Average flow constraints and stabilizability in uncertain production-distribution systems

We consider a multi-inventory system with controlled flows and uncertain demands (disturbances) bounded within assigned compact sets. The system is modelled as a first-order one integrating the discrepancy between controlled flows and demands at different sites/nodes. Thus, the buffer levels at the nodes represent the system state. Given a long-term average demand, we are interested in a control strategy that satisfies just one of two requirements: (i) meeting any possible demand at each time (worst case stability) or (ii) achieving a predefined flow in the average (average flow constraints). Necessary and sufficient conditions for the achievement of both goals have been proposed by the authors. In this paper, we face the case in which these conditions are not satisfied. We show that, if we ignore the requirement on worst case stability, we can find a control strategy driving the expected value of the state to zero. On the contrary, if we ignore the average flow constraints, we can find a control strategy that satisfies worst case stability while optimizing any linear cost on the average control. In the latter case, we provide a tight bound for the cost

Predictors of enhancing human physical attractiveness: Data from 93 countries

People across the world and throughout history have gone to great lengths to enhance their physical appearance. Evolutionary psychologists and ethologists have largely attempted to explain this phenomenon via mating preferences and strategies. Here, we test one of the most popular evolutionary hypotheses for beauty-enhancing behaviors, drawn from mating market and parasite stress perspectives, in a large cross-cultural sample. We also test hypotheses drawn from other influential and non-mutually exclusive theoretical frameworks, from biosocial role theory to a cultural media perspective. Survey data from 93,158 human participants across 93 countries provide evidence that behaviors such as applying makeup or using other cosmetics, hair grooming, clothing style, caring for body hygiene, and exercising or following a specific diet for the specific purpose of improving ones physical attractiveness, are universal. Indeed, 99% of participants reported spending >10 min a day performing beauty-enhancing behaviors. The results largely support evolutionary hypotheses: more time was spent enhancing beauty by women (almost 4 h a day, on average) than by men (3.6 h a day), by the youngest participants (and contrary to predictions, also the oldest), by those with a relatively more severe history of infectious diseases, and by participants currently dating compared to those in established relationships. The strongest predictor of attractiveness-enhancing behaviors was social media usage. Other predictors, in order of effect size, included adhering to traditional gender roles, residing in countries with less gender equality, considering oneself as highly attractive or, conversely, highly unattractive, TV watching time, higher socioeconomic status, right-wing political beliefs, a lower level of education, and personal individualistic attitudes. This study provides novel insight into universal beauty-enhancing behaviors by unifying evolutionary theory with several other complementary perspectives

Validation of the Short Version (TLS-15) of the Triangular Love Scale (TLS-45) Across 37 Languages

Love is a phenomenon that occurs across the world and affects many aspects of human life, including the choice of, and process of bonding with, a romantic partner. Thus, developing a reliable and valid measure of love experiences is crucial. One of the most popular tools to quantify love is Sternberg’s 45-item Triangular Love Scale (TLS-45), which measures three love components: intimacy, passion, and commitment. However, our literature review reveals that most studies (64%) use a broad variety of shortened versions of the TLS-45. Here, aiming to achieve scientific consensus and improve the reliability, comparability, and generalizability of results across studies, we developed a short version of the scale—the TLS-15—comprised of 15 items with 5-point, rather than 9-point, response scales. In Study 1 (N = 7,332), we re-analyzed secondary data from a large-scale multinational study that validated the original TLS-45 to establish whether the scale could be truncated. In Study 2 (N = 307), we provided evidence for the three-factor structure of the TLS-15 and its reliability. Study 3 (N = 413) confirmed convergent validity and test–retest stability of the TLS-15. Study 4 (N = 60,311) presented a large-scale validation across 37 linguistic versions of the TLS-15 on a cross-cultural sample spanning every continent of the globe. The overall results provide support for the reliability, validity, and cross-cultural invariance of the TLS-15, which can be used as a measure of love components—either separately or jointly as a three-factor measure

Potential Impacts of Energy and Climate Policies on the U. S. Pulp and Paper Industry

Many energy and climate policies are being debated in the United States that could have significant impact upon the future of the pulp and paper industry. Five of these policies are examined here in terms of their possible directional influences on biomass energy and paper production: (1) a national renewable electricity standard, (2) a U.S. greenhouse gas cap and trade system, (3) stronger renewable fuels standards, (4) expanded state incentives for biomass pilot plants, and (5) more favorable taxation of forest property. The observed trends reinforce the value of forest product diversification through the addition of biomass power generation and transportation fuels/chemicals production as co-products of the pulp and paper industry. Therefore, directing capital expenditures to the increasingly cost-competitive and expanding biopower and biofuels markets would appear to have merit in anticipation of the promulgation of new energy and climate legislation. Accelerated investments in new facilities such as biorefineries and cogeneration units and in energy-efficiency upgrades would position the pulp and paper industry to profit from current trends and likely policy initiatives

Aircraft recovery model with flight time controllability

[No abstract available

A Combined Lagrangian, Linear Programming and Implication Heuristic for Large-Scale Set Partitioning Problems

Given a finite ground set, a set of subsets and costs on the subsets, the set partitioning problem is to find a minimum cost partition of the ground set. Many combinatorial optimization problems can be formulated as set partitioning problems. We present an approximation algorithm that produces high quality solutions in an acceptable amount of computation time. The algorithm is iterative and combines problem size reduction techniques, such as logical implications derived from feasibility and optimality conditions and reduced cost fixing, with a primal heuristic based on cost perturbations embedded in a Lagrangian dual framework. Computational experiments illustrate the effectiveness of the approximation algorithm. Keywords: set partitioning, preprocessing, linear programming, Lagrangian dual September 1995 1 Introduction Given a finite ground set, a set of subsets and costs on the subsets, the set partitioning problem is to find a minimum cost partition of the ground set. Let A be an..

Piecewise regression equations for estimating stature: an anthropometric study in Spanish females

In forensic anthropology, generic equations are generally preferred for estimation of stature. However, recent studies have demonstrated that regression equations specific to stature groups yield more accurate predictions. Almost all previous studies have been conducted on male subjects, and it is not currently known how well such equations work for females. Therefore, this study aims to test whether regression equations specific to stature groups work for females as well. To this end, a cross-sectional study was conducted to estimate stature on a sample of 351 Spanish adult females. The participants were randomized into a calibration group (n = 185) and a validation group (n = 166). Equations for stature estimation based on tibial length were developed in the calibration group, which was categorized according to stature (short, medium, and tall) using the 15th and 85th percentiles as cut-off points. The standard errors of the estimations (SEEs) for the group-specific regression equations (SEE = 2.35-2.66 cm) were lower than for the general formula derived for all participants of the calibration group (SEE = 3.46 cm). The specific equations resulted in smaller differences between estimated and recorded statures than the generic equation when we tested the equations with the validation group. Additionally, the SEE values of the stature-specific equations are lower compared to generic equations applied to other human populations. In conclusion, the group-specific equations from tibial length have high accuracy compared with previously derived equations for Spanish females and other populations. This procedure for estimating stature thereby improves the tools available to forensic scientists