Efficient Portfolio Selection

Merak believed that an efficient frontier analysis method that combined the robustness of the Monte Carlo approach with the confidence of the Markowitz approach would be a very powerful tool for any industry. However, it soon became clear that there are other ways to address the problem that do not require a Monte Carlo component. Three subgroups were formed, and each developed a different approach for solving the problem. These were the Portfolio Selection Algorithm Approach, the Statistical Inference Approach, and the Integer Programming Approach

On Lossless Compression of 1-bit Audio Signals

In this paper we consider the problem of lossless compression of 1-bit audio signals. We study the properties of some existing proposed solutions. We also discuss possible improvements. Other methods have been considered, and the results are reported

Dynamics of Large Mining Excavators

In this report, parametric and non-parametric regression models and their suitability to determining the mass in the bucket of large mining excavators are compared. Although the problem of determining the force on the bucket teeth could be modelled in a similar fashion, it is not clear that there is a single force acting on the teeth and not a more complex contact between the bucket and the ground, so the report focuses on the problem of determining the payload mass. The parametric model is found to be the better approach, because although a detailed model of each type of machine must be developed, an exact measurement of the model parameters is not required, and the model requires far less data for training that the non-parametric one

Constrained isentropic models of tropospheric dynamics

A two-layer isentropic model consisting of a tropospheric and a stratospheric layer is simplified using perturbation analysis while preserving the Hamiltonian structure. The first approximation applies when the thickness of the stratospheric layer is much larger than the tropospheric layer, such that the Froude number of the stratospheric layer is a small number. Using leading-order perturbation theory in the Hamiltonian formulation yields a conservative one-and-a-half isentropic layer model. Furthermore, when the Rossby number in this active lower layer is small, Hamiltonian theory either directly leads to (Salmon's) L1-dynamics using a geostrophic constraint, following a more concise derivation than shown before, or yields quasigeostrophic dynamics. The extension to multilayer isentropic balanced models for use in idealized climate forecasting is discussed

About the Non Relativistic Structure of the AdS/CFT Superalgebras

The property of the conformal algebra to contain the Schr\"odinger algebra in one less space dimension is extended to the supersymmetric case. More precisely, we determine the counterpart of any field theory admissible super conformal algebra. Even if each type of superalgebra provides a different solution, its basis decomposition into two copies of the super Schr\"odinger algebra, differing only by their super Heisenberg part, remains valid in all the cases, so generalizing a feature already observed in the non supersymmetric conformal case.Comment: 30 page

The Formation, Structure, and Stability of a Shear Layer in a Fluid with Temperature-Dependent Viscosity

The presence of viscosity normally has a stabilizing effect on the flow of a fluid. However, experiments show that the flow of a fluid might form shear bands or shear layers, narrow bands in which the velocity of the fluid changes sharply. In general, adiabatic shear layers are observed not only in fluids but also in thermo-plastic materials subject to shear at a high-strain rate and in combustion. Therefore there is widespread interest in modeling the formation of shear layers. In this paper we investigate the basic system of conservation laws for a one-dimensional flow with temperature-dependent viscosity using a combination of analytical and numerical tools. We present results to substantiate the claim that the formation of shear layers is due to teh fact that viscosity decreases sufficiently quickly as temperature increases and analyze the structure and stability properties of the layers

Correlating Lepton Flavour (Universality) Violation in BB Decays with μ→eγ\mu\to e\gamma using Leptoquarks

Motivated by the measurements of $b\to s\ell^+\ell^-$ transitions, including $R(K)$ and $R(K^*)$, we examine lepton flavour (universality) violation in $B$ decays and its connections to $\mu\to e\gamma$ in generic leptoquark models. Considering all 10 representations of scalar and vector leptoquarks under the Standard Model gauge group we compute the tree-level matching for semileptonic $b$-quark operators as well as their loop effects in $\ell\to\ell^\prime\gamma$. In our phenomenological analysis we correlate $R(K)$, $R(K^*)$ and the other $b\to s\mu^+\mu^-$ data to $\mu\to e\gamma$ and $b\to s\mu e$ transitions for the three leptoquark representations that generate left-handed currents in $b\to s\ell^+\ell^-$ transitions and, therefore, provide a good fit to data. We find that while new physics contributions to muons are required by the global fit, also couplings to electrons can be sizeable without violating the stringent bounds from $\mu\to e\gamma$. In fact, if the effect in electrons in $b\to s\ell^+\ell^-$ has opposite sign than the effect in muons the bound from $\mu\to e\gamma$ can always be avoided. However, unavoidable effects in $b\to s\mu e$ transitions (i.e. $B_s\to\mu e$, $B\to K\mu e$, etc.) appear which are within the reach of LHCb and BELLE II.Comment: 17 pages, 2 figures and 5 tables, version accepted for publication in PR

Tripwire Detection for Landmines

Pre-processed Radon transform-based detection methods were identified as the most viable technique. There are some issues that arose when testing the various methods. A) The 'log' edge detection in Matlab seemed better than the default 'sobel' method, but is still worth considering other edge detection algorithms that might deal more effectively with noisy or grainy image. B) The algorithm works best when the wire is horizontal and spans the length of the image. If constrained to thin-strip type images then a simple solution is to run the algorithm twice, once with the image and a second time with the same image rotated through 45 degrees

STUDI FORMULASI SEDIAN MASKER PEEL OFF DARI EKSTRAK ETANOL DAUN BELIMBING WULUH (Averrhoa blimbi L.)

ABSTRACT The leaves of Starfruit (Averrhoa bilimbi L.) contain active anti-acne compounds. This study aims to determine the study of the ethanol extract formulation of starfruit leaves as a peel off mask. The research method is experimental. Evaluation of peel off mask preparation included organoleptic observation (smell and color), and irritation test for volunteers. This research was conducted at the Chemical Laboratory of AKAFARMA Banda Aceh and the FKIP Kimia Unsyiah laboratory. The sample used was a peel off mask with four formulas, namely blank (F0), a formula with the addition of 7% (FI), 9% (FII), and 11% (FIII) ethanol extract concentrations. The results showed that all peel off mask formulas were homogeneous. The observation result of the peel off mask showed that the color and smell of the mask preparation did not change for 4 weeks of storage at room temperature. The color for F0 is colorless (clear) while the formula for FI and FII is light brown and FIII is dark brown. The smell for F0 smells of ethanol while FI, FII, and FIII have a distinctive smell, namely the smell of starfruit leaves. This shows that the resulting peel off mask is stable. The peel-off mask did not irritate the skin of 12 volunteers. So, the peel off mask of ethanol extract of starfruit leaves (Averrhoa bilimbi L.) is safe to use. Keywords: formulation, peel off mask, and starfruit leaves, Study of Peel off Mask Formulation from Ethanol Extract of Wuluh Starfruit Leaves, article, symposium, national