Original Research Paper
Software Systems
S. Hekmat; S. Parsa; B. Vaziri
Abstract
Background and Objectives: Several service identification methods have been proposed to identify services using a business process-based strategy. However, these methods are still not accurate enough and adequately automated and thus need improvements. The present study addresses this gap by proposing ...
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Background and Objectives: Several service identification methods have been proposed to identify services using a business process-based strategy. However, these methods are still not accurate enough and adequately automated and thus need improvements. The present study addresses this gap by proposing a new semi-automated combinational method that applies process mining techniques and simultaneously considers different aspects of the business domain (e.g., goal and data). We argue that this method facilitates service identification more comprehensively and accurately and helps enhance organizational performance and lower cost structure.Methods: Our method includes three Phases. In the first phase, the system log is inspected, and the running business process is extracted using process mining techniques. After validating this model, we create a goal and data model in the next phase. In the third phase, we establish connections between the introduced models by defining some matrices. These connections are of two types: structural and conceptual. Finally, we propose a couple of algorithms that lead to the identification of services. Results: We evaluate the utility of our proposed method by conducting a case study and using the experts’ opinions from different perspectives as follows: (1) assessing the accuracy and reusability of the identified services, (2) appraising the efficiency of employing this method in more complex processes, (3) calculating the cohesion to coupling ratio, and (4) assessing the performance of the method and other service quality measures. The results indicate that the average accuracy of this method is about 12 % higher than the previously identified methods for both simple and complex processes. Additionally, it empirically proves that using the process mining techniques improves the service identification considerably (8%). Moreover, according to the experts’ opinions, the combination of goal and data model and process mining has increased the performance by 8%. In comparison, the cohesion to coupling ratio demonstrated a 7% increase compared to other methods. In sum, we conclude that this method is an advanced and reliable way of service identification regardless of the process size and the complexity. Conclusion: The findings reveal that considering different aspects of business processes together and using process mining techniques improves the ratio of cohesion to coupling and accuracy of the identified services. Adherence to this approach enables companies to mine their business processes, modify them, and quickly identify services with higher performance. Besides, using this method provides a semi-automated and more effective way of service identification
Original Research Paper
Artificial Intelligence
M. Khazaei
Abstract
Background and Objectives: IP multimedia subsystems (IMS) have been introduced as the Next Generation Network (NGN) platform while considering Session Initiation Protocol (SIP) as the signaling protocol. SIP lacks a proper overload mechanism. Hence, this challenge causes decline in the multimedia QoS. ...
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Background and Objectives: IP multimedia subsystems (IMS) have been introduced as the Next Generation Network (NGN) platform while considering Session Initiation Protocol (SIP) as the signaling protocol. SIP lacks a proper overload mechanism. Hence, this challenge causes decline in the multimedia QoS. The main propose of overload control mechanism is to keep the network throughput at the same network capacity with overload.Methods: NGN distributed with IMS is a complex innovative network consisting of interacting subsystems. Hence, multi-agent systems (MAS) receiving further attention for solving complex problems can solve the problem of overload in these networks. To this end, each IMS server is considered as an intelligent agent that can learn and negotiate with other agents while maintaining autonomy, thus eliminating the overload by communication and knowledge transfer between the agents. In the present research, using MAS and their properties, the intelligent hop by hop method is provided based on Q-learning and negotiation capability for the first time.Results: In the proposed method, parameters of overload controller are obtained by reinforcement learning. In order to check the validity of controller performance, a comparison is made with the similar method in which the optimal parameters are achieved based on trial and error. The result of the comparison confirms the validity of the proposed method. In order to evaluate the efficiency of the learner method, it is compared with similar and standard methods, for which the results are compared to show performance. The results show, the proposed method has approximately improved the throughput by 13%, the delay by 49% and the number of rejected sessions by 17% compare with methods, passing control messages through the network such as CPU occupancy methods. While compare with external controller methods like holonic, throughput is improved by 1% and the number of rejected requests is decreased by 10%, but delay is increased by 6% due to the convergence time of the learning and negotiation process.Conclusion: To overcome overload, complex IMS servers are considered as learner and negotiator agents. This is a new method to achieve the required parameters without relying on expert knowledge or person as well as, heterogeneous IMS entities can be inserted into the problem to complete study in future.
Original Research Paper
Electronics
A. Shokri; M. Amirmazlaghani
Abstract
Background and Objectives: The Field-effect Bipolar Junction Transistor (FEBJT) is a device with a bipolar junction transistor (BJT) characteristics except that it is designed with standard CMOS technology. Therefore, it can be implemented in nanometer dimensions without the usual restrictions in fabricating ...
