Crime Around the World: Using Mathematical Modeling Techniques to Model Aggregated Worldwide Crime Rates

This aim of this study was to determine what affects aggregate crime rates around the world. This thesis used Mathematical Modeling techniques to build generalized linear models for homicide rates and burglary and housebreaking rates using the following predictive factors: economic indicators, education rates, government quality indicators, ethno-linguistic fractionalization, GDP per capita and its growth, drug consumption rates, and age and gender ratios. We used a series of factor selection techniques including linear and stepwise regressions, principal component analysis, and regression analysis to select factors to use to build final models of homicide and burglary and housebreaking

The growth of decagonal Al-Co-Ni single crystals as a function of chemical composition

Decaprismatic single crystals taken from a series of alloys of nominal compositions within Al65-77Co3-22Ni3-22 have been studied by means of x-ray diffraction techniques. The substitution of Co by Ni in increasing amounts changes the (pseudo)decagonal diffraction patterns drastically and indicates structural changes which range from a single-crystalline approximant via orientationally ordered nanodomain structures and quasiperiodic phases with different types of ordering phenomena, to a basic decagonal phase. A quantum phase diagram analysis shows a clear separation of the stability regions of the ternary systems described in this study and other decagonal phase

Cross-platform validation of notional baseline architecture models of naval electric ship power systems

To support efforts in assessing the relative merit of alternative power system architectures for future naval combatants, the Electric Ship Research and Development Consortium (ESRDC) has developed notional baseline models for each of the primary candidate architectures currently considered, medium-voltage DC (MVDC), conventional 60 Hz medium-voltage (MVAC), and high-frequency medium-voltage (HFAC). Initial efforts have focused on the development of a consistent set of component models, of which the system models can be comprised, and the basic definition of the system models. The broader objectives of the consortium, however, go beyond the definition of the baseline models. The focus is on the process by which the models are implemented in software and validated, the process by which the performance of the disparate system models are objectively and quantitatively assessed and compared, and, ultimately, the process by which the relative merits of the architectures may be assessed. This paper focuses specifically on cross-platform component validation.Center for Electromechanic

First-principles prediction of a decagonal quasicrystal containing boron

We interpret experimentally known B-Mg-Ru crystals as quasicrystal approximants. These approximant structures imply a deterministic decoration of tiles by atoms that can be extended quasiperiodically. Experimentally observed structural disorder corresponds to phason (tile flip) fluctuations. First-principles total energy calculations reveal that many distinct tilings lie close to stability at low temperatures. Transfer matrix calculations based on these energies suggest a phase transition from a crystalline state at low temperatures to a high temperature state characterized by tile fluctuations. We predict B$_{38}$Mg$_{17}$Ru$_{45}$ forms a decagonal quasicrystal that is metastable at low temperatures and may be thermodynamically stable at high temperatures.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Let

A remark on the trace-map for the Silver mean sequence

In this work we study the Silver mean sequence based on substitution rules by means of a transfer-matrix approach. Using transfer-matrix method we find a recurrence relation for the traces of general transfer-matrices which characterizes electronic properties of the quasicrystal in question. We also find an invariant of the trace-map.Comment: 5 pages, minor improvements in style and presentation of calculation

Waveform-level time-domain simulation comparison study of three shipboard power system architectures

Detailed waveform-level modeling and simulation of three alternative shipboard power system architectures is presented herein. The three system architectures are based on conventional 60Hz medium-voltage ac (MVAC), higherfrequency 240Hz medium-voltage ac (HFAC) and mediumvoltage dc (MVDC) technologies. To support the quantitative assessment and comparison of these three different power system architectures, each technology was modeled using a common representative, notional baseline ship. The baseline ship represents a multi-mission destroyer fitted with an 80MW next generation integrated power system (NGIPS). Modeling of each power system architecture is set forth along with simulation studies for three fault scenarios. Each of the three power system architectures was implemented within the MATLAB/ Simulink environment. Continuity of service was evaluated for each architecture along with a fault scenario using an operability metric. After a brief description of the three power system architectures and the operability metric, quantitative results are presented.Center for Electromechanic

Cognitive-behavioural treatment for weight loss in primary care : a prospective study

Questions under Study: Cognitive-behavioural treatment (CBT) is effective for weight loss in obese patients, but such programmes are difficult to implement in primary care. We assessed whether implementation of a community-based CBT weight loss programme for adults in routine care is feasible and prospectively assessed patient outcome. Patients and Methods: The weight loss programme was provided by a network of Swiss general practitioners in cooperation with a community centre for health education. We chose a five-step strategy focusing on structure of care rather than primarily addressing individual physician behaviour. A multidisciplinary core group of trained CBT instructors acted as the central element of the programme. Overweight and obese adults from the community (BMI >25 kg/m2) were included. We used a patient perspective to report the impact on delivery of care and assessed weight change of consecutive participants prospectively with a follow-up of 12 months. Results: Twenty-eight courses, with 16 group meetings each, were initiated over a period of 3 years. 44 of 110 network physicians referred patients to the programme. 147 of 191 study participants were monitored for one year (attrition rate: 23%). Median weight loss after 12 months for 147 completers was 4 kg (IQR: 1-7 kg; intention-to-treat analysis for 191 participants: 2 kg, IQR: 0-5 kg). Conclusions: The programme produced a clinically meaningful weight loss in our participants, with a relatively low attrition rate. Implementation of an easily accessible CBT programme for weight loss in daily routine primary care is feasible

Structure factors of harmonic and anharmonic Fibonacci chains by molecular dynamics simulations

The dynamics of quasicrystals is characterized by the existence of phason excitations in addition to the usual phonon modes. In order to investigate their interplay on an elementary level we resort to various one-dimensional model systems. The main observables are the static, the incoherent, and the coherent structure factor, which are extracted from molecular dynamics simulations. For the validation of the algorithms, results for the harmonic periodic chain are presented. We then study the Fibonacci chain with harmonic and anharmonic interaction potentials. In the dynamic Fibonacci chain neighboring atoms interact by double-well potentials allowing for phason flips. The difference between the structure factors of the dynamic and the harmonic Fibonacci chain lies in the temperature dependence of the phonon line width. If a bias is introduced in the well depth, dispersionless optic phonon bands split off.Comment: 12 pages, 15 figure

Magic numbers in the discrete tomography of cyclotomic model sets

We report recent progress in the problem of distinguishing convex subsets of cyclotomic model sets $\varLambda$ by (discrete parallel) X-rays in prescribed $\varLambda$-directions. It turns out that for any of these model sets $\varLambda$ there exists a `magic number' $m_{\varLambda}$ such that any two convex subsets of $\varLambda$ can be distinguished by their X-rays in any set of $m_{\varLambda}$ prescribed $\varLambda$-directions. In particular, for pentagonal, octagonal, decagonal and dodecagonal model sets, the least possible numbers are in that very order 11, 9, 11 and 13.Comment: 6 pages, 1 figure; based on the results of arXiv:1101.4149 [math.MG]; presented at Aperiodic 2012 (Cairns, Australia