As technology continues to scale to smaller geometries and newer dimensions (3-D), with increasingly complex manufacturing processes, the ability to reliably manufacture 100% defect-free circuitry becomes a significant challenge. While implementing additional circuitry to improve yield is economically justifiable, this thesis addresses the cost of defect tolerance by providing lower cost solutions or alternatively more defect tolerance for the same cost in state-of-the-art ICs, including three-dimensional ICs (3-D ICs). Conventional defect tolerance techniques involve incorporating redundancy into the design. This thesis introduces novel designs to maximize the utility of spare elements with minimal circuitry overhead, thereby improving the yield. One idea proposed is Selective Row Partitioning (SRP), a technique which allows a single spare column to be used to repair multiple defective cells in multiple columns. This is done by selectively decoding the row address bits when generating the select signals for the column multiplexers. This logically segments the spare column allowing it to replace different columns in different partitions of the row address space. All the chips are identical, but fuses are used to customize the row decoding circuitry on a chip-by-chip basis. An implementation procedure and results are presented which show improvement in overall yield at a minimal overhead cost. Moreover, new yield-enhancing design techniques for 3-D ICs are introduced. When assembling a 3-D IC, there are several degrees of freedom including which die are stacked together, in what order, and with what rotational symmetry. This thesis describes strategies for exploiting these degrees of freedom to reduce the cost and complexity of implementing defect tolerance. One strategy is to enable asymmetric repair capability within a 3-D memory stack by exploiting the degree of freedom that the order of the die in the stack can be selected. This technique optimizes the number of fuses, and in some cases, the number of spares as well, required to implement defect tolerance. Another innovative technique is to exploit rotational symmetry of the dies to do implicit reconfiguration to implement defect tolerance. Results show that leakage power and performance overhead for defect tolerance can be significantly reduced by this technique. / text

Since arbitrage-free is a desirable theoretical feature in a healthy financial market, many efforts have been made to construct arbitrage-free models for yield curves. However, little attention is paid to review if such restriction will improve yield forecast. We evaluate the importance of arbitrage-free restriction on dynamic Nelson-Siegel term structure when forecasting yield curves. We find that it doesn’t help. We also compare these two Nelson-Siegel dynamic models with a benchmark dynamic model and show that Nelson-Siegel structure improve forecasts for long-maturity yields. / text

Hierarchical crop growth models can contribute signi®cantly to land quality research because the yield gap between the estimated optimum and the actual crop production has been identi®ed as a major land quality indicator. This study describes a three-level, hierarchical crop production model, simulating radiation-thermal, water-limited and natural production potentials of annual crops. Input requirements have been kept low to ensure its applicability to developing regions, which often have access only to limited data. The simplicity of this model also has disadvantages: inconsistencies have been reported when applying this model in semiarid regions, which are characterized by very irregular rainfall patterns. Revision of the water balance, which simulates the availability of water, was required. The modi®ed model was validated using the experimental yields of maize and sun¯ower in Guquka, a semiarid region of South Africa. Yields were estimated very well, possible improvements to crop production were identi®ed and implications for land-use planning highlighted. Yield gap analysis revealed that radiation, sunshine and temperature are favourable for crop production, but the heavy dependence on rainfall makes the region very vulnerable to drought, with devastating impact on yields. The generally low chemical soil fertility further reduces crop performance.

No description available.

No description available.

The purpose of a greenhouse is to maintain desirable growing conditions for plants during the different seasons of the year. The glass-covered greenhouse has been found to be suitable for this purpose through many yeara of use and improvement. It has been very popular for providing a controlled environment in which out-of-season crops can be grown and also as a research house for the study of plant growth. The sturdy construction required to support the weight of glass involves a high initial cost. With the development of plastic sheeting suitable for use as a glazing material, a new type of greenhouse has evolved. Greenhouses covered with plastic do not require the sturdy structure necessary to support glass, although a permanent construction may be used. To date the plastic greenhouse has found its greatest use as a temporary low cost structure. The possibility of growing crops intolerant of frost during the winter months in the southwestern United States where mild winters keep heating costs low, has increased interest in plastic greenhouses. Since high temperatures occur during the summer months in the Southwest, cooling as well as heating have to be provided if the greenhouse is to be operated through the entire year. This study was designed to measure the modification of the environment within a plastic greenhouse and to evaluate the growth response of tomatoes under these conditions. Studies were conducted to determine the temperatures which could be maintained in a plastic greenhouse during the summer, winter and spring seasons. The growth response of tomatoes under plastic was studied using winter and spring variety trials.

