Temporal Support in Relational Databases

Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission. © 2012 Higher Education AcademyThis paper examines the current state of temporal support in relational databases and the type of situations where we need that support. There has been much research in this area and there were attempts in the American National Standards Institute (ANSI) and the International Organisation for Standardisation (ISO) standards committees in the late 1990s to add an extension called TSQL2 to the existing SQL standard. However no agreement could be reached as it was felt that some of the suggested extensions did not fit well with the relational model, as well as being difficult to implement. TSQL2 was abandoned and since then vendors have added their own data types, and if we are lucky, operators too in an attempt to provide support. However, to novice students and database designers it is often not apparent why some temporal concepts are difficult to deal with in a relational database. In teaching these concepts to students we use a Case Study (based on a real example) which illustrates the problems of providing temporal support by using examples of the data types which could be useful to solve temporal problems and the operators which are necessary to provide this

Feasibility of the Spin-Light Polarimetry Technique for Longitudinally Polarized Electron Beams

A novel polarimeter based on the asymmetry in the spacial distribution of synchrotron radiation will make for a fine addition to the existing M{\o}ller and Compton polarimeters. The spin light polarimeter consists of a set of wiggler magnet along the beam that generate synchrotron radiation. The spacial distribution of synchrotron radiation will be measured by ionization chambers. The up-down (below and above the wiggle) spacial asymmetry in the transverse plain is used to quantify the polarization of the beam. As a part of the design process, effects of a realistic wiggler magnetic field and an extended beam size were studied. The perturbation introduced by these effects was found to be negligible. Lastly, a full fledged GEANT-4 simulation was built to study the response of the ionization chamber.Comment: International Nuclear Physics Conference 2013, 4 Pages, 7 Figure

Simulation modeling for energy consumption of residential consumers in response to demand side management.

Energy efficiency in the electricity distribution system continues to gain importance as demand for electricity keeps rising and resources keep diminishing. Achieving higher energy efficiency by implementing control strategies and demand response (DR) programs has always been a topic of interest in the electric utility industry. The advent of smart grids with enhanced data communication capabilities propels DR to be an essential part of the next generation power distribution system. Fundamentally, DR has the ability to charge a customer the true price of electricity at the time of use, and the general perception is that consumers would shift their load to a cheaper off-peak period. Consequently, when designing incentives most DR literature assumes consumers always minimize total electricity cost when facing energy consumption decisions. However, in practice, it has been shown that customers often override financial incentives if they feel strongly about the inconvenience of load-shifting arrangements. In this dissertation, an energy consumption model based on consumers‟ response to both cost and convenience/comfort is proposed in studying the effects of differential pricing mechanisms. We use multi-attribute utility functions and a model predictive control mechanism to simulate consumer behavior of using non-thermostatic loads vi (prototypical home appliances) and thermostatically controlled load (HVAC). The distributed behavior patterns caused by risk nature, thermal preferences, household size, etc. are all incorporated using an object-oriented simulation model to represent a typical residential population. The simulation based optimization platform thus developed is used to study various types of pricing mechanisms including static and dynamic variable pricing. There are many electric utilities that have applied differential pricing structures to influence consumer behavior. However, majority of current DR practices include static variable pricings, since consumer response to dynamic prices is very difficult to predict. We also study a novel pricing method using demand charge on coincident load. Such a pricing model is based on consumers‟ individual contribution to the monthly system peak, which is highly stochastic. We propose to use the conditional Markov chain to calculate the probability that the system will reach a peak, and subsequently simulate consumers‟ behavior in response to that peak. Sensitivity analysis and comparisons of various rate structures are done using simulation. Overall, this dissertation provides a simulation model to study electricity consumers‟ response to DR programs and various rate structures, and thus can be used to guide the design of optimal pricing mechanism in demand side management

