Portfolio optimisation models and properties of return distributions

Mean-risk models have been widely used in portfolio optimisation. However, such models may produce portfolios that are dominated with respect to second order stochastic dominance and therefore not optimal for rational and risk-averse investors. This paper considers the problem of constructing a portfolio which is nondominated with respect to second order stochastic dominance and whose return distribution has specified desirable properties. The problem is multi-objective and is transformed into a single objective problem by using the reference point method, in which target levels, known as aspiration points, are specified for the objective function values. A model is proposed in which the aspiration points relate to ordered return outcomes of the portfolio return. The model is extended by additionally specifying reservation points, which act pre-emptively in the optimisation. The theoretical properties of the models are studied. The performance of the models on real data drawn from the Hang Seng index is also investigated

Carbon deposition model for oxygen-hydrocarbon combustion. Task 6: Data analysis and formulation of an empirical model

The formation and deposition of carbon (soot) was studied in the Carbon Deposition Model for Oxygen-Hydrocarbon Combustion Program. An empirical, 1-D model for predicting soot formation and deposition in LO2/hydrocarbon gas generators/preburners was derived. The experimental data required to anchor the model were identified and a test program to obtain the data was defined. In support of the model development, cold flow mixing experiments using a high injection density injector were performed. The purpose of this investigation was to advance the state-of-the-art in LO2/hydrocarbon gas generator design by developing a reliable engineering model of gas generator operation. The model was formulated to account for the influences of fluid dynamics, chemical kinetics, and gas generator hardware design on soot formation and deposition

A two-stage stochastic programming with recourse model for determining robust planting plans in horticulture

A two-stage stochastic programming with recourse model for the problem of determining optimal planting plans for a vegetable crop is presented in this paper. Uncertainty caused by factors such as weather on yields is a major influence on many systems arising in horticulture. Traditional linear programming models are generally unsatisfactory in dealing with the uncertainty and produce solutions that are considered to involve an unacceptable level of risk. The first stage of the model relates to finding a planting plan which is common to all scenarios and the second stage is concerned with deriving a harvesting schedule for each scenario. Solutions are obtained for a range of risk aversion factors that not only result in greater expected profit compared to the corresponding deterministic model, but also are more robust

Anxiety, depression, and fear of dependency in middle and older adults

Negative stereotypes of aging, such as dependency, tend to paint a picture of older adults as frail or a burden on society. This study aimed to explore the relationship between the Fear of Dependency Scale and anxiety and depression, evaluating gender, age, and physical health as moderators. Findings suggest that age moderated the relationship between fear of dependency and depression and anxiety in women, with middle-aged women reporting the highest levels of depression and anxiety. Similarly, poor physical health in women with high fear of dependency being related to higher levels of depression and anxiety. Fear of dependency was related to higher levels of depression, but not anxiety in men. Age did not moderate the relationship between fear of dependency and mental health measures, but physical health did moderate the relationship. Men with poor perceived health and a high fear of dependency reported higher levels of depression

Debating Development Help: NGO Fieldworker Perspectives on Street and Urban Poor Children in Ghana

This ethnographic investigation of the non-governmental organization (NGO) Catholic Action for Street Children (CAS) questions the cultural appropriateness of its policies and practices. By situating CAS in a historical context of colonialism and structural adjustment reforms, I show how it is responsive to a legitimating environment that consists of private donors, international finance institutions, and the Ghanaian government, all of which put pressure on CAS to specifically target street children and to adopt a policy of choice that places primary responsibility for development on the individual child. I argue that the legitimating environment is neoliberal in orientation, especially with respect to who is identified as a recipient of aid and what type of aid the recipient should receive, and which is further connected to a global transformation in representation from the street child as innocent victim to one who is more like an adult and so responsible for his or her own choices. Through an analysis of the perspectives of CAS’s own fieldworkers, I argue that the conceptualization of street children as miniature adults promotes policies that help only more advantaged street children, masks social inequalities, and does not include children’s support networks in a formulation of aid. Based on my findings, I recommend a more participatory approach that includes fieldworkers’ ideas and perspectives in the design and implementation of CAS policies

Unethical aspects of homeopathic dentistry

In the last year there has been a great deal of public debate about homeopathy, the system of alternative medicine whose main principles are that like cures like and that potency increases relative to dilution. The House of Commons Select Committee on Science and Technology concluded in November 2009 that there is no evidence base for homeopathy, and agreed with some academic commentators that homeopathy should not be funded by the NHS. While homeopathic doctors and hospitals are quite commonplace, some might be surprised to learn that there are also many homeopathic dentists practising in the UK. This paper examines the statements made by several organisations on behalf of homeopathic dentistry and suggests that they are not entirely ethical and may be in breach of various professional guidelines

Advanced Biofuel Production in Louisiana Sugar Mills: an Application of Real Options Analysis

In order to more fully study the risks and uncertainty involved in cellulosic ethanol production, we examine a simulated plant in South Louisiana using Real Options Analysisreal options, risk, uncertainty, cellulosic ethanol, energy cane, sorghum, bagasse, simulation, Agribusiness, Agricultural Finance, Production Economics, Resource /Energy Economics and Policy, Risk and Uncertainty, q42, q14, q16, d81, g31,

R-matrix calculations of electron impact electronic excitation of BeH

The R-matrix method is used to perform high-level calculations of electron collisions with beryllium mono-hydride at its equilibrium geometry with a particular emphasis on electron impact electronic excitation. Several target and scattering models are considered. The calculations were performed using (1) the UKRMol suite which relies on the use of Gaussian type orbitals (GTOs) to represent the continuum and (2) using the new UKRMol+ suite which allows the inclusion of B-spline type orbitals in the basis for the continuum. The final close-coupling scattering models used the UKRMol+ code and a frozen core, valence full configuration interaction, method based on a diffuse GTO atomic basis set. The calculated electronic properties of the molecule are in very good agreement with state-of-the-art electronic structure calculations. The use of the UKRMol+ suite proved critical since it allowed the use of a large R-matrix sphere (35 Bohr), necessary to contain the diffuse electronic states of the molecule. The corresponding calculations using UKRMol are not possible due to numerical problems associated with the combination of GTO-only continuum and a large R-matrix sphere. This work provides the first demonstration of the utility and numerical stability of the new UKRMol+ code. The inelastic cross sections obtained here present a significant improvement over the results of earlier studies on BeH

Assessment of Uncertainty in the Determination of Kinetic Reaction Parameters for Polymeric Materials

The use of thermogravimetric analysis to obtain data describing the thermal response of a polymeric resin with temperature. This data can then be used to obtain activation energy and pre-exponential factor used in an Arrhenius representation of material ablation. The methods which allow to assess the uncertainties associated with the experimental determination of activation energy and pre-exponential factor are employed