Investors\u27 Asset Allocations versus Life-Cycle Funds

Life-cycle funds, among the newest asset allocation fund offerings, are managed according to investors\u27 time horizons and risk tolerances. Partly in response to the appearance of these funds, we examined the relationships among the risk in individual investors\u27 portfolios, their financial-planning time horizons, and their risk tolerances. Generally, we found that portfolio risk increases as time horizon and willingness to take risk increase. This relationship held when we used willingness to take risk increase. This relationship held when we used multivariate analysis. Additional factors related to portfolio risk were found to be the investors\u27 expectations of a future economic downtown, age, education, and marital status

Model-based prognosis for intergranular corrosion

Among the advantages of Aluminium-based alloys for structural use is their corrosion resistance. However, while Aluminium alloys are highly resistant to uniform (general) corrosion, they are much more susceptible to types of localised corrosion, especially intergranular corrosion, which is a localised attack along the grain boundaries which leaves the grains themselves largely unaffected. In order to estimate the progress of such corrosion in a given sample, it is considered possible to generate a numerical model of some sort. While there has been much effort spent in the development of electrochemistry-based models, the use of grey and black-box models remains largely unexplored. One exception to this is the use of Cellular Automata (CA) models which have recently been exploited to model the progression of uniform corrosion. The object of the current paper is to apply the CA methodology to the case of intergranular corrosion. The first phase of the work has been concerned with generating appropriate CA rules which can qualitatively reproduce observed physics, and this work is reported here. A model is proposed which shows qualitative agreement with experimental data on the advance of the corrosion front

Frequency-Based Monitoring of Small-Scale Explosive Volcanic Activity

Strombolian activity is one of the most common types of volcanic activity. When this activity occurs at remote volcanoes it often goes undetected and cannot be monitored easily or safely by direct methods. Satellite remote sensing can be useful in the routine monitoring of this activity. Numerous remote volcanoes in the North Paci c exhibit Strombolian activity, often as a precursor to more vigorous activity which can a ect communities and transportation. Factors a ecting the visibility the explosions include satellite and crater geometry, time of image capture, and most importantly, weather. These factors eliminate a signi cant number of satellite passes. The remaining passes are used to calculate the probability of a clear view at the volcano and the likelihood of detecting an explosion. All of these factors are used to detect changes in relative frequency of explosions

Comparison of Breien and Canonball Volcanic Tuffs in Southern North Dakota

Volcanic tuffs of Cretaceous age are found sandwiched in many outcrops in southwestern North Dakota. The lateral extent of many of these tuffs has been mapped, but distinguishing discrete tuffs is a work in progress. This report looks at two tuffs found along the Cannonball River south of Bismarck. The Breien Tuff was collected in southeastern Morton County and the Cannonball Tuff was collected in northwestern Sioux County, but research had not yet been done to determine whether these two tuffs are distinct, or if one is merely an extension of the other. The proximity of the two sample sites allows the possibility that the Breien Tuff may be an extension of the Cannonball Tuff. In order to distinguish the tuffs multiple comparative and analytical tests must be performed on both tuffs. Conclusions were made about the possible distinction or correlation of the Cannonball and Breien Tuffs using grain size analysis, x-ray diffraction, magnetic separation, and grain mount petrographic analysis. The Breien and Cannonball Tuffs have few different properties when examined by the unaided eye. By the methods available for this research, insufficient evidence was found to show that the Cannonball Tuff and Breien Tuff were from the same depositional episode. However, further analytical tests of the two tuffs could determine the distinctness of these two tuffs. Scanning electron microscopy, as well as trace element and glass grain chemical analysis are some methods that could further the fingerprinting of these tuffs

Bayesian System Identification of Nonlinear Systems: Informative Training Data through Experimental Design

This paper addresses the situation where one is performing Bayesian system identification on a nonlinear dynamical system using a set of experimentally - obtained training data. To be more specifi c, an investigation is performed to find the optimum form of excitation that should be used during generation of the training data. To that end, the Shannon entr opy is used as an information measure such that, through analysing the information content of t he posterior parameter distribution, the `informativeness' of different sets of training data can be assessed. In the current work the form of excitation is parameterised thus allowing the choosing of an appropriate excitation to be phrased as an optimisat ion problem (where one is aiming to maximise the information content of the training data)

Emerging trends in optimal structural health monitoring system design: From sensor placement to system evaluation

This paper presents a review of advances in the field of Sensor Placement Optimisation (SPO) strategies for Structural Health Monitoring (SHM). This task has received a great deal of attention in the research literature, from initial foundations in the control engineering literature to adoption in a modal or system identification context in the structural dynamics community. Recent years have seen an increasing focus on methods that are specific to damage identification, with the maximisation of correct classification outcomes being prioritised. The objectives of this article are to present the SPO for SHM problem, to provide an overview of the current state of the art in this area, and to identify promising emergent trends within the literature. The key conclusions drawn are that there remains a great deal of scope for research in a number of key areas, including the development of methods that promote robustness to modelling uncertainty, benign effects within measured data, and failures within the sensor network. There also remains a paucity of studies that demonstrate practical, experimental evaluation of developed SHM system designs. Finally, it is argued that the pursuit of novel or highly efficient optimisation methods may be considered to be of secondary importance in an SPO context, given that the optimisation effort is expended at the design stage

Simplifying transformations for nonlinear systems: Part I, an optimisation-based variant of normal form analysis

This paper introduces the idea of a ‘simplifying transformation’ for nonlinear structural dynamic systems. The idea simply stated; is to bring under one heading, those transformations which ‘simplify’ structural dynamic systems or responses in some sense. The equations of motion may be cast in a simpler form or decoupled (and in this sense, nonlinear modal analysis is encompassed) or the responses may be modified in order to isolate and remove certain components. It is the latter sense of simplification which is considered in this paper. One can regard normal form analysis in a way as the removal of superharmonic content from nonlinear system response. In the current paper, this problem is cast in an optimisation form and the differential evolution algorithm is used

Competing Interactions among Supramolecular Structures on Surfaces

A simple model was constructed to describe the polar ordering of non-centrosymmetric supramolecular aggregates formed by self assembling triblock rodcoil polymers. The aggregates are modeled as dipoles in a lattice with an Ising-like penalty associated with reversing the orientation of nearest neighbor dipoles. The choice of the potentials is based on experimental results and structural features of the supramolecular objects. For films of finite thickness, we find a periodic structure along an arbitrary direction perpendicular to the substrate normal, where the repeat unit is composed of two equal width domains with dipole up and dipole down configuration. When a short range interaction between the surface and the dipoles is included the balance between the up and down dipole domains is broken. Our results suggest that due to surface effects, films of finite thickness have a none zero macroscopic polarization, and that the polarization per unit volume appears to be a function of film thickness.Comment: 3 pages, 3 eps figure

Fueling the Credit Crisis: Who Uses Consumer Credit and What Drives Debt Burden?

Excessive household debt contributed to the worst recession in decades. Insights about borrowing and spending behavior can inform economic recovery forecasts, policy decisions, and financial education. This study identifies life cycle and credit attitude as key determinants of who uses debt. Younger households are more likely to borrow for consumption, as are those who believe that it is all right to borrow to purchase luxury goods or cover living expenses. Furthermore, households that condone borrowing for these purposes have a higher consumer debt burden. Debt capacity (or creditworthiness) and financial discipline are also significant factors in determining household debt use