Alcohol Advertising and Alcohol Consumption by Adolescents

The purpose of this paper is to empirically estimate the effects of alcohol advertising on adolescent alcohol consumption. The theory of brand capital is used to explain the effects of advertising on consumption. The industry response function and the evidence from prior studies indicate that the empirical strategy should maximize the variance in the advertising data. The approach in this paper to maximizing the variance in advertising data is to employ cross sectional data. The Monitoring the Future (MTF) and the National Longitudinal Survey of Youth 1997 (NLSY97) data sets, which include only data for adolescents, are employed for the empirical work. These data sets are augmented with alcohol advertising data, originating on the market level, for five media. Use of both the MTF and the NLSY97 data sets improves the empirical analysis since each data set has its own unique advantages. The large size of the MTF makes it possible to estimate regressions with race and gender specific subsamples. The panel nature of the NLSY97 makes it possible to estimate individual fixed effects models. In addition, very similar models can be estimated with both data sets. Since the data sets are independent, the basically consistent findings increase the confidence in all the results. The results indicate that blacks participate in alcohol less than whites and their participation cannot be explained with the included variables as well as it can for whites. A comparison of male and female regressions shows that price and advertising effects are generally larger for females. Models which control for individual heterogeneity result in larger advertising effects implying that the MTF results may understate the effect of alcohol advertising. The results based on the NLSY97 suggest that a compete ban on all alcohol advertising could reduce adolescent monthly alcohol participation by about 24 percent and binge participation by about 42 percent. The past month price-participation elasticity was estimated at about -0.28 and the price-binge participation elasticity was estimated at about -0.51. Both advertising and price policies are shown to have the potential to substantially reduce adolescent alcohol consumption.

THE CURRENT MACROECONOMIC CRISIS

Professor Crotty once casually observed that in his view economics could not be properly thought of as a science. This paper investigates the implications of this view in light of the question of how the scientific method has recently contributed to the evolution of economic practice. It is argued that agent-based models might provide a platform for an integration of recent micro and macroeconomic theories.Agent-based models, macroeconomics, Keynes, James Crotty.

Relative Geologic Time By Dynamic Time Warping

This thesis considers an approach to tackle a core problem within seismic interpretation, which is bringing an autonomously generated interpretation of the seismic data, which is now known as a Relative Geologic Time. The proposed method readily utilizes the method of Dynamic Time Warping, which is an established method within signal processing. Using Dynamic Time Warping is thought to replicate similar interpretations an interpreter would conduct when fulfilling an interpretation of the subsurface. Utilizing Dynamic Time Warping to seismic data results in a fully autonomous interpretation of the subsurface, conducted in minutes and seconds. The method is simple and extendable, which can easily be further expanded. The workflow established during the thesis work results in a method that successfully produces an RGT volume. However, problems related to the method must be improved to enhance the outcome further and diminish errors present in the result. Furthermore, even with problems associated with the method, potential solutions are described in detail in the discussion and appendix. Discussion affiliated with previous attempts in solving Relative Geologic Time volumes is emphasized. The research conducted in Dynamic Time Warping is promising and emits potential for further research. LaTeX setup by Gunn and Patel (2017)

Track wear-and-tear cost by traffic class: Functional form, zero output levels and marginal cost pricing recovery on the French rail network

