Weak signal detection is very important in the downhole acoustic telemetry system. This paper introduces the Duffing oscillator weak signal detection method for the downhole acoustic telemetry systems. First, by solving the Duffing equation, analyzed the dynamics characteristic of Duffing oscillator and weak signal detection principle; and then on this basis, built Duffing oscillator circuit ba...

The dual simplex algorithm has become a strong contender in solving large scale LP problems. One key problem of any dual simplex algorithm is to obtain a dual feasible basis as a starting point. We give an overview of methods which have been proposed in the literature and present new stable and efficient ways to combine them within a state-of-the-art optimization system for solving real world l...

Background: NPs (NPs) with unique chemical and physical properties can be used for therapeutic purposes because of their strong antimicrobial activates. NPs have been used as an antimicrobial agents to inhibit microbial growth.Objectives: In view of the strong antimicrobial activity of NPs, the biogenic synthesis and leishmanicidal activity of rod-shaped ...

Using the theory and method of artificial neural network, this paper established a decision-making model of bid evaluation for engineering projects based on back propagation neural network (BPNN). BP neural network was trained and tested by the learning sample that was attained by using order relation analysis method (G1-method). At the same time, we used the momentum BP algorithm to solve the ...

A large portion of automated testing techniques has been developed for the statement or branch test coverage criteria. Among structural criteria, however, research on basis path testing has received little attention. The basis path testing requires a set of basis paths to be executed during testing. However, traditional testing methods for basis path generation consider only the control flow of...

This paper addresses a multi-scale finite element method for second order linear elliptic equations with arbitrarily rough coefficient. We propose a local oversampling method to construct basis functions that have optimal local approximation property. Our methodology is based on the compactness of the solution operator restricted on local regions of the spatial domain, and does not depend on an...

Background and Objectives: Iran, as a developing country, is experiencing high burdens of Helicobacter pylori (Hp)-associated non-communicable diseases. Hp stool antigen test (HpSA) is widely used as an inexpensive and feasible noninvasive method to diagnose Hp infection, instead of invasive approaches. The current study aimed at evaluating th...

We prove Feasible Disjunction Property for modal propositional logics K, K4, K4Grz, GL, T, S4, and S4Grz, by a uniform and simple proof based on modular modal sequent proof systems. We derive Feasible Interpolation Theorem for all the logics. Our results are weaker than Hrubeš’ obtained in [9].

Carrier multiplication (CM) is a process in which absorption of a single photon produces not just one but multiple electron-hole pairs (excitons). This effect is a potential enabler of next-generation, high-efficiency photovoltaic and photocatalytic systems. On the basis of energy conservation, the minimal photon energy required to activate CM is two energy gaps (2Eg). Here, we analyze CM onset...

In railway applications possible interaction between power train and signalling system requires efforts to Electro Magnetic Compatibility (EMC) problems. With the progress of power device technology in recent years, it has become feasible to improve performances of power electronics systems; however EMI noise, caused by fast switching commutations in power converters, has to be managed. EMC con...