Sharif Digital Repository

The purpose of the research is to define and analyze the dominant organizational culture in Kish and to conduct a pilot research in Iran. Designed as a survey, the research employs the five cultural dimensions of Hofstede in organizations, and by different methodology, defines the ranking of each dimension. The sample consists of 254 employees working in two public and five private organizations on Kish-Island. In addition to define the ranking for each of the five dimensions, for the first time in Iran, the survey measures the ranking of long-term orientation, and shows differences between dominant culture in Iran and the Arab countries (opposed to Hofstede's recommendation). The... 

Cooling system is essential for high power fuel cells to maintain cells temperature in an acceptable limit. In this paper a suitable cooling system for the PEM fuel cell has been designed and optimized. The design includes the number of the cooling plates, the proper circuit of the cooling channels in the plates, the channel dimensions, the flow rate of the cooling fluid and its temperature. The optimization technique is minimization of the entropy generation through the cooling plates. The design of the cooling channels and plates is such that the plate temperature doesn't exceed from a desired temperature and the temperature variation in the plate becomes minimized. In this design, the... 

Single nucleotide polymorphism (SNP) in human genomes is considered to be highly associated with complex genetic diseases. As a consequence, obtaining all SNPs from human populations is one of the primary goals of recent studies on human genomics. The two sequences of SNPs in diploid human organisms are called haplotypes. In this paper, the problem of haplotype reconstruction from SNP fragments with and without genotype information is studied. Minimum error correction (MEC) is an important model for this problem but only effective when the error rate of the fragments is low. MEC/GI, as an extension to MEC model, employs the related genotype information besides the SNP fragments and,... 

Cell temperature in fuel cells is an important parameter which highly affects fuel cell stack efficiency. A suitable cooling system should satisfy an acceptable temperature range. In this research a relevant cooling system for a specified PEM fuel cell stack has been proposed complying with the criteria and cooling requirements of the fuel cell. The effect of various parameters on the entropy generation and temperature distribution in the cooling plates are surveyed. The number of cooling plates, the number of channels in each cooling plate and the channel width is determined. Two flow regimes namely laminar and turbulent flows of the cooling fluid in channels are analyzed and a design... 

Earlier, we engineered a wireless power transfer (WPT) system whose key element is a self-activating and self-decoupling transmitting (Tx) antenna called the high-impedance coil (HIC) that grants a high efficiency for a receiving (Rx) antenna with a free position in front of the Tx array. When the Rx antenna is located in front of the Tx one, the input impedance of the last one drastically decreases, which results in efficient power transfer. This impedance is initially so high that the Tx antenna in the absence of the Rx one does not accept power, which implies negligible open-circuit losses. This feature grants the automatic activation/deactivation of the WT system. In the present work, we... 

Reconstructing haplotype in MEC (Minimum Error Correction) model is an important clustering problem which focuses on inferring two haplotypes from SNP fragments (Single Nucleotide Polymorphism) containing gaps and errors. Mutated form of human genome is responsible for genetic diseases which mostly occur in SNP sites. In this paper, a fuzzy clustering approach is performed for haplotype reconstruction or haplotype assembly from a given sample Single Nucleotide Polymorphism (SNP). In the best previous approach based on reconstruction rate (Wang 2007[2]), all SNP-fragments are considered with equal values. In our proposed method the value of the fragments are based on the degree of membership... 

Using two different capacitive cell probes; and monitoring capacitance and resistance values of the air and water liquids, the cell length and conductance effects of the water liquids are studied. Variations of the dielectric air capacitance and reactance capacitance parameter of liquids with cylinder length are investigated. In another study the probe length affects on the capacitance and resistance measurements for the liquid filling process are investigated. Different theories are also developed to calculate the capacitance values for the constructed probes. Capacitance per unit length from the Coulomb theory is different from the Gauss law that is a constant value. Measured air... 

Load Balancing has many applications in various systems, but specifically plays a major role in the efficiency of parallel and distributed systems. In these systems, by load balancing we mean scheduling the jobs in a way that every job could be executed concurrently while it is mapped to a processing unit, such as a processor (in a multi-processor system) or a computer (in a grid computer). By developing effective methods the whole program time execution will be decreased and process utilization will be optimized. In this paper, a solution is proposed for dynamic load balancing. Because of the NP-hard nature of the problem, heuristic methods are desired. A simple scheduling method, Round... 

During the last two decades, energy production has been directed towards renewable resources, one of the most important of which is geothermal energy. Despite the reliability of geothermal energy as a resource, its effects on the surrounding environment have not been investigated in detail. This study focuses on reservoir deformation as one of the environmental concerns of geothermal energy extraction. A coupled thermo-hydro-mechanical (THM) model is employed for simulating the reservoir deformations. The validity of the model results is examined by comparing the numerical results with the analytical solution of a benchmark THM problem. The model is then utilised to study the behaviour of a... 

Silver-based nanomaterials have attracted considerable attention due to their antimicrobial activities. In this work, a silver (Ag)-based metal organic framework (Ag-MOF) is embellished with graphene-oxide (GO), leading to the fabrication of a novel Ag-based nanocomposite (GO-Ag-MOF) whose biocidal activity is higher than those of Ag-MOF and GO nanomaterials. The nanocomposite is characterized using X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscope, Fourier transform infrared spectra, ultraviolet−visible absorption spectra, X-ray powder diffraction, dynamic light scattering, and nitrogen gas adsorption/desorption. The characterization shows that... 

In traditional game theory, the players play with policy of maximizing their payoffs. In real world, there are many situations where payoffs have uncertainty and are fuzzy in nature. In this paper, a new method for finding pure strategy Nash equilibriums, to realistically analyze the games with fuzzy payoffs is investigated. Using ranking fuzzy numbers, a fuzzy preference relation is constructed over payoffs. The priorities of payoffs are considered as the degree of being Nash equilibriums  

In this study, a new multi-input high step-up inverter, based on isolated soft-switching DC-DC converter blocks is proposed. Each of these blocks can provide zero-voltage and zero-current switching for its semiconductors, which improve power efficiency. The interesting feature of this DC-DC converter is using bidirectional switches to generate both positive and negative output voltage levels in each DC-DC block with an appropriate control scheme. Each DC-DC converter operates by simple pulse width modulation control through fixed frequency and has two degrees of freedom, which provide the capability of output voltage regulation or maximum power point tracking. The proposed inverter consists...