For the exponential response η_u = α + βe^γZ_u (u = 1,2,…,N) where α and β lie on the real line (-∞,∞), and γ is a positive integer; the designs are given which minimize the bias due to the inherent inability of the approximation function ŷ_u = Σ_j=0<sup>d</sub>b_je^jZ_u to fit such a model. Transformation to η_u = α + βx_u^γ and ŷ_u = Σ_j=0<sup>d</sub>b_jx_u^j facilitates the solution for minimum bias designs. The requirements for minimum bias designs follow along lines similar to those given by Box and Draper (J. Amer. Stat. Assoc., 54, 1959, p. 622). The minimum bias designs are obtained for specific values of N with a maximum protection level, γ_d*(N), for the parameter γ and an approximation function of degree d. These designs obtained possess several degrees of freedom in the choice of the design levels of the x_u or the Z_uu , which may be used to satisfy additional design requirements. It is shown that for a given N, the same designs which minimize bias for approximation functions of degree one also minimize bias for general degree d, with a decrease in γ_d*(N) as d increases. In fact γ_d*(N) = γ₁*(N) - d + 1, but with the decrease in γ_d*(N) is a compensating decrease in the actual level of the minimum bias. Furthermore, γ_d*(N) increases monotonically with N, thereby allowing the maximum protection level on 1 to be increased as desired by increasing N. In the course of obtaining solutions, some interesting techniques are developed for determining the nature of the roots of a polynomial equation which has several known coefficients and several variable coefficients. / Ph. D.

The primary objectives this investigation are: 1. To present a discussion of known submerged arc welding variables and their general affect on weld bead appearance 2. To design an experiment to investigate the affect on weld joint strength and hardness distribution across the weldment by using (1) Four different welding currents (450, 500, 550, and 650 amps). (2) Three different steels (M 1020, SAE 1045 and SAE 1095) and (3) Two different electrodes (Hobart type C-10 and C-20) as variables in the experiment. 3. To establish the welding technique and procedure to control welding variables. 4. To collect unavailable data about the submerged arc process by experimentation and statistically interpret this data. After the preliminary investigation, the author statistically designed the testing procedure for the randomized test specimens for hardness of weld zone and hear-affected zone and applied statistical technique to determine significant effects on weld quality due to the variables. The conclusions are given in chapter I. / Master of Science

In asthma therapy, the use of theophylline to prevent bronchial spasm and glucocorticoids to decrease inflammation is widely indicated. Apart from the acute asthma attack oral theophylline is treated for chronic therapy in order to minimize inflammation and to enhance the efficiency of corticosteroids and recover steroids’ anti-inflammatory actions in COPD treatment. The preferred application route for respiratory disease treatment is by inhalation, such as dry powder inhalers (DPI) being the delivery systems of first choice. As shown recently, there is an advantageous effect if the drugs are given simultaneously which is caused by a synergistic effect at the same target cell in the lung epithelia. Therefore, it seems rational to combine both substances in one particle. This type of particle has the advantage over a combination product containing both drugs in a physical mixture which occurs rather randomly deposition leading to API segregation and non-dose-uniformity. Dry powder inhalers (DPIs) is a type of therapeutic pharmaceutical formulations usually present in the solid form. Due to the nature of the solid-state, an understanding of chemical and physical properties must be established for acquiring optimum performance of the active pharmaceutical ingredients (APIs). In recent year, generation of DPIs is a destructive procedure to meet the micron size. Such processes are inefficient and difficult to control. Moreover, according to current researches on combination APIs formulation, this type of DPIs performed a greater variability in does delivery of each active, leading to poor bioavailability and limit clinical efficient. This result suggest that combination formulations require advanced quality and functionality of particles with suitable physicochemical properties. Hence, in order to production of binary and combination DPIs products, the aim of this study was to develop the spray drying and ultrasonic process for engineering of combination drug particles that will be delivered more efficiently and independently of dose variations to the lung. Microparticles were produced by spray drying or/and ultrasonic technique. The processing parameters and addition of excipients (polymers) were optimized using a full factorial design such that microparticles were produced in a narrow size range suitable for inhalation. Employing excipients resulted in high saturation environment leading to minimized sphere particles when compared to conventional solvent. Solid state characterization of microparticles using powder x-ray diffraction and differential scanning calorimetry indicated that the particles contained crystalline but no cocrystal. The combination particles comparable to or better than micronized drug when formulated as a powder blended with lactose. It was concluded that the use of HPMC enhanced crystallinity suitable for inhalation; and combination particles improved uniform distribution on the stage of NGI.

Ph. D.

