Browse

You are looking at 1 - 10 of 508 items for :

  • Fundamentals of Electrical Engineering x
Clear All
Open access

Rafał Miętkiewicz

Abstract

In order to first Baltic LNG terminal in Świnoujście construction, issues concerning maritime critical infrastructure protection as a part of Maritime Security appeared. With the increasing natural gas demand LNG terminal in Świnoujście could be a possible terrorist attack target as well as the LNG carriers crossing the choke point of Baltic Straits and sailing through the littoral waters of Polish and other Baltic counties coastline. Experts do not fully agree on possible effects and results of successful terrorist assault on LNG carrier at sea nor at harbor.

Unmanned platforms begin to play prominent role in military, oceanography or academic applications. With the announcement of reducing the hazard for deck operators especially in high-risk regions, it is predicted that unmanned platforms will play crucial role in Maritime Security systems in the nearest future. This paper discusses the design of the USV dedicated to LNG terminal protection tasks introduces potential equipment options and missions scenarios of first Polish unmanned platform ‘Edredon’.

Open access

Piotr Szymak and Michał Przybylski

Abstract

In the recent years, a dynamical development of an underwater robotics has been noticed. One of the newest group of underwater robots are biomimetic underwater vehicles. These vehicles are driven by undulating propulsion imitating fins of underwater creatures, e.g. a fish, a seal, etc.

This paper undertakes problem of thrust measurement of new biomimetic underwater vehicle equipped with undulating propulsion. At the beginning, the stand for thrust measurement is described. Then, two constructions of BUVs imitating a fish and a seal are presented. Further, the results of thrust measurement for two different undulating propulsions are inserted. At the end of the paper containing conclusions from performed measurements and foreseen research is included.

Open access

P. Sivaprakash and S. Kanchana

Abstract

There are about 8.5 million workers employed in the construction sector in India. Construction workers constitute a major portion of the unorganized labour and are characterized by their casual nature of employment, temporary relationship with the employer, prolonged and uncertain working hours, lack of safety and health measures, and inadequacy of basic amenities and welfare facilities. There are many legislation clauses providing safeguards for contract workers in India. Construction safety has been made legally enforceable after the enactment of The Building and Other Construction Workers (Regulation of Employment and Conditions of Service) Act in 1996 and the Central Rules in 1998. This paper details various statutory provisions for construction safety in India with specific reference to the BOCW Act, Central Rules, and State Rules.

Open access

Krzysztof Just and Paweł Piskur

Abstract

In this paper a results of a static analysis of the tubular linear electromagnetic actuator is presented. The linear actuator consist of two parts: a cylindrical unmovable coils surrounded by a soft ferromagnetic case, and a runner made from sequence of permanent magnet with a soft ferro-magnetic gasket. In the first part of the paper the analytical method was performed for preliminary analysis. In the second part of the paper the more detailed analysis was depicted with using finite element method (FEM). The magnetic circuit shape and impact of selected dimensions on static characteristics is presented. Then the axial and radial electromagnetic force as a function of the runner dimensions were analysed.

Open access

Ryszard Kłos

Abstract

This article is one of the series dedicated to the DiveSMART Baltic project conducted to better coordination of international underwater rescue operations in the Baltic Sea. The project DiveSMART Baltic has received Flagship status.

The article is the forth in the planned cycle of articles referring tasks realised in the Naval Academy in the framework of DiveSMART Baltic project. This article describes selected decompression procedures for victims who became saturated by air at maximum depth to H =30 mH 2 O in the air pockets of the hull of a sunken wreck. This subject is associated with the work package four ‘Medical treatment’ of the DiveSMART Baltic project: Identifies methods for different medical treatments in operational areas.

