arXiv subjects

Petr Novikov

Publications and source records attributed to Petr Novikov.

3 recordsLinked to original sources

arXiv2014

Robotic positioning device for three-dimensional printing

Additive manufacturing brings a variety of new possibilities to the construction industry, extending the capabilities of existing fabrication methods whilst also creating new possibilities. Currently three-dimensional printing is used to produce small-scale objects; large-scale three-dimensional printing is difficult due to the size of positioning devices and machine elements. Presently fixed Computer Numerically Controlled (CNC) routers and robotic arms are used to position print-heads. Fixed machines have work envelope limitations and can't produce objects outside of these limits. Large-scale three-dimensional printing requires large machines that are costly to build and hard to transport. This paper presents a compact print-head positioning device for Fused Deposition Modeling (FDM) a method of three-dimensional printing independent from the size of the object it prints.

cs.RO↗

arXiv2010

Locally most powerful sequential tests of a simple hypothesis vs. One-sided alternatives for independent observations

Let $X_1,X_2,..., X_n,...$ be a stochastic process with independent values whose distribution $P_θ$ depends on an unknown parameter $θ$, $θ\inΘ$, where $Θ$ is an open subset of the real line. The problem of testing $H_0:$ $θ=θ_0$ vs. a composite alternative $H_1:$ $θ>θ_0$ is considered, where $θ_0\inΘ$ is a fixed value of the parameter. The main objective of this work is the characterization of the structure of the locally most powerful (in the sense of Berk) sequential tests in this problem.

stat.ME↗

arXiv2009

Locally most powerful sequential tests of a simple hypothesis vs one-sided alternatives

Let $X_1,X_2,...$ be a discrete-time stochastic process with a distribution $P_θ$, $θ\inΘ$, where $Θ$ is an open subset of the real line. We consider the problem of testing a simple hypothesis $H_0:$ $θ=θ_0$ versus a composite alternative $H_1:$ $θ>θ_0$, where $θ_0\inΘ$ is some fixed point. The main goal of this article is to characterize the structure of locally most powerful sequential tests in this problem. For any sequential test $(ψ,ϕ)$ with a (randomized) stopping rule $ψ$ and a (randomized) decision rule $ϕ$ let $α(ψ,ϕ)$ be the type I error probability, $\dot β_0(ψ,ϕ)$ the derivative, at $θ=θ_0$, of the power function, and $\mathscr N(ψ)$ an average sample number of the test $(ψ,ϕ)$. Then we are concerned with the problem of maximizing $\dot β_0(ψ,ϕ)$ in the class of all sequential tests such that $$ α(ψ,ϕ)\leq α\quad{and}\quad \mathscr N(ψ)\leq \mathscr N, $$ where $α\in[0,1]$ and $\mathscr N\geq 1$ are some restrictions. It is supposed that $\mathscr N(ψ)$ is calculated under some fixed (not necessarily coinciding with one of $P_θ$) distribution of the process $X_1,X_2...$. The structure of optimal sequential tests is characterized.

math.ST↗