An improved chacha algorithm for securing data on IoT devices

In recent years, revolution of development was exceedingly quick in the Internet. Nevertheless, instead of only linking personal computers, mobiles and wearable equipment's, Internet growths from a web binding to true world physical substances that is indicated to novel connotation, which is labeled as Internet of Things (IoT). This concept is utilized in many scopes like education, health care, agriculture and commerce. IoT devices are presented with batteries to have independence from electric current; consequently, their working time is specified by the total time of the power of these batteries. In many IoT applications, data of IoT devices are extremely critical and should be encrypted. Current encryption approaches are created with a high complexity of an arithmetical process to provide a high level of security. However, these arithmetical processes lead to troubles concerning the efficiency and power consumption. ChaCha cipher is one of these approaches, which recently attracted attention due to its deployment in several applications by Google. In the present study, a new stream cipher procedure is proposed (called Super ChaCha), which performs low duty cycles for securing data on IoT devices. The proposed algorithm represents an improved revision to the standard ChaCha algorithm by increasing resistance to cryptanalysis. The modification focuses on rotation procedure which has been changed from a fixed constant to a variable constant based on random value. Also, the inputs of the cipher are changing in the columns form followed by diagonals form to zigzag form and then by alternate form to provide improved diffusion in comparison with the standard ChaCha. Results regarding the security illustrate that Super ChaCha needs 2512 probable keys to break by brute-force attack. Furthermore, the randomness of Super ChaCha successfully passed the five benchmark and NIST test.

Modeling the Influence of a Magnetomechanical Effect on the Permeability Tensor of a Tensductor Core

This paper presents a new method of modeling the influence of mechanical stresses on a magnetic permeability tensor of soft magnetic materials. The proposed method utilizes the principal stresses concept to compensate the influence of shear stresses. As a result, the stress dependence of a magnetic permeability tensor may be assessed with only the knowledge about the influence of axial stresses on magnetic properties of isotropic material. The proposed method was used for a finite element method based model of a tensductor designed for measurements of tensile forces. Due to the fact that 2D stresses distribution occurs in a tensductor, simplification of both principal stresses and a magnetic permeability tensor rotation procedure was proposed. As a result, good agreement was reached between the results of modeling and the results of experimental tests. This result validates the possibility of utilization of the proposed modeling method for the design of magnetomechanical devices.

MEMS Gyro Aided Calibration of Electronic Compass

In this paper, an MEMS gyro aided on line calibration algorithm for electronic compass is presented. This electronic compass module consists of a three-axis AMR sensor, a two-axis MEMS tilt sensor and a one-axis MEMS gyro. The automatic calibration method requires to rotate the electronic compass two full 360-degree revolution. In this rotation procedure, magnetic field data, attitude data and angular rate data are recorded. Based on recorded magnetic field data and attitude data, raw heading data is calculated. This raw heading data is verified by angular rate output of MEMS gyro. Results of experiment show that the accuracy of calibrated compass is better than 0.5 deg and MEMS gyro aided on line calibration algorithm is effective for electronic compass.

Increasing a large petrochemical company efficiency by improvement of decision making process

The paper shows the results of a research conducted in a large petrochemical company, in a state under transition, with the aim to "shed light" on the decision making process from the aspect of personal characteristics of the employees, in order to use the results to improve decision making process and increase company efficiency. The research was conducted by a survey, i.e. by filling out a questionnaire specially made for this purpose, in real conditions, during working hours. The sample of the respondents is representative for the goal of the research and consists of 82 employees, of all level of decision making, education, age structure, and years of service. The data has been processed by appropriate mathematical-statistical techniques: factor analysis, cluster analysis, correlation. For determining the important factors in decision making process, a type of factor analysis was used - the principal components analysis and the normalized Varimax rotation procedure. The basic hypotheses of research related to the readiness of the employees for independent decision making, readiness for risk taking, determining the level of usage of intuition, organization atmosphere, general and personal characteristics of employees, have been proved. The results of the research indicate that the process of decision making is complex one in the organization and that there is a tendency of the employees towards collective decision making, as it was used to be done. A significant result is that the employees at the managing positions are more ready for independent decision making than the employees at the executive positions. Based on the results of the research, it is possible to draft managerial and organizational measures for increasing the level of readiness for independent and individual decision making, and increase company efficiency, as well.

