Triboelectric nanogenerators (TENG): Factors affecting its efficiency and applications

The demand for energy is increasing tremendously with modernization of the technology and requires new sources of renewable energy. The triboelectric nanogenerators (TENG) are capable of harvesting ambient energy and converting it into electricity with the process of triboelectrification and electrostatic-induction. TENG can convert mechanical energy available in the form of vibrations, rotation, wind and human motions etc., into electrical energy there by developing a great scope for scavenging large scale energy. In this review paper, we have discussed various modes of operation of TENG along with the various factors contributing towards its efficiency and applications in wearable electronics.

Adaptive method to predict and track unknown system behaviors using RLS and LMS algorithms

This study investigates the ability of recursive least squares (RLS) and least mean square (LMS) adaptive filtering algorithms to predict and quickly track unknown systems. Tracking unknown system behavior is important if there are other parallel systems that must follow exactly the same behavior at the same time. The adaptive algorithm can correct the filter coefficients according to changes in unknown system parameters to minimize errors between the filter output and the system output for the same input signal. The RLS and LMS algorithms were designed and then examined separately, giving them a similar input signal that was given to the unknown system. The difference between the system output signal and the adaptive filter output signal showed the performance of each filter when identifying an unknown system. The two adaptive filters were able to track the behavior of the system, but each showed certain advantages over the other. The RLS algorithm had the advantage of faster convergence and fewer steady-state errors than the LMS algorithm, but the LMS algorithm had the advantage of less computational complexity.

Wavelet-based audio features of DC motor sound

The usage of wavelets is widespread in many fields nowadays, especially in signal processing. Their nature provides some advantages in comparison to the Fourier transform, and therefore many applications rely on wavelets rather than on other methods. The decomposition of wavelets into detail and approximation coefficients is one of the methods to extract representative audio features. They can be used in signal analysis and further classification. This paper investigates the usage of various wavelet families in the wavelet decomposition to extract audio features of direct current (DC) motor sounds recorded in the production environment. The purpose of feature representation and analysis is the detection of DC motor failures in motor production. The effects of applying different wavelet families and parameters in the decomposition process are studied using sounds of more than 60 motors. Time and frequency analysis is also done for the tested DC motor sounds.

Synthesis of composite logic gate in QCA embedding underlying regular clocking

Quantum-dot Cellular Automata (QCA) has emerged as one of the alternative technologies for current CMOS technology. It has the advantage of computing at a faster speed, consuming lower power, and work at Nano- Scale. Besides these advantages, QCA logic is limited to its primitive gates, majority voter and inverter only, results in limitation of cost-efficient logic circuit realization. Numerous designs have been proposed to realize various intricate logic gates in QCA at the penalty of non-uniform clocking and improper layout. This paper proposes a Composite Gate (CG) in QCA, which realizes all the essential digital logic gates such as AND, NAND, Inverter, OR, NOR, and exclusive gates like XOR and XNOR. Reportedly, the proposed design is the first of its kind to generate all basic logic in a single unit. The most striking feature of this work is the augmentation of the underlying clocking circuit with the logic block, making it a more realistic circuit. The Reliable, Efficient, and Scalable (RES) underlying regular clocking scheme is utilized to enhance the proposed design?s scalability and efficiency. The relevance of the proposed design is best cited with coplanar implementation of 2-input symmetric functions, achieving 33% gain in gate count and without any garbage output. The evaluation and analysis of dissipated energy for both the design have been carried out. The end product is verified using the QCADesigner2.0.3 simulator, and QCAPro is employed for the study of power dissipation.

Cuckoo search algorithm to solve the problem of economic emission dispatch with the incorporation of facts devices under the valve-point loading effect

The essential objective of optimal power flow is to find a stable operating point which minimizes the cost of the production generators and its losses, and keeps the power system acceptable in terms of limits on the active and reactive powers of the generators. In this paper, we propose the nature-inspired Cuckoo search algorithm (CSA) to solve economic/emission dispatch problems with the incorporation of FACTS devices under the valve-point loading effect (VPE). The proposed method is applied on different test systems cases to minimize the fuel cost and total emissions and to see the influence of the integration of FACTS devices. The obtained results confirm the efficiency and the robustness of the Cuckoo search algorithm compared to other optimization techniques published recently in the literature. In addition, the simulation results show the advantages of the proposed algorithm for optimizing the production fuel cost, total emissions and total losses in all transmission lines.

Acceptance of cloud computing in an airline company based on Roger’s diffusion of innovation theory

using cloud computing develops, one of the problems that managers face at the organization level is that the personnel cannot work with these systems, users do not accept these new systems and the problem of accepting these technologies, effective factors in accepting them and the existing barriers in accepting them by users are very important. In many organizations wherein cloud computing has been launched, a time period is required to accept this new system by their personnel. If this time period is less and the personnel can work with these systems earlier, the productivity increases in the organization. The present paper aims the analysis of effective factors on acceptance of cloud computing by personnel working in Birjand International Airport in South Khorasan County (Iran) based on Roger?s diffusion of innovation theory. Examination of effective factors on acceptance of cloud computing in an organization can pave the way for improving its implementation and performance. This research has been done by descriptive survey method and its community includes personnel working in different official and informatics departments of Birjand International Airport. The data gathering instrument was questionnaire and for determining questionnaire validity opinions of masters and for determining consistency Cronbach's alpha has been used. For data analysis descriptive and inferential statistics have been used. The results of present paper indicated that there is meaningful and positive relationship between acceptance features of cloud computing and perception elements of testability, comparative advantage, visibility, complexity, and compatibility of cloud computing with its acceptance rate and there is meaningful and negative relationship between features of perception of not needing cloud computing and its acceptance rate. But there was no meaningful relationship between perception of cloud computing test opportunity and its acceptance rate. As one of the modern ways of providing electronic service has been cloud computing in recent years and it has many benefits for air transportation systems, this paper presents a model for analysis of effective factors in acceptance of cloud computing among personnel of an airline company (airport) and it can be used for examining cloud acceptance in other air companies.

