Batman University

About: Batman University is a education organization based out in Batman, Turkey. It is known for research contribution in the topics: Diesel fuel & Diesel engine. The organization has 300 authors who have published 810 publications receiving 10346 citations. The organization is also known as: Batman Üniversitesi.

I – V – T analysing an inhomogeneous Au/Poly(4-vinyl phenol)/p-Si structure with a double Gaussian distribution of barrier heights

Abstract: In this study, the current–voltage (I–V) characteristics of Au/Poly(4-vinyl phenol)/p-Si structures have been measured over a wide temperature range (100–300 K). These structures have been analyzed according to thermionic emission (TE) theory, as a result of which an abnormal decrease occurred in the zero-bias barrier height ( $$ \phi_{b0} $$ ) and an increase in the ideality factor (n) was observed with temperature decrease and nonlinearity in the activation energy plot. By assuming a Gaussian distribution (GD) of barrier heights of the Au/Poly(4-vinyl phenol)/p-Si structures, barrier inhomogeneities are believed to responsible for this behavior. Evidence is given for the existence of a double GD with mean barrier heights ( $$ \bar{\phi }_{b0} $$ ) of 1.042 and 0.623 eV, standard deviations of 0.138 and 0.081 V, and ideality factors 2.76 and 7.26, which remain effective in the temperature ranges of 180–300 and 100–160 K, respectively. As a result, without using the temperature coefficient of the barrier height, the modified ln(I o /T 2) − q 2 σ 2 /2(kT)2 vs. q/kT plot gives $$ \bar{\phi }_{b0} $$ values and Richardson constants (A * ) as 1.036 and 0.623 eV, and 36.20 and 19.99 A/cm2 K2, respectively. The effective Richardson constant value of 36.20 A/cm2 K2 is very similar to the theoretical value of 32 A/cm2K2 for p-Si. Consequently, the temperature dependence of the forward bias I–V characteristics of Au/Poly(4-vinyl phenol)//p-Si (MIS) structure could be attributed to the thermionic emission (TE) mechanism with double GD of the barrier heights.

Harris Hawks Optimization Approach for Tuning of FOPID Controller in DC-DC Buck Converter

Abstract: In this work, a new nature-inspired, population-based meta-heuristic optimization method, Harris Hawks Optimization (HHO), is applied for the first time for tuning the parameters of both the traditional PID controller and the fractional order PID (FOPID) controller used in a DC-DC buck converter. The PID and FOPID controllers, whose parameters optimally tuned by HHO algorithm, are used for improving the transient response of a DC-DC buck converter by minimizing the maximum overshoot, settling time and rise time of converter's output voltage and for eliminating the steady state error. In addition, to illustrate the superiority of the proposed HHO-PID and HHO-FOPID controllers, beside the transient response analysis, the frequency response analysis and performance indices analysis were also conducted and compared with GA-PID and WOA-PID controllers, which are available in literature and are tuned by genetic algorithm (GA) and whale optimization algorithm (WOA), respectively. The numerical and graphical results demonstrated that the proposed HHO-FOPID controller has better control performance than the proposed HHO-PID, GA-PID, and WOA-PID controllers. The obtained simulation results confirmed the superiority and effectiveness of the proposed HHO-FOPID controller in terms of both algorithm and controller structure.

A novel improved arithmetic optimization algorithm for optimal design of PID controlled and Bode’s ideal transfer function based automobile cruise control system

Abstract: This paper considers the development of a novel hybrid metaheuristic algorithm which is proposed to achieve an optimum design for automobile cruise control (ACC) system by using a proportional-integral-derivative (PID) controller based on Bode’s ideal transfer function. The developed algorithm (AOA-NM) adopts one of the recently published metaheuristic algorithms named the arithmetic optimization algorithm (AOA) to perform explorative task whereas another well-known local search method known as Nelder–Mead (NM) simplex search to perform exploitative task. The developed hybrid algorithm was initially tested on well-known benchmark functions by comparing the results with only its original version since AOA has already been shown to be better than other state-of-the-art algorithms. The statistical results obtained from benchmark functions have demonstrated better capability of AOA-NM. Furthermore, a PID controller based on Bode’s ideal transfer function was adopted to regulate an ACC system optimally. Statistical, convergence rate, time domain and frequency domain analyses were performed by comparing the performance of AOA-NM with AOA. The respective analyses have shown better capability of the proposed hybrid algorithm. Moreover, the capability of the proposed AOA-NM based PID control scheme was compared with other available approaches in the literature by using time domain analysis. The latter case has also confirmed enhanced capability of the proposed approach for regulating an ACC system which further verified the ability of the proposed AOA-NM algorithm. Lastly, other recently reported and effective metaheuristic algorithms were also used to assess the performance of the proposed approach. The obtained comparative results further confirmed the AOA-NM to be a greater tool to achieve more successful results for ACC system.

Examination of a New Defense Mechanism: Honeywords

Abstract: Past experiences show us that password breach is still one of the main methods of attackers to obtain personal or sensitive user data. Basically, assuming they have access to list of hashed passwords, they apply guessing attacks, i.e., attempt to guess a password by trying a large number of possibilities. We certainly need to change our way of thinking and use a novel and creative approach in order to protect our passwords. In fact, there are already novel attempts to provide password protection. The Honeywords system of Juels and Rivest is one of them which provides a detection mechanism for password breaches. Roughly speaking, they propose a method for password-based authentication systems where fake passwords, i.e., “honeywords” are added into a password file, in order to detect impersonation. Their solution includes an auxiliary secure server called “honeychecker” which can distinguish a user’s real password among her honeywords and immediately sets off an alarm whenever a honeyword is used. However, they also pointed out that their system needs to be improved in various ways by highlighting some open problems. In this paper, after revisiting the security of their proposal, we specifically focus on and aim to solve a highlighted open problem, i.e., active attacks where the adversary modifies the code running on either the login server or the honeychecker.