35 research outputs found
Using semantic clustering to support situation awareness on Twitter: The case of World Views
In recent years, situation awareness has been recognised as a critical part of effective decision making, in particular for crisis management. One way to extract value and allow for better situation awareness is to develop a system capable of analysing a dataset of multiple posts, and clustering consistent posts into different views or stories (or, world views). However, this can be challenging as it requires an understanding of the data, including determining what is consistent data, and what data corroborates other data. Attempting to address these problems, this article proposes Subject-Verb-Object Semantic Suffix Tree Clustering (SVOSSTC) and a system to support it, with a special focus on Twitter content. The novelty and value of SVOSSTC is its emphasis on utilising the Subject-Verb-Object (SVO) typology in order to construct semantically consistent world views, in which individuals---particularly those involved in crisis response---might achieve an enhanced picture of a situation from social media data. To evaluate our system and its ability to provide enhanced situation awareness, we tested it against existing approaches, including human data analysis, using a variety of real-world scenarios. The results indicated a noteworthy degree of evidence (e.g., in cluster granularity and meaningfulness) to affirm the suitability and rigour of our approach. Moreover, these results highlight this article's proposals as innovative and practical system contributions to the research field
Identification of influence of part tolerances of 1PWR-SE pump on its total efficiency taking into consideration multi-valued logic trees
This paper presents a methodology for identifying
the influence of the tolerances used in model pump
(TYPE 1PWR – SE) construction on the total efficiency.
The identification of the sensitive control dimensions
(Value/Tolerance) of examined pumps has been made by
means of multi-valued logic and inductive decision trees.
The innovation of the prototype unit is based on oblique
gears with involute teeth, modified in the lower and
upper part of the profile. The modification in the lower
part was made using the so-called tooth root undercutting
technique. Through the use of multivalent logic
trees, the designated rank of importance of both structural
and operational parameters is identified, taking
into account the effect of tolerances on construction. The
area is increased by cutting the oblique teeth
The influence of gear micropump body asymmetry on stress distribution
The paper presents the results of numerical calculations of stress distributions in the gear micropump body for applications in hydraulic systems, especially in the marine sector. The scope of the study was to determine the most favorable position of bushings and pumping unit in the gear pump body in terms of stress and displacement distribution in the pump housing. Fourteen cases of gear pump bushings and pumping unit locations were analyzed: starting from the symmetrical position relative to the central axis of the pump, up to a position shifted by 2.6 mm towards the suction channel of the pump. The analysis of the obtained calculation results has shown that the most favorable conditions for pump operation are met when the bushings are shifted by 2.2 mm towards the suction channel. In this case the maximal stress was equal to 109 MPa, while the highest displacement was about 15μm. Strength and stiffness criteria in the modernized pump body were satisfied
Baroclinic Rossby radius of deformation in the southern Baltic Sea* Baroclinic Rossby radius Brunt-Väisälä frequency Southern Baltic Sea Mesoscale dynamics
Abstract The first baroclinic Rossby radius of deformation (R 1 ) is a fundamental horizontal scale of mesoscale processes. This scale is important for planning both numerical modelling and study areas. R 1 was computed on the basis of an 11-year series of high resolution CTD measurements collected during r/v 'Oceania' cruises. The data set covered the three main basins of the Baltic Proper: the Bornholm Basin (BB), the Słupsk Furrow (SF) and the Gdańsk Basin (GB). The smallest mean value of R 1 was found in the Gdańsk Basin (5.2 km), the largest one in the Bornholm Deep (7.3 km). The seasonal variability of R 1 is lower in the western basin than in the eastern one. The seasonal cycle of R 1 may be broken by extreme events, e.g. main Baltic inflows (MBI) of saline water. The inflowing water rebuilds the vertical stratification in the southern Baltic Sea and dramatically changes the R 1 values. The difference of R 1 between a stagnation period and an inflow situation is shown Analysis of stagnation and saltwater inflow events may throw light on the value of R 1 in future climatic scenarios. The potential influence of climate change on Baltic Sea salinity, especially a decrease in MBI activity, may change the baroclinic Rossby radius of deformation and the mesoscale dynamics. Values of R 1 are expected to be lower in the future climate than those measured nowadays
