module, the functions it performs, as well as the relationship between the modules. Also described are technologies, with which the system will be developed, and reasons for their selection. This system is developed with the server programming language PHP and MySQL database. The structure of the database is given in the article. A description of the most important database tables and their parameters is given. The article identifies different users roles within the system, their capabilities and functions in each module. It also presents their relationships in the form of UML diagrams and describes access levels by roles. The system will assist teachers with the process of generating assignments for various tests or exams. It will also facilitate educational monitoring of each student, identify their learning strengths and weaknesses, and assess their level of knowledge, thus saving teachers’ and students’ time. The teacher will only need to specify the necessary parameters for the test generation application, and the system itself will generate the appropriate assignments with the relevant tasks. The system will also allow students to take a test or exam from any device anywhere. The possible further improvements of the system are described, as well as potential issues that would have to be considered and addressed in the future.

Conditional tail independence in Archimedean copula models

Consider a random vector $\textbf{U}$ whose distribution function coincides in its upper tail with that of an Archimedean copula. We report the fact that the conditional distribution of $\textbf{U}$ , conditional on one of its components, has under a mild condition on the generator function independent upper tails, no matter what the unconditional tail behavior is. This finding is extended to Archimax copulas.

ARTHROSCOPY OF THE KNEE

Introduction: Arthroscopy has a significant efficacy amongst patients, butis dependent on the anasthesia used. This is particularly important, as research on kneearthroscopy has established importance on anasthesia, particularly the type and number used.Study Research Objective: This study conducted over a period of 2 years, included all patientsundergoing knee arthroscopy, irrespective of age, gender and underlying conditions (whethertraumatic, degenerative, infective or inflammatory). In this study the Impact of postoperativepain management on patient recovery was evaluated. There is evidence that the knee joint hasmorphine receptors, thus nalbuphin was used. Study Design: Randomized Case Control Study.Setting: Department of KRL Hospital. Period: Jan 2014 to Dec 2015. Methodology: Randomizationwas done through the random number generator function provided by Open EPI Ver. 3.01.The random numbers generated were compared with serial numbers assigned to patientsthrough consent forms and then assigned to the three groups accordingly (Control, Lignocaine,Lignocaine + Nalbucin). Out of 117 patients 6 patients were given general anesthesia and 111were given spinal anesthesia. Arthroscopy was done under tourniquet control. To measure painthresholds, a visual analogue scale from 1 to 9 was used and then made into three groups:mild (1-3), moderate (4-6) and severe (7-9). Patient Mobilization was measured 4, 6, 8, 10, 12,14, and 16 hours post operation. Analysis was done using OpenEPI Ver. 3.01 and MicrosoftExcel 2013 separately for both Lignocaine and Lignocaine + Nalbuphin. A systematic literaturereview was done to compare the results found in this study with those found in this study. Forthis purpose, the following string was used in Google Scholar and Pubmed: “Arthroscopy”AND “TB” AND “Synovial Biopsy” and “Postoperative Pain Management” AND “Arthroscopy”AND “Knee Joint”. Results: Interventions of Lignocaine and Lignocaine + Nalbucin were moreeffective than control. Lignocaine + Nalbucin combined showed higher chances of mobilitywhen compared to Lignocaine and control. Systematic Literature Review also provided similarresults. Conclusion: If this procedure is performed with the correct expertise and the patientgiven intra articular lignocaine and Nalbuphin, the patients show early and good recovery andtherefore they can be discharged the same day thus reducing the cost on the patient as wellas the hospital.