Zambian Cotton in a Regional Context: Performance under Liberalization and Future Challenges

This paper is directed toward policy makers and private stakeholders in Zambia’s cotton sector. Its purpose is: 1) to assess key elements of the performance of Zambia’s cotton sector relative to other selected African countries; 2) to develop preliminary insights into the driving forces behind Zambia’s performance and also the threats to improved future performance; and 3) to identify key issues within the sector that merit continued applied research and dialogue with stakeholders.food security, food policy, Zambia, cotton, Crop Production/Industries, Q18,

Operations research investigations of satellite power stations

A systems model reflecting the design concepts of Satellite Power Stations (SPS) was developed. The model is of sufficient scope to include the interrelationships of the following major design parameters: the transportation to and between orbits; assembly of the SPS; and maintenance of the SPS. The systems model is composed of a set of equations that are nonlinear with respect to the system parameters and decision variables. The model determines a figure of merit from which alternative concepts concerning transportation, assembly, and maintenance of satellite power stations are studied. A hybrid optimization model was developed to optimize the system's decision variables. The optimization model consists of a random search procedure and the optimal-steepest descent method. A FORTRAN computer program was developed to enable the user to optimize nonlinear functions using the model. Specifically, the computer program was used to optimize Satellite Power Station system components

A microprocessor-based one dimensional optical data processor for spatial frequency analysis

A high degree of accuracy was obtained in measuring the spatial frequency spectrum of known samples using an optical data processor based on a microprocessor, which reliably collected intensity versus angle data. Stray light control, system alignment, and angle measurement problems were addressed and solved. The capabilities of the instrument were extended by the addition of appropriate optics to allow the use of different wavelengths of laser radiation and by increasing the travel limits of the rotating arm to + or - 160 degrees. The acquisition, storage, and plotting of data by the computer permits the researcher a free hand in data manipulation such as subtracting background scattering from a diffraction pattern. Tests conducted to verify the operation of the processor using a 25 mm diameter pinhole, a 39.37 line pairs per mm series of multiple slits, and a microscope slide coated with 1.091 mm diameter polystyrene latex spheres are described

Telecommunications media for the delivery of educational programming

The technical characteristics of various telecommunications media are examined for incorporation into educational networks. FM radio, AM radio, and VHF and UHF television are considered along with computer-aided instruction. The application of iteration networks to library systems, and microform technology are discussed. The basic principles of the communications theory are outlined, and the operation of the PLATO 4 random access system is described

Correlation of electrical conductivity and radiation-induced free radical concentration in poly/ethylene terephthalate/ and related compounds

Gamma and ultraviolet radiation effects on electronic properties of polyethylene terephthalate and related compound

Two-axis controller Patent

Two axis flight controller with potentiometer control shafts directly coupled to rotatable ball member

Cotton in Zambia: An Assessment of its Organization, Performance, Current Policy Initiatives, and Challenges for the Future

This paper grows out of earlier work on cotton by the Food Security Research Project. It is directed towards policy makers and private stakeholders in Zambia’s cotton sector, and has four main purposes: (a) To provide a detailed descriptive overview of the organization of the sector and of the behavior of key public and private participants in the sector; (b) To assess cotton’s role in smallholder livelihood strategies, and its competitiveness at the farm level with a key alternative crop–maize; (c) To critically evaluate recent policy initiatives in the sector and suggest key modifications that might be needed; and (d) To identify the primary challenges that the sector faces to ensure its future competitiveness in regional and international markets.food security, food policy, Zambia, cotton, smallholder livelihood, Crop Production/Industries, Q18,

The Welfare Cost of Distortions in the United States Tax System: A General Equilibrium Approach

Using a general equilibrium model of the United States economy,we examine the combined welfare cost of all taxes in the U.S. revenue system.We find that the welfare losses caused by distortionary taxation can be very large, both on average and at the margin.The marginal welfare loss to consumers from raising an additional dollar of revenue is in the range of 34 cents to 48 cents, depending on certain elasticities. This has very important implications for cost-benefit analysis.If a public project must be financed by distortionary taxes which cause dead-weight loss, this excess burden must be taken into account when we decide whether to undertake the project. Our calculations indicate that the marginal deadweight loss is between one-third and one-half of marginal revenues. This large wedge could cause us to approve many fewer projects than we would approve if we were to use the simple condition that the sum of the marginal rates of substitution should equal the marginal rate of transformation.The average deadweight loss per dollar of revenue is smaller than the marginal deadweight loss, but it is still substantial. We estimate that the present value of the gain from replacing the distortionary tax system with certain lump sum taxes would be in the range of $1.8 trillion to$3.1 trillion,or 13 cents to 22 cents per dollar of revenue. The gains would be about 60 percent as great if the existing system were replaced with a proportional income tax. Replacing the existing system with a consumption-type value-added tax would give even greater gains than those from switching to a proportional income tax.

The Broken Beef Cattle Industry: COOL, COVID and CattleTrace

While the Kansas City Stockyards themselves are gone, just like in the early 20th Century, a beef monopoly has once again found its way into the industry, and a way around the Packers and Stockyards Act of 1921 and is again suffocating the industry. While at the time of the act’s passage in 1921 five companies controlled the market, today the market is even more consolidated in the “Big Four,” as the four biggest meat packing companies in America are commonly known (Cargill, Tyson, JBS and National Beef/Marfrig), and are again arguably stifling the free-market. If Americans do not act quickly to address this extreme consolidation, then the free-market, independent cattle rancher will soon face the same fate as the Kansas City Stockyards, and soon, like the Stockyards, will simply be history and a distant memory. This is not only bad news for the American rancher, but is even worse news for the American consumer, as the consolidation creates food security and food safety issues, as highlighted by the recent events of 2020-2021 surrounding the COVID-19 pandemic

Minimizing Communication in Linear Algebra

In 1981 Hong and Kung proved a lower bound on the amount of communication needed to perform dense, matrix-multiplication using the conventional $O(n^3)$ algorithm, where the input matrices were too large to fit in the small, fast memory. In 2004 Irony, Toledo and Tiskin gave a new proof of this result and extended it to the parallel case. In both cases the lower bound may be expressed as $\Omega$(#arithmetic operations / $\sqrt{M}$), where M is the size of the fast memory (or local memory in the parallel case). Here we generalize these results to a much wider variety of algorithms, including LU factorization, Cholesky factorization, $LDL^T$ factorization, QR factorization, algorithms for eigenvalues and singular values, i.e., essentially all direct methods of linear algebra. The proof works for dense or sparse matrices, and for sequential or parallel algorithms. In addition to lower bounds on the amount of data moved (bandwidth) we get lower bounds on the number of messages required to move it (latency). We illustrate how to extend our lower bound technique to compositions of linear algebra operations (like computing powers of a matrix), to decide whether it is enough to call a sequence of simpler optimal algorithms (like matrix multiplication) to minimize communication, or if we can do better. We give examples of both. We also show how to extend our lower bounds to certain graph theoretic problems. We point out recently designed algorithms for dense LU, Cholesky, QR, eigenvalue and the SVD problems that attain these lower bounds; implementations of LU and QR show large speedups over conventional linear algebra algorithms in standard libraries like LAPACK and ScaLAPACK. Many open problems remain.Comment: 27 pages, 2 table