Academic literature on the topic 'Estimace stavu'

The postglacial sedimentary record of 59 km2 Stave Lake was investigated using 3.5 kHz subbottom profiles and cores from the sediment surface. The acoustic data show a thin cover of acoustically transparent sediment (unit 1) overlying bedrock or glacial sediment on the floor of the lake. Overlying acoustically stratified sediment is divided into unit 2, which thins from 28 m in the south of the lake to less than 12 m in the north, and unit 3, which thins from 20 m in the north to about 12 m in the south. Unit 1 is interpreted as resulting from deposition in a relatively quiet lacustrine or marine environment following retreat of Vashon glaciers about 13 ka ago. Unit 2 is ascribed to deposits of sediment in runoff to Stave Lake from the Sumas ice sheet in the Fraser Valley and connecting valleys to the Stave Basin. Following the retreat of the Sumas ice about 11 ka ago, deposition of unit 3 resulted almost entirely from sediment input from Stave River entering at the north end of the lake. Raising the lake in 1912 by damming for hydroelectric generation resulted in deposition of a thin but distinct marker horizon in the sediment, from which modern rates of accumulation averaging 3 mm/a are estimated. These are more than twice the average rates for the Holocene estimated from the total thickness of unit 3. The rates of sediment yield calculated from accumulation in Stave Lake are 4.5 × 105 kg∙km−2∙a−1 (modern) and less than 2 × 105 kg∙km−2∙a−1 (averaged over the Holocene).

This paper focuses on the Norwegian medieval religious buildings called stave churches. The word stave (meaning ‘post, pole’ in Norwegian) derives from the buildings’ post and lintel construction, giving the churches their characteristic style. The structures display a highly developed tradition of wooden Christian buildings, which during the Middle Ages (1050–1500) where the most common in Norway, their number can be estimated at around a thousand. There were probably at least as widespread in other areas (e.g. on the territory of present-day Germany and Russia), but they did not remain in such a large number from the early period. However, the number have declined dramatically, and today only 28 are preserved. The article aims to expand the knowledge of the unique and irreplaceable wooden architecture of the stave churches. Although we consider the wooden churches to be one of the characteristics of Scandinavia traditionally, they mix and carry the influences of other cultures and countries. The heritage and memorial role of wooden churches, as well as the motif of the combination of different architectural and religious elements, represent an interesting comparison to similar phenomena in the Carpathian Basin. Transylvania and especially the Maramureş region are also famous for their wooden churches and the rich carved and painted iconostasis.

Abstract Maintenance cost of the equipment is one of the most important portions of the operating expenditures in mines; therefore, any change in the equipment productivity can lead to major changes in the unit cost of the production. This clearly shows the importance and necessity of using novel maintenance methods instead of traditional approaches, in order to reach the minimum sudden occurrence of the equipment failure. For instance, the tires are costly components in maintenance which should be regularly inspected and replaced among different axles. The paper investigates the current condition of equipment tires at Sungun Copper Mine and uses neural networks to estimate the wear of the tires. The Input parameters of the network composed of initial tread depth, time of inspection and consumed tread depth by the time of inspection. The output of the network is considered as the residual service time ratio of the tires. The network trained by the feed-forward back propagation learning algorithm. Results revealed a good coincidence between the real and estimated values as 96.6% of correlation coefficient. Hence, better decisions could be made about the tires to reduce the sudden failures and equipment breakdowns.

OBJECTIVE Endoscope-assisted methods for treatment of craniosynostosis have reported benefits over open calvarial vault reconstruction. In this paper, the authors evaluated 2 methods for endoscope-assisted correction of sagittal synostosis: wide vertex suturectomy and barrel stave osteotomies (WVS+BSO) and narrow vertex suturectomy (NVS). METHODS The authors evaluated patients with nonsyndromic sagittal synostosis treated with either wide vertex suturectomy (4–6 cm) and barrel stave osteotomies (WVS+BSO) or narrow vertex suturectomy (NVS) (approximately 2 cm) between October 2006 and July 2013. Prospectively collected data included patient age, sex, operative time, estimated blood loss (EBL), postoperative hemoglobin level, number of transfusions, complications, and cephalic index. Fourteen patients in the NVS group were age matched to 14 patients in the WVS+BSO group. Descriptive statistics were calculated, and Student t-tests were used to compare prospectively obtained data from the WVS+BSO group with the NVS group in a series of univariate analyses. RESULTS The mean age at surgery was 3.9 months for WVS+BSO and 3.8 months for NVS. The mean operative time for patients undergoing NVS was 59.0 minutes, significantly less than the 83.4-minute operative time for patients undergoing WVS+BSO (p < 0.05). The differences in mean EBL (NVS: 25.4 ml; WVS+BSO: 27.5 ml), mean postoperative hemoglobin level (NVS: 8.6 g/dl; WVS+BSO: 8.0 g/dl), mean preoperative cephalic index (NVS: 69.9; WVS+BSO: 68.2), and mean cephalic index at 1 year of age (NVS: 78.1; WVS+BSO: 77.2) were not statistically significant. CONCLUSIONS The NVS and WVS+BSO produced nearly identical clinical results, as cephalic index at 1 year of age was similar between the 2 approaches. However, the NVS required fewer procedural steps and significantly less operative time than the WVS+BSO. The NVS group obtained the final cephalic index in a similar amount of time postoperatively as the WVS+BSO group. Complications, transfusion rates, and EBL were not different between the 2 techniques.