Form Generation Of Polyhedric Building Shapes

The Platonic - or regular - and the Archimedean - or semi-regular - polyhedra can be considered as portions of space that are completely surrounded by one or more kinds of regular polygons. The numbers and positions in space of these polygons are strictly ruled by universal criteria. It is therefore possible to form these polyhedra by placing polygons around the centre of the coordinate system in distinct numbers, at certain distances and under certain angles in accordance with these rules. This is called here ‘rotation’ and the forelying paper describes a method where this is done for the regular and semi-regular polyhedra and for related figures that are found by derivation from these polyhedra. The figures that are rotated have not necessarily to be regular polygons, nor do have to be strictly planar. This method thus allows the rotation of arbitrary figures – also spatial ones – and the rotation procedure can even be used repeatedly, so that very complex configurations can be described.

The quest for academic excellence: aspects relating to the assessment of the performance of University teaching staff

In an attempt to assess the views of academics about issues relating to performance appraisal/ and to test the views expressed by several authors, a questionnaire consisting of 23 items was developed and distributed to a random sample of senior lecturers, associate professors and professors from all South African universities. The research participants were requested to evaluate the importance of each of the items, as well as the extent to which these activities in fact existed in their departments. The resulting data were subjected to a principal factor analysis and an oblique rotation procedure, and five readily interpretable dimensions were identified for both sets of ratings. In the main, these dealt with Feedback and advice, Regular and formal appraisals, staff development, the Role of external examiners, and Consumer evaluation. While no differences were found between faculties, different degrees of experience, different qualification levels, and ranks, it was apparent that there were sizable differences between the importance that academics ascribe to the different aspects of appraisal and development and current practices in their departments. The findings have important implications for the management of academics. Opsomming In 'n poging om akademici se beskouings van aspekte rakende hulle eie prestasies, en outeurs se menings oor die onderwerp te ondersoek, is 'n vraelys met 23 items saamgestel. Die vraelys is onder 'n ewekansige steekproef van senior lektore/ mede-professore en professore versprei. Die navorsingsdeelnemers is versoek om die items te beoordeel aan die hand van die belangrikheid van die aktiwiteite wat deur die items verteenwoordig word, en die mate waarin die onderhawige aktiwiteite in hulle tuisdepartemente toegepas word. Die twee datastelle is aan 'n hooffaktorontleding en skuinsrotasie onderwerp en vyf komponente is gei'dentifiseer/ naamlik Terugvoer en advies, Gereelde en formele evaluerings, Personeelontwikkeling, dieRol van eksterne eksaminatore en Verbruikersevaluering. Geen verskille is ten opsigte van fakulteit/ rang/ oopvoedkundige kwalifikasies of doseerervaring gevind nie. Dit was egter duidelik dat daar 'n betekenisvolle verskil tussen akademici se beskouings van die belangrikheid van aspekte van evaluering en bestaande praktyke binne hulle onderskeie departemente bestaan. Die bevindings het belangrike implikasies vir die wyse waarop akademici bestuur word.

ADIABATIC ROTATION FOR THE SKYRMIONS

We study the electromagnetic properties of the skyrmions of the O(3) nonlinear sigma model in (2+1) dimensions coupled with the Chern-Simons field by the adiabatic rotation procedure. It is shown that there is no Poynting vector for the skyrmion configuration and the Chern-Simons gauge field. In the process, an explicit derivation of the angular momentum is presented, which connects with the fractional statistics for the skyrmions.

Modeling The Microwave Frequency Dielectric Properties of Thermoplastic Composite Materials

ABSTRACTMixture models were studied in an effort to predict the microwave frequency permittivities of unidirectional-fiber-reinforced thermoplastic-matrix composite materials as a function of fiber volume fraction, fiber orientation relative to the electric field, and temperature. The permittivities of the constituent fiber and plastic materials were measured using a resonant cavity perturbation technique at 9.4 GHz and at 2.45 GHz. The permittivities of the composite specimens were measured using a reflection cavity technique at 9.4 GHz and at 2.45 GHz. Simple “rule-of-mixtures” models that use the fiber and plastic permittivities have been found to approximate the complex dielectric properties of the composite for varied fiber volume fractions. The permittivities of oriented composites were modeled using a tensor rotation procedure. Composite permittivities were modeled with temperature up to the glass transition temperature of the thermoplastic matrix.