Economic considerations are significantly important in designing a dam and its related hydraulic structures. Considering the methods used for economic design of hydraulic structures such as a spillway, they are also dependent on the construction costs of the spillway. In addition to the spillway type and capacity being associated with the magnitude of floods. Selecting different options of a spillway, considering all their aspects, has always been one of the biggest issues in decision‐making. The present study determined the best spillway type (free‐flow, stepped, semicircular and cylindrical) for Qeshlagh Dam, Iran, by considering different aspects (costs, time and performance) and using the TOPSIS method. The obtained dimensions of the spillway from multi‐criteria decision‐making were then optimized using meta‐heuristic Harmony Search Algorithm (HSA). The results identified a free‐flow spillway was the best option in terms of cost and time, whereas a cylindrical spillway is the best choice in terms of performance. The optimal free‐flow spillway length is 31.8 m, and height is 3.45 m, being capable of passing a flood discharge of 452 m3/s. This discharge was calculated by a reservoir routing method. Moreover, the obtained solution led to reducing the spillway construction costs, one of the most important issues in civil engineering projects. 相似文献
In this paper, isogeometric analysis (IGA) is employed to solve the problem of a curved beam with free-form geometry, arbitrary loading, and variable flexural/axial rigidity. The main objective of the study is to develop a unified approach for full free-from curved beam problems that can be integrated with a newly developed semi-analytical sensitivity analysis to solve pre-bent shape design problems. The required set of B-spline control points are calculated using an interpolation technique based on chord-length parameterization. The one-to-one correspondence is considered for parameters of the geometry, loading, and rigidity which is proven to have extreme importance. An IGA curved beam element is suggested based on the Euler-Bernoulli beam theory for the general curvilinear coordinate. The validity and effectiveness of the proposed formulation is confirmed by application to a variety of examples. Moreover, three shape optimization examples are taken into consideration. In the first two examples, the pre-bent shapes of spiral and Tschinhausen curved beams with free-form geometry under distributed loading are obtained. In the third example, the pre-bending problem of wind turbine blades is addressed as an industrial example. 相似文献
In this paper, a new representation of neural tensor networks is presented. Recently, state-of-the-art neural tensor networks have been introduced to complete RDF knowledge bases. However, mathematical model representation of these networks is still a challenging problem, due to tensor parameters. To solve this problem, it is proposed that these networks can be represented as two-layer perceptron network. To complete the network topology, the traditional gradient based learning rule is then developed. It should be mentioned that for tensor networks there have been developed some learning rules which are complex in nature due to the complexity of the objective function used. Indeed, this paper is aimed to show that the tensor network can be viewed and represented by the two-layer feedforward neural network in its traditional form. The simulation results presented in the paper easily verify this claim.
Despite the large number of existing buyer coalition schemes and increasing need for trusting relationship in buyer coalitions, no current buyer coalition scheme explicitly addresses trust issues within these schemes in a formalised manner. Without establishing a trusting relationships among various roles, many buyers may not be willing to join the coalitions. This study proposes a solution, in the form of an algorithmic design, as a response to the above need. Specific features of the proposed solution are: (i) the use of ‘group signature’ in order to guarantees anonymity within a group that results in trustfulness of the relationships and (ii) introducing a new role called ‘authority’ to maintain and implement anonymity. In addition, the proposed scheme is capable of maintaining ‘correctness’ and ‘accountability’ by both identifying misbehaved buyers as well as implementing various punishment methods.Knowledge domain of the study is the common space between three overlapping fields including Electronic Commerce, Communication Technologies and Information Systems. 相似文献
Wireless Networks - Conventional planning and optimization of cellular mobile networks for supporting the peak-time user demand leads to substantial wastage of electrical energy. Infrastructure... 相似文献
Nowadays, many people perform their commercial activities, such as electronic payment and electronic banking, through their mobile phones. Mobile commerce (m‐commerce) refers to manipulating electronic commerce (e‐commerce) by using mobile devices and wireless networks. Radio‐frequency identification (RFID) is a technology which can be employed to complete payment functions on m‐commerce. As an RFID subsystem is applied in m‐commerce and supply chains, the related security concerns are very important. Recently, Fan et al. have proposed an ultra‐lightweight RFID authentication scheme for m‐commerce (ULRAS) and claimed that their protocol is efficient enough and provides a high level of security. In this paper, we show that their protocol is vulnerable to secret disclosure and reader impersonation attacks. Finally, we improve it to a protocol that is resistant to the attacks presented in this paper and the other known attacks in the context of RFID authentication. We further analyze the security of the improved protocol through the Burrows–Abadi–Needham logic (BAN‐logic). Moreover, our proposed improvement does not impose any additional workload on the RFID tag. 相似文献
Multidimensional Systems and Signal Processing - In the current paper, linear dynamical system identification by relevant and irrelevant multi-sensor observations is presented. In common system... 相似文献