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Background and Objectives: The Field-effect Bipolar Junction Transistor (FEBJT) is a device with a bipolar junction transistor (BJT) characteristics except that it is designed with standard CMOS technology. Therefore, it can be implemented in nanometer dimensions without the usual restrictions in fabricating the nanoscale BJTs. In addition to the advantages that FEBJT has as a bipolar junction transistor in analog circuits, it can also be used to design digital circuits. Here, we have investigated the capability of FEBJT as the base of a new digital family in nanometer scales.Methods: To do this, we have designed and simulated an inverter logic gate based on FEBJT. We have presented this logic gate's static and dynamic assessment criteria and compared these characteristics with other technologies. Also, a three-stage ring oscillator circuit based on FEBJT is designed and presented. A three-dimensional TCAD Mixed-Mode simulator has been used for the simulations.Results: The value of maximum frequency, PDP, dynamic power, and ring frequency are calculated 0.25THz, 38×10-17 J, 94uW, and 85GHz, respectively.Conclusion: The excellent function of the FEBJT-based inverter gate and oscillator demonstrates that this device can be used as the base of new digital circuits and can open a doorway to the nanoscale CMOS digital family.
Original Research Paper
Computer Architecture
Z. Torabi; Armin Belghadr
Abstract
Background and Objectives: Residue number system (RNS) is considered as a prominent candidate for high-speed arithmetic applications due to its limited carry propagation, fault tolerance, and parallelism in “Addition”, “Subtraction”, and “Multiplication” operations. ...
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Background and Objectives: Residue number system (RNS) is considered as a prominent candidate for high-speed arithmetic applications due to its limited carry propagation, fault tolerance, and parallelism in “Addition”, “Subtraction”, and “Multiplication” operations. Whereas, “Comparison”, “Division”, “Scaling”, “Overflow Detection” and “Sign Detection” are considered as complicated operations in residue number systems, which have also received a surge of attention in a multitude of publications. Efficient realization of Comparators facilitates other hard-to-implement operations and extends the spectrum of RNS applications. Such comparators can substitute the straightforward method (i.e. converting the comparison operands to binary and comparing them with wide word binary comparators) to compare RNS numbers. Methods: Dynamic Range Partitioning (DRP) method has shown advantages for comparing unsigned RNS numbers in the 3-moduli sets {2^n,2^n±1} and {2^n,2^n-〖1,2〗^(n+1)-1}, in comparison with other methods. In this paper, we employed DRP components and designed a unified unit that detects the sign of operands and also compares numbers, for the 5-moduli set γ={2^2n,2^n±1,2^n±3}. This unit can be used for comparison of signed and also unsigned RNS numbers in the moduli set γ.Results: Synthesized comparison results reveal 47% (54%) speed-up, 35% (32%) less area consumption, 25% (24%) lower power dissipation, and 60% (65%) less energy for n=8 (16) in comparison to the straightforward signed comparator. Conclusion: According to the results of this study, DRP method for sign detection and comparison operations outperforms other methods in different moduli sets including 5-moduli set γ={2^2n,2^n±1,2^n±3}.
Original Research Paper
Image Processing
M. Masoudifar; H. R. Pourreza
Abstract
Background and Objectives: Depth from defocus and defocus deblurring from a single image are two challenging problems caused by the finite depth of field in conventional cameras. Coded aperture imaging is a branch of computational imaging, which is used to overcome these two problems. Up to now, different ...
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Background and Objectives: Depth from defocus and defocus deblurring from a single image are two challenging problems caused by the finite depth of field in conventional cameras. Coded aperture imaging is a branch of computational imaging, which is used to overcome these two problems. Up to now, different methods have been proposed for improving the results of either defocus deblurring or depth estimation. In this paper, an asymmetric coded aperture is proposed which improves results of depth estimation and defocus deblurring from a single input image.Methods: To this aim, a multi-objective optimization function taking into consideration both deblurring results and depth discrimination ability is proposed. Since aperture throughput affects on image quality, our optimization function is defined based on illumination conditions and camera specifications which yields an optimized throughput aperture. Because the designed pattern is asymmetric, defocused objects on two sides of the focal plane can be distinguished. Depth estimation is performed using a new algorithm, which is based on perceptual image quality assessment criteria and can discern blurred objects lying in front or behind the focal plane.Results: Extensive simulations as well as experiments on a variety of real scenes are conducted to compare the performance of our aperture with previously proposed ones.Conclusion: Our aperture has been designed for indoor illumination settings. However, the proposed method can be utilized for designing and evaluating appropriate aperture patterns for different imaging conditions.
