Today, information is a key role in economic decision-making and no doubt the quality of such information is based on accuracy in the preparation of it. Among the profit of one of the most important information that will be announced by the companies. The present study was to investigate the relationship between Real Activities Manipulation with Accrual-Based Earnings Management using Recursive Equation Systems Approach in the Tehran Stock Exchange (TSE). Accordingly, a sample 79 companies selected for the 6-year period 2009 to 2014 (474 firm-year observations). It should be noted that information was collected in 2008 and 2015 to collect some research data. The results are expressing the inverse relationship between real activities manipulation with accrual-base earnings management. This means that managers increase (decrease) the extent of accrual-based earnings management when real activities manipulation turns out to be unexpectedly low (high). The result of this study is consistent with research by Zhang (2012) and Jie and et. al (2017).

In this article, an attempt has been made to estimate the amount of sound transmission loss in a flat oval channel by applying the Approach of statistical energy analysis. Correct estimation of sound transmission loss in an air conditioning channel is of great importance due to the harmful effects of noise pollution in the environment on human health. Simulation with the statistical energy analysis method is a powerful Approach to estimate sound and vibration in problems in which we deal with complex and multi-part Systems; is considered. In this method, first, a system is divided into several subSystems, and then by writing a matrix Equation that includes the energy exchanges between subSystems and energy loss coefficients; It is investigated from the perspective of vibration and sound estimation.On average, the model presented in this research is able to estimate the sound transmission loss in different dimensions of the air conditioning channels according to the experimental results in the accuracy range of ± 2.5 dB. Considering that it seems that the results obtained from modeling with this method are in good agreement with the experimental data; The results of this research can be used as an efficient Approach to estimate noise in oval shaped channels stretched in different lengths.

This study was conducted during summer and winter of 2018- 2019 in the agricultural research field of Shahid Chamran University. Experimental design was split- plot based on RCBD with three replications. The main plot was the type of agricultural system in three levels including conventional (Conv), organic (Org) and sustainable (Sust) (integrated between Conv and Org) and sup- plot was the type of pre- cultivated crop in sequence with wheat including cultivation of mung bean (M- W), corn (C- W), sesame (S- W) and fallow (F- W). Yield quantity (yield and its component) and quality (grain protein), an estimate of photosynthesis matter transfer index of wheat and soil organic carbon (SOC) after one double-cropping were measured. The result showed that the highest (545.04 g/m2) and the lowest (409.28 g/m2) seed yields were obtained in Conv and Org respectively. In contract, with the changing type of system from Conv to Org, grain protein was increased significantly (from 8.3 to 9.6 %). In addition, the highest (535.47 g/m2) yield of wheat was obtained from M- W double cropping. On the other hands the highest remobilization and current photosynthesis matter were obtained in the organic agricultural system with M- W and conventional with M- W double cropping. The situation of SOC showed that the highest (33.18 mg/g) SOC was obtained in the organic agricultural system with C- W double cropping. The reason for improving SOC in the organic and sustainable agricultural system was application of organic matter (compost and vermicompost) and crop residue management. Totally, from the crop ecology point of view, sustainable agricultural method with a sequence of M- W was the most desirable system.

This paper proposes a new hierarchical identification method for fractional-order Systems. In this method, a SISO (single input, single output) state space model has been considered in which parameters and also state variables should be estimated. By using a linear transformation and a shift operator, the system will be transformed into a form appropriate for identification of a fractional order system. Then, the unknown parameters will be identified through a Recursive least squares method and the states will be estimated using a fractional order Kalman filter. This identification method is based on the hierarchical identification principle that reduces the computational burden and is easy to implement on computer. The promising performance of the proposed method is verified using two stable fractional-order Systems.

In this paper a new systematic method for deriving the Equation of motion of n-rigid robotic manipulators with revolute-prismatic joints is considered. The Equation of motion for this robotic system is obtained based on Gibbs- Appell formulation. All the mathematical operations are done by only 3x3 and 3x1 matrices. Also, all dynamic characteristicsof a link are expressed in the same link local coordinate system. Based on the developed formulation, an algorithm is proposed that Recursively and systematically derives the Equation of motion. Finally, a computational simulation for a manipulator with three revolute-prismatic joints is presented to show the ability of this algorithm in deriving and solving high degree of freedom of robotic system.

Binary array pairs with optimal/ideal correlation values and their algebraic counterparts \difference set pairs" (DSPs) in abelian groups are studied. In addition to generalizing known 1-dimensional (sequences) examples, we provide four new Recursive constructions, unifying previously obtained ones. Any further advancements in the construction of binary sequences/arrays with opti-mal/ideal correlation values (equivalently cyclic/abelian difference sets) would give rise to richer classes of DSPs (and hence binary perfect array pairs). Discrete signals arising from DSPs nd applications incryptography, CDMA Systems, radar and wireless communications.

Digital image has special cryptography algorithms for its specific properties. A mathematics sequence in most image cryptography has been used for image scrambling. The used mathematics sequence has a Recursive Equation which it has some coefficients that changes of these coefficients can generate different sequences. Performance of this sequence in image cryptography is evaluated with different standard criteria. Due to complexity of system and no direct relation between the coefficient and evaluation criteria, selection of the suitable coefficient is not easily possible. In this article, by considering a general form of Recursive Equation and define a fitness function, the proper coefficients are calculated by genetic algorithm that satisfies the evaluation criteria. The experimental results show that Recursive Equation that is computed by the genetic algorithm has satisfactory performance from some schemes.

Discrete multitone (DMT) is a line code which has been adopted as a standard for the asymmetric digital subscriber line (ADSL) Systems by the American National Standards Institute (ANSI). The DMT uses the IFFT and FFT for modulation and demodulation, respectively. The large size of the IFFT/FFT results in a heavy computational load on the programmable DSP processors. It also proves that a costefficient hardware implementation of radix-2 IFFT/FFT butterfly structure is not feasible, since it requires a large number of multipliers and adders. For cost-efficient hardware implementation, we have proposed two schemes to develop the IFFT/FFT architecture based on the time-Recursive Approach. In fact, these methods require approximately a maximum of only 12.5% of the multipliers and 15.6% of the adders when compared to the conventional butterfly type of implementation.