On the Fairness of Centralised Decision-Making Strategies in multi-TSO Power Systems

In this paper, we consider an interconnected power system, where the different Transmission System Operators (TSOs) have agreed to transferring some of their competences to a Centralised Control Center (CCC). In such a context, a recurrent difficulty for the CCC is to define decision-making strategies which are fair enough to every TSO of the interconnected system. We address this multiobjective problem when the objective of every TSO can be represented by a real-valued function. We propose an algorithm to elect the solution that leads to the minimisation of the distance with the utopian minimum after having normalised the different objectives. We analyse the fairness of this solution in the sense of economics. We illustrate the approach with the IEEE 118 bus system partitioned in 3 areas having as local objective the minimisation of active power losses, the maximisation of reactive power reserves, or a combination of both criteria.multi-area power system, centralised control, multi-objective optimisation, fairness.

Prevalence of asthma and COPD and blood eosinophil count in a middle-aged Belgian population

Various phenotypes exist in asthma and Chronic Obstructive Pulmonary Disease (COPD). These are important to identify in order to guide treatment decisions. We aim to investigate the prevalence and clinical characteristics of obstructive airway diseases in the middle-aged population. We estimated the prevalence of COPD and/or asthma in the Asklepios cohort study (Belgium), using information from the third European Community Respiratory Health Survey (ECRHS3), medical records, and spirometry. Respiratory symptoms, respiratory medication, and current disease status distinguished clinical from sub-clinical cases. In addition, we compared the blood eosinophil count/mu L (median [IQR]) between cases and controls. Of the 2221 participants (mean age 56.1 +/- 5.9 years; 48.7% males), 138 (6.2%) participants had clinical current asthma, 22 (1.0%) participants had sub-clinical ever asthma, 102 (4.6%) had sub-clinical spirometry-defined COPD, 104 (4.6%) participants had clinical spirometry-confirmed COPD, and 11 (0.5%) had asthma and COPD overlap (ACO). Clinical current asthma (160.0 [110.0-250.0]), sub-clinical ever asthma (170.0 [110.0-230.0]), and clinical COPD (160.0 [110.0-220.0])-but less sub-clinical COPD (140.0 [90.0-210.0])-had higher eosinophil counts, compared to controls (130.0 [80.0-200.0]). We conclude that obstructive airway diseases are prevalent in the middle-aged Asklepios cohort. Moreover, the systemic eosinophil count is increased in clinical COPD cases, and in asthma cases regardless of clinical remission

Application of Ewald's Method for Efficient Summation of Dyon Long-Range Potentials

We study a model of dyons for SU(2) Yang-Mills theory at finite temperature T < T_c, in particular its ability to generate a confining force between a static quark antiquark pair. The interaction between dyons corresponds to a long-range 1/r potential, which in naive treatments with a finite number of dyons typically gives rise to severe finite volume effects. To avoid such effects we apply the so-called Ewald method, which has its origin in solid state physics. The basic idea of Ewald's method is to consider a finite number of dyons inside a finite cubic volume and enforce periodicity of this volume. We explain the technicalities of Ewald's method and outline how the method can be applied to a wider class of 1/r^p long-range potentials.Comment: 8 pages, 4 figures, contribution to conference "Confinement X

Thyroid hormone levels within reference range are associated with heart rate, cardiac structure, and function in middle-aged men and women

Background: Triiodothyronine (T3) has many effects on the heart, and marked changes in cardiac function and structure occur in patients with (subclinical) thyroid disease. We investigated whether between-subject variation in thyroid hormone levels within the euthyroid range is also associated with heart rate and echocardiographic heart function and structure. Methods: Subjects were selected from the Asklepios study (n=2524), a population-representative random sample of patients aged between 35 and 55 years, free from overt cardiovascular disease at baseline. Analyses were restricted to 2078 subjects (1013 women and 1065 men), not using antihypertensive or thyroid medication nor having antithyroperoxidase antibody levels above clinical cut-off or thyrotropin (TSH) levels outside the reference range. All subjects were phenotyped in-depth and underwent comprehensive echocardiography, including diastolic evaluation. Thyroid function parameters were determined by automated electrochemiluminescence. Results: Heart rate was robustly positively associated with (quartiles of) free T3 (FT3) and T3, both in subjects with TSH levels within reference (0.27-4.2 μU/L) and in narrow TSH range (0.5-2.5 μU/L; p<0.0001). FT3 and T3 were negatively associated with left ventricular (LV) end-diastolic volume but positively associated with relative wall thickness. Total T3 (TT3) was associated with enhanced ventricular contraction (as assessed by tissue Doppler imaging). Free thyroxine, FT3, and TT3 were positively associated with late ventricular filling, and TT3 was associated with early ventricular filling. Conclusion: We have demonstrated a strong positive association between thyroid hormone levels within the euthyroid range and heart rate, and more subtle effects on cardiac function and structure. More specifically, we suggest a smaller LV cavity size (with increased relative wall thickness), an enhanced atrial and ventricular contraction, and LV relaxation with higher circulating thyroid hormones. These results illustrate that variation in thyroid hormone levels, even within the reference range, exerts effects on the heart

