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}. ...
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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.
علوم انسانی دریا
hassan jafari; s s; a k; e n; h h
Abstract
This applied research has been conducted to evaluate the competitiveness of port services using exploratory factor analysis and importance- performance analysis methods. First, by literature review, 53 indicators of competitiveness of port services has been identified, then exploratory factor analysis ...
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This applied research has been conducted to evaluate the competitiveness of port services using exploratory factor analysis and importance- performance analysis methods. First, by literature review, 53 indicators of competitiveness of port services has been identified, then exploratory factor analysis was used to ensure the effectiveness of the identified indicators. Based on the obtained results from 53 identified indicators, in the factor analysis, only 27 of indicator have loadings on the eight factors of Logistics Cost, Connectivity, Port facility, Port Service and Availability, Safety and security, Efficiency and Productivity, Reliability, Hinterland condition. The results of the importance and performance analysis showed that among of eight factors, respectively efficiency and productivity factor has the highest and Hinterland condition has the lowest the difference between the performance average from importance average. And also the Position of each factor in the quarters of the importance and performance matrix indicates that other than the second factor (Connectivity) and fifth factor (Safety and Security) all other factors located in a quarter one.
Amir Ashtari Larki; Masoud Sadri Nasab; Matias Tomchek; Vahid Chegini; Amer Kabi
Volume 12, Issue 2 , April 2014, , Pages 16-24
Abstract
Khowr Doragh located at the northern end of the Khowr Mousa in the southwest of Iran.In present study; tide in Khowr Doragh was simulated by the hydro dynamical part of COHERENS model using the relationship between the potential energy and sea surface. Model was based on a five layers sigma vertical ...
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Khowr Doragh located at the northern end of the Khowr Mousa in the southwest of Iran.In present study; tide in Khowr Doragh was simulated by the hydro dynamical part of COHERENS model using the relationship between the potential energy and sea surface. Model was based on a five layers sigma vertical coordinate.
Taking into consideration the connection between Imam Khomeini Port Complex, Special Economic Zone and the presumed location of the plant, various options for energy supply in the study area is defined based on the demand. In the simplest case, without any interference with existing port activities, 32 MW in average and 11.2 MW (35% efficiency) electric energy can be extracted. Electricity production will be possible both in the ebb and flood by installing two directional turbines with more technical complexity and higher price. By dividing area into two separate pools, electricity would be produced throughout day and night.
By constructing a dam at the main entrance of Khowr Doragh a 20 Km2 natural pool would be created which can produce 25 MW of electricity per day. By assumption of dredging and clearance of land surrounding by Khowr Doragh and Khowr Zangi , model was run for 29 and 60 Km2 pools that would be created. Calculated results show the possibilities of producing 36 and 74 MW of electricity in the 29 and 60 Km2 respectively.
hassan jafari; s s; a k; e n; h h
Abstract
This applied research has been conducted to identify and rank the causes of delay in container handling operation in two stages. In the first, having considered the daily census of container handling operation in the pertinent terminal of the port, As well, brain storming cessions attended by experts ...
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This applied research has been conducted to identify and rank the causes of delay in container handling operation in two stages. In the first, having considered the daily census of container handling operation in the pertinent terminal of the port, As well, brain storming cessions attended by experts from the studied container terminals were held during which twenty seven numbers of causes of delay were detected. In the second stage, having considered the detected factors from the first stage, the probability of the causes occurrence, the extent of impact of causes on process after their occurrence and probability of causes detection before having effect on process have been determined by experts in form of a scale ranging from one to ten, Finally based on the obtained scores by each one of the causes, the decision matrix was formed and the mentioned causes were ranked by TOPSIS method. The abstained results showed that the causes of delays in loading and unloading operations in studied container terminals have significant different in the terms of probability of the causes occurrence, the extent of impact of causes on process after their occurrence and probability of causes detection before having effect on process. Finally to mitigation of these causes several strategies have been presented.