Portfolio optimization and index tracking for the shipping stock and freight markets using evolutionary algorithms

This paper reproduces the performance of an international market capitalization shipping stock index and two physical shipping indexes by investing only in US stock portfolios. The index-tracking problem is addressed using the differential evolution algorithm and the genetic algorithm. Portfolios are constructed by a subset of stocks picked from the shipping or the Dow Jones Composite Average indexes. To test the performance of the heuristics, three different trading scenarios are examined: annually, quarterly and monthly rebalancing, accounting for transaction costs where necessary. Competing portfolios are also assessed through predictive ability tests. Overall, the proposed investment strategies carry less risk compared to the tracked benchmark indexes while providing investors the opportunity to efficiently replic ate the performance of both the stock and physical shipping indexes in the most cost-effective way

Heuristic algorithms for the cardinality constrained efficient frontier

This paper examines the application of genetic algorithm, tabu search and simulated annealing metaheuristic approaches to finding the cardinality constrained efficient frontier that arises in financial portfolio optimisation. We consider the mean-variance model of Markowitz as extended to include the discrete restrictions of buy-in thresholds and cardinality constraints. Computational results are reported for publicly available data sets drawn from seven major market indices involving up to 1318 assets. Our results are compared with previous results given in the literature illustrating the effectiveness of the proposed metaheuristics in terms of solution quality and computation time.Efficient frontier Genetic algorithm Portfolio optimisation Simulated annealing Tabu search

Association of Some Indices of Iron Status with Gestational Periods of Pregnancy in Nigerian Pregnant Women.

Background: Maternal iron status during pregnancy is vital to the health of the mother and the foetus. Iron deficiency is common in our setting but there is no consensus as to when the deficiency reaches the peak during pregnancy.Objective: To evaluate some indices of iron status in both pregnant and non-pregnant women and to correlate their levels with gestational periods of pregnancy.Materials and Methods: Some indices of iron status such as total iron, haemoglobin (Hb), haematocrit (Hct), total iron binding (TIBC) and percent transferrin were evaluated in 100 pregnant women and 50 non-pregnant women of similar age group. The pregnant women were divided into three groups depending on the duration of pregnancy: first trimester, second trimester and third trimester. Serum total iron, TIBC and percent transferrin saturation were evaluated using colorimetric technique while full blood count was done using automated haematology analyzer.Results: Statistically significant decreases were observed in serum iron (P=0.05), TIBC (p=0.002), percent transferrin saturation (p=0.05), Hb (p=0.005), Hct (p=0.014), red blood cell (p<0.001), MCV (p=0.029), MCH (p=0.007) and MCHC(p=0.003) when compared with values in non-pregnant women. There were gradual decreases in serum iron, TIBC, Hb and Hct as pregnancy progresses from 1st trimester to 2nd trimester and 3rd trimester of pregnancy. Pregnant women in their 3rd trimester had the lowest levels of study indices of iron status apart from percent transferrin saturation which value was highest in the third trimester of pregnancy. Serum iron concentrations correlated negatively (r=-0.068; p=0.044) with gestational period while TIBC (r=0.089;p=0.041) and percent transferrin saturation (r=0.047;p=0.036) correlated positively with gestation periods of pregnancy.Conclusion: The measured indices of iron status were significantly lower in pregnant women compared to non-pregnant women. Iron status correlates with gestational periodsof pregnancy. Evaluation of iron status should be routinely conducted in pregnant women to avoid complications associated with iron deficiency.Keywords: Anaemia, pregnancy, total iron and total iron binding capacity

Thermal Decomposition of Stichtite

The mineral stitchtite was synthesised and its thermal decomposition measured using thermogravimetry coupled to an evolved gas mass spectrometer. Mass loss steps were observed at 52, 294, 550 and 670 °C attributed to dehydration, dehydroxylation and loss of carbonate. The loss of carbonate occurred at higher temperatures than dehydroxylation