Evaluation of the Feasibility of Parametric Estimation in Devops Continuous Planning

DevOps aims to shorten project schedules, boost productivity, and manage quick development-deployment cycles without compromising business or quality. It necessitates good sprint management. Continuous Testing detects integration issues considerably earlier in the development process. It reduces the cost of defect resolution and frees up the tester's time for exploratory testing and value-added activities. Continuous testing allows for more frequent, shorter, and more efficient releases. It ties people, technology, and processes together. Continuous Planning, particularly effort estimation, is closely linked to Continuous Testing. This paper examines the state of the art in DevOps parametric estimate in continuous planning, as well as the difficulties and best practises. Keywords: Project, Testing, Continuous, Planning

Sibling Models, Categorical Outcomes, and the Intra-Class Correlation

In sibling models with categorical outcomes the question arises of how best to calculate the intraclass correlation, ICC. We show that, for this purpose, the random effects linear probability model is preferable to a random effects non-linear probability model, such as a logit or probit. This is because, for a binary outcome, the ICC derived from a random effects linear probability model is a non-parametric estimate of the ICC, equivalent to a statistic called Cohen’s κ. Furthermore, because κ can be calculated when the outcome has more than two categories, we can use the random effects linear probability model to compute a single ICC in cases with more than two outcome categories. Lastly, ICCs are often compared between groups to show the degree to which sibling differences vary between groups: we show that when the outcome is categorical these comparisons are invalid. We suggest alternative measures for this purpose.

Evidence for radially independent size growth of early-type galaxies in clusters

It is not well understood whether the growth of early-type cluster galaxies proceeds inside-out, outside-in, or at the same pace at all radii. In this work we measured the galaxy size, defined by the radius including 80% of the galaxy light, non-parametrically. We also determined a non-parametric estimate of galaxy light concentration, which measures the curvature of the surface brightness profile in the galaxy outskirts. We used an almost random sampling of a mass-limited sample formed by 128 morphologically early-type galaxies in clusters with log M/M⊙ ≳ 10.7 spanning the wide range 0.17 < z < 1.81. From these data we derived the size-mass and concentration-mass relations, as well as their evolution. At 80% light radius, early-type galaxies in clusters are about 2.7 times larger than at 50% radius at all redshifts, and close to de Vaucouleurs profiles in the last 10 Gyr. While between z = 2 and z = 0 both half-light and 80% light sizes increase by a factor of 1.7, concentration stays constant within 2%, that is to say the size growth of early-type galaxies in cluster environments proceeds at the same pace at both radii. Existing physical explanations proposed in the literature are inconsistent with our results, demonstrating the need for dedicated numerical simulations to identify the physical mechanism affecting the galaxy structure.

Russian Stock Index volatility: Oil and sanctions

Since 2014, the Russian stock market has been under pressure due to both sanctions and a sharp drop in oil prices, which led to its increased volatility. This paper analyzes the impact of the price volatility of Brent oil and sanctions on the volatility of the Russian stock index RTS. Under volatility the paper understands both its parametric estimate obtained from the GARCH model estimation as well as non-parametric estimate — realized volatility. To estimate the effect of oil price volatility and sanctions, several cointegrated regressions were analyzed. The robustness of the results in relation to the choice of volatility assessment is demonstrated. The results show that RTS index volatility still depends on oil prices volatility in 2007—2018. This dependence is most pronounced in the periods of crisis. The paper also demonstrates the adjustment of the Russian stock market to the previous sanctions, which calls into question their long-term efficiency.

A numerical algorithm for fully nonlinear HJB equations: An approach by control randomization

We propose a probabilistic numerical algorithm to solve Backward Stochastic Differential Equations (BSDEs) with nonnegative jumps, a class of BSDEs introduced in [`Feynman–Kac representation for Hamilton–Jacobi–Bellman IPDE', Ann. Probab., to appear] for representing fully nonlinear HJB equations. This includes in particular numerical resolution for stochastic control problems with controlled volatility, possibly degenerate. Our backward scheme, based on least-squares regressions, takes advantage of high-dimensional properties of Monte Carlo methods, and also provides a parametric estimate in feedback form for the optimal control. A partial analysis of the algorithm error is presented, as well as numerical tests on the problem of option superreplication with uncertain volatilities and/or correlations, including a detailed comparison with the numerical results from the alternative scheme proposed in [J. Comput. Finance 14 (2011), 37–71].

Valuing preferences for the removal of a disamenity from the Port Elizabeth harbour

This paper examines the Nelson Mandela Bay public’s willingness to pay (WTP) for the removal of a local undesirable land use, the manganese ore dumps and the oil tank farm situated within the boundaries of the Port Elizabeth harbour, Eastern Cape, South Africa, by means of the contingent valuation method. Both a non-parametric and parametric estimate of the WTP is derived. Estimated WTP for the removal of this disamenity ranges from R47.09 to R93.21 per household. The aggregate WTP ranges from R13 489 683 to R26 701 496. Due to the sensitivity of the parametric estimate of WTP to functional form specification and the distribution of the random part of preferences, the less restricted non-parametric WTP estimate (R47.09) is more appropriate. The results of this study show that policy-makers should take heed of the importance communities attach to the location of pollution-creating activities in urban areas.