111 research outputs found
Chat and Shared Drawing Board for Pocket PCs with Bluetooth
Cílem projektu je navrhnout a implementovat aplikaci pro kapesní počítač, která majitelům umožní vzájemnou výměnu textových zpráv a jednoduchého grafického obsahu. Přenos dat probíhá bezdrátově díky použití technologie bluetooth, které je na začátku práce věnován prostor. Dále se v krátkosti zmiňuje o platformě Pocket PC a možnostech komunikace. Největší část se zabývá návrhem programu a jeho implementací ve vývojovém prostředí eMbedded Visual C++ od firmy Microsoft. V závěru jsou uvedeny možnosti dalšího rozšíření aplikace.The aim of the project is to design and implement an application for a pocket PC that allows users to exchange short text messages and provides shared drawing board. On the beginning of this work, there is described bluetooth technology which is used for data-tranfer. In the next part are mentioned Pocket PC platform and possibilities of communication. The main part describes implementation in Microsoft's eMbedded Visual C++. At the end, there are listed possibilities of future development.
Updating the aerodynamic resistance for subsurface ventilation
For the safety works in the mines good ventilation is one of the main requirements. For miners’ performance, the subsurface ventilation creates healthier and more hygienic conditions. Mine ventilation has always belonged to the field of mining. Moreover, nowadays the mining operations progress to greater depths, shafts are deepened and the under-level mining space develops. This brings an increase in the temperature of rocks, mine air gets heated due to the technologies used and, thus, it is necessary to pay constant attention to mine ventilation. The knowledge of aerodynamic resistance becomes crucial for the good ventilation and ventilation planning. The article describes updating and complementing the aerodynamic resistance of the powered coalface supports, dam and wind structures and auxiliary ventilation components
Effect of natural pressure drop in mine main ventilation
Natural ventilation in a mine is ventilation without the use of means of artificial ventilation. The flow of mine air is induced by the difference between the mass column in an intake and that in a return. The difference in mine air density is a result of difference between the temperature of intake air and that of return air. To a certain extent, the influence of differences in mine air humidity and chemical composition can act as well.
Gassy mines in the Czech Republic and Ukraine are ventilated merely artificially, i.e. by means of exhaust ventilation. However, even in the case of this type of ventilation, when the total mine air flow is produced by fans, a natural current of air exists and acts in the ventilation network of the mine.Web of Science59250850
Braille Reader
Práce se zabývá problematikou převodu Braillova písma zachyceného na fotografii do podoby běžného textu. Věnuje se specifikaci Braillova písma a jejím principům. Stručně jsou také popsány způsoby snímání obrazu. Rozebírá jednotlivé fáze zpracování obrázku a jejich implementaci v C++. V závěru jsou uvedeny možnosti budoucího pokračování projektu.The aim of work is conversion of a photographed Braille into ordinary text. On the beginning, there are described Braille specification and principles. In the next part are mentioned types of sensors for taking photos. The main part describes phases of image processing and their implementation in C++. At the end, there are listed possibilities of future development.
OTPLINJAVANJE RUDNIKA KAO TEMELJNI SIGURNOSNI ELEMENT U PODZEMNIM DIJELOVIMA PLINOVITIH RUDNIKA UGLJENA NA UGLJENONOSNOM PODRUČJU OSTRAVA - KARVINÁ
In the article, degasification methods to drain the gas from the
underground parts of coal mines in the Czech Republic are described.
The authors are concerned with the possibilities of and new trends in
ensuring safety by means of drilling operations. Examples of applications
of degasification in mine plants in the Czech Republic, above all in a
hard coal deposit in the Ostrava-Karviná Coalfield in the Upper Silesian
Basin are presented.U članku su opisane metode otplinjavanja podzemnih dijelova
rudnika ugljena u Republici Češkoj. Autori se bave mogućnostima i
novim trendovima u osiguranju sigurnosti primjenom bušačkih operacija.
Prikazani su primjeri primjene otplinjavanja rudnika u Republici Češkoj
i to posebno u ležištima kamenog ugljena na eksploatacijskim poljima
Ostrava-Karviná u ugljenom bazenu gornje Šleske
Results from dealing with rock and gas outburst prevention in the Czech Republic
In the Czech Republic, the prevention of rock and gas outbursts is carried out in the course of driving mine workings in seams and in sandstone and conglomerate beds classified into a category with the highest degree of rock and gas outburst hazard. It is a case of active methods that aim at prevention of rock and gas outbursts by creating a protection zone in front of and in sides of mine workings being driven and passive methods that mitigate the effects of outbursts (Hudeček et al., 2009, 2010).
In this article, authors present recommendations and proposals for changes in rock and gas outburst prevention. These proposed changes should reflect in increased efficiency in coping with this anomalous geomechanical events.Działania w celu zapobiegania wybuchom skał i gazów w Republice czeskiej podejmowane są już na
etapie drążenia wyrobisk w złożach oraz w piaskowcach oraz w pokładach zlepieńców sklasyfikowanych
jako lokalizacje o najwyższym stopniu zagrożenia wybuchami skał i gazów. W tym przypadku mamy do
dyspozycji metody aktywne, których celem jest zapobieżenie wybuchom skał i gazów poprzez stworzenie
strefy ochronnej w części czołowej i bocznych częściach wyrobiska oraz metody bierne, mające na celu
złagodzenie skutków wybuchu (Hudecek et al., 2009, 2010).