Original Research Paper
Micro Sensors
M. Kookhaee; A. Khooshehmehri; A. Eslami Majd
Abstract
Background and Objectives: The Hemispherical Resonator Gyroscope (HRG) is an inertial sensor that is a good choice for space missions and inertial navigation due to their low noise, low energy consumption, long life, and excellent accuracy and sensitivity. It consists of three main parts: the shell, ...
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Background and Objectives: The Hemispherical Resonator Gyroscope (HRG) is an inertial sensor that is a good choice for space missions and inertial navigation due to their low noise, low energy consumption, long life, and excellent accuracy and sensitivity. It consists of three main parts: the shell, the excitation and detection system, and the control circuits. In recent years, with using MEMS technology in the construction of HRG, vibrating shells with low volume and low price are made.Methods: The hemispherical shell is the main part and the beating heart of hemispherical resonator gyroscopes and is responsible for sensing. An optimized shell is required to implement the excitation and detection system and operate the gyroscope properly. In this research, the structure of a spherical shell with an environmental base that does not need to release the shell from its environment for its excitation and detection system is selected and the relationships governing this type of shell to improve the parameters of the glass blowing method will be investigated. Also, all sub-processes of this type method of fabrication to optimize the glass-blown spherical shell are implemented.Results: The process of making spherical shell by glass blowing using the chemical foaming process is used to obtain shells with height to radius ratio greater than 1, and finally, a glass shell with an etched cavity with a radius of 562 μm and depth of 524 μm created by the CNC process, with height to radius ratio of approximately 1.8 Has been achieved. In this method, using direct transfer of calcium carbonate to the etched cavity, before anodic bonding, the glass shell volume has been increased from 0.602 nL to 1.04 nL.Conclusion: The result is that to achieve a glass shell with a height to radius ratio of more than 1, in addition to improving the fabrication process, it is necessary to transfer the solid foaming agent to the etched cavity. Finally, in the fabrication of the glass-blown spherical shell, we have used the chemical foaming process (CFP) to obtain shells with a height to radius ratio greater than 1.
Original Research Paper
Electromagnetic
S.H. Mohseni Armaki; M. Tohidlo; M. Kazerooni
Abstract
Background and Objectives: This study aims to present a new structure based on coaxial waveguide, which can change the bandwidth, return losses, and input impedance by changing the plasma parameters of the coaxial waveguide. This structure consists of a metal body and a gas tube inside it, which uses ...
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Background and Objectives: This study aims to present a new structure based on coaxial waveguide, which can change the bandwidth, return losses, and input impedance by changing the plasma parameters of the coaxial waveguide. This structure consists of a metal body and a gas tube inside it, which uses a high voltage alternating current converter, can change the plasma parameters and, consequently the waveguide parameters. The input and output of the waveguide are also designed using the indirect capacitive coupling method.Methods: In the Field of plasma research and related emerging technologies, recently, it has achieved a special place in various industries such as radar and Aerospace industries. The creation of telecommunication structures such as antennas and Waveguides with plasma, has given features such as adaptability, the ability to reconfigure the characteristics of the structure, and improve the sensitivity of this type of structure.Results: By applying and changing the plasma excitation parameters, a change in the bandwidth was observed in the frequency band range of 0.5-4 GHz and a maximum of 1.38 GHz. Also, increasing the intensity of the excitation current improved the return losses in the resonance frequencies and, on the other hand, increased the band ripple.Conclusion: According to the results, the change of Plasma parameters depends on the change of plasma excitation frequency, and the value of Excitation current applied. As the Value of excitation current increases, the matching to the resonance frequencies improves, but on the other hand, the passband ripple of the plasma waveguide filter increases. As the plasma excitation pulse frequency increases, the bandwidth and resonance frequencies change to higher frequencies, and the matching to the resonance frequencies improves. But on the other hand, the passband ripple increases. This new waveguide filter can be used in cognitive/ adaptive telecommunication systems due to the constant change of frequency band.
Original Research Paper
Information Systems
M. R. Behbahani Nejad; H. Rashidi
Abstract
Background and Objectives: Big data is a combination of structured, semi-structured and unstructured data collected by organizations that must be stored and used for decision-making. Businesses that deal with the business intelligence system, as well as their data sources, have a major challenge in exploiting ...