No description available.

No description available.

Methodologies have been devised to genotype the $ kappa$-casein ($ kappa$-CN) and $ beta$-lactoglobulin ($ beta$-LG) loci using the polymerase chain reaction (PCR) and restriction fragment length polymorphisms (RFLPs) analysis. A fragment of 432 base pair from the $ kappa$-CN gene which contains the nucleotide substitutions diagnostic of the A- and B-alleles of $ kappa$-CN was amplified. DNA amplified from the A-variant contained a unique HinfI restriction site, whereas DNA amplified from the B-variant contained a unique TaqI site. Thus, the genotype of the animal could be determined by restriction enzyme analysis. A region extending from exon IV to V of the $ beta$-LG gene was also amplified using PCR. In this region, the B-allele contains 2 HaeIII restriction sites which are not present in DNA amplified from the A-allele. The digestion of the PCR product with HaeIII thus allowed discrimination between the A- and B-alleles. Analysis of bulls (n = 68) used by artificial insemination (AI) centres after 1980, bulls (n = 27) used before 1960, a random sample of male calves (n = 102) and cows (n = 123) revealed a frequency of the B allele of $ kappa$-CN as 0.13, 0.37, 0.22 and 0.19 in these populations, respectively. In the populations of bulls (n = 69) used by AI centres after 1980, bulls (n = 27) used before 1960, a random sample of male calves (n = 99), and cows (n = 129), the B-allele of $ beta$-LG was present at frequencies of 0.60, 0.52, 0.67, and 0.65, respectively. Statistical analysis of these data shows the frequency of the B-allele of $ kappa$-CN was significantly higher in sires (n = 27) which were used by the AI centre before 1960 compared to more modern proven sires (n = 68) (P $<$ 0.01).

Estimates of genetic and phenotypic parameters of lifetime performance traits and estimates of correlations between these and first lactation traits were obtained using multitrait mixed model and Restricted Maximum Likelihood (REML) methodologies, and accounting for all known additive genetic relationships amongst animals in sires pedigree. Part-lifetime performance traits, i.e. two-, three, and four-parity totals of yield and profit, were also included in the analysis. Data were on 82,835 Holstein cows, daughters of 703 sires, calving first between September 1979 and December 1984 in the herds enrolled in Quebec Dairy Herd Analysis Service (QDHAS). Lifetime performance records, however, continued through December 1989. / Results of analysis indicated low estimates of heritability for lifetime performance traits, e.g., lifetime production and profit (.11$ sim$.13) and longevity (.07$ sim$.09). However, production per day of productive life traits had moderate heritability (.28$ sim$.32). Estimates of genetic and phenotypic parameters decreased from part-lifetime to total lifetime performance because residual variances increased at a greater rate compared to rate of increase in sire variances. Both genetic and phenotypic correlations amongst lifetime production, lifetime profit and longevity traits were very high and approached unity in all cases. / Estimates of genetic and phenotypic correlations of first lactation production and profit traits with all measures of part and total lifetime performance were positive and high. These correlations decrease from part-lifetime to total lifetime performance due to part to whole relationships. / Estimates of parameters of lifetime performance traits were mostly free of the effects of selection on milk production. Positive and high genetic correlation of first lactation milk yield with all lifetime performance traits indicated that selection on first lactation milk yield alone will improve all measures of lifetime performance. However, some consideration should be given to measures of reproduction and health which may help in improving the longevity of dairy cattle. (Abstract shortened by UMI.)