Open access

Iulian Dinulescu and Cristian Troncotă

Abstract

Human behavior has generated a series of threats to human security throughout history, generating major violence at the time when it was doubled by an exaggerated religiosity. Religious fanaticism has manifested itself in all societies, regardless of their forms of organization. The consequences of the phenomenon deeply marked inter-human relationships, both within the community, but especially in communities that have other religions. The article shows the characteristics of religious fanaticism and the factors that cause people to adopt such a behavior of exacerbating religious zeal doubled into intolerance towards those of opponents, both of other faiths and those within their own confession.

The issue is not generated by the religious phenomenon or religiosity that such sectarians or religious organizations and religious fanaticism have with some of the members of such religious entities. They are transformed into perfect soldiers because they respond to clergy ‘requests, even with the sacrifice of their own lives, without counting for these individuals, the feelings for their own family members or the duty to support them. In such situations the phenomenon mentioned can not be prevented until it is truly understood from the religious point of view. Therefore, particular attention must be paid to the motivations that lead some individuals to such behavior, as well as to the characteristics of such religious fanatics, and to the way they create risks to human security. In this article we will only address the religious fanaticism manifested by Christianity and Islam, because these are the ones that can have an impact at European and national level. To this end, we will look at some elements of religious fanaticism that indicate this kind of behavioral pattern. After that we will clarify and show the reader the connection between religious fanaticism, the behavior of the followers influenced by this phenomenon, and the inter-human relationships determined by this type of actors.

Open access

Róbert Szabolcsi

Abstract

Unmanned aerial vehicles are famous for their wide range of applications. In D3 (Dirty-Dull-Dangerous) UAV applications flight conditions may vary on large scale. External disturbances like atmospheric turbulences and gusts may be subjected to UAV, and as a result, UAV flight mission might be conducted with high level of the degradation of the accuracy. Sensor noises are also present, and theirs negligence might lead to improper dynamic performances of the closed loop control systems. Uncertainties of the control systems being structured or unstructured may tend the closed loop control system to stability bounds. In worst case, uncertainties may destabilize closed loop control systems. The purpose of the author is to present a robust controller design method called H2-optimal design ensuring stability of the closed loop control systems with simultaneous dynamic performances predefined for the closed loop control system.

Open access

Tomasz Praczyk, Piotr Szymak, Krzysztof Naus, Leszek Pietrukaniec and Stanisław Hożyń

Abstract

The paper presents the second part of the final report on all the experiments with biomimetic autonomous underwater vehicle (BAUV) performed within the confines of the project entitled ‘Autonomous underwater vehicles with silent undulating propulsion for underwater ISR’, financed by Polish National Center of Research and Development. The report includes experiments on the swimming pool as well as in real conditions, that is, both in a lake and in the sea. The tests presented in this part of the final report were focused on navigation and autonomous operation.

Open access

Franciszek Grabski

Abstract

Some generalizations of the Poisson process and their properties are presented in the paper. The non-homogeneous Poisson process allows to construct a probabilistic model describing the different kinds of accidents number. The nonhomogeneous compound Poisson process enables to describe mathematically the various types of accidents consequences. Theoretical results give possibility to anticipate the accidents number and their consequences.

Open access

Annamaria Sârbu, Marius Sârbu and Cosmin Șumălan

Abstract

Operating in probably the most crowded radio frequency bandwidth, the 2.4 GHz Wi-Fi is still common in the majority of living environments. Besides having to face problems regarding co-channel and adjacent channel influence, Wi-Fi often coexists with other radio technologies operating in this bandwidth which makes it ideal for interference testing.

In this article authors propose the use of freely available mobile applications to measure Wi-Fi signal spreading within a residential home as well as to quantify Wi-Fi performance in the presence of some commonly available interferers. A complete analysis of spectrum use is also provided by using a spectrum analyzer. We have found that Wi-Fi throughput degradation due to Bluetooth technology operated in the immediate vicinity of a mobile client is on average 26,5 % and decreases with distance from the Wi-Fi client. The presence of an active video baby monitor leads to a 7,5 % throughput degradation, but its functionality in heavy Wi-Fi traffic environment is however limited. The use of spectrograms in interference analysis is essential for a better understanding of the measured results.