W artykule autor rekomenduje i zaleca dokonanie pewnych zmian w systemie zapobiegania wybuchom
skał i gazów. Proponowane zmiany skutkować powinny zwiększoną skutecznością działania w przypadku
wystąpienia zjawisk geomechanicznych uznawanych za anomalie.Web of Science58378777
Obliczanie stężenia metanu w rejonie przodka
The Paskov Mine belongs to the company OKD, a.s. with the production of hard coking coal from
1970. The applied mining method is the slabbing method in controlled caving, excavating the coal pillar
by means of coal plough equipment loading mine run on rake conveyers and securing the excavation
area with individual hydraulic or mechanical supports. The coal face is planned as one of the coal faces
in continuous extraction of the seam by a shearer.
Using the shearer at mines in the Paskov Mine is not a novelty. Shearer mining represents some problems.
Besides the hazard of methane-air ignition, there is a mixture of coal dust – methane – air, which
is more dangerous even in the case of lower concentrations of dust and methane than their individual
lower limits of explosiveness. A decision was made then that shearers would gradually be replaced with
coal ploughs in all coal faces.
The article contains the calculation of the volume of methane emitted as a result of excavation, determining
methane concentration during excavation, lowering the hazard of methane layers being formed,
and finally evaluating the suitability of the proposed system of the coal face ventilation.Kopalnia Paskov należy do zakładów OKD, gdzie od lat 70-tych trwa produkcja węgla koksowniczego.
Stosowana metoda wydobycia to wybieranie ścianowe grubych pokładów z prowadzeniem stropu
na zawał, eksploatacja filarów przy użyciu strugów węglowych z załadunkiem urobku na przenośniki,
zabezpieczenie rejonu wydobycia z wykorzystaniem obudowy zmechanizowanej oraz podpór hydraulicznych.
Wydobycie w rejonie przodka odbywa się metodą ciągłą, przy użyciu wrębiarek.
Wykorzystywanie wrębiarek do wydobycia ścianowego nie jest nowością w kopalni Paskov, jednakże
wykorzystywanie ich w kopalniach powoduje pewne problemy. Oprócz zagrożenia zapaleniem mieszanki
metanu i powietrza, powstaje również mieszanina pyłu węglowego, metanu i powietrza, która okazuje
się bardziej niebezpieczna nawet przy niskich stężeniach metanu i pyłu niż ich obecność w postaci pojedynczych
składników w stężeniu odpowiadającym niskiej skłonności do wybuchu. Podjęto więc decyzję
o stopniowym zastępowaniu wrębiarek przy eksploatacji przodków strugami węglowymi. W pracy dokonano obliczenia objętości metanu wydzielanego w wyniku prowadzenia wydobycia,
określono stężenia metanu w trakcie prowadzenia prac, przeanalizowano możliwość zmniejszenia
zagrożenia powstawania warstw metanu oraz efektywność promowanego systemy wentylacji przodka.Web of Science611938
Measuring the metallurgical supply chain resilience using fuzzy analytic network process
The article presents a methodology for measuring the metallurgical supply chain resilience, which enables the ascertainment
of key resilience capabilities and measurable criteria, and determining a level of the resilience. The
methodology is based on Analytic Network Process (ANP), which is used to solve the complex decision-making
problems, whose structures can be mapped as non-linear networks. Since ambiguous pairwise comparisons expressed
by fuzzy sets are considered, the Fuzzy Analytic Network Process (FANP) is applied. The methodology is
verified on the generalised model of a metallurgical supply chain. The SuperDecisions software was used for the
application. The experiments performed demonstrate the high level of suitability of the FANP approach for measuring
metallurgical supply chain resilience.Web of Science55478678
Environmental Effects among Differently Located and Fertile Sites on Forest Basal-Area Increment in Temperate Zone
Environmental properties differently influence the growth of forest tree species. The antagonistic effects of variable environmental properties classify the forest response according to various tree compositions among different sites. The division of the forest response was assessed in 52 stands arranged into 26 types of 13 site management populations (MPs) in 5 areas in the Czech Republic territory. The assessment was performed using time-series multiple regressions of basal-area increment from pure immature stands of Norway spruce (Picea abies), Scots pine (Pinus sylvestris), oaks (Quercus sp.), ash (Fraxinus excelsior) and willows (Salix sp.) dependent on the interpolated average temperatures, annual precipitation, atmospheric concentrations of SO2, NOx and O3 and soil properties over the period 1971-2008 at p < 0.05. Site MPs differentiated the forest response to a greater extent than tree species. The response of the forests was significantly distributed by means of the montane, upland and waterlogged sites. The multiple determination index (r2) GREATER-THAN OR EQUAL TO 0.6 indicated an adaptable tree increment but an interval of r2 between 0.80-0.92 implied forest sensitivity to variability in environmental properties on non-waterlogged sites. The index r2 < 0.6 suggested a fluctuating forest increment that reflects environmental variability inconsistently. The fluctuating increment most affected the spruce and pine stands grown from upland to submontane locations. Montane spruce stands, as well as rock pines, appeared to be one of the most sensitive ones to environmental change. Floodplain forests seemed as adaptable to variable environmental properties.O
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