A modified racetrack betting system

Hausch, Ziemba & Rubinstein (1981) developed a betting system (the Dr. Z system) that empirically demonstrated positive profits in two racetracks. The Dr. Z system assumes running times are distributed exponentially but the use of other distributions for running times (Henery (1981) and Stern (1990)) produces a better fit in some racetracks although the better fit is at the cost of severely increased complexity in computing ordering probabilities. Lo & Bacon-Shone (1992) proposed a simple model of computing ordering probabilities which is a good approximation to those based on the Henery model and the Stern model. In this paper. we add this model to the Dr. Z system and use a simple way of computing ordering probabilities which is a good approximation to those based on the Henery model. With data sets in the U.S. and Hong Kong, we show improved profit over the Dr. Z system at lower levels of risk. With the special return formula in Japan. our model does not have a big difference in profits from the Dr. Z system.postprin

A radiological assessment of nuclear power and propulsion operations near Space Station Freedom

Scenarios were identified which involve the use of nuclear power systems in the vicinity of Space Station Freedom (SSF) and their radiological impact on the SSF crew was quantified. Several of the developed scenarios relate to the use of SSF as an evolutionary transportation node for lunar and Mars missions. In particular, radiation doses delivered to SSF crew were calculated for both the launch and subsequent return of a Nuclear Electric Propulsion (NEP) cargo vehicle and a Nuclear Thermal Rocket (NTR) personnel vehicle to low earth orbit. The use of nuclear power on co-orbiting platforms and the storage and handling issues associated with radioisotope power systems were also explored as they relate to SSF. A central philosophy in these analyses was the utilization of a radiation dose budget, defined as the difference between recommended dose limits from all radiation sources and estimated doses received by crew members from natural space radiations. Consequently, for each scenario examined, the dose budget concept was used to identify and quantify constraints on operational parameters such as launch separation distances, returned vehicle parking distances, and reactor shutdown times prior to vehicle approach. The results indicate that realistic scenarios do not exist which would preclude the use of nuclear power sources in the vicinity of SSF. The radiation dose to the SSF crew can be maintained at safe levels solely by implementing proper and reasonable operating procedures

Proportional justice versus efficient deterrence in Hong Kong criminal sentencing

Analysispublished_or_final_versio

Dynamic scaling in the vicinity of the Luttinger liquid fixed point

We calculate the single-particle spectral function A (k, omega) of a one-dimensional Luttinger liquid by means of a functional renormalization group (RG) approach. Given an infrared energy cutoff Lambda = Lambda_0 e^{- l}, our approach yields the spectral function in the scaling form, A_{\Lambda} (k_F + p, omega) = tau Z_l tilde{A}_l (p xi, omega tau), where k_F is the Fermi momentum, Z_l is the wave-function renormalization factor, tau = 1 / \Lambda is the time scale and xi = v_F / \Lambda is the length scale associated with Lambda. At the Luttinger liquid fixed point (l rightarrow infty) our RG result for A (k, omega) exhibits the correct anomalous scaling properties, and for k = \pm k_F agrees exactly with the well-known bosonization result at weak coupling. Our calculation demonstrates that the field rescaling is essential for obtaining the crossover from Fermi liquid behavior to Luttinger liquid behavior from a truncation of the hierarchy of exact RG flow equations as the infrared cutoff is reduced.Comment: 15 pages, 5 figure

Dynamic structure factor of Luttinger liquids with quadratic energy dispersion and long-range interactions

We calculate the dynamic structure factor S (omega, q) of spinless fermions in one dimension with quadratic energy dispersion k^2/2m and long range density-density interaction whose Fourier transform f_q is dominated by small momentum-transfers q << q_0 << k_F. Here q_0 is a momentum-transfer cutoff and k_F is the Fermi momentum. Using functional bosonization and the known properties of symmetrized closed fermion loops, we obtain an expansion of the inverse irreducible polarization to second order in the small parameter q_0 / k_F. In contrast to perturbation theory based on conventional bosonization, our functional bosonization approach is not plagued by mass-shell singularities. For interactions which can be expanded as f_q = f_0 + f_0^{2} q^2/2 + O (q^4) with finite f_0^{2} we show that the momentum scale q_c = 1/ | m f_0^{2} | separates two regimes characterized by a different q-dependence of the width gamma_q of the collective zero sound mode and other features of S (omega, q). For q_c << q << k_F we find that the line-shape in this regime is non-Lorentzian with an overall width gamma_q of order q^3/(m q_c) and a threshold singularity at the lower edge.Comment: 33 Revtex pages, 17 figure