Opracowanie metody wyznaczenia zastępczych charakterystyk sprawnościowych dla pomp wyporowych
W artykule przedstawiona została metoda wyznaczania zastępczych charakterystyk sprawnościowych. Opisane zostało zastosowanie metody, warunki przeprowadzenia badań oraz algorytm opracowania i przedstawiania uzyskanych charakterystyk.This paper presents method of creating vicarious efficiency characteristics. Here is described utility, conditions for research and the method of elaborate and present the characteristics
Badania mocy cieplnej w pompie zębatej 3PZ4
Zbyt wysoka temperatura cieczy hydraulicznej uniemożliwia poprawną pracę układu hydraulicznego i skraca trwałość jego elementów. Pompa zębata o zazębieniu zewnętrznym, z powodu ograniczonej sprawności wynikającej z cech konstrukcyjnych, jest znacznym źródłem ciepła w układzie. Ciepło to w znacznej części odbierane jest przez ciecz hydrauliczną w warunkach konwekcji wymuszonej oraz przez powietrze otoczenia, głównie poprzez konwekcję naturalną. W artykule zaprezentowano wyniki badań dotyczące wzrostu temperatury cieczy hydraulicznej pomiędzy stroną tłoczną a ssawną oraz źródeł ciepła w pompie 3PZ4 produkcji WPH. Wykonano w ramach projektu p.t. „Opracowanie konstrukcji wysokociśnieniowych pomp zębatych”, realizowanego w ramach Programu Badań Stosowanych w ścieżce A Umowa Nr PBS3/A6/22/2015.Too high hydraulic fluid temperature prevents the correct operation of the hydraulic and reduces the durability of its components. Gear pump with external gear due to reduced efficiency resulting from construction is a significant source of heat in the system. The heat is largely received by hydraulic fluid under conditions of forced convection and ambient air, mainly through natural convection. The article presents the results of tests on the hydraulic fluid temperature rise between the discharge and suction and heat sources in the pump 3PZ4 WPH production. Was performed within the framework of the project entitled “Development of a design of the high-pressure gear pumps” in the framework of the Research Used in the path A, the agreement No PBS3/A6/22/2015
Methods of pressure pulsation and vibration analysis in industrial network for gas transmission
W pracy przedstawiono współczesne metody analizy pulsacji ciśnienia oraz drgań w sieci przemysłowej do przesyłu gazu. Zjawisko pulsacji ciśnienia gazu jest niekorzystne ze względu na zwiększenie kosztów procesu sprężania oraz generowanie hałasu. Ponadto pulsacja wywołuje drgania mechaniczne konstrukcji, co może skutkować uszkodzeniem lub zniszczeniem elementów instalacji. W celu zapobieżenia niekontrolowanej pulsacji ciśnienia gazu niezbędne jest projektowanie sieci przemysłowych zgodnie z określonymi wytycznymi. Niestety aktualne normy nie uwzględniają obligatoryjnych obliczeń pulsacji ciśnienia i drgań, w związku z czym podjęto prace rozwojowo-badawcze nad opracowaniem metodyki obliczeń, pozwalające na prawidłową ocenę wytężenia konstrukcji w warunkach rzeczywistych.The paper presents the modern methods of pressure pulsation and vibration analysis in industrial networks for natural gas transportation. Gas pressure pulsation phenomena is disadvantageous due to the cost increase of the compression process and the generation of noise. Furthermore, pulsation causes mechanical vibration of the construction, which can result in damage or destruction of installation components. In order to prevent uncontrolled gas pressure pulsation, it is necessary to design industrial networks in accordance with specified guidelines. Unfortunately, current standards do not take into account the mandatory calculations of pressure pulsation and vibration, therefore the scientific research was undertaken to develop the calculation methodology allowing for a proper assessment of the construction effort in the real operation conditions