This paper presents a method to optimize the energy efficiency of walking bipedal robots by more than 80 % in a speed range from 0.3 to 2.3 m/s using elastic couplings – mechanical springs with movement speed independent parameters. The considered planar robot consists of a trunk, two two-segmented legs, two actuators in the hip joints, two actuators in the knee joints and an elastic coupling b...

We provide an equivalent condition for the monogenity of ring integers any cyclic cubic field. Although a large part main results is covered by classical one Gras, we write more explicitly. First, show that if field monogenic then it simplest $K_t$ defined Shanks' polynomial $f_t(x):=x^3-tx^2-(t + 3)x-1$ with $t \in \mathbf{Z}$. Then give when monogenic, which explicitly written in terms $t$.

In this paper we highlight the connection between Ramanujan cubic polynomials (RCPs) and a class of polynomials, the Shanks cubic polynomials (SCPs), which generate cyclic cubic fields. In this way we provide a new characterization for RCPs and we express the zeros of any RCP in explicit form, using trigonometric functions. Moreover, we observe that a cyclic transform of period three permutes t...

It has been well-observed that an inequality of the type π(x; q, a) > π(x; q, b) is more likely to hold if a is a non-square modulo q and b is a square modulo q (the so-called “Chebyshev Bias”). For instance, each of π(x; 8, 3), π(x; 8, 5), and π(x; 8, 7) tends to be somewhat larger than π(x; 8, 1). However, it has come to light that the tendencies of these three π(x; 8, a) to dominate π(x; 8, ...

aslan hashemi1, ali reza shokuhfar*1 1-department of agronomy, islamic azad university, ahvaz branch, ahvaz, iran author for correspondence * corresponding author email address: [email protected] received: 10 june 2015                                                                         accepted: 20 october 2015 abstract soil compaction is a main factor that reduces sugarcane yield...