28 research outputs found

    The Physics of the B Factories

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    Rozbor vlivů provozních proměnných a regresní analýza výstupních proměnných v systému hlubinného dobývání vybavených zařízením SDL používaných v indických dolech

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    V Indické republice je asi 90 % uhlí těženo hlubinným způsobem a to metodou pilířování. Z toho je 60 % dobýváno pomocí důlní mechanizace. Hlavní mechanizaci v hlubinných dolech a to plných 78 % tvoří dobývání pomocí nakládačů s bočním vyklápěním. (SDL) Hlubinné dobývání je zde závislé na poloze uhelných slojí a jejích poruchách, které se během dobývání poměrně často mění. Jak těžba tak i doprava těženého uhlí je ovlivněna celou řadou proměnných, které se mění stochasticky a nelze je popsat žádnou standardní statistickou metodou. Způsob výpočtu se nachází při použití analýzy stochastického řešení, které je dosti složité na to, aby byl celý cyklus popsán pomocí matematických vzorců. Pro řešení dané problematiky se nám nabízí metoda počítačové simulace. v tomto příspěvku byla použita pro stanovení vzájemných vztahů regresní analýza. Pomocí sledování vlivů odchylky variace několika vstupních proměnných, kterými jsou průměrná produkce na směnu s SDL, porubní výkon na hlavu a směnu (OMS) a procentové využití SDL (indikátory produktivity práce a stroje) jsme došli k dále uvedeným výsledkům.In India about 90% of underground coal is produced by bord & pillar mining method and 60% of total underground coal production comes from mechanized mining operation. 78% of total mechanized coal production is from SDL based system only. Underground mining operations and the resources deployed therein are subjected to random failures and have to face various types of operational irregularities at different points of time during working. Both coal winning and handling operations are influenced considerably by a number of random variables, the trend of variation of which does not generally follow any standard statistical distribution. This finds a widespread application in the analysis of stochastic system that is complex enough to be represented by the mathematical formulae. Therefore, it is the problem domains that can be conveniently and appropriately solved by computer simulation. In this paper the effect of variation of some input variables on the system performance as well as the values ofthree variables such as average shift production per SDL, output per manshift (OMS) and percentage utilization of SDL (labour and machine productivity indices) have been used to establish their inter-relationships through regression analysis

    A Study of the Workload of Underground Trammers in the Ranigang Coal Field Area of West Bengal, India

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    Thirty healthy trammers were examined in underground haulage mines during their normal activity. Physiological strain in terms of heart rate (HR) varied between 101.6 and 104.7 beats/min with mean net cardiac cost of 33.06 and 34.06 beats/min for younger and older groups respectively. The average relative cardiac cost was lower for younger subjects than for older ones. Oxygen consumption (VO2) was measured with an Oxylog-II machine (UK); subsequently values were estimated. Maximum aerobic capacity was estimated with an indirect method following a standard step test protocol. The responses revealed that the average VO2 during the activity was 0.75 and 0.8 L/min, which corresponded to energy expenditure (EE) of 3.8 and 3.97 Kcal/min for younger and older subjects respectively. The workload in terms of HR and EE was moderate, whereas the aerobic strain experienced by aged workers was above the acceptable level

    iCAP: Interactive prototyping of context-aware applications

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    Abstract. Although numerous context-aware applications have been developed and there have been technological advances for acquiring contextual information, it is still difficult to develop and prototype interesting context-aware applications. This is largely due to the lack of programming support available to both programmers and end-users. This lack of support closes off the context-aware application design space to a larger group of users. We present iCAP, a system that allows end-users to visually design a wide variety of context-aware applications, including those based on if-then rules, temporal and spatial relationships and environment personalization. iCAP allows users to quickly prototype and test their applications without writing any code. We describe the study we conducted to understand end-users ’ mental models of context-aware applications, how this impacted the design of our system and several applications that demonstrate iCAP’s richness and ease of use. We also describe a user study performed with 20 end-users, who were able to use iCAP to specify every application that they envisioned, illustrating iCAP’s expressiveness and usability.
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