As consumers have become enlightened to the dangers of the sun, they have turned increasingly to sunscreens to stave off not only a sunburn but also life-threatening skin cancer. In the last decade, the incidence of skin cancer has grown a startling 500%. The increase in the number of skin cancers in adults is most likely the result of exposure to the sun as a child. Therefore, the current and continued rise in the number of skin cancers in adults is not remediable. However, as adult consumers seek to prevent further damage to their skin and protect their children from the same fate, the market for sunscreens has grown and is estimated to be worth between $170 and $650 million dollars. The increased demand for sunscreens, combined with the incorporation of sunprotection ingredients into everyday products such as makeup and skin lotions, has led the United States Food and Drug Administration (FDA) to subject sunscreens to increased regulatory scrutiny.

Amphotericin B (AmB) exerts its pharmacological effects by forming a barrel-stave assembly in fungal membranes. To examine the interaction between AmB and ergosterol or cholesterol, 13C- and 19F-labeled covalent conjugates were prepared and subjected to solid-state NMR measurements. Using rotor-synchronous double resonance experiments such as REDOR and RDX, we estimated the distance between the fluorine atom and its nearest carbon in the heptaene moiety to be less than 8.6 Å, indicating that the B ring of ergosterol comes close to the AmB polyene moiety. Conformational search of the AmB-ergosterol conjugate using the NMR-derived constraints suggested that ergosterol molecules surround the AmB assembly in contrast to the conventional image where ergosterol is inserted into AmB molecules. AmB-AmB bimolecular interaction was examined by using 13C- and 19F-labeld AmBs in dimyritoylphosphatidylcholine membrane without sterols. 13C-19F dipolar interactions deriving from both head-to-head and head-to-tail orientations were observed in the REDOR experiments. The interactions between AmB and acyl chains of the phospholipid were also detected.

Recent evidence suggests that many densely populated areas of the world will be uninhabitable in the coming century due to the depletion of resources, climate change, and increasing urbanization. This poses serious questions regarding the actions that require immediate attention, and opportunities to stave off massive losses of infrastructure, populations, and financial investments. The present study utilizes microclimate modeling to examine the role of landscape features as they affect ambient temperatures in one of the fastest growing regions of the world: Doha, Qatar. By modeling three study sites around Doha—one highly urbanized, one newly urbanizing, and one coastal low-density urbanized—the research indicates that at the neighborhood scale, the most effective scenario was that of adding mature trees along the sides of roads. In the coastal study area, the model results estimated a maximum hourly air temperature reduction of 1.35 °C, and in the highly urbanized inland site, surface temperature reductions were up to 15 °C at 12:00. While other scenarios were effective at reducing air and surface temperatures, the mean radiant temperature was also increased or nearly neutral for most of the other scenarios. This result highlights the need to develop improved shading measures for pedestrian pathways and outdoor recreational areas, especially for highly urbanized inland areas in Doha and cities with similar climatic conditions.

