مهندسی دریا
Javad Ahsan; Mohammad Esmaeildoust; Amer Kaabi; vahid Zareii
Abstract
The residue number system has a parallel computational structure with carry-free operations and is widely used in cases such as digital signal processing, cryptography, design of FIR filters, etc. In this paper we design an efficient reverse converter for the four-moduli set {〖2^(n-2)+1,2〗^(n-3)-1,2^(n-3)+1,2^(n-5)-1}. ...
Read More
The residue number system has a parallel computational structure with carry-free operations and is widely used in cases such as digital signal processing, cryptography, design of FIR filters, etc. In this paper we design an efficient reverse converter for the four-moduli set {〖2^(n-2)+1,2〗^(n-3)-1,2^(n-3)+1,2^(n-5)-1}. In this moduli set, due to the selection of well-formed and balanced modulus, it leads to optimal hardware implementation, with minimum area utilization and minimum time delay. The main advantage of this design is the use of a ROM free and adder base hardware structure. The proposed moduli set are relatively prime to most existed moduli sets in literature and as results it can be employed in the implementation of Montgomery multiplication. The proposed reverse converter has a two-level structure. In the first level, the Chinese remainder theorem is used, and in the second level, the Mixed-radix conversion is used to calculate the final weighted number. The results of computational theory show low time latency and minimal hardware space in this design.
مهندسی دریا
Amir Zarepour; Mehdi Behdarvandi Askar; Saham-eddin Cheraghi; vahid Zareii
Abstract
The aim of this research is to investigate the hydrodynamic status of Mahshahr export port. Initially, the modeling of tidal streams in the starting point of Khurmousa by the tidal inputs of Rahnamaian station was performed in logical manner and the results obtained from the inner point of Khurmousa ...
Read More
The aim of this research is to investigate the hydrodynamic status of Mahshahr export port. Initially, the modeling of tidal streams in the starting point of Khurmousa by the tidal inputs of Rahnamaian station was performed in logical manner and the results obtained from the inner point of Khurmousa was calibrated with inputs from Imam Khomeini station port and satisfactory results were achieved. During the next stage, by considering the main aim of this research, a model specific to the area of export port of Mahshar was developed. Based on the results from field measurements and the results obtained from the model, the tidal amplitude balance in export port of Mahshahr is 4.25 meters, the maximum annual ebb is 2.25 meters and the annual minimum is 2 meters. The velocity of tidal streams in Mahshahr export port parallel to the channel and during the most part of the year is between 0.5 to 1 meters per second. The pattern of tidal streams is constant throughout the year and experiences no changes
علوم زیستی دریا
Mohammad Khosravizadeh; Ainaz Khodanazary; vahid Zareii
Abstract
Different stunning/slaughtering methods could significantly influence flesh quality of fish during storage time. Hence, the aim of present study was to explore the effects of two stunning/slaughtering methods including electroshock and asphyxia in the air on sensory, microbiological and chemical alterations ...
Read More
Different stunning/slaughtering methods could significantly influence flesh quality of fish during storage time. Hence, the aim of present study was to explore the effects of two stunning/slaughtering methods including electroshock and asphyxia in the air on sensory, microbiological and chemical alterations of silver carp during 5 days storage in ice. The results showed a gradual increase in counts with time for mesophilic and psychrophilic bacteria in both methods. However, comparing the results showed mesophilic and psychrophilic counts were significantly lower in fish stunned by electroshock methods at the end of study. In case of chemical characteristics, no significant differences between two stunning/slaughtering methods were observed. Also the results of sensory analysis did not show significant differences between the two methods and quality index was highly correlated with time during ice storage. Hence, despite of no significant differences in chemical and sensory characteristics, the results showed growth rate and total counts of bacteria were significantly lower in fish slaughtered by electroshock.