An industry case of large-scale demand forecasting of hierarchical components

Demand forecasting of hierarchical components is essential in manufacturing. However, its discussion in the machine-learning literature has been limited, and judgemental forecasts remain pervasive in the industry. Demand planners require easy-to-understand tools capable of delivering state-of-the-art results. This work presents an industry case of demand forecasting at one of the largest manufacturers of electronics in the world. It seeks to support practitioners with five contributions: (1) A benchmark of fourteen demand forecast methods applied to a relevant data set, (2) A data transformation technique yielding comparable results with state of the art, (3) An alternative to ARIMA based on matrix factorization, (4) A model selection technique based on topological data analysis for time series and (5) A novel data set. Organizations seeking to up-skill existing personnel and increase forecast accuracy will find value in this work

Fabry-Perot Bound States in the Continuum in an Anisotropic Photonic Crystal

An anisotropic photonic crystal containing two anisotropic defect layers is considered. It is demonstrated that the system under can support a Fabry-Perot bound state in the continuum (FP-BIC). A fully analytic solution of the scattering problem as well as a condition for FP-BIC have been derived in the framework of the temporal coupled-mode theory

Electrodynamic Model of the Heart to Detect Necrotic Areas in a Human Heart

To diagnose the conditions and diseases of the cardiovascular system is the main task of electrocardiology. The problem of the cardiovascular system diagnostics is caused by a complex multi-level mechanism of its functioning, and only experienced specialists are able to establish a correct diagnosis. Since the working heart is inaccessible to direct observations in real life, diagnostics of diseases is based on noninvasive methods such as electrocardiography. By assumption, weak "bursts" (micropotentials) of electrocardiographic signals in different areas are the precursors of dangerous arrhythmias. The amplitude of these signals on the body surface is insignificant and tends to be commensurate with the noise level of the measuring system. Advances in electrocardiography make it possible to generate a high resolution ECG signal and to detect the heart micropotentials. The method of modeling helps to understand causes of micropotentials in the ECG signal by selecting the model parameters. The model of the heart should allow generating a signal close to the high resolution ECG signal. The research aims to find a numerical model that allows solving the inverse problem of the heart tissue characteristics recovery using a high resolution ECG signal and CT data on the heart geometry. The proposed computer model and highly sensitive methods for the ECG measurement are the part of the hardware-software complex to detect dangerous precursors of cardiac arrhythmias

Enhanced light absorption in Tamm metasurface with a bound state in the continuum

We consider light absorption in a germanium grating placed on top of photonic-crystalline substrate. Such a system supports an optical Tamm state decoupled from the continuous spectrum with its frequency within the photonic band gap. We have demonstrated that application of the Tamm state makes in possible to engineer extremely narrow absorber which provides a 100% absorption in a semiconductor grating in the critical coupling regime. The proposed design may be used at both normal and oblique incidence at the telecom wavelength

Analysis of the effectiveness of the systems for providing thermal conditions of the local working areas based on the gas infrared emitters

One of the urgent tasks in recent years is to reduce the cost of thermal energy to ensure the thermal regime of the local working areas in the production facilities. For these purposes, the gas infrared emitters (GIE) are increasingly used, but due to the lack of an informative base that provides the regulated thermal regime of the big-sized workrooms, their implementation is constrained. The article presents the results of the experimental and theoretical studies carried out to assess the efficiency of using such systems. The measurements of the temperatures of the floor surface at the characteristic points were carried out during the operation of the emitter of average power. The article presents the results of mathematical modeling of heat transfer in the surface layer of the floor which receives the heat flux from the GIE

Experimental study of the temperature distribution over the surface of a heat supply object under heating conditions with a gas infrared emitter

The experimental studies of the heat transfer processes in the system of radiator – air – heat supply object have been carried out to measure the surface temperatures of the fabric covering the model of the worker. The results obtained give grounds to conclude that when developing systems for ensuring the scheduled thermal regime of the local working zones of the large industrial premises under the conditions of radiant heating, it is necessary to take into account the spatial orientation of the surface areas of the clothing of the worker relative to the vector of the radiant energy flux