Improved Online Algorithm for Weighted Flow Time

We discuss one of the most fundamental scheduling problem of processing jobs on a single machine to minimize the weighted flow time (weighted response time). Our main result is a $O(\log P)$-competitive algorithm, where $P$ is the maximum-to-minimum processing time ratio, improving upon the $O(\log^{2}P)$-competitive algorithm of Chekuri, Khanna and Zhu (STOC 2001). We also design a $O(\log D)$-competitive algorithm, where $D$ is the maximum-to-minimum density ratio of jobs. Finally, we show how to combine these results with the result of Bansal and Dhamdhere (SODA 2003) to achieve a $O(\log(\min(P,D,W)))$-competitive algorithm (where $W$ is the maximum-to-minimum weight ratio), without knowing $P,D,W$ in advance. As shown by Bansal and Chan (SODA 2009), no constant-competitive algorithm is achievable for this problem.Comment: 20 pages, 4 figure

Les nouveaux usages des générations internet : un défi pour les bibliothèques et les bibliothécaires

What are for libraries and librarians the consequences of new practices introduced by the digital natives regarding OPAC user interface, library web sites, ressource sharin

Improved and Deterministic Online Service with Deadlines or Delay

We consider the problem of online service with delay on a general metric space, first presented by Azar, Ganesh, Ge and Panigrahi (STOC 2017). The best known randomized algorithm for this problem, by Azar and Touitou (FOCS 2019), is $O(\log^2 n)$-competitive, where $n$ is the number of points in the metric space. This is also the best known result for the special case of online service with deadlines, which is of independent interest. In this paper, we present $O(\log n)$-competitive deterministic algorithms for online service with deadlines or delay, improving upon the results from FOCS 2019. Furthermore, our algorithms are the first deterministic algorithms for online service with deadlines or delay which apply to general metric spaces and have sub-polynomial competitiveness.Comment: Appears in STOC 202

The Multidimensional Impacts of External Price Shocks on the Algerian Economy by using of CGEM

The global economy has gone through the past ten years a severe recession triggered by the financial catastrophe and the collapse of the commercial and industrial activity in the world. This slowdown has weighed its effects on the growth of economies around the world. Algeria, which is not fully integrated into the international economy, knowledge and know likely in the near future indirect effects of the crisis, but in a less severe than in Europe. Algeria has all the potential human and material to be a pivotal country in development at the Euro-Mediterranean and Arab Africa. This requires a development based on a coherence and visibility in the economic policy of the State. We propose in this paper an analysis of the multidimensional impacts of external price shocks on the Algerian economy with particular focus of hydrocarbon revenue. An applied computable general equilibrium model (CGEM) is utilized in my study to simulate the Algerian economic impact by three scenarios. First is food import price increase by 25 percent (scenario1), second is the oil price decrease by 30 percent (scenario2) and the finally scenario that combines scenario 1 and 2simultanneously (scenario 3).The results depict the multidimensional impacts on major macroeconomic indicators from recession to economic instability. My results indicate that the price catastrophe either in scenario 1 or 2 or in scenario 3, depress overall Algerian domestic output and exports. Reduced output also reduces employment thus causing a fall in household’s income and consumers can afford less quantity of  both domestic and imported goods, in the scenario 1, overall imports decreased by 0.3 percent. But in the scenario 2 and 3 increased by 2.05 and 3.21 percent respectively. Finally results were concerned highlight the structural weaknesses of the Algerian economy remains extroverted and strongly oriented towards the exploitation of unprocessed raw materials. Keywords: External Shocks, Algerian Economy, Computable General Equilibrium Mode

The multidimensional impacts of external price shocks on the Algerian economy by using of CGEM

The global economy has gone through the past ten years a severe recession triggered by the financial catastrophe and the collapse of the commercial and industrial activity in the world. This slowdown has weighed its effects on the growth of economies around the world. Algeria, which is not fully integrated into the international economy, knowledge and know likely in the near future indirect effects of the crisis, but in a less severe than in Europe. Algeria has all the potential human and material to be a pivotal country in development at the Euro-Mediterranean and Arab Africa. This requires a development based on a coherence and visibility in the economic policy of the State. We propose in this paper an analysis of the multidimensional impacts of external price shocks on the Algerian economy with particular focus of hydrocarbon revenue. An applied computable general equilibrium model (CGEM) is utilized in my study to simulate the Algerian economic impact by three scenarios. First is food import price increase by 25 percent (scenario1), second is the oil price decrease by 30 percent (scenario2) and the finally scenario that combines scenario 1 and 2simultanneously (scenario 3).The results depict the multidimensional impacts on major macroeconomic indicators from recession to economic instability. My results indicate that the price catastrophe either in scenario 1 or 2 or in scenario 3, depress overall Algerian domestic output and exports. Reduced output also reduces employment thus causing a fall in household’s income and consumers can afford less quantity of  both domestic and imported goods, in the scenario 1, overall imports decreased by 0.3 percent. But in the scenario 2 and 3 increased by 2.05 and 3.21 percent respectively. Finally results were concerned highlight the structural weaknesses of the Algerian economy remains extroverted and strongly oriented towards the exploitation of unprocessed raw materials. Keywords: External Shocks, Algerian Economy, Computable General Equilibrium Mode

