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This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

The objective of this research was to characterize the performance of a downflow bubblecontact (DBCA) hypolimnetic aerator — Speece Cone-. The effect of two key design factors, inlet water velocity and the ratio of gas flow rate to water flow rate on four standard units of measure was examined: (a) the Oxygen Transfer Coefficient, KLa, corrected to 20°C, KLa₂₀ (hr­-¹), (b) the Standard Oxygen Transfer Rate, SOTR (g0₂.hr­-¹) (c) the Standard Aeration Efficiency, SAE (gO₂kWhr­-¹), and (d) the Standard Oxygen Transfer Efficiency, SOTE (%). Two sources of oxygen, Pressure Swing Adsorption (PSA) oxygen (87% purity) and air, were compared. KLa₂₀, SOTR, and SAE increased with an increase in the ratio of gas flow rate to water flow rate for both air and oxygen, over a range of 0.5% to 5.0%; while SAE deceased. An increase in inlet water velocity resulted in a decrease in KLa, corrected to 20°C, SOTR, and SAE, but an increase in the SOTE. Treatments on air showed similar, but much less dramatic effect of the gas flow rate to water flow rate ratio and water inlet velocity on KLa₂₀, SOTE, SAE, and SOTE, when compared to treatments on PSA oxygen. The best performance was achieved with an inlet water velocity of 6.9-7.6 ms­-¹ and oxygen flow rate to water flow rate ratio of about 2.5%. At this combination, the SOTE was about 66-72%.

Adaptive modulation has been actively researched as a means to increase spectral efficiency of wireless communications systems. In general, analytic closed form models have been derived for the performance of the communications system as a function of the control parameters. However, in systems where general error correction coding is employed, it may be difficult to derive closed form performance functions of the communications systems. In addition, in closed form optimization, real time adaptation is not possible. Systems designed with deterministic state optimization are developed offline for a certain set of parameters and hardwired into mobile devices. In this thesis we present stochastic learning algorithms for adaptive modulation design. The algorithms presented allow for adaptive modulation system design in-dependent of error correction coding and modulation constellation requirements. In real time, the performance of the system is measured and stochastic approximation techniques are used to learn the optimal transmission parameters of the system. The technique is applied to Software Defined Radio (SDR) platforms, an emerging wireless technology which is currently being researched as a means of designing intelligent communications devices. The fundamental property that sets SDR apart from traditional radios is that the communications parameters are controlled in software, allowing for real-time control of physical layer communications. Our treatment begins by modeling the time evolution of the adaptive modulation process as a general state space Markov chain. We show the existence and uniqueness of the invariant measure and model performance functions as expectations with respect to the invariant measure. We consider constrained and unconstrained throughput optimization. We show that the cost functions considered are convex. Next we present stochastic approximation algorithms that are used to estimate the gradient of the cost function given only noisy estimates. We conclude by presenting simulation results obtained by the presented method. The learning based method is able to achieve the maximum throughput as dictated by exhaustive Monte Carlo simulation of the communications system, which provide an upper bound on performance. In addition, the learning algorithm is able to optimize communications under various error correction schemes. The tracking abilities of the algorithm are also demonstrated. We see that the proposed method is able to track optimal throughput settings as constraints are changed in time.

With increasing energy costs and competitive pressures, interest has increased in surveying installed pumps for potential energy savings. Field pump efficiency tests are required to assess pumping performance and help to identify improvement opportunities. This work concerns the on-site measurements of pulp-suspension pumping efficiency. This involves the measurement of pump head, flow rate and power consumption. Provided that consistent flow measurements are available, it is possible to reliably and non-invasively measure actual pump system efficiencies in pulp suspension flow, with a minimum process disturbance. As part of a most appropriate measurement-procedure study, four portable nonintrusive flow meters were evaluated on site for pulp suspension flow. The Fast Fourier Transform Doppler was found to be the most suitable for a pulp mill pump survey. Efficiency measurements were performed on six pump systems with motors between 100 and 700 HP. It is shown that as-installed pump efficiency can be used to help predict the degradation of the pump and also its effect on the pumping system’s operation. A system approach analysis was performed in each case, which can be effective in assessing system performance and finding potential enhancements. The use of variable speed drives allows the operating point to move along the system curve, requiring less energy to drive the pump. VSD of larger motors are expensive and their profitability compared to other modification alternatives should always be carefully checked by calculations based on accurate on site measurements and life cycle costs. Finally, in this survey of six pump systems, significant potential savings of around 30% of present power consumption were found.

