Multi-objective integer programming: An improved recursive algorithm

This paper introduces an improved recursive algorithm to generate the set of all nondominated objective vectors for the Multi-Objective Integer Programming (MOIP) problem. We significantly improve the earlier recursive algorithm of \"Ozlen and Azizo\u{g}lu by using the set of already solved subproblems and their solutions to avoid solving a large number of IPs. A numerical example is presented to explain the workings of the algorithm, and we conduct a series of computational experiments to show the savings that can be obtained. As our experiments show, the improvement becomes more significant as the problems grow larger in terms of the number of objectives.Comment: 11 pages, 6 tables; v2: added more details and a computational stud

The Impact of Natural Disasters on Children in the United States

The goal of this paper is to consider the unique experiences of children in natural disaster preparedness, response and recovery. This paper seeks to stress the importance of taking special interest in children’s needs during times of crisis. Through a case study of Hurricane Katrina, an exploration of the disservice children receive in noted. In closing, a possible solution-oriented approach is discussed

Estimating the association between Facebook adoption and well-being in 72 countries

Social media's potential effects on well-being have received considerable research interest, but much of past work is hampered by an exclusive focus on demographics in the Global North and inaccurate self-reports of social media engagement. We describe associations linking 72 countries' Facebook adoption to the well-being of 946 798 individuals from 2008 to 2019. We found no evidence suggesting that the global penetration of social media is associated with widespread psychological harm: Facebook adoption predicted life satisfaction and positive experiences positively, and negative experiences negatively, both between countries and within countries over time. Nevertheless, the observed associations were small and did not reach a conventional 97.5% one-sided credibility threshold in all cases. Facebook adoption predicted aspects of well-being more positively for younger individuals, but country-specific results were mixed. To move beyond studying aggregates and to better understand social media's roles in people's lives, and their potential causal effects, we need more transparent collaborative research between independent scientists and the technology industry

A multiverse analysis of the associations between internet use and well-being

Internet technologies’ and platforms’ potential psychological consequences remain debated. While these technologies have spurred new forms of commerce, education, and leisure, many are worried that they might negatively affect individuals by, for example, displacing time spent on other healthy activities. Relevant findings to date have been inconclusive and of limited geographic and demographic scope. We examined whether having (mobile) internet access or actively using the internet predicted eight well-being outcomes from 2006 to 2021 among 2,414,294 individuals across 168 countries. We first queried the extent to which well-being varied as a function of internet connectivity. Then, we examined these associations’ robustness in a multiverse of 33,792 analysis specifications. 84.9% of these resulted in positive and statistically significant associations between internet connectivity and well-being. These results indicate that internet access and use predict well-being positively and independently from a set of plausible alternatives

Optimising a nonlinear utility function in multi-objective integer programming

In this paper we develop an algorithm to optimise a nonlinear utility function of multiple objectives over the integer efficient set. Our approach is based on identifying and updating bounds on the individual objectives as well as the optimal utility value. This is done using already known solutions, linear programming relaxations, utility function inversion, and integer programming. We develop a general optimisation algorithm for use with k objectives, and we illustrate our approach using a tri-objective integer programming problem.Comment: 11 pages, 2 tables; v3: minor revisions, to appear in Journal of Global Optimizatio

A Rapid Method for Determining the Oxidative Stability of Oils Suitable for Breeder Size Samples

A method utilizing thin-layer chromatography with a flame ionization detector (TLC-FID) was developed for assessing the stability of breeder’s oil seed samples based on the formation of polar compounds. The results showed a linear relationship between peroxide value (PV) and the content of polar material in the oxidized oil. Oil samples oxidized very readily on chromarods, even at low temperature, which is a particular advantage for antioxidant screening. At 45 °C, the oil oxidation rate was relatively low, but the relationship between the content of polar material and reaction time was linear. At 65 °C, if the content of polar material was below 50 %, the above relationship was still linear. At different temperatures, the action of tocopherol appeared to vary slightly. For example, at 65 °C, the oxidative stability of the oil sample was determined by the content of tocopherol, especially γ-tocopherol. At 45 and 55 °C, the oxidative stability was determined by both the content of tocopherol and polyunsaturated fatty acids. Of the tocopherol isomers, γ-tocopherol exhibited the highest antioxidant potency, consistent with the published literature. These results suggest that chromarods provide good media for monitoring oil oxidation for antioxidant screening. A particular advantage is the use of very small oil samples, usually 1–2 μL, and the ability to analyze multiple samples at the same time

Affective uplift during video game play:A naturalistic case study

Do video games affect players’ well-being? In this case study, we examined 162,325 intensive longitudinal in-game mood reports from 67,328 play sessions of 8,695 players of the popular game PowerWash Simulator. We compared players’ moods at the beginning of play session with their moods during play, and found that the average player reported 0.034 [0.032, 0.036] visual analog scale (VAS; 0-1) units greater mood during than at the beginning of play sessions. Moreover, we predict that 72.1% [70.8%, 73.5%] of similar players experience this affective uplift during play, and that the bulk of it happens during the first 15 minutes of play. We do not know whether these results indicate causal effects or to what extent they generalize to other games or player populations. Yet, these results based on in-game subjective reports from players of a popular commercially available game suggest good external validity, and as such offer a promising glimpse of the scientific value of transparent industry-academia collaborations in understanding the psychological roles of popular digital entertainment

Bilateral double-layered patella in a patient with advanced knee osteoarthritis

Double layered patella (DLP) is a rare anomaly of the patella that may go undiagnosed, especially in patients with progressive knee dysfunction and early degenerative changes. Clinical symptoms such as motion-dependent pain and anterior knee pain most typically occur in adolescents or young adults; however, gradually increasing pain and early generalised degenerative changes have also been seen in patients over 40 years old. Diagnosis of DLP could be difficult, especially in cases with coexisting arthrosis. DLP is considered to be pathognomonic for the diagnosis of multiple epiphyseal dysplasia and usually coexists with other anomalies seen in this syndrome, such as hip dysplasia. In extremely rare cases, DLP can occur as a solitary disorder. The prevalence of such cases, however, is unknown, and they could be easily misdiagnosed. Computed tomography and magnetic resonance imaging are the most sensitive radiological methods used in DLP diagnosis. This case report presents a case of a bilateral DLP incidentally found in a 47-year-old patient with advanced arthritis referred for arthroplasty because of increasing symptoms of knee joint failure with no other abnormalities recorded. An important goal of our case study is to raise the awareness of this abnormality with radiologists and orthopaedic surgeons