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Background and Objectives: Big data is a combination of structured, semi-structured and unstructured data collected by organizations that must be stored and used for decision-making. Businesses that deal with the business intelligence system, as well as their data sources, have a major challenge in exploiting Big Data. The current architecture of business intelligence systems is not capable of incorporating and exploiting Big Data. In this paper, an architecture is developed to respond to this challenge. Methods: This paper focuses on the promotion of business intelligence to create an ability to exploit Big Data in business intelligence. In this regard, a new architecture is proposed to integrate both Business Intelligence and Big Data architectures. To evaluate the proposed architecture, we investigated business intelligence architecture and Big Data architecture. Then, we developed a Unified Modeling Language diagram for the proposed architecture. In addition, using the Colored Petri-Net, the proposed architecture is evaluated in a case study. Results: The results show that our architectural system has a higher efficiency in performing all steps, average time, and maximum time compared to business intelligence architecture.Conclusion: The proposed architecture can help companies and organizations gain more value from their data sources and better support managers and organizations in their decision-making.
Original Research Paper
M. Karimipour
Abstract
Background and Objectives: Cylindrical scanning technique is a well-established indirect measurement method to characterize a wide range of antenna patterns such as fan-beam antennas and phased array antennas with versatile radiation patterns.Methods: Cylindrical scanning technique which is based on ...
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Background and Objectives: Cylindrical scanning technique is a well-established indirect measurement method to characterize a wide range of antenna patterns such as fan-beam antennas and phased array antennas with versatile radiation patterns.Methods: Cylindrical scanning technique which is based on the nearfield-to-far-field transformation based on cylindrical mode coefficients (CMCs), cannot predict the antenna radiation pattern with a very narrow beamwidth in the azimuth plane accurately, because a remarkable error occurs during the calculation of the derivative of high-order Hankel functions in the CMCs extraction. We aim to address this issue and introduce a simple yet rigorous technique namely the sequential sampling method (SSM) in conjunction with the two-dimensional Fast Fourier Transform (2D-FFT) to efficiently calculate the far-field radiation pattern of a super-directive antenna with a very narrow beamwidth in the azimuth plane. Briefly, the SSM offers several sequences of progressive azimuth angles and the corresponding order of Hankel functions in such a way that CMCs fully span 360 degrees of azimuth angles (φ) in the cylindrical coordinate system in each sequence. Afterward, by putting the far-field obtained by these sequences together, the final radiation pattern will have a high angular resolution. This technique can also be applied to determine the necessary criteria in the data acquisition step which should be satisfied to precisely measure the radiation pattern of super-directive antennas. These criteria are the maximum acceptable sampling resolution and the minimum value of the required azimuth angle (φ) in the data acquisition step if the far-field pattern is merely desired on the front side of the antenna. Results: For verifications, the far-field radiation pattern of an electrically large slot array antenna including 81×15 slots is calculated at 8.75 GHz by the proposed technique and the results are compared with the array theory. The results show that the azimuth pattern can accurately be measured as small as 0.1° resolution by the SSM.Conclusion: By comparing the results obtained by the proposed method and the traditional cylindrical scanning method, it can be inferred that the far-field pattern of an antenna with narrow beamwidth in the azimuth plane can easily be characterized by a cylindrical scanning system without any huge computational burden
Innovative Paper
Electronics
A. Saleh; A.S. Arifin
Abstract
Background and Objectives: In general, traditional salt farmers determine the time to harvest salt by visiting and monitoring their salt ponds. Therefore, to assist salt farmers in determining the right time to harvest salt and determine the quality of the harvested salt, a wireless-based electronic ...
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Background and Objectives: In general, traditional salt farmers determine the time to harvest salt by visiting and monitoring their salt ponds. Therefore, to assist salt farmers in determining the right time to harvest salt and determine the quality of the harvested salt, a wireless-based electronic device is needed that can monitor the salt content and viscosity of the brine.Methods: An electronic device that is made to measure salt content (salinity) with a conductivity sensor and to measure fluid viscosity using a data processing method from sensor readings which is first converted to digital data with a program on the microcontroller. To find out whether the brine is ready to be harvested or not, the data obtained in the form of conductivity and stress are converted into percentages of NaCl and degrees of Baume. Then the data is sent to the ESP8266 wifi module to be stored in a database and displayed on the Web.Results: The results of the data obtained are based on testing in salt ponds for young water but it has been quite a long time the results have approached old water of around 64% and 14o Be. The results of the old water test that had just been moved to the last reservoir were close to harvest time of around 94% and 21o Be. If it has reached 25o Be then it is enough to be moved to the crystallization site. To determine the harvest period based on two parameters, namely the salt content and the viscosity of the liquid is 86-90% and the viscosity of the liquid is 20-24o Be. If you have reached both of these parameters, the salt can be harvested in about 7-10 days to make the water crystallize.Conclusion: Equipment Indicators for determining salt harvest time based on salinity and liquid viscosity using a microcontroller that has been made have been successfully used to determine salt harvest time properly. The salt quality of this indicator tool is the salt content including the K-3 quality or the lowest quality of the 3 existing qualities.
