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Amini M.,Imam Reza University | Younesi H.,Imam Reza University | Zinatizadeh Lorestani A.A.,Razi University | Najafpour G.,Babol Noshirvani University of Technology
Bioresource Technology | Year: 2013

In this study, the granular sludge was generated for simultaneous nitrification, denitrification and phosphorus removal (SNDPR) and studied on a laboratory scale. Analyzing the nutrients removal percentages from wastewater were scrutinized by using an optimization of the variables, i.e., COD:N:P ratio, OLR, aeration time, MLSS, F:M and HRT. These 6 interrelated parameters were evaluated as the process response. Microscopic observations of the performance of the SNDPR process revealed that the granules included Bacillus sp. in the bacterial community. According to these results, the UAASB system produced an effluent that lends dairy wastewater suitable for land irrigation and that this an attractive process of using granular sludge is appropriate for achieving carbon, nitrogen and phosphorus removal from nutrient-rich wastewater by a biological method. © 2013 Elsevier Ltd.


Rezaee R.,Ferdowsi University of Mashhad | Houshmand M.,Ferdowsi University of Mashhad | Houshmand M.,Imam Reza University
Genetic Programming and Evolvable Machines | Year: 2013

Quantum-Dot Cellular Automata (QCA) is a promising nanotechnology that has been recognized as one of the top emerging technologies in future computers. Size density of several orders of magnitude smaller than Complementary Metal-Oxide Semiconductor, fast switching time and extremely low power, has caused QCA to become a topic of intense research. The majority gate and the inverter gate together make a universal set of Boolean primitives in QCA technology. Reducing the number of required primitives to implement a given Boolean function is an important step in designing QCA logic circuits. Previous research has shown how to use genetic programming to minimize the number of gates implementing a given Boolean function with one output. In this paper, we first show how to minimize the gates for the given Boolean truth tables with an arbitrary number of outputs using genetic programming. Then, another criterion, reduction of the delay of the implementing circuit is considered. Multi-objective genetic programming is applied to simultaneously optimize both objectives. The results demonstrate the proposed approach is promising and worthy of further research. © 2012 Springer Science+Business Media New York.


Mir O.,Imam Reza University | Nikooghadam M.,Imam Reza University
Wireless Personal Communications | Year: 2015

Lately, many of developed countries that have healthcares services use telecare medicine information systems (TMIS). In TMIS, a patient can obtain sorts of healthcare delivery services. Furthermore, physicians and also caregivers can check vital signs of patients remotely. Patient’s privacy is protected by employing a proper authentication and encryption mechanism. Recently, many user authentication schemes have been proposed that are applicable to TMIS. However, security of most proposed schemes is vulnerable. Recently, Yan et al. proposed an efficient biometrics-based authentication scheme for TMIS. In this paper, by an explanation of some active attacks, it is shown that Yan et al.’s scheme has still some security flaws. Later, an improved biometrics-based authentication and key agreement scheme is proposed. The Security of the proposed authentication and key agreement scheme is proved in the random oracle model. Furthermore, we use the BAN logic to prove the correctness of the proposed scheme. In addition, we simulate our scheme for the formal security analysis using the Automated Validation of Internet Security Protocols and Applications tool. It is shown that due to better security and also efficiency in computational time, the proposed scheme is more suitable for employment in TMIS. © 2015, Springer Science+Business Media New York.


Arshad H.,Imam Reza University | Nikooghadam M.,Imam Reza University
Multimedia Tools and Applications | Year: 2014

The session initiation protocol (SIP) is a powerful and superior signaling protocol for the voice over internet protocol (VoIP). Authentication is an important security requirement for SIP. Hitherto, many authentication schemes have been proposed to enhance the security of SIP. Recently, Irshad et al. proposed an improved authentication scheme concerning SIP, in which they claimed that their scheme is secure against various security attacks. However, in this paper, we conclude that Irshad et al.’s scheme is vulnerable to user impersonation attacks. Furthermore, a novel authentication and key agreement scheme is proposed for SIP using elliptic curve cryptosystem (ECC). Security and performance analyses demonstrate that the proposed scheme is secure against security attacks of various types and has low computation cost compared to previously proposed schemes. © 2014 Springer Science+Business Media New York.


Hassanpour S.,Imam Reza University | Houshmand M.,Imam Reza University
Quantum Information Processing | Year: 2014

In this paper, a three-party controlled quantum secure direct communication protocol based on GHZ-like state is proposed. In this scheme, the receiver can obtain the sender’s two secret bits under the permission of the controller. By using entanglement swapping, no qubits carrying secret messages are transmitted. Therefore, if the perfect quantum channel is used, the protocol is completely secure. The motivation behind utilizing GHZ-like state as a quantum channel is that if a qubit is lost in the GHZ-like state, the other two qubits are still entangled. The proposed protocol improves the efficiency of the previous ones. © 2014, Springer Science+Business Media New York.