We address the issue of the allocation of railway track maintenance (wear-and-tear) costs to traffic output classes and consider a very general function relating maintenance cost C to a set of technical production characteristics K used to produce traffic output vector T. We neglect other rail cost categories, such as traffic control and track renewal. The data base pertains to over 1500 sections of the French rail infrastructure in 1999, representing about 90% of the total network of 30000 km of lines in regular service. In addition to the maintenance cost C, it provides by track section 15 technical characteristics (both state S and quality Q) and 4 train traffic outputs T. Input prices, assumed to be uniform in space, disappear from the analysis, as in other national cross-sectional cases. With database subsets of approximately 1000 observations, several functional forms are tested: Linear, Log-Log, trans-Log and generalized Box-Cox. All are embedded in an unrestricted extension (U-GBC) of Khaled's seminal restricted generalized Box-Cox (R-GBC) functional specification. The U-GBC architecture, compared with its 4 principal nested variants, turns out to be by far the most appropriate, in particular when some observed zero traffic sample values are included - an issue rather neglected previously in the literature. It appears that several technical characteristics, such as maximum allowed speed and number of switches, are highly significant maintenance cost factors, which gives a hint that derived marginal costs are short term; also, the relation between maintenance costs and traffic is non linear and differs significantly by train category. Implications of different specifications for marginal infrastructure cost charges by traffic type are outlined.Ce texte traite de l'allocation des coûts d'entretien de l'infrastructure ferroviaire, entendus au sens de "coûts à périodicité annuelle", aux divers types de trafic. Sont exclus de l'analyse les coûts de circulation (contrôle du trafic) et de renouvellement des voies dits "coût de régénération". La fonction de coût utilisée, très générale, relie le coût C à un ensemble de caractéristiques techniques K et à un vecteur de produits T. Les données utilisées proviennent d'une base de données relative à la France sur une décomposition en 1500 segments environ d'un réseau ferroviaire de 30000 km de lignes en service en 1999. On dispose par segment, en plus du coût d'entretien C, de leurs 15 principales caractéristiques techniques (tant d'état S que de qualité Q) et du trafic T décomposé en 4 catégories de service. Les prix, supposés constants à travers le pays, disparaissent de l'analyse, à l'instar d'autres exemples construits à partir de coupes transversales nationales. A partir de sous-ensembles d'approximativement 1000 observations, différentes spécifications de relations fonctionnelles sont testées et évaluées : linéaire, Log-Log, trans-Log et Box-Cox généralisée. Elles sont toutes comprises dans un prolongement non contraint (U-GBC) de la formulation fondatrice Box-Cox généralisée contrainte (R-GBC) de Khaled. La structure générale U-GBC, comparée aux 4 principales formes qui y sont emboîtées, ressort clairement comme préférable, en particulier lorsqu'on retient dans l'échantillon les observations nulles sur certains trafics - un sujet plutôt négligé à ce jour dans la littérature. Il appert que le coût dépend des caractéristiques techniques telles que la vitesse maximale autorisée sur le segment de ligne et le nombre de croisements de voies, ce qui laisse entendre, comme les caractéristiques techniques couvrent les plus importantes caractéristiques de l'équipement, que les coûts marginaux déduits des ajustements représentent correctement des coûts de court terme ; en outre, la relation entre le trafic et les coûts d'entretien est non-linéaire et varie par type de train. On étudie enfin les implications des diverses spécifications pour la tarification des infrastructures au coût marginal par type de trafic

Track wear-and-tear cost by traffic class: Functional form, zero output levels and marginal cost pricing recovery on the French rail network

We address the issue of the allocation of railway track maintenance (wear-and-tear) costs to traffic output classes and consider a very general function relating maintenance cost C to a set of technical production characteristics K used to produce traffic output vector T. We neglect other rail cost categories, such as traffic control and track renewal. The data base pertains to over 1500 sections of the French rail infrastructure in 1999, representing about 90% of the total network of 30000 km of lines in regular service. In addition to the maintenance cost C, it provides by track section 15 technical characteristics (both state S and quality Q) and 4 train traffic outputs T. Input prices, assumed to be uniform in space, disappear from the analysis, as in other national cross-sectional cases. With database subsets of approximately 1000 observations, several functional forms are tested: Linear, Log-Log, trans-Log and generalized Box-Cox. All are embedded in an unrestricted extension (U-GBC) of Khaled's seminal restricted generalized Box-Cox (R-GBC) functional specification. The U-GBC architecture, compared with its 4 principal nested variants, turns out to be by far the most appropriate, in particular when some observed zero traffic sample values are included - an issue rather neglected previously in the literature. It appears that several technical characteristics, such as maximum allowed speed and number of switches, are highly significant maintenance cost factors, which gives a hint that derived marginal costs are short term; also, the relation between maintenance costs and traffic is non linear and differs significantly by train category. Implications of different specifications for marginal infrastructure cost charges by traffic type are outlined.rail track wear-and-tear ; cost function ; CES ; trans-Log ; generalized Box-Cox ; zero sample values ; maintenance cost allocation by traffic class ; marginal cost by traffic class ; power axle weight damage laws ; cross-sectional data ; rail line sections ; France ; marginal cost pricing