Logistic analyses for complicated bets

The problem discussed is estimating the probabilities of finishing order in a horse race based on simple winning probabilities only. Some models have been proposed based on different assumptions of running time distributions of horses for this problem. However, no detailed data analyses for comparing these models can be found. In this paper, we apply logit models and utilize several data sets and bet types to study the goodness of these models in detail. These complicated bet types include exacta, trifecta and quinella bets. Formal tests for non-nested models are applied whenever possible. Our empirical results suggest that the model based on independent normal running times is better than the others. To predict the winning probabilities of horses, many previous studies suggested that the win bet fractions are reasonable estimates. We utilize this information of winning probabilities to predict the ordering probabilities. Harville (1973) predict the ordering probabilities. Harville (1973) proposed a simple and convenient model that bettors can easily use in practice. In fact, the betting system proposed by Hausch, Ziemba & Rubinstein (1981) used the Harville model in determining the optimal bet amounts to place and show. The Harville model is equivalent to assuming that the running times are exponentially distributed. Henery (1981) and Stern (1990) assumed normal and gamma distributions respectively for the running times. Based on a likelihood approach, this paper considers the comparison among these models and the particular bet fractions. One conclusion is that in exacta and trifecta bets, no method based on the win bet fractions can outperform the exacta and trifecta bet fractions in predicting the relevant ordering probabilities.postprin

Modelling the winning probabilities

Previous studies conclude that a favourite-longshot bias exists in win betting at horse race tracks and this is interpreted as risk-preferring behaviour. However, the statistical techniques used contain certain weaknesses, including the neglect of the necessary correlation between bet fractions which must sum to one in every race. We propose some classes of logit models to analyse the relationship between winning probabilities and the bet fractions. A simple logit model is proposed after going through a modelling process and. by Cox's test, it is preferred to previous models (Ali (1977) and Asch, Malkiel & Quandt (1984)). Empirical results are obtained for several racetracks in the U.S., Hong Kong, Japan and China. No strong conclusion for risk preference can be maintained.postprin

Ferromagnetic Luttinger Liquids

We study weak itinerant ferromagnetism in one-dimensional Fermi systems using perturbation theory and bosonization. We find that longitudinal spin fluctuations propagate ballistically with velocity v_m << v_F, where v_F is the Fermi velocity. This leads to a large anomalous dimension in the spin-channel and strong algebraic singularities in the single-particle spectral function and in the transverse structure factor for momentum transfers q ~ 2 Delta/v_F, where 2 Delta is the exchange splitting.Comment: 4 pages, 3 figure

COMPETITION AMONG HOSPITALS AND ITS MEASUREMENT: THEORY AND A CASE STUDY

Our paper provides several insights on the characteristics of the concept of “Poles d’Excellence Rurale” (PER) through bilateral comparisons with that of Competitive Pole (CP) and cluster. The concept of PER is a French government’ initiative designed for the development of rural areas similar to that of the Competitive Pole. We emphasize important particularities of these concepts by analyzing some of their similarities and major differences.Pole d’Excellence Rurale, Competitive Pole, cluster, rural development

The Randomized Shortened Dental Arch Study: Tooth Loss

The evidence concerning the management of shortened dental arch (SDA) cases is sparse. This multi-center study was aimed at generating data on outcomes and survival rates for two common treatments, removable dental prostheses (RDP) for molar replacement or no replacement (SDA). The hypothesis was that the treatments lead to different incidences of tooth loss. We included 215 patients with complete molar loss in one jaw. Molars were either replaced by RDP or not replaced, according to the SDA concept. First tooth loss after treatment was the primary outcome measure. This event occurred in 13 patients in the RDP group and nine patients in the SDA group. The respective Kaplan-Meier survival rates at 38 months were 0.83 (95% CI: 0.74-0.91) in the RDP group and 0.86 (95% CI: 0.78-0.95) in the SDA group, the difference being non-significant