Article presented below is a prelude to the process of autonomous underwater systems positioning. An article include description of positioning methods and guidelines for the operators of autonomous underwater vehicles (AUVs), concerning above mentioned process.
The company’s success depends on many factors. One of them is the ability to meet the customers’ expectations and adjust to the needs reported by market. Mathematical methods and tools are helpful in assessing demand. Forecasts should take into account all factors shaping the demand for goods and services, but they are often difficult to define, not only because of their large number, but also due to the impact of individual variables, which is difficult to determine. In many cases, the number of placed orders strongly depends on the time at which they are submitted. The needs can vary according to the time of day, week and year. Then we are dealing with the so-called seasonality, the inclusion of which is very important in the company and enables to better adapt its activity to the customers’ requirements.
This article describes the seasonality of demand in a company providing domestic and road transport services with high-tonnage vehicles. The validity of such analyses and potential benefits were indicated.
The article contains the chosen results of research on the use of energy profiles controlling the operation of a group of devices powered by a hybrid power source. The concept of using alternative energy sources allows to reduce the total weight of the power system and model its behavior during work. Modern fuel cells are characterized with a very high energy density to mass ratio [Wh/kg], and the additional cooperation of supercapacitors and lithium-ion batteries supporting their operation ensures continuous operation and the required dynamics response while maintaining a low mass of the power supply system. The author presented the general configuration of the layout model, as well as the results of tests of individual elements included in the physical implementation of the hybrid power system.
The effectiveness and efficiency of production system is a guarantee of the company’s success, especially in times of dynamic growth of trade (including online trade), as well as increasing customers’ requirements, who want to have goods always available and delivered, preferably on the day of order. A modern customer of services raises the bar high not only for production systems, but also for transport systems. Therefore, IT tools supporting the management process of all areas of its activity are implemented in enterprises. This article describes selected of them, focusing primarily on the support of production planning process.
As the use of IT systems should be preceded by deepening the knowledge of algorithms applied in them, first of all a calculation example of the use of material requirements planning procedure for complex products with a modular structure was presented, and then the characteristics of selected IT tools supporting the processes of material requirements planning and enterprise resource planning have been made.
Marek Blok, Bartosz Czaplewski, Sylwester Kaczmarek, Jacek Litka, Marcin Narloch and Maciej Sac
Security of national borders requires utilization of multimedia surveillance systems automatically gathering, processing and sharing various data. The paper presents such a system developed for the Maritime Division of the Polish Border Guard within the STRADAR project. The system, apart from providing communication means, gathers data, such as map data from AIS, GPS and radar receivers, videos and photos from camera or audio from phone calls and SMS messages, from multiple mobile units and stationary points located along the coastline. All gathered data can be visualized on a multidisplay by the personnel that can dynamically select presented data and configure form of presentation. The paper describes system functionalities, its hardware and software implementation, and presents results of acceptance tests that the system have recently passed.
Dominik Filipiak, Milena Stróżyna, Krzysztof Węcel and Witold Abramowicz
The paper presents results of spatial analysis of huge volume of AIS data with the goal to detect predefined maritime anomalies. The maritime anomalies analysed have been grouped into: traffic analysis, static anomalies, and loitering detection. The analysis was carried out on data describing movement of tankers worldwide in 2015, using sophisticated algorithms and technology capable of handling big data in a fast and efficient manner. The research was conducted as a follow-up of the EDA-funded SIMMO project, which resulted in a maritime surveillance system based on AIS messages enriched with data acquired from open Internet sources.
The paper presents results of research based on analysis of weather conditions during the storm front on 11th and 12th August, 2017, which has been relocated through a significant area of Poland. The front with an unprecedented force struck the infrastructure of the Academic Training Centre in the village of Czernica (ATC Czernica) on 11th August, 2017 about 23:05 CET. Due to wind impact of near-hurricane force, significant damage in the facility’s infrastructure and the biggest losses are incurred in forest resources. The data from the front passage through Gdynia was observed on a mobile meteorological station located at the Naval Academy in Gdynia. Describing the phenomenon and displaying the losses caused is one of the historical goals set before the article, because such a rapid weather phenomenon has not been recorded in the more than 50-years history of the Center in Czernica.
Letychiv (pl. Latyczów) is a town located in central Ukraine in the Khmelnytskyi Oblast. It has a unique and complicated history. Second World War left it in ruin, destroying buildings, infrastructure and decimating its once large population. Perhaps the most prominent part of the town currently is the building Dominican convent with adjoin Letychiv Assumption Church. This object is surrounded by what is left of the previously impressive Letychiv Castle, founded by Jan Potocki in 1598. Past 30 years have been dedicated by this small Catholic parish towards rebuilding monastery-castle-church complex. Since this is an ongoing project, it was decided to perform a photographic inventory of the current state of the construction and to create a 3D digital model of the castle, facade of the church and monastery, and the altar. This task have proven to be difficult due to complicated structure of the object. Facades and inner parts of the church are almost white with limited number of distinctive elements, painted in pail gold. Elements other than white are almost identical to each other. It leads to various errors in the processing of Structure-from-motion. This article describes how various versions of SfM algorithm work thru mention difficulties, compares results in terms of accuracy, level of detail and overall look. It also describes how SfM can help to document various stages of restoration of important historical objects.
Along with the development of the technology of drone construction (UAV - Unmanned Aerial Vehicles), the number of applications of these solutions in the industry also grew. The aim of the research is to check the accuracy of data obtained using the new technology of UAV scanning and to compare them with one that is widely spread - high-altitude airborne Lidar, in terms of quality and spectrum of applications in industry and infrastructure. The research involved two infrastructure objects: a reinforced concrete one-span bridge and Lattice transmission tower with powerlines. The density of measurement, internal and external cohesion of point clouds obtained from both methods were compared. Plane fitting and deviation analysis were used. The data of UAV origin in both cases provided a sufficient density, allowing the recognition of structural elements, and internal coherence and precision of measurements important in modeling. The study shows that UAV mounted scanning may be used in the same applications as Airborne Lidar, as well as in other tasks requiring greater precision.
Sajad Esmaielzadeh, Hassan Ahmadi and Seyed Abbas Hosseini
Damage detection in concrete gravity dams using Hilbert-Huang Method, as one of the most common signal processing techniques, is studied in this research. After considering a typical geometry for dams, damage is modelled by a reduction in the modulus of elasticity in the dam’s body (in three levels of damage) and in different areas of the structure. The dam is excited by a horizontal earthquake and the primary natural frequencies of the dam are calculated by applying Hilbert-Huang Method to the measured response, which is the acceleration of five points in the system. Based on the changes in the frequencies of the damaged and undamaged structure, a parameter, called relative frequency error, has been introduced. The results show that the proposed criterion used in this study can not only properly identify the location of damage but also predict the severity of the structural damage in concrete gravity dams accurately.