Programmed Translational Readthrough in Drosophila melanogaster

Translational readthrough (TR) is extensively used by viruses to expand their limited genome capacity. The pervasiveness of TR across eukaryotic genomes is only recently being explored. Systems biology approaches such as comparative phylogenetics, combined with ribosome profiling studies have led to the identification of several hundred genes that can undergo TR in Drosophila melanogaster. However, only limited number of these genes have been experimentally studied. Due to the lack of systemic biochemical studies, the actual mechanism of TR regulation and the role of regulated TR in proteome expansion in D. melanogaster remains largely unexplored. In this study, we develop a dual luciferase reporter assay system to analyze a set of genes from D. melanogaster that have been phylogenetically predicted to undergo TR. We provide experimental validation and quantification of the extent of TR in these genes and also analyze the impact of immediate stop codon context on TR modulation. For one particular candidate, aPKC, we use systematic mutational analysis to delineate the minimal primary sequence motif responsible for driving efficient TR. Furthermore, in order to understand the biological significance and phenotypic outcome of gene-specific TR, we employ CRISPR/Cas9-based genome editing to create genetic mutants of the large Maf transcription factor, traffic jam (tj), that exhibit constitutive TR or abolished it. We identify tissue-specific regulation of TR in tj, wherein the expression of Tj-TR isoform is restricted to the nervous tissues. The TR extension selectively attenuates the native Tj function, specifically in the determination of morphogenetic behavior and spatial distribution of cap cells in adult ovaries. Conversely, the TR extension positively amplifies the selective gene regulatory function of native Tj in downregulation of the adhesion protein Fasciclin III. Using high-throughput RNA sequencing, we further dissect the role of TR in tj in shaping the transcriptome profile in adult brains. Our results hint towards a complex mode of regulation of Tj function by TR that operates via conditional fine-tuning of its specific gene regulatory functions

Development of alternative baits based on rest raw materials, low-valued and surplus fish for baited gear fishing of Atlantic cod (Gadus morhua)

The experiment was conducted to develop the alternative baits from low-valued and surplus fish for pot and longline fishing of Atlantic cod. Minced herring and capelin were used to produce baits for pots with increasing level of alginate (2%, 4%, and 6%) and microbial transglutaminase (TG) (0.5%, 1.5% and 2.5%) as the binding agents to attain the optimal handling and water stable baits using a low binder. Alginate-based baits were shaped through stuffing technique while TG-based baits through molding and setting. Alginate supplementation at 4% of the total weight of the bait (4g/100g) gave good handling properties and satisfactory water stability which was easily processed. This level was used to make pot baits from the other two species of fish namely whole minced sprat and minced trimmings of saithe. Four types of baits (5 bait pieces per tank) were subjected to a behavioral study with cod (5 fishes per tank) in three experimental tanks to study their species preference over baits of different species. Response graphs from multivariate principal component analysis of different behavioral patterns showed that herring and sprat gave more attractive baits than capelin and saithe. Herring and capelin baits made with TG did not produce suitable baits. Although, it was compared with alginate-based baits of respective species to study the response difference of binders in cod. There was not observed a substantial difference in behavior of cod in response to the two binders in baits. Industry-processed skin from saithe was used for making baits for longlines, and compared with the baits made from the skin of manually deskinned herring and mackerel. Only the saithe skin was suitable for longline baits owing to its better hooking strength. Behavioral analysis of cod showed poor response to saithe skin bait when compared to highly preferred weak herring and mackerel skin baits. Improvement in taste factor of saithe skin bait was made by either incorporating Ecobait attractants (EA) (5% and 10%) or by coating saithe skin layer over highly preferred herring bait. Response graph and PCA biplot showed improvement in sensory characteristics of these baits compared to pure saithe skin baits. The breaking strength declined linearly with increase in EA concentration while skin coated bait gave the lowest value. All the improvised skin baits showed appreciable hooking stability.M-F

EXPERIMENTAL INVESTIGATION OF WHITMORE SECTION AND BLOCK SHEAR FAILURES IN STEEL GUSSET PLATES USING DIGITAL IMAGE CORRELATION

Gusset plates are necessary for transferring loads from one structural member to another. During load transfer gussets can undergo shear, net section rupture and gross section yielding. Gusset design is a complex process and there is still a lack of knowledge regarding the stress and strain distribution in gusset plates. Current design practices which use Whitmore method, may not be sufficient to accurately predict the capacity of a gusset plate. An experimental study was conducted at The University of Texas at Tyler to understand the failure mechanism of gusset plates under uniaxial tensile loading. Variables considered for the experiment are pitch distance, number of bolts used and dimensions of the gusset plate. A 3/16 inch thick gusset plate was used for each test in the experiment. A WT3*8 section was used as the tension member for the experimental analysis. Limit state checks of gross section yielding, net section fracture, block shear rupture and bearing strength at holes were performed to calculate the design strength of the connection using the Load and Resistance Factor Design (LRFD) method. Digital Image Correlation (DIC) was used for analyzing major strains in the gusset plate around the bolted connection of the WT and gusset plate. All of the plates failed in block shear at loads significantly higher than those predicted by Whitmore effective width fracture mode. Furthermore, the variability of the error in prediction was significantly lower for predictions using block shear (coefficient of variance 0.05) versus those using Whitmore fracture (coefficient of variance 0.192). DIC results clearly showed evidence of strains associated with block shear including measurement of necking and clear evidence that Whitmore fracture did not occur- relatively high strains in the areas associated with a Whitmore fracture were not seen. The study ultimately shows that Whitmore fracture was not a realistic failure mode for these uniaxially loaded gusset plates