Cyclic Coloring of Plane Graphs with Maximum Face Size 16 and 17

Plummer and Toft conjectured in 1987 that the vertices of every 3-connected plane graph with maximum face size D can be colored using at most D+2 colors in such a way that no face is incident with two vertices of the same color. The conjecture has been proven for D=3, D=4 and D>=18. We prove the conjecture for D=16 and D=17

Planning and Scheduling in Additive Manufacturing

Recent advances in additive manufacturing (AM) and 3D printing technologies have led to significant growth in the use of additive manufacturing in industry, which allows for the physical realization of previously difficult to manufacture designs. However, in certain cases AM can also involve higher production costs and unique in-process physical complications, motivating the need to solve new optimization challenges. Optimization for additive manufacturing is relevant for and involves multiple fields including mechanical engineering, materials science, operations research, and production engineering, and interdisciplinary interactions must be accounted for in the optimization framework. In this paper we investigate a problem in which a set of parts with unique configurations and deadlines must be printed by a set of machines while minimizing time and satisfying deadlines, bringing together bin packing, nesting (two-dimensional bin packing), job shop scheduling, and constraints satisfaction. We first describe the real-world industrial motivation for solving the problem. Subsequently, we encapsulate the problem within constraints and graph theory, create a formal model of the problem, discuss nesting as a subproblem, and describe the search algorithm. Finally, we present the datasets, the experimental approach, and the preliminary results

Optimization of Nonuniform Linear Antenna Array Topology

This paper deals with the use of a Nonuniform Linear Antenna array (NLA) for determining the Directions of Arrival (DOA) of a signal in 2450MHz frequency band. First, the principle of the DOA estimation method is described for the case of the MUSIC method. This paper also discusses the possibilities of optimizing the position of antenna elements in the NLA configuration, which are performed in analytical solutions and simulations. The simulation results are compared to the analytical results to obtain optimal NLA configurations for determining the signal DOA. Simulation results show that the probability of resolution and accuracy in determining the signal DOA are dependent on the antenna array aperture essentially. Furthermore, the realized NLA configuration was verified by an experimental measurement. The obtained experiment results demonstrate that the applied MUSIC method for NLA configuration is suitable and also highly accurate in determining the signal DOA, which was verified

TiO2 ALD Coating of Amorphous TiO2 Nanotube Layers: Inhibition of the Structural and Morphological Changes Due to Water Annealing

The present work presents a strategy to stabilize amorphous anodic self-organized TiO2 nanotube layers against morphological changes and crystallization upon extensive water soaking. The growth of needle-like nanoparticles was observed on the outer and inner walls of amorphous nanotube layers after extensive water soakings, in line with the literature on water annealing. In contrary, when TiO2 nanotube layers uniformly coated by thin TiO2 using atomic layer deposition (ALD) were soaked in water, the growth rates of needle-like nanoparticles were substantially reduced. We investigated the soaking effects of ALD TiO2 coatings with different thicknesses and deposition temperatures. Sufficiently thick TiO2 coatings (≈8.4 nm) deposited at different ALD process temperatures efficiently hamper the reactions between water and F− ions, maintain the amorphous state, and preserve the original tubular morphology. This work demonstrates the possibility of having robust amorphous 1D TiO2 nanotube layers that are very stable in water. This is very practical for diverse biomedical applications that are accompanied by extensive contact with an aqueous environment

Industry 4.0 impact on logistics

ndustrija 4.0, ki jo poznamo tudi pod imenom četrta industrijska revolucija, je danes neizogibna tema tako v poslovnem svetu kot tudi v vsakdanjem življenju, saj vpliva na celotne panoge ter spreminja način oblikovanja in izdelave produktov, dostave in plačila blaga. Gre za povezovanje digitalnega in fizičnega sveta, ki ga omogočajo nove tehnologije. V vsakdanjem življenju smo tem tehnologijam že izpostavljeni ali pa za njih slišimo preko modnih besed kot so “internet stvari“, “računalništvo v oblaku“, “agumentirana realnost“, “pametne tovarne“ in podobno. Namen diplomskega projekta je predstaviti industrijo 4.0, razumeti njene gradnike ter to smiselno povezati z področjem logistike. Dobavne verige, zaradi vse večjih zahtev potrošnikov, postajajo vedno bolj kompleksne in zahtevnejše za obvladovati in nadzirati. Industirja 4.0 bo imela pozitivne vplive na določene logistične procese, saj bo pravilna uporaba novih tehnologij pripomogla k večji učinkovitosti in optimizaciji vsakdanjih procesov. Posledično pa prinesla večjo dodano vrednost končnim potrošnikom. Videli bomo, da se določena podjetja temu že intenzivno prilagajajo in uživajo v njenih koristih.Industry 4.0, also known as the Fourth Industrial Revolution, is an unavoidable topic today in the business world as well as in everyday life, as it affects entire industries and changes the way we design and manufacture products, deliver and pay for goods. It is about connecting the digital and physical worlds made possible by new technologies. In everyday life, we are already exposed to these technologies or we hear about them through buzzrowds words such as "Internet of Things", "cloud computing", "argumentative reality", "smart factories" and similar. The purpose of the diploma project is to present Industry 4.0, understand its building blocks and connect this in a meaningful way with the field of logistics. Supply chains, due to the growing demands of consumers, are becoming more complex and more demanding to manage and control. Industirja 4.0 will have a positive impact on certain logistics processes, as the correct use of new technologies will help to increase efficiency and optimize everyday processes. As a result, it brought greater added value to end consumers. We will see that certain companies are already intensively adapting to this and enjoying its benefits

The Response of Polarization Maintaining Fibers upon Temperature Field Disturbance

The paper deals with the response of polarization maintaining (PM) fibers upon the variation of the temperature field, on condition both polarization axes are excited. Proper use can be applied in the area of optical fiber thermal field disturbance sensor. For a description of polarization properties the coherent Jones and Muller matrices were used. The Poincare sphere was applied to depict the development of the output of the polarization state of PM fibers for wavelengths 633 nm, 1310 nm and 1550 nm were arranged in a proposed sensor setup and were studied in the laboratory. A wide file of results containing dependencies of phase shift variations upon different configurations of measured PM fiber was obtained. The thermal field disturbance of the PM fiber was applied by an object with defined proportions and a defined range of temperatures. Dependencies of phase shift upon the object´s temperature, its distance from the fiber and exposed length of PM fiber were measured

The Analysis of Fiber Sensor of Temperature Field Disturbance by Human Body Part Access

The principle of this sensor function is based on polarization maintaining fiber (PMF) sensitivity during excitation of both two polarization modes. This excitation is caused by temperature change, when absorbing thermal radiation. This mechanism is used for detection of temperature field disturbance as an indicator. In the case described below, attention was devoted to temperature field disturbance on a part of the human body. Thus this sensor system could be used for protection of some entity. The aim of this study was to determine the sensitivity of PMF to radiating heat, the space configuration and time response

Optical Birefringence Fiber Temperature Sensors in the Visible Spectrum of Light

This article describes experimental tests to determine PM fibers Panda style responses to a thermal source with different initial temperature. The aim of this study was to determine the sensitivity of a polarization maintaining fiber to the radiating heat, and to upgrade the space configuration and time response when using the 635 nm light. The sensitivity of the polarization maintaining fiber during excitation of both polarization modes is the principle of this sensor function. This excitation is caused by temperature change and by absorption of thermal radiation. This mechanism is used as an indicator for detection of temperature field disturbance. This article also provides links to previously published results and compares them to the results in this article