This thesis is concerned with measuring and explaining the productive efficiency of firms or organizations. In particular, the study compares three alternative methods of measuring efficiency, namely, the deterministic frontier method, the stochastic frontier method, and the data envelopment analysis method (DEA). The dissertation consists of two parts. In Part I, the relative merits of the three methods are discussed and evaluated through a Monte Carlo study under certain known conditions. The study focuses on the effects of exogenous variables on efficiency estimates. The results show that the stochastic frontier method generally produces better efficiency estimates than the other two methods. The DEA, however, has a slight advantage in cases where there are weak input substitution and large variations in input variables. In Part II, the three methods are examined empirically through their applications to a panel of 19 railways in OECD countries and a panel of 36 international airlines. Comparison of the three sets of efficiency estimates confirms that on average the stochastic frontier method yields higher efficiency estimates than the other two methods, as indicated by the Monte Carlo results. The efficiency estimates by the two parametric methods are highly correlated, whereas there are considerable differences between the DEA estimates and those from the parametric methods. This is also consistent with the Monte Carlo results. By comparing the alternative efficiency estimates in the two applications, it is found that there is less discrepancy among the three sets of efficiency estimates in the airline case than in the railway case. This can be partly attributed to the fact that there are fewer variations in the operating environments in the airline case than in the railway case. The simulation results in Part I provide some general guidelines regarding the relative merits of the three alternative methods under certain known conditions. The two applications of the three methods in Part II serve as examples of how these three methods can be applied to practical problems where no a priori knowledge of either the production technology nor the efficiency profile exists. They illustrate some of the problems that may be encountered in empirical applications.

The aim of the study: to identify the effect of pedaling rate of cyclists to the indices of vegetative systems during consistently increasing workload. Hypothesis. We claimed that the rate of pedaling will have impact on some indices of cyclists’ vegetative systems during consistently increasing workload. The objectives 1. To evaluate the effect of pedaling rate to indices of maximal aerobic power. 2. To evaluate the effect of pedaling rate to indices of anaerobic metabolism threshold. 3. To identify the effect of pedaling rate to the efficiency of aerobic work. Subjects: 7 Lithuanian cyclists – the members of the selected. Their age: 18,1±2,04 years, height: 178±6,4 cm, and body mass 71,6±8,4 kg. The methods of the study: 1) the identification of aerobic fitness during the consistently increasing workload on the veloergometer with different pedaling rates (70, 90, 110 rpm). The warming-up was performed (10 min with the 50 W power). The initial testing load (20 W) was increased every 5 s, consistently by 2 W. The load was increased until the fatigue. After that the subject rested in lying position for 5 minutes. The workload was applied once a day; 3 tests were conducted during a week. 2) The first (VeT1) and the second (VeT2) ventilatory thresholds were determined according to the dependence of lungs ventilation and also of ventilatory oxygen and CO2 equivalents on the power of the work. After 5 minutes of the rest period the capillary blood samples were taken from the... [to full text]

Theoretical and practical methods of assessment of the bank‘s activities of variuos foreign and Lithuanian authors are analyzed and systemized in the master‘s final paper. There are mentioned such methods of assessment of the bank‘s activities: Economic Value Added, Economical and book-keepinng methods of estimate of the bank‘s activities and ect. A great attention is turned on the role of risk management in the commercial bank and its influence on the rezults of bank‘s activities in this research work. The urgent problems of the bank‘s capital adequancy and liquidity management are investigated in the master‘s final paper. Moreover, the participation place of the bank is ascertained in the financial institutes‘ activity. Therefore, the analisys of the balance sheet of Snoras bank is carried out, the standarts of risk‘s limits are looked over and investment activities are evaluated in this work. The author‘s couched hypothesis of the scientific research that correctly chosen policy of assets management of the commercial bank has direct impact on the efficiency of the commercial bank‘s activities, is corroborated.