مجله فناوری اطلاعات در طراحی مهندسی
سال هشتم شماره 1 (بهار و تابستان 1394)

The annual fastest wind analysis of the important requirements in the design of tall building, Dams, etc. The annual fastest winds of grate Khorasan province synoptic stations selected for statistically analysis. The data were screened and the basic tests (randomness, homogeneity, independence, etc.) were investigated. The data of four station have outliers and not random. Five stations were not stationery and heterogeneous. The seven distribution functions Gumble type 1, gamma 2 parameters, lognormal 2 and 3 parameters, Generalized Pareto, generalized Extreme values and Pearson type 3 with five estimation methods (conventional moments, maximum likelihood, probable weighted moments, maximum entropy and modified moments) were fitted. The Ks goodness of fit test applied to determine the suitability of the chosen distribution and superior distribution. Three priorities for each station were established. Because of the physical behavior of this phenomenon is well justified. Generalized Pareto 21 times and General Extreme value 11 times were the best fitted distributions. Probability weighted moments were the best estimation methods in all distributions.

Diffusion of hydrogen in metals and alloys is effects on material behavior such as loss in mechanical properties. In this work to evaluated the effect of alloying elements on the several chemical composition of the cladding aisi 347 with hydrogen was studied. For this purpose a piece of carbon steel St37 was prepared and cladding with filler metal with two different chemical compound 347 stainless steel. In this regard, a non-hazardous electrochemical charging method to hydrogen charge the specimens. Mechanical properties and Microstructure of the specimens were studied by means of micro hardness testing, tensile strength, toughness, optical microscopy and microanalysis techniques (EDS). Results indicate that both overlay werewithout any defects in the interfaces. Also the results of the cladding samples showed the presence of elements such as Cr, Mn, Ti, Nb can reduce hydrogen permeation and diffusion, while Ni probability can increase permeation and hydrogen embrittlement.

Storms, as the main cause of producing floods, runoffs, soil erosion and the like, have important specifications which affects differently on the resulting floods. Temporal patterns are functions of rainfall intensity in time. These patterns in their one-peak states are estimated by triangle. If the length of the storm peak point is given, then the triangular shape of the storm intensity function for the basin is available. In the present study, a new profile for storm intensity function in different regions in Iran is considered and according to other important specifications such as rainfall amount, rainfall duration, and storm peak intensity, the storm peak time is measured in a nonlinear relationship. The total number of storm gauging stations throughout Iran is 396. The number of the acceptable stations in terms of the rainfall duration less than 6 hours is 130. According to maximum daily precipitation, Iran is regionalized to 7 areas. A sample of each area’s storm with different duration is selected by systematic sampling method. The results showed that the storms with duration less than 6 hours behave properly in all our regions and about 43.6% of them have one-peak. About 34.6% of the total storms in Iran have one-peak and contain 10 to 48 hours duration. In this study, the analyzed storms had one-peak and less than six hours duration. Through linear and nonlinear regression and multiple regressions, the relationship between peak-time and other storm specifications was gained for all the regions in Iran. The most fitted patterns were nonlinear (log-regression) patterns. These patterns include 3 log-regression variables, namely duration specifications (Td), the proportion of rainfall amount (P) to rainfall intensity (IP), for regions 1 to 5. The best pattern for regions 6 and 7 was gained through 2 log-regression variables according to rainfall duration. Comparison of the presented patterns in this study showed their advantageous over other patterns which had been suggested so far.

The past decade has witnessed a rapid development of social networks.Community detection is a very important problem in social network analysis. Finding a community in a social network is to identify a set of nodes such that they interact with each other more frequently than with the nodes outside the group. Classical clustering approach, K-means, has been shown to be very efficient to detection community. However it is sensitive to the initial seeds.To solve this problem, in this study, we first find K seeds using PageRank and second extract community structure of the network using heat diffusion similarity and K-means. Using heat diffusion similarity, we can get the network’s global information about any pair of vertices. The empirical study on real networks show that our algorithm in most social networks studied is better than algorithms including K-rank, K-means, BGLL, OSLOM ,LPA , Infomap and is efficient to be used for sparse large networks.

In this research is investigated the free vibration analysis of two dimensional functionally graded material beams with considering Timoshenko's theory. Material properties of the beam are assumed to vary continuously in the length and thickness direction and follow from exponentially function. The governing equations of motions are derived by using Hamilton's principle. Both axial and rotary inertia of the beam are considered in present analysis. The governing differential equations of motions are converted to a set of first order differential equations using the state space technique and natural frequencies are determined. The effects of length to thickness ratio, gradient indices and boundary conditions on natural frequencies are investigated.