Description of the ICCAT length at age data base for bluefin tuna from the eastern Atlantic, including the Mediterranean Sea

This study aims to describe the current length at age database available for Eastern Atlantic bluefin tuna management area. A total of 8 500 spines and 5 000 otoliths were read from specimens caught from 1984 to 2017 in both the Atlantic Ocean and Mediterranean Sea. Obtaining ALKs for this species is difficult, as it has a wide length range and spatial distribution, and sampling is costly. Unfortunately, there are practically no contributions to this database from the East Atlantic and Mediterranean Sea countries, and only thanks to the initiative of the GBYP has it been possible to increase the number of samples in the ICCAT database in the last 10 years. As a result, the current ICCAT length at age database has incomplete spatial, temporal and size range coverage. However, it may be suitable as conditional age-at-length data for the Stock Synthesis model

Indoor visible light communication localization system utilizing received signal strength indication technique and trilateration method

Visible light communication (VLC) based on light-emitting diodes (LEDs) technology not only provides higher data rate for indoor wireless communications and offering room illumination but also has the potential for indoor localization. VLC-based indoor positioning using the received optical power levels from emitting LEDs is investigated. We consider both scenarios of line-of-sight (LOS) and LOS with non-LOS (LOSNLOS) positioning. The performance of the proposed system is evaluated under both noisy and noiseless channel as is the impact of different location codes on positioning error. The analytical model of the system with noise and the corresponding numerical evaluation for a range of signal-to-noise ratio (SNR) are presented. The results show that an accuracy of 12 dB

Applying mixed-effects growth models to back-calculated size-at-age data for Atlantic bluefin tuna (Thunnus thynnus)

We fit growth models to back-calculated size-at-age data for Atlantic bluefin tuna (Thunnus thynnus) captured in the western Atlantic management area to inform alternative growth scenarios within the current management framework of the species. The Modified-Fry function was the best-performing of three back-calculation functions based on a leave-one-out cross-validation for within-cohort comparisons. We fit multiple growth models to the back-calculated growth trajectories, and demonstrated that growth parameters were highly sensitive to whether the lack of independence between back-calculated lengths from each individual was accounted for by the model. Non-linear mixed-effects modelling provides a suitable approach for accounting for this lack of independence and the autocorrelation between back-calculated lengths from the same individual. We further demonstrated the utility of mixed-effects models for predicting future growth of individuals using a forecasting test. We used this modelling approach to demonstrate that male bluefin tuna had greater estimated asymptotic length than females, and found that there was no significant difference in growth parameters between individuals assigned to genetically distinct spawning stocks.1,58

A novel simplified mathematical model for antennas used in medical imaging applications

In this paper a new technique is proposed to model the current across a monopole antenna and thereby the radiation fields of the antenna can be calculated. Generally, the Method of Moments (MOM) technique is used for this purpose whereby the integral equations are discretised to find the fields of an antenna. The proposed model requires only the knowledge of three parameters (Initial Current I0, Damping coefficient a and the radial parameter ?) and hence considerably reduces the computational time and space as its results do not depend on the number of functions involved. The new technique is also developed to take account of the conductivity property of the surrounding medium. Hence this technique can be used in field prediction for antennas employed in medical imaging applications. Initial results obtained from the new technique show good correlation in comparison with the MOM technique

Updated comparison of age estimates from paired calcified structures from Atlantic bluefin tuna

In this paper we present an updated comparison of age estimates from otoliths and spines from the same specimen, with the intention to analyze whether it is possible to use both structures in obtaining age-length keys for this species. The agreement between otolith and spine age estimates was good for bluefin tuna younger than 14 years old with less than one year difference. Tests of symmetry showed the asymmetrical distribution of ages. However no significant differences were found between the growth parameters estimated from both paired hard parts. It is suggested using both structures readings for constructing agelength keys for bluefin tuna younger than 14 years.En prensa0,000

Determination of annual periodicity in annuli formation in Atlantic bluefin tuna otoliths.

Controversies remain regarding the periodicity, or seasonality, of otolith growth band formation which directly influences a correct age determination of Atlantic bluefin tuna using otoliths. Thereby, the aim of this work was to apply marginal increment analysis (MIA) and marginal edge analysis (EA) to determine the timing of band deposition. The index of completion (MIA) was also analyzed using General Additive Models. Results indicated that the opaque band begin to form in July and would finish forming in November. From the end of the year and the beginning of the following year there is minimal marginal edge growth and this is when the translucent band begins to form and reaches its maximum development in June. MIA and EA has evidenced that the annulus has been formed in November in the Atlantic Bluefin tuna otolith. This would mean to delay the date of the current