This article is a brief description of a new methodology1 for utilising the Nx – SCR CRABE SCUBA rebreather 2. This new approach differs from that described in a previous article [1,2]. The new methodology is based on a Polish theory3 mainly consisting of deterministic methods4 of modelling semi-closed circuit rebreathers. Further research5 can henceforth be carried out in a more reliable and efficient manner than ever before.
The search and detection of objects under water is carried out by groups of specialised divers. However, their time underwater and their ability to penetrate the depths are limited. For these reasons, the use of unmanned underwater vehicles equipped with technical observation equipment, including TV cameras, is becoming increasingly popular for these tasks. Video images from cameras installed on vehicles are used to identify and classify underwater objects. The process of recognition and identification of objects is tedious and difficult and requires the analysis of numerous sequences of images, and so it is desirable to automate this process. In response to these needs, this article presents the concept of identification of underwater objects based on visual images from an underwater body of water sent from an unmanned underwater vehicle to a base vessel. The methods of initial processing of the observed images from an underwater area as well as the method of searching for selected objects in these images and their identification with the use of the Hough transform will be described. Furthermore, the paper presents the results of the preliminary processing and identification of the observed images following a deconvolution operation.
This material is a continuation of the article published in the PHR no. 3(52)2015 concerning the methodology of selecting underwater exploration strategies for process development purposes. The article proposes to use one of the methods of decision optimization for the selection of the appropriate course of action in such cases.
Dorota Niewiedział, Maria Miłkowska, Piotr Siermontowski, Zbigniew Dąbrowiecki, Dorota Kaczerska, Dariusz Juszczak and Romuald Olszański
The aim of the article is a review of psychological literature relating to the problem of anxiety in divers, where an emphasis is placed on the degree of mental adaptation of the individual to the underwater environment, primarily highlighting the trait of anxiety and the neuroticism of a person involved in a specific type of diving. The article presents selected reports from all over the world regarding research on anxiety in divers. Treating a high level of the indicator of anxiety as a predictor of panic anxiety reveals the importance of this trait in predicting the risk of an occurrence of diving accidents during the operation under water. In the own research presented in the article, the results on the levels of anxiety as a trait and a state in divers taking part in hyperbaric exposures indicate the fact that the majority of the examined divers have low levels of anxiety both as a trait and a state, which most probably indicates the good psychological condition of the examined divers.
The analysis of Berezin and Kiselev’s concept assuming linear association of molecules in a localised adsorption monolayer on the homogeneous surface of a solid adsorbent was carried out. An inconsistency due to the lack of consideration of equilibrium concentration of free adsorption sites in the formulation of the expression for the association constant has been pointed out. It was shown that the correct form of this function leads to the final adsorption equation being identical to the specific case of the Fowler-Guggenheim equation. The obtained result has been generalised to cases of branched adsorbateadsorbate associations. A new adsorption equation limiting the association to at most the dimers has been introduced. Critical conditions for the two-dimensional condensation of the adsorption layer were determined. By applying the formalism of canonical ensemble, full equivalence of the phenomenological and statistical methods was demonstrated in the description of the intermolecular interactions in the localised adsorption monolayer.
This article addresses the practical aspects of the synthesis of an automatic control system for the thrust allocation strategy in the propulsion system of an unmanned underwater vehicle. The vehicle under consideration is a robot submarine equipped with a multi-propulsion system providing four degrees of freedom of movement. The power distribution algorithms are based on limited optimisation methods that allow the determination, on the basis of generalised torques and forces, of how much thrust is required to be produced by individual propulsors. Considering the issue of power distribution as a task of square and linear programming, two algorithms of thrust allocation were proposed and compared. The conducted model tests made it possible to evaluate their quality and efficiency in relation to speed and computational complexity.
Scientific diving is increasingly being used for numerous studies. Moreover, this form of diving allows for the conduction of interdisciplinary research. The current nomenclature of this type of dive is defined as scuba diving to collect information to support science by using diving techniques. Underwater research is particularly important in the natural sciences where it allows for the non-invasive observations of fauna and flora of aquatic ecosystems in their natural environment. At the same time, the use of diving for scientific purposes avoids mistakes made in random sampling, which is related to the use of classical sampling methods. As a result, such diving is crucial in systematic, ecological and behavioural analysis. Nevertheless, dive techniques, however versatile, require optimisation, separate study and systematisation, depending on the type of research conducted. This article is an attempt to present an outline of the topic, to systematise basic concepts in presenting the principles of legal regulations in Poland and abroad..
Recently, the Polish Navy has extended its capability for the implementation of underwater works with autonomous dives conducted beyond the saturation zone to a depth of 80 mH2O. In the near future it is also planned to introduce long-term dives within typical depths of the saturation plateau.
One of the activities resulting from the analysis of the risk associated with the extension of these competences is the need to conduct a critical review of the system for securing hyperbaric treatment of cases of decompression sickness1.
This paper describes the concept of didactic communication and verifies the course of teaching selected disciplines of water based recreation, i.e. swimming (at the standard technique level), handling a sailing boat whilst undertaking simple manoeuvres, and the basics of diving. At the same time, research in the area of experiments conducted in the field of teaching methods of these disciplines was reviewed in terms of teaching effectiveness, as well as the health and safety of the participants, and ways of communicating while in, on and under the water. Communication between an instructor and a student in any environment which is different from the norm, is difficult owing to its specificity. Additionally, teaching skills on, in or under water requires strict observance of safety rules. Lack of student’s readiness to act in a different water environment, be that based on anxiety or fear, may interfere with or, even prevent didactic communication. Consequently, the effectiveness of teaching decreases. The aim of this work is to search for innovative forms of information transfer that will enable a permanent change in the student’s behaviour, especially when acting in a difficult environment – on the water, in the water and under the water. There are premises to believe that immediate verbal instruction and emphasising the metalinguistic function in it should improve the quality and effectiveness of the process of teaching activities in various water based environments.