Frameworks for Nonclairvoyant Network Design with Deadlines or Delay

Clairvoyant network design with deadlines or delay has been studied extensively, culminating in an O(log n)-competitive general framework, where n is the number of possible request types (Azar and Touitou, FOCS 2020). In the nonclairvoyant setting, the problem becomes much harder, as ?(?n) lower bounds are known for certain problems (Azar et al., STOC 2017). However, no frameworks are known for the nonclairvoyant setting, and previous work focuses only on specific problems, e.g., multilevel aggregation (Le et al., SODA 2023). In this paper, we present the first nonclairvoyant frameworks for network design with deadlines or delay. These frameworks are nearly optimal: their competitive ratio is O?(?n), which matches known lower bounds up to logarithmic factors

Energetics in wild female Assamese macaques (Macaca assamensis): a behavioral and physiological approach

Energy is a key requirement of life. It is involved in life history traits such as body maintenance, growth and reproduction. Energy is a limiting resource and therefore has to be strategically allocated. When facing an energetic challenge (e.g. low food availability), an individual energy balance, i.e. the difference between energy intake and expenditure, is likely to decrease, leading to shifts in energy-allocation strategies. Such challenging situations can bear drastic fitness consequences and two important adaptations have emerged in order to offset these energetic costs. First, individuals can modify their behavior to maximize energy intake and/or decrease energy expenditure. By adapting their feeding behavior and activity budget, individuals can therefore compensate the costs induced by energetic challenges. Second, physiological adaptations also participate in overcoming such costs. Major hormones such as insulin, thyroid hormones and glucocorticoids are involved in energy metabolism since they regulate energy assimilation, energy expenditure (through metabolic rate) and energy store mobilization. Their concentrations are typically modulated in times of energy deficit or heightened energy demands. A considerable advantage of these hormones is that they can be assessed non-invasively from urine samples. Behavioral and physiological shifts contribute to offsetting energetic costs. However, to date few studies have used an integrative approach investigating how such adaptations can act in concert when facing an energetic challenge. Such investigations are needed to determine complementary adaptations that have emerged concomitantly and to assess on a fine-scale energetic conditions induced by different challenges among mammals. In addition, this integrative approach will allow a better evaluation of the magnitude of the energetic costs of various challenges which will lend valuable insight into the way such energetic constraints might have driven life history traits in different species. In this thesis, I aim at investigating the behavioral and physiological responses to potential energetic challenges faced by female Assamese macaques (Macaca assamensis) in their seasonal natural habitat. I specifically examined the effects of cold ambient temperature, physical activity, low energy intake and female reproduction on female behavior and hormone levels. I collected behavioral and nutritional data and assessed urinary C-peptide (uCP, a marker of insulin production), triiodothyronine (T3, a thyroid hormone) and cortisol (one of the main glucocorticoids in vertebrates) levels. The results showed that the four energetic challenges triggered a specific combination of physiological and behavioral responses. First, low ambient temperatures induced a rise in cortisol but no rise in T3. This likely illustrates the fact that ambient temperatures did not decrease low enough or for long enough to trigger thermogenesis through an increase in T3 levels. A rise in cortisol alone might therefore be enough for female to cope with cold temperatures. Second, travel distance was not associated with a cortisol or a T3 response, suggesting that walking distances are not very energetically demanding in females. Third, a rise in cortisol was paired with a decline in T3 when energy intake is low. Energy intake can therefore be limited enough for females to mobilize their fat stores and reduce their metabolic rate in order to support their energetic needs and save energy, respectively. Fourth, a rise in cortisol was combined with a rise in T3 during late gestation, illustrating elevated energy requirements at this stage of the reproductive cycle. In addition, uCP levels were also high in late gestation which is likely induced by insulin resistance and maternal metabolic shifts in order to spare readily available energy to the fetus needs. The interpretation of similar levels of cortisol, T3 and uCP between lactating and non-gestating – non-lactating females were promoted by the integration of behavioral responses. Contrary to the other reproducing females, early lactating females follow a behavioral energy-conserving strategy (they rest more and feed efficiently), which might offset the energetic costs of lactation. This dissertation contributes to the growing body of literature in the use of non-invasive markers of energy. Integrating my findings with the other reported ones, I also highlight some uncertainty and inconsistencies and suggest some directions for future investigations. Lastly, my dissertation provides a powerful integrative approach when investigating energetic costs. I shed light on the importance of tackling research questions on energetics through a multifaceted prism by considering both physiological and behavioral responses, since one promotes the interpretation of the other.2021-08-2

A CGE analysis of the impact of climate change on sustainable development: the case of High Plateaux region, Algeria

The aim of the paper is to assess the impact of climate change on sustainable development in the case of the High Plateaux region of Algeria. A baseline “climate change” scenario and an “adaptation” scenario were assessed as part of our work. The methodological approach implemented is broken down into three interconnected evaluation phases, pre-modelling phase, modelling phase and post-modelling phase. The work has shown that these complex ex-ante evaluation approaches are adaptable and applicable in the context of Algeria. Our findings indicate that climate change would have a significant impact on economic aggregates on a regional scale. It also highlighted that the calculation of a single index of the impact of environmental policies on the sustainability of arid regions confirms the hypothesis of gaining sustainability by working towards a strategy of adaptation to climate change