As the Earth's atmosphere evolves due to human activity, today's modern industrial society relies significantly on the scientific community to foresee possible atmospheric complications such as the celebrated greenhouse effect. Scientists, in turn, rely on accurate measurements of the Earth Radiation Budget (ERB) in order to quantify changes in the atmosphere. The Thermal Radiation Group (TRG), a laboratory in the Department of Mechanical Engineering at Virginia Polytechnic Institute and State University, has been at the edge of technology designing and modeling ERB instruments. TRG is currently developing a new generation of thermoelectric detectors for ERB applications. These detectors consist of an array of thermocouple junction pairs that are based on a new thermopile technology using materials whose electro-thermophysical properties are not completely characterized. The objective of this investigation is to design experiments aimed at determining the electro-thermophysical properties of the detector materials. These properties are the thermal conductivity and diffusivity of the materials and the Seebeck coefficient of the thermocouple junctions. Knowledge of these properties will provide fundamental information needed for the development of optimally designed detectors that rigorously meet required design specifications. / Master of Science

In experiments with repeated measurements made on the same subjects, the repeated observations in time may be correlated. Therefore, the assumption of independent observations cannot be made in general. This thesis considers the experimental design with treatments in a two-way classification with a disproportionate number of subjects allocated to each treatment combination and repeated measurements made on the subjects. A procedure is shown to be applicable for computing an analysis under somewhat restrictive assumptions. It is assumed that the variances are equal for all times and the correlations in time are equal. The tests obtained are for the three-factor interaction, the two-factor interactions assuming the three-factor interaction zero, and the main effects assuming all interactions zero. The procedure requires the inverse of one matrix, some matrix multiplication, and the calculation of some standard sums of squares. / Master of Science

The statistical problems of intercropping experiments (which involve the growing of two or more crops together) are investigated in this study. Measures of combined yield are discussed; the Land Equivalent Ratio (LER) is shown to be the 'best' index for intercropping. Problems that arise in the standardization of LER are investigated, and use of a single pair of divisors is recommended. The use of systematic designs are advocated for yield-density studies, to reduce the number of guard rows. A 3-way systematic design is proposed and methods of analysis are suggested. A regression model is employed for the combined yield data (LER), from which estimates of the optimum densities can be calculated. The study also deals with varietal trials in intercropping. Methods for reducing the large number of possible varietal combinations to be tested in the field and ways of reducing the block size are given. The field layout is discussed, and illustrated by examples. Stability measures that can be used in intercropping are derived and it is shown how they can be used in evaluating stable varietal combinations. It is also shown how information about the contribution to stability of each crop can be obtained. The best proportions of the component crops in the intercropping mixture is also investigated. Design and analysis for an experiment on proportions in conjunction with varying densities is given. / Ph. D. / incomplete_metadata

No description available.

This research focuses on developing a comprehensive framework for designing and modeling experiments in the presence of multiple sources of competing prior knowledge. In particular, methodology is proposed for process optimization in high-cost, low-resource experimental settings where the underlying response function can be highly non-linear. In the first part of this research, an initial experimental design criteria is proposed for optimization problems by combining multiple, potentially competing, sources of prior information--engineering models, expert opinion, and data from past experimentation on similar, non-identical systems. New methodology is provided for incorporating and combining conjectured models and data into both the initial modeling and design stages. The second part of this research focuses on the development of a batch sequential design procedure for optimizing high-cost, low-resource experiments with complicated response surfaces. The success in the proposed approach lies in melding a flexible, sequential design algorithm with a powerful local modeling approach. Batch experiments are designed sequentially to adapt to balance space-filling properties and the search for the optimal operating condition. Local model calibration and averaging techniques are introduced to easily allow incorporation of statistical models and engineering knowledge, even if such knowledge pertains to only subregions of the complete design space. The overall process iterates between adapting designs, adapting models, and updating engineering knowledge over time. Applications to nanomanufacturing are provided throughout.

SammanfattningLångvarig smärta orsakar stort lidande för individen och belastar samhället ekonomiskt. Syftet med denna uppsats var att undersöka om en exponering in vivo-behandling inspirerad av Dialektisk beteendeterapi (DBT) för människor med långvarig ländryggssmärta var görbar samt om behandlingen gav effekt på smärtrelaterad problematik. Designen var en single case experimental design vilket är en beprövad design för att testa nya terapimetoder. Studien bestod av sex deltagare, alla med hög grad av smärtrelaterade katastroftankar, något som litteraturen visat predicera sämre behandlingsutfall. Behandlingen var DBT-inspirerad och indelad i tre faser; en första valideringsfas, en andra färdighetsfas och en tredje exponeringsfas. Fem av sex deltagare fick förbättringar på alla de primära utfallsmått, tre av sex deltagare fick förbättringar på samtliga primära- och sekundära utfallsmått. Framtida replikationer är motiverade. / AbstractChronic pain causes great suffering for the individual and burden society economically. The aim of this study was to examine whether an exposure in vivo treatment inspired by Dialectical Behavior Therapy (DBT) for people with chronic low back pain was feasible and whether the treatment had effect on pain-related problems. The design was a single case experimental design, which is a widely used design to test new therapy methods. The study consisted of six participants, all with high levels of pain catastrophizing, something that in the literature been linked to poor treatment outcomes. The treatment was inspired by DBT and divided into three phases: an initial validation phase, a second phase for skills training and a third exposure phase. The results were promising: five out of six participants had improved in all primary outcome measures. Three out of six participants had improvements in all primary and secondary outcome measures. Future replications are warranted.