Application of Grey Wolf Optimizer Algorithm for Optimal Power Flow of Two-Terminal HVDC Transmission System

This paper applies a relatively new optimization method, the Grey Wolf Optimizer (GWO) algorithm for Optimal Power Flow (OPF) of twoterminal High Voltage Direct Current (HVDC) electrical power system. The OPF problem of pure AC power systems considers the minimization of total costs under equality and inequality constraints. Hence, the OPF problem of integrated AC-DC power systems is extended to incorporate HVDC links, while taking into consideration the power transfer control characteristics using a GWO algorithm. This algorithm is inspired by the hunting behavior and social leadership of grey wolves in nature. The proposed algorithm is applied to two different case-studies: the modified 5-bus and WSCC 9-bus test systems. The validity of the proposed algorithm is demonstrated by comparing the obtained results with those reported in literature using other optimization techniques. Analysis of the obtained results show that the proposed GWO algorithm is able to achieve shorter CPU time, as well as minimized total cost when compared with already existing optimization techniques. This conclusion proves the efficiency of the GWO algorithm

Molecular characterization of genetic diversity in some durum wheat (Triticum durum Desf.) in Palestine

Random amplified polymorphic DNA (RAPD) analysis was conducted to estimate the genetic diversity and relatedness among 10 wheat cultivars and landraces. Five out of 70 decamer random primers showed distinctly polymorphic bands when used to amplify genomic DNA. The primers yielded a total of 157 RAPD markers of which 150 were considered as polymorphic. Each primer produced 18 to 37 polymorphic bands with an average of 30 markers per primer. DNA fragments size ranged from 350 to 1910 bp. The mean similarity indices ranged from 0.05 to 0.68 with an average of 0.29. The unweighted pair group method with arithmetic mean (UPGMA) dendrogram based on Jaccard genetic similarity index, grouped the 10 landraces and cultivars into four main clusters. Despite the clustering of most landraces in the same cluster, high genetic variation was observed within cluster-I in which the genetic distance ranged from 73% between Hiteyah8 and White Dibeyah to 32% between Black Hiteyah and Yellow Hiteyah. The result of this study confirms high genetic diversity within these cultivars and landraces, and therefore, underlined the significant values of these cultivars and landraces as gene pool for durum wheat genetic improvement. Thus, RAPD offer a potentially simple, rapid and reliable method to evaluate genetic variation and relatedness among ten wheat landraces and cultivars.Keywords: Random amplified polymorphic DNA (RAPD), Triticum, genetic variatio

Passive smoking in the etiology of non-syndromic orofacial clefts:a systematic review and meta-analysis

Background Studies have found a consistent positive association between maternal smoking and nonsyndromic orofacial clefts (NSOFC). However, no comprehensive assessment of the association between NSOFC and passive smoking has been undertaken. This systematic review and meta-analysis explores the relationship between maternal passive smoking and NSOFC, and compares the associations between passive and active smoking. Methods and Findings Search strategy, inclusion / exclusion criteria, and data extraction from studies reporting maternal passive smoking and NSOFC was implemented without language restrictions. Risks of bias in the identified studies were assessed and this information was used in sensitivity analyses to explain heterogeneity. Meta-analysis and meta-regression of the extracted data were performed. Egger's test was used to test for small study effects. Fourteen eligible articles were identified. Maternal passive smoking exposure was associated with a twofold increase in risk of NSOFC (odds ratio: 2.11, 95% confidence interval: 1.54-2.89); this was apparent for both cleft lip with and without palate (OR: 2.05, 95% CI: 1.27-3.3) and cleft palate (OR: 2.11, 95% CI: 1.23-3.62). There was substantial heterogeneity between studies. In the studies that provided data enabling crude and adjusted odd ratios to be compared, adjustment for potential confounders attenuated the magnitude of association to about a 1.5-fold increase in risk. Conclusion Overall, maternal passive smoking exposure results in a 1.5 fold increase in risk of NSOFC, similar to the magnitude of risk reported for active smoking, but there is marked heterogeneity between studies. This heterogeneity is not explained by differences in the distribution of cleft types, adjustment for covariates, broad geographic region, or study bias/quality. This thorough meta-analysis provides further evidence to minimize exposure to environmental tobacco smoke in policy making fora and in health promotion initiatives.</p

Novi zakoni adaptivnog upravljanja referentnim modelom zasnovani na nekvadratnoj Ljapunovljevoj funkciji

