Assessment of the likelihood of suffusion in alluvial soils: case history

Suffusion is a process of soil particle transfer in the soil body due to the effect of seepage flow on it. Although up to now internal instability has been considered in hydraulic structures such as dikes, dams and canals, todays, occurring of this phenomenon in arid regions and non-hydraulic constructions was seen. Shahriyar County in Iran, located on alluvial soil deposits, is an area where the non-hydraulic structures built there have been damaged by erosion. Even though there is no surface water flow, a seepage force has been generated by water leakage from buried pipes and sewage disposal wells. In this article, we tried to determine whether suffusion occurs in Shahriyar. Because of the limited number of available methods for the assessment of suffusion, in this article, a new approach is presented using statistical analysis to assess the internal instability of alluvial soils. This approach was developed and verified using a relatively large database of unstable soils. The performance of the presented approach was compared with those of three commonly used methods. It is showed this approach can predict the likelihood of internal instability with a relatively high accuracy rate.     

Design,analysis and simulation of a novel linear capacitive tilt micro-sensor

A new capacitive structure for tilt sensor based on the MEMS technology is designed, analyzed and simulated. With a detailed analysis, we achieve to a precise relation between capacitance and inclination angle. Taking advantage of cylindrical structure in our design, we reach to a linear relationship between capacitance and tilt angle. In three designs of our capacitive tilt micro-sensor, there are 1, 2 and 4 micro capacitors. These capacitors have a common plate of mercury which is movable. Another plate is fixed. Displacement of mercury according to the deflection tends to the variations of capacitors and subsequently total capacitance of the tilt micro-sensor changes. In each of three designs for this micro-sensor, output capacitance (C_out) is introduced with a special equation for obtaining a linear and continues relationship between C_out and tilt angle. The last proposed micro-sensor structure with 4 micro capacitors, shows linear relationship for C_out over tilt measurement range of ?180° to +180° on one axis besides proper sensitivity.     

Proxy signatures and buyer–seller watermarking protocols for the protection of multimedia content

Watermarking techniques are developed to deal with multimedia distribution, authentication and copyright protection. It is usually the seller who embeds a watermark in multimedia content to identify the buyer. The embedded watermark can then be used to trace the traitors identity if unauthorized copies are found. However, repudiation and framing issues might arise in this approach. To solve these problems, buyer–seller watermarking protocols have been proposed based on watermarking in the encrypted domain. Such watermarks combine encryption, digital watermarking, and fingerprinting to preserve digital rights of both the buyer and the seller. Unfortunately, most existing watermarking techniques do not provide convincing proofs to ensure that they achieve the claimed level of security and informal proofs abound in the literature. In this paper, we propose a buyer–seller watermarking protocol based on proxy signatures and homomorphic encryption. Formal proofs are provided to show that in the proposed protocol, watermarks are generated such that the seller is unable to fabricate piracy, but he can trace copyright violators. The protocol further protects anonymity of the buyer until he is adjudicated to be guilty. Moreover, we solve the conspiracy problem without imposing any unrealistic assumptions about thrust-worthiness of the parties involved.     

A new hybrid algorithm for global optimization and slope stability evaluation

A new hybrid optimization algorithm was presented by integrating the gravitational search algorithm （GSA） with the sequential quadratic programming （SQP）, namely GSA-SQP, for solving global optimization problems and minimization of factor of safety in slope stability analysis. The new algorithm combines the global exploration ability of the GSA to converge rapidly to a near optimum solution. In addition, it uses the accurate local exploitation ability of the SQP to accelerate the search process and find an accurate solution. A set of five well-known benchmark optimization problems was used to validate the performance of the GSA-SQP as a global optimization algorithm and facilitate comparison with the classical GSA. In addition, the effectiveness of the proposed method for slope stability analysis was investigated using three ease studies of slope stability problems from the literature. The factor of safety of earth slopes was evaluated using the Morgenstern-Price method. The numerical experiments demonstrate that the hybrid algorithm converges faster to a significantly more accurate final solution for a variety of benchmark test functions and slope stability problems.     

GHFHC: Generalized Hesitant Fuzzy Hierarchical Clustering Algorithm

Dealing with uncertainty is an undeniable challenge in the real‐world problems. In this paper, we focus on hesitant environment such as generalized hesitant fuzzy sets introduced by Qian et al. So we propose a new generalized hesitant fuzzy hierarchical clustering (GHFHC) algorithm based on Atanassov's intuitionistic fuzzy set theory. We extend conventional hierarchical clustering, which just works on the crisp data, and introduce a clustering algorithm, which can be applied on large data set with generalized hesitant fuzzy data. The run time of the GHFHC algorithm shows that its computational complexity will be low. Also, the GHFHC algorithm produces the clusters with arbitrary shapes by using the various distance measures. Finally, an example is provided to illustrate the practicality of the proposed algorithm.     

Demand bidding construction for a large consumer through a hybrid IGDT-probability methodology

This paper provides a technique to derive the bidding strategy in the day-ahead market for a large consumer that procures its electricity demand in both day-ahead market and a subsequent adjustment market. It is considered that hourly market prices are normally distributed and this correlation is modeled by variance–covariance matrix. The uncertainty of procurement cost is modeled using concepts derived from information gap decision theory which allows deriving robust bidding strategies with respect to price volatility. First Order Reliability Method is applied to construct the robust bidding curve. The proposed technique is illustrated through a realistic case study.     

THERMOELASTIC BUCKLING OF ISOTROPIC AND ORTHOTROPIC PLATES WITH IMPERFECTIONS

The nonlinear strain-displacement relations for thin orthotropic plates are considered and substituted into the potential energy function of thermoelastic loadings. The Euler equations are then applied to the functional of energy, and the general thermoelastic equations of thin orthotropic plates are obtained. The stability equations are then derived through the second variation of the potential energy function. The thermal loadings include the uniform temperature rise, axial temperature difference, and the gradient temperature through the thickness. The thermoelastic buckling of a thin plate under these thermal loadings is investigated. The results are extended to isotropic and orthotropic thin plates with and without imperfections.     

BUCKLING OF COMPOSITE CYLINDRICAL SHELLS UNDER MECHANICAL AND THERMAL LOADS

In this article the buckling of specially orthotropic laminated composite cylindrical shells is investigated. The nonlinear equilibrium equations based on the Sander's assumption of simplified nonlinear strain-displacement relations and the linearized stability equations for a circular cylindrical thin shell are considered. The equations include the rotations and transverse shear force. The resulting equations are improved compared to the Donnell stability equations. The mechanical and thermal buckling loads of a thin composite circular cylindrical shell based on Donnell and improved stability equations are obtained.