Arshad H.,Imam Reza University | Nikooghadam M.,Imam Reza University
Journal of medical systems | Year: 2014

Nowadays, with comprehensive employment of the internet, healthcare delivery services is provided remotely by telecare medicine information systems (TMISs). A secure mechanism for authentication and key agreement is one of the most important security requirements for TMISs. Recently, Tan proposed a user anonymity preserving three-factor authentication scheme for TMIS. The present paper shows that Tan's scheme is vulnerable to replay attacks and Denial-of-Service attacks. In order to overcome these security flaws, a new and efficient three-factor anonymous authentication and key agreement scheme for TMIS is proposed. Security and performance analysis shows superiority of the proposed scheme in comparison with previously proposed schemes that are related to security of TMISs.


Ghorbanzadeh M.,Imam Reza University | Soleymani F.,Islamic Azad University at Zahedan
Algorithms | Year: 2015

In this work, we propose a new fourth-order Jarratt-type method for solving systems of nonlinear equations. The local convergence order of the method is proven analytically. Finally, we validate our results via some numerical experiments including an application to the Chandrashekar integral equations. © 2015 by the authors.


Senobary S.,Imam Reza University | Naghibzadeh M.,Ferdowsi University of Mashhad
2014 6th International Conference on Computer Science and Information Technology, CSIT 2014 - Proceedings | Year: 2014

This paper presents a semi-partitioned scheduling algorithm for periodic tasks on multiprocessor platforms. The scheduling policy used within each processor is based on delayed rate monotonic algorithm. Delayed rate monotonic is a modified version of rate monotonic algorithm, which can achieve higher processor utilization than rate monotonic. First, it is formally proved that any task which is feasible under rate monotonic is feasible under delayed rate monotonic, as well. Then, based on delayed rate monotonic, a new scheduling algorithm called adapted delayed rate monotonic (ADRM) is designed for multiprocessor systems. ADRM is composed of delayed rate monotonic algorithm and a semi-partitioned technique. Semi-partitioned is a new approach for allocating tasks on multiprocessor platforms. According to the simulation results, ADRM is safer against possible overload than rate monotonic algorithm. Then, a procedure is proposed to achieve processor utilization under ADRM algorithm more than the rate monotonic algorithm. © 2014 IEEE.


Houshmand M.,Imam Reza University | Wilde M.M.,McGill University
IEEE Transactions on Information Theory | Year: 2013

Poulin discovered an important separation between the classical and quantum theories of convolutional coding, by proving that a quantum convolutional encoder cannot be both noncatastrophic and recursive. Noncatastrophicity is desirable so that an iterative decoding algorithm converges when decoding a quantum turbo code whose constituents are quantum convolutional codes, and recursiveness is as well so that a quantum turbo code has a minimum distance growing nearly linearly with the length of the code, respectively. Their proof of the aforementioned theorem was admittedly 'rather involved,' and as such, it has been desirable since their result to find a simpler proof. In this paper, we furnish a proof that is arguably simpler. Our approach is group-theoretic-we show that the subgroup of memory states that are part of a zero physical-weight cycle of a quantum convolutional encoder is equivalent to the centralizer of its 'finite-memory' subgroup (the subgroup of memory states which eventually reach the identity memory state by identity operator inputs for the information qubits and identity or Pauli-Z operator inputs for the ancilla qubits). After proving that this symmetry holds for any quantum convolutional encoder, it easily follows that an encoder is nonrecursive if it is noncatastrophic. Our proof also illuminates why this no-go theorem does not apply to entanglement-assisted quantum convolutional encoders-the introduction of shared entanglement as a resource allows the above symmetry to be broken. © 1963-2012 IEEE.


Babayan-Mashhadi S.,Imam Reza University | Sarvaghad-Moghaddam M.,Imam Reza University
22nd Iranian Conference on Electrical Engineering, ICEE 2014 | Year: 2014

The need for ultra-low power and area-efficient analog-to-digital converters (ADCs) is pushing towards the use of low-voltage (LV) dynamic clocked comparators to maximize power efficiency and speed. In this paper, a delay analysis for a conventional body-driven LV dynamic comparator is presented. Then based on the analysis results, the circuit of a conventional body-driven comparator is modified for fast operation even in small supply voltages. Simulation results in 90nm CMOS technology reveal that comparator delay time is remarkably reduced. The maximum clock frequency of the proposed comparator can be increased to 333 MHz and 50 MHz at supply voltages of 0.5V and 0.35V, while consuming 2.3μW and 184nW, respectively. The standard deviation of the input-referred offset voltage is 5.1mV at 0.5V supply. © 2015 IEEE.

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