In the design of model reference adaptive control (MRAC) schemes, adaptive laws have been developed based on Lyapunov stability theory. Over the past few decades, it has been a common practice to use Quadratic Lyapunov Functions (QLF). In contrast to such development, using a new Non-Quadratic Lyapunov Function (NQLF), this paper presents new adaptive laws for the MRAC. These new laws have the same advantage of assurance of stability of the overall system, as the earlier adaptive laws developed using the QLF. Over and above, they have an additional advantage of improved performance: in fact, the use of NQLF improved the system output error signal converging to zero. Finally, this paper also presents simulation results supporting the arguments.Za projektiranje sustava adaptivnog upravljanja referentnim modelom (MRAC) razvijeni su adaptivni zakoni koji se zasnivaju na Ljapunovljevoj teoriji stabilnosti. U zadnjih se nekoliko desetljeća uobičajeno koristi kvadratna Ljapunovljeva funkcija (QLF). Suprotno tome, u ovome se radu zakoni upravljanja referentnim modelom izvode na osnovi nove nekvadratne Ljapunovljeve funkcije (NQLF). Za izvedene je nove zakone upravljanja cjelokupni sustav stabilan, kao i kod prijašnjih zakona adaptivnog upravljanja kvadratnom Ljapunovljevom funkcijom. Povrh toga predloženim novim zakonima upravljanja NQLF funkcijom poboljšava se konvergencija izlaznog signala pogreške prema nuli. Na kraju su u radu predstavljeni rezultati simulacija koji podupiru navedene tvrdnje

Fault Location Effect on Short-Circuit Calculations of a TCVR Compensated Line in Algeria

This research work investigated the effect of fault location on short-circuit calculations for a high voltage transmission line equipped with a novel FACTS device, namely Thyristor Controlled Voltage Regulator (TCVR). This main function of this device was to control the voltage and active power of the line. The paper considered a study case for a 220 kV transmission line, in the Algerian transmission power network, which was subjected to a phase to earth fault in the presence of a fixed fault resistance. The paper presented theoretical analysis of the short-circuit calculations which was confirmed by the illustrated simulation results. Simulation results showed the impact of the fault location on the symmetrical current and voltage components of the line, and transmission line phase currents and voltages; before using TCVR and in the presence of TCVR for both cases of positive and negative TCVR controlled voltage

Novi zakoni adaptivnog upravljanja referentnim modelom zasnovani na nekvadratnoj Ljapunovljevoj funkciji

In the design of model reference adaptive control (MRAC) schemes, adaptive laws have been developed based on Lyapunov stability theory. Over the past few decades, it has been a common practice to use Quadratic Lyapunov Functions (QLF). In contrast to such development, using a new Non-Quadratic Lyapunov Function (NQLF), this paper presents new adaptive laws for the MRAC. These new laws have the same advantage of assurance of stability of the overall system, as the earlier adaptive laws developed using the QLF. Over and above, they have an additional advantage of improved performance: in fact, the use of NQLF improved the system output error signal converging to zero. Finally, this paper also presents simulation results supporting the arguments.Za projektiranje sustava adaptivnog upravljanja referentnim modelom (MRAC) razvijeni su adaptivni zakoni koji se zasnivaju na Ljapunovljevoj teoriji stabilnosti. U zadnjih se nekoliko desetljeća uobičajeno koristi kvadratna Ljapunovljeva funkcija (QLF). Suprotno tome, u ovome se radu zakoni upravljanja referentnim modelom izvode na osnovi nove nekvadratne Ljapunovljeve funkcije (NQLF). Za izvedene je nove zakone upravljanja cjelokupni sustav stabilan, kao i kod prijašnjih zakona adaptivnog upravljanja kvadratnom Ljapunovljevom funkcijom. Povrh toga predloženim novim zakonima upravljanja NQLF funkcijom poboljšava se konvergencija izlaznog signala pogreške prema nuli. Na kraju su u radu predstavljeni rezultati simulacija koji podupiru navedene tvrdnje

CRITERIA FOR THE RETURN TO SPORT AFTER RECONSTRUCTION OF THE ANTERIOR CRUCIATE LIGAMENT (RACL)

Background: One of the objectives of the reconstruction of the anterior cruciate ligament (RACL) is the return of athletes to existing activity before the injury. Thus, it is essential to understand the variables that influence the return. Associations between the return to sport and the variables representing the strength of the quadriceps, instability and symmetry of the members, and the psychological state have not been studied in athletes following the RACL. Purpose: The purpose of this study is to summarize the literature relating to the proposed variables to be associated with the return to sport following a reconstruction of the anterior cruciate ligament. Method: During this study, we searched electronic databases, PubMed, Medline, Embase, and Cochrane Database to find the most recent articles about returning to the sport after the RACL criteria. Therefore, the articles included in this review meets these criteria: 1) patients who underwent a RACL; 2) reported at least one measurement of quadriceps strength, symmetry between members, and the psychological state; 3) the return to the sport identified by subjective measures or action to identify the level of sports participation of patients; and 4) any relationship analysis between the measures and the return to sport. Conclusion: Despite the fact that there are a number of important criteria influencing the return to sport, some have remained critical which have been considered and supported. By analyzing the items, the following results were obtained as described below: A quadriceps strength [IQ = 90%] and a motivating psychological state are the two criteria that ensures sport participation and reduction of the rate of re-injury or injury to the contralateral side. However, other criteria should not be neglected, with a view of their interaction with quadriceps strength and psychological status influence on the overall condition of the athlete wishing to return to the sport