Parallel Sparse Matrix-Matrix Multiplication

The thesis investigates the BLAS-3 routine of sparse matrix-matrix multiplication (SpGEMM) based on the outer product method. Sev- eral algorithmic approaches have been implemented and empirically an- alyzed. The experiments have shown that an algorithm presented by Gustavson [22] outperforms other alternatives. In this work we propose optimization techniques that improve the scalability and the cache efficiency of the Gustavson’s algorithm for large matrices. Our approach succeeded to reduce the cache misses by more than a factor of five and to improve the net running time by 30% with some instances. The thesis also presents an algorithm for flops estima- tion, which can be used to determine an upper bound for the density of the result matrix. Furthermore, the work analyzes and empirically evaluates techniques for parallelization of the multiplication in a shared memory model by using Intel TBB and OpenMP. We investigate the cache efficiency of the algorithm in a parallel setting and compare several approaches for load balancing of the computation

Amortised Inference in Bayesian Neural Networks

Meta-learning is a framework in which machine learning models train over a set of datasets in order to produce predictions on new datasets at test time. Probabilistic meta-learning has received an abundance of attention from the research community in recent years, but a problem shared by many existing probabilistic meta-models is that they require a very large number of datasets in order to produce high-quality predictions with well-calibrated uncertainty estimates. In many applications, however, such quantities of data are simply not available. In this dissertation we present a significantly more data-efficient approach to probabilistic meta-learning through per-datapoint amortisation of inference in Bayesian neural networks, introducing the Amortised Pseudo-Observation Variational Inference Bayesian Neural Network (APOVI-BNN). First, we show that the approximate posteriors obtained under our amortised scheme are of similar or better quality to those obtained through traditional variational inference, despite the fact that the amortised inference is performed in a single forward pass. We then discuss how the APOVI-BNN may be viewed as a new member of the neural process family, motivating the use of neural process training objectives for potentially better predictive performance on complex problems as a result. Finally, we assess the predictive performance of the APOVI-BNN against other probabilistic meta-models in both a one-dimensional regression problem and in a significantly more complex image completion setting. In both cases, when the amount of training data is limited, our model is the best in its class.Comment: This thesis served as the author's final project report for the University of Cambridge part IIB Engineering Tripos. 37 pages, 7 figure

The Shape of Silence: The Solution-State Conformation of Sir Heterochromatin: A Dissertation

Heterochromatin is a silenced chromatin region essential for maintaining genomic stability in eukaryotes and for driving developmental processes in higher organisms. A hallmark of heterochromatin is the presence of specialized architectural proteins that alter chromatin structure to inhibit transcription and recombination. Although it is generally assumed that heterochromatin is highly condensed, surprisingly little is known about the structure of heterochromatin or its dynamics in solution. In budding yeast, heterochromatin assembly at telomeres and the HM silent mating type loci requires the Sir proteins: Sir3, believed to be the major structural component of SIR heterochromatin, and the Sir2/4 complex, responsible for SIR recruitment to silencing regions and deacetylation of lysine 16 of the histone H4 tail, a mark associated with active chromatin. A combination of sedimentation velocity, atomic force microscopy, and nucleosomal array capture was used to characterize the stoichiometry and conformation of SIR nucleosomal arrays. The results indicate that Sir3 interacts with nucleosomal arrays with a stoichiometry of two Sir3 monomers per nucleosome, and that Sir2/4 may additionally bind at a ratio of one per nucleosome. Despite Sir3’s ability to repress transcription in vivo and homologous recombination in vitro in the absence of Sir2/4, Sir3 fibers were found to be significantly less compact than canonical magnesium-induced 30 nanometer fibers. However, heterochromatin fibers composed of all three Sir proteins did adopt a more condensed, globular structure. These results suggest that heterochromatic silencing is mediated both by the creation of more stable nucleosomes and by the steric exclusion of external factors