The development of damage detection techniques for offshore jacket structures is vital for preventing catastrophic events. This paper applies a frequency response based method for the purpose of structural health monitoring. In this approach, the concept of a minimum rank perturbation theory is used. The feasibility of using a finite number of sensors and its effect on damage detection capabilities is investigated. In addition, the performance of the proposed method is evaluated in the case of multiple damages. The aforementioned points are illustrated using the numerical study of a two dimensional jacket platform.

The presence of fast and slow modes in vehicle suspension systems based on a half car model, is utilized in the design of active suspension control using singular perturbation theory. This strategy is based on the slow-fast control design. The suspension system performance is optimised with respect to ride comfort, road holding and suspension rattle space as expressed by the mean-square-values of body acceleration (including effects of heave and pitch), tire deflections and front and rear suspension travels. The method of design in this study is based on LQG feedback control combined with singular perturbation theory, and at the end, a composite LQG controller has been proposed. Numerical simulations in the time domain evaluate the performance of the active suspension system. In spite of the simplified structure of the composite model, simulation results indicate that its performance is comparable to that of the full-state feedback design.

Perturbation theory is a helpful tool in many branches of theoretical physics, and also the statistical mechanics of classical liquids. The perturbation strategy not only plays an important role in bulk fluid thermodynamic properties, but also, in recent year, has become more important in bulk solids, in classical density functional theory and integral equation thermodynamic theory. On the base of thermodynamic perturbation theory, thermodynamic quantities are related to molecular structures via THE radial distribution function and molecular structures are extremely established with hard sphere potential interaction. In the last two decades, there have been advances in all types of theories. All versions of this theory includ 1) Zwanzig approach which expressed so-called high temperature series expansion and formulate the first term of perturbation expansion 2) Barker-Henderson theory for the second order term and higher order terms, and also some modification of Barker-Henderson theory 3) Week-Chandler-Anderson soft-core perturbation theory has been developed by Ben-Amotz and Stell (BAS) via introduction of Boltzmann factor criterion as the effective diameter. In this work, different versions of thermodynamic perturbation theory for the bulk fluids are investigated and Zhoul -expansion approach as a new version of thermodynamic perturbation theory will be introduced and compared with the Barker-Henderson macroscopic compressibility approach.

The traditional method for studying non-stationary signals is spectrogram based on the short-time Fourier transform (STFT). The well known limitation of the STFT is the inherent trade-off between time and frequency resolution. The Wigner-Ville (WV) distribution has the best time-frequency resolution, but its draw back is generating cross-terms. The matching pursuit (MP) distribution based on using the Gaussian atom is always positive, does not include crossterm, and has convenient resolution. In this paper, we have shown in addition to the known properties, the MP distribution can also remove the additive noise inherently. On the other words, we are able to remove the noise just by limiting the algorithm iterations and without paying any additional cost. Although the MP distribution based on using the Gaussian atoms is always positive and it has convenient resolution, according to the MP the time marginal and the frequency marginal will not be obtained accurately. In this paper, it has been shown that by implementing the minimum cross entropy (MCE) technique according to the MP distribution as a priory positive distribution, the new extracted distribution has the most similarity to the MP distribution and it also satisfies the correct time and frequency marginal.

One of the factors that can be the link between our intentions and actions and their external consequences is human agency, which indicates the conscious design and intentional execution of actions by the individual in order to influence future events.Objective and Method: This research with a developmental approach of psychometric method and method 1, examines the psychometric indices of the Human Factor Characteristics Scale using the classical theory of test score measurement and the graduated question-answer theory. The purpose of this study, which included high school students in Tehran, was selected by cluster sampling of 500 people as a sample size and statistical analysis was performed on 481 data. To collect the data, the ion Human Agent Characteristics Scale (2011) was used and the research questions were evaluated using IRTPRO and SPSS software.Results:The assumption of local independence based on Pearson x2 index was established by applying Simjima's calibrated question-answer theory and the assumption of being one-dimensional based on the analysis of multidimensional question-answer theory. Diagnosis parameters with question-answer approach and classical approach Test score Both item 25 approach had the lowest and item 2 had the highest diagnosis parameter. The answer thresholds for all the questions were so far apart that no option was covered by the other option, and the options were independently selected by individuals at intervals of theta. The total scale was calculated with Cronbach's alpha of 0.945, intentionality of 0.894, foresight of 0.780, self-reactivity of 0.871 and rethinking of 0.762. Also, the role of each item in internal consistency was investigated by the loop method, which all questions had a favorable role in internal consistency of this scale. The value of the validity coefficient obtained from the question-answer theory was obtained by marginal method for intentionality 0.92, forethought 0.85, self-reaction 0.91, rethinking 0.83..