Abstract Despite the clear and compelling association between social connections and well-being, the underlying mechanisms that help stave off adverse health impacts are not well understood, particularly among older adults in disadvantaged groups. Social relationships in older age may be instrumental for exchanging and gaining knowledge that further influence health and help increase awareness about misconceptions and lifestyle behaviors known to delay or reduce cognitive decline. This study used cross-sectional survey data from 147(aged 58-90 years; 75% female) low-income African American homebound community dwellers to investigate heterogeneity in dementia literacy profiles and its association with social connectedness. Eleven items (false=0, true=1, don’t know=2) from a validated instrument were used to measure dementia literacy (DL). The Lubben’s social network scale was used for a social connectedness construct. We employed a 2-stage latent class modeling approach to examine heterogeneity in DL and estimate the regressions among the derived classes and the predictors (social connectedness, education level and age). A 3-class model produced a reasonable fit and classification (entropy=0.852) of “dementia literacy patterns” labeled as (high-literacy:37%), moderate-literacy:45.2%), low-literacy:17.8%)). Social connectedness was highly predictive of class membership. A high level of social relationships increased the probability of being in the “high-dementia-literacy” class compared to the “low-dementia-literacy” class (OR=2.189, p=0.016). For a unit increase in social connectedness, the odds of being in the “high-dementia-literacy” class compared to the “low-dementia-literacy” class increased by a factor of 2.2. Tailored and focused interventions to reduce social disconnectedness may also help increase dementia awareness and reduce barriers to early diagnosis.

Rýchlosť vozidla je jednou z kľúčových stavových premenných, ktorej znalosť je potrebná v reálnom čase a s vysokou presnosťou, aby mohla slúžiť ako vstupná veličina pre systémy kontroly dynamiky vozidla. Jej priame meranie vo vozidle je však finančne náročné. Riešením tohoto problému môže byť použitie meraní zo senzorov bežne dostupných na palube vozidla a ich následný prepočet na rýchlosť vozidla. Tieto merania sú však veľmi zaťažené procesným šumom, čo vyplýva z komplexnosti pohybu vozidla. Preto je nutné vyvinúť algoritmus so schopnosťou vysporiadať sa s týmito negatívnymi vplyvmi. Algoritmus prezentovaný v tejto práci odhaduje pozdĺžnu rýchlosť vozidla s použitím meraní uhlových rýchlostí štyroch kolies, pozdĺžnej akcelerácie, momentov motora, rýchlosti otáčania okolo zvislej osi a natočenia volantu. Algoritmus bol testovaný na veľkom počte situácií považovaných za kritické na odhad rýchlosti vozidla, ako napríklad prudká akcelerácia na vozovke s nízkym koeficientom trenia, núdzové brzdenie s aktiváciou ABS, či jazda v kopci s kolesami v preklze, prinášajúc uspokojujúce výsledky.

Tato práce je zaměřena na výzkum moderních metod automatického řízení letu a jejich ověření s ohledem na současný stav poznání a budoucí využití bezpilotních letadlových systémů. Práce představuje proces návrhu automatického systému řízení letu s důrazem na přístupy z oblasti návrhu založeného na modelování (Model-Based Design). Nedílnou součástí tohoto procesu je tvorba matematického modelu letounu, který byl využit k syntéze zákonů řízení a k vytvoření simulačního rámce pro evaluaci stability a kvality regulace automatického systému řízení letu. Jádro této práce se věnuje syntéze zákonů řízení založených na unikátní kombinaci teorie optimálního a adaptivního řízení. Zkoumané zákony řízení byly integrovány do digitálního systému řízení letu, jenž umožňuje vysoce přesné automatické létání. Závěrečná část práce se zabývá ověřením a analýzou navrženého systému řízení letu a je rozdělena do 3 fází. První fáze ověření obsahuje evaluaci robustnosti a analyzuje stabilitu a robustnost navrženého systému řízení letu ve frekvenční oblasti. Druhá fáze, evaluace kvality regulace, probíhala v rámci počítačových simulací s využitím vytvořených matematických modelů v časové oblasti.  V poslední fázi ověření došlo k integraci navrženého systému řízení letu do experimentálního letounu, sloužícího jako testovací platforma pro budoucí bezpilotní letadlové systémy a jeho evaluaci v rámci série letových experimentů.

Simultaneous evaluation of the whole set of the model parameters of different orders together with an ability to track unmodeled dynamics are desired features in the tasks of parameter estimation. A technique handling with the factors produced by an augmented covariance (ACM) or information (AIM) matrices is considered to be an appropriate tool for designing multiple model estimation. This is where the name augmented identification (AI) by using the least-squares method was taken. The method AI attains numerical stability of the calculation of the conventional least squares method while in the same time, fully extracts information contained in the observation. In order to track time varying parameters can be found that all the information pertinent to recursive identification and thus to data driven forgetting is concentrated in ACM as well as in AIM. In this thesis will be introduced how to selective forgetting to ACM should be applied in an effective way. It means forget only a portion of accumulated information which will be further modified by the newest data included in the regressor. In the estimation problems the knowledge of the inner states of the identified system is often required. Because the augmented identification belongs within the class so called prediction error method (PEM), some rational requirements can be deduced. As a result, state filter should constitute optimization procedure minimizing the predicted error of given state space model representation with respect to the vector of states. The proposed scheme will considerably extend the family of algorithms based on processing of ACM (AIM) about augmented filtering (AF). This all will establish a comprehensive concept of parametric estimation that compared with conventional approaches is characterized by versatility, low demands on a priori process information and by excellent numerical properties (robust against overparametrization, capable solving the multiple model problem).