MEMS resonator mass loading noise model: The case of bimodal adsorbing surface and finite adsorbate amount

Modeling of adsorption and desorption in microelectromechanical systems (MEMS) generally is crucial for their optimization and control, whether it is necessary to decrease the adsorption-desorption influence (thus ensuring stable operation of ultra-precise micro and nanoresonators) or to increase it (and enhancing in this manner the sensitivity of chemical and biological resonant sensors). In this work we derive and use analytical mathematical expressions to model stochastic fluctuations of the mass adsorbed on the MEMS resonator (mass loading noise). We consider the case where the resonator surface incorporates two different types of binding sites and where non-negligible depletion of the adsorbate occurs in a closed resonator chamber. We arrive at a novel expression for the power spectral density of mass loading noise in resonators and prove the necessity of its application in cases when resonators are exposed to low adsorbate concentrations. We use the novel approach presented here to calculate the resonator performance. In this way we ensure optimization of these MEMS devices and consequentially abatement of adsorption-desorption noise-caused degradation of their operation, both in the case of micro/nanoresonators and resonant sensors. This work is intended for a general use in the design, development and optimization of different MEMS systems based on mechanical resonators, ranging from the RF components to chemical and biological sensors.

Autoscalabile ditributed anti-spam SMTP system based on kubernetes

Due to the increasing amount of spam email traffic, email users are in increasing danger, while email server resources are becoming overloaded. Therefore, it is necessary to protect email users, but also to prevent SMTP system overload during spam attacks. The aim of this paper is to design and implement an autoscalable distributed anti-spam SMTP system based on a Proof of work concept. The proposed solution extends SMTP protocol in order to enable the evaluation of the client?s credibility using the Proof of work algorithm. In order to prevent resource overload during spam attacks, the anti-spam SMTP system is implemented in a distributed environment, as a group of multiple anti-spam SMTP server instances. Kubernetes architecture is used for system distribution, configured with the possibility of autoscaling the number of antispam SMTP server instances depending on the system load. The implemented system is evaluated during a distributed spam attempt, simulated by a custom-made traffic generator tool. Various performance tests are given: (1) The proposed system?s impact on client?s behaviour and the overall amount of spam messages, (2) The performance of the undistributed anti-spam SMTP server during spam attack, in terms of resource load analysis (3) Autoscaling demonstration and evaluation of proposed distributed system?s performance during a spam attack. It is shown that the proposed solution has the possibility of reducing the amount of spam traffic, while processing tens of thousands of simultaneous SMTP client requests in a distributed environment.

A high efficiency pneumatic drive system using vane-type semi-rotary actuators

A compressed air driven generator is proposed, where the pneumatic energy is converted into mechanical energy using two vane-type rotational actuators. The use of a second actuator with a higher displacement in order to produce a thermodynamic expansion allows to reach a better energetic efficiency in comparison to the classical operation of such actuators. The alternating movement of the angular actuators is transformed into a unidirectional rotational motion with the help of a mechanical motion rectifier. The paper analyses the enhancement of the energetic performance of the system. An experimental set-up is also described. The performance of the new system is described, and the limits of its realization is commented on the base of experimental recordings of the evolution of the pressure in the chambers.

Evaluation of electronic readiness level: A case of financial institution

Electronic readiness is the ability to accept, use and apply information and communication technology in an organization. To effectively implement information and communication technologies, the first step is to measure the electronic readiness of companies and organizations to adopt these new technologies. In this research, the level of electronic readiness of Mellat Bank has been studied in Khorasan Razavi province in Iran, from the perspective of the employees in cities of Feyz Abad, Kashmar, Bajestan, Gonabad and Bazar and Central branches in Khorasan Razavi province. Electronic readiness levels of Bank Mellat have been evaluated in the following dimensions: Strategy readiness and IT policies, IT infrastructure readiness, management readiness, legal-juridical readiness, culture and human resource (personnel) readiness and Process readiness. This research is based on descriptive research design and applied purpose. The statistical population of the personnel includes people with sufficient and necessary information in the field of financial and banking activities regarding e-commerce issues and e-readiness, which was a total population of 74 people. 50 questionnaires consisting of 30 questions were distributed using non-probability convenience sampling method of which 42 questionnaires were accurate. The SPSS15 software was used for analysis. The results of the analysis showed that the level of electronic readiness of Mellat Bank in Khorasan Razavi province in the studied branches is significantly higher than the average theoretical score (3) (p <0.001) in total and its components. This demonstrates the level of electronic readiness of Mellat Bank in Khorasan Razavi is high (above average) from the perspective of the studied personnel. Also, there is no significant difference in the average score of the perspective of personnel based on gender, age, years of service, level of education, field of study and organizational position concerning the level of electronic readiness in Mellat Bank in Khorasan Razavi.