Triiodothyronine and free thyroxine levels are differentially associated with metabolic profile and adiposity-related cardiovascular risk markers in euthyroid middle-aged subjects

Background: We previously showed that in healthy young men a less favorable body composition is associated with higher FT3 levels within the euthyroid range. Besides, a higher FT3-to-FT4 ratio has been related to a less favorable metabolic phenotype and more placental growth in pregnant women. In the present study, we therefore investigated whether serum TSH, thyroid hormone levels and the FT3-to-FT4 ratio are associated with metabolic and adiposity-related cardiovascular risk markers in a healthy population of middle-aged euthyroid men and women. Methods: Thyroid parameters were measured in 2524 generally healthy subjects from the Asklepios study (35-55yrs, mean age 46 years). Analyses were restricted to 2315 subjects (1138 women and 1177 men), not using thyroid medication, not having anti-TPO levels above clinical cut-off values nor TSH levels outside the reference range (0.27-4.2 mU/L). Twenty-seven percent of the women and 47.5% of the men were overweight, while 13% of women and 17% of men were obese. Twenty percent of the subjects were active smokers. Serum thyroid function parameters were determined by electrochemiluminescence. Results: (F) T3 and the FT3-to-FT4 ratio were positively related to BMI, waist circumference and components of the metabolic syndrome, i.e. triglycerides, systolic and diastolic blood pressure and fasting plasma glucose, and negatively with HDL-cholesterol levels, whereas FT4 was negatively associated to BMI, waist circumference and triglycerides (all p-values <0.001). TSH related positively to total cholesterol levels (p<0.01), triglycerides and to systolic and diastolic blood pressure (all p<0.001). The FT3-to-FT4 ratio was further positively associated to the adiposity-related inflammation markers interleukin-6 (IL6) and high-sensitive CRP (hs-CRP) and to pulse wave velocity. All associations were adjusted for sex, age, height and smoking and most associations persisted after additional adjustment for weight or waist circumference. Conclusion: In healthy euthyroid middle-aged men and women, higher (F) T3 levels, lower FT4 levels and thus a higher FT3-to-FT4 ratio are consistently associated with various markers of unfavorable metabolic profile and cardiovascular risk

Predictability is necessary for closed-loop visual feedback delay adaptation

Rohde M, van Dam L, Ernst MO. Predictability is necessary for closed-loop visual feedback delay adaptation. Journal of Vision. 2014;14(3):4.In case of delayed visual feedback during visuomotor tasks, like in some sluggish computer games, humans can modulate their behavior to compensate for the delay. However, opinions on the nature of this compensation diverge. Some studies suggest that humans adapt to feedback delays with lasting changes in motor behavior (aftereffects) and a recalibration of time perception. Other studies have shown little or no evidence for such semipermanent recalibration in the temporal domain. We hypothesize that predictability of the reference signal (target to be tracked) is necessary for semipermanent delay adaptation. To test this hypothesis, we trained participants with a 200 ms visual feedback delay in a visually guided manual tracking task, varying the predictability of the reference signal between conditions, but keeping reference motion and feedback delay constant. In Experiment 1, we focused on motor behavior. Only training in the predictable condition brings about all of the adaptive changes and aftereffects expected from delay adaptation. In Experiment 2, we used a synchronization task to investigate perceived simultaneity (perceptuomotor learning). Supporting the hypothesis, participants recalibrated subjective visuomotor simultaneity only when trained in the predictable condition. Such a shift in perceived simultaneity was also observed in Experiment 3, using an interval estimation task. These results show that delay adaptation in motor control can modulate the perceived temporal alignment of vision and kinesthetically sensed movement. The coadaptation of motor prediction and target prediction (reference extrapolation) seems necessary for such genuine delay adaptation. This offers an explanation for divergent results in the literature

On the Fairness of Centralised Decision-Making Strategies in multi-TSO Power Systems

International audienceIn this paper, we consider an interconnected power system, where the different Transmission System Operators (TSOs) have agreed to transferring some of their competences to a Centralised Control Center (CCC). In such a context, a recurrent difficulty for the CCC is to define decision-making strategies which are fair enough to every TSO of the interconnected system. We address this multiobjective problem when the objective of every TSO can be represented by a real-valued function. We propose an algorithm to elect the solution that leads to the minimisation of the distance with the utopian minimum after having normalised the different objectives. We analyse the fairness of this solution in the sense of economics. We illustrate the approach with the IEEE 118 bus system partitioned in 3 areas having as local objective the minimisation of active power losses, the maximisation of reactive power reserves, or a combination of both criteria