The thesis is divided in two parts. The first part deals with the areal distribution of short-term convective rainfalls with regard to the influence of altitude. Precipitation estimates based on combination of rain gauge and radar data are used for this purpose. Statistical tests proved that the areal distribution of hourly convective rainfalls does not depend on altitude. Besides data containing precipitation events only, all measured data were statistically analysed regardless of the fact whether precipitation occurred or not. In this case it was found out that the relationship between hourly rainfall totals and altitude depends on the considered threshold of rainfall totals. When all data were considered, i.e. a threshold value was set to zero, an increase of rainfall totals well correlated with altitude. The dependence slowly disappeared with an increasing threshold. The areal distribution of 6 hour rainfall totals proved higher values in the area of south Bohemia. The most frequent synoptic patterns were northwest cyclonic situations (NWC) and cyclone over the Central Europe (C). The second part of the thesis is focused on satellite data exploitation, as measured by meteorological satellite Meteosat Second Generation, for convective precipitation estimates. The Convective Rainfall Rate (CRR) algorithm,...

Abstract A Major Operating Company in UAE planned and drilled a challenging 6 inch horizontal drain after crossing twenty-seven formation sub-layers. The heterogeneity of pore pressure varied from equivalent mud weights as high as 10.6 ppg to as low as 7.1 ppg across the exposed reservoirs. Control of the equivalent circulating density (ECD) values to safely drill across these multi-reservoir sections and diverse reservoir pressures was one of the top challenges on this well, as the fracture gradients (FG) ranged from 13.5 ppg across the competent reservoirs to as low as 11ppg across the fractured reservoir section. The offset well data review show that 4 out of 6 wells encountered moderate, severe and total losses with mud weight (MW) ranging from 11 ppg to 11.3 ppg, which were cured by using heavy LCM treatments and in some cases, after several failed attempts to cure losses, cement plugs were used. Historically, the average time spent curing total losses in these wells varied from 2-3.5 weeks causing well cost increments as consequence of this non-productive time. All of the above, without mentioning the extra efforts, resources and risks were faced due to well control and stuck pipe events which occurred on those wells. Engineering and Operation teams worked together to engineer a solution to drill this well in one run while safely maintaining the well under control and managing the losses. The Bottom Hole Assembly (BHA) was designed to withstand the well challenges including multiple contingency options. These options allowed:Improving hole quality while tripping using a special type of eccentric reamer stabilizer.Pumping various LCM concentration scenarios through a multi-cycle circulation valve. In addition, a special type of float valve was placed on the top of the BHA as barrier, stopping back flow under surface backpressure or kick scenarios.Optimizing mud weight by using formation pressure while drilling (FPWD) and monitoring both equivalent circulating density ECD and equivalent static density (ESD) by pressure while drilling tools. The drilling fluid was loaded with non-damaging loss circulation material without compromising the MWD/LWD limits. Additionally, the mud rheology was carefully selected and monitored to achieve the desired ECD. On surface, a managed pressure while drilling system was deployed to give control on reservoir pressures. In instances of influx, MPD allows to early detect any kick and controlled by surface back pressure without requiring shut in for applying standard well control techniques. Keeping the well under control by surface back pressure (SBP) during connections time (flow–off). Additionally, MPD also enables the contingency of applying pressurized mud capping in case of unable to control the losses. As decision point, a loss management plan was prepared and implemented. Also, a dynamic formation integrity test was planned and performed to calibrate the fracture gradient across the loss zones. The problematic zone was successfully drilled with one BHA in under six days (5.73 days). The estimated savings for the company were 8 days, which equates to ±1MMUS$ after including the MPD cost which increased the well cost by 200MUS$. To further complement the outright savings, the engineered solution managed to safely stave off operational complications as well as incurring the related complexities and non-productive time (NPT) as recorded on the offset wells. Additionally, well was successfully landed and geo-steered across the target formation and 4½ in liner was run and cemented off-bottom avoiding the need to develop a slot recovery scope on this well with an extra duration of +/-35 days. The engineered solution provided a high level of preparation and contingencies within the BHA, Managed Pressure Drilling Equipment, real time monitoring, mud and cement formulation. The applied techniques allowed the operating company to successfully execute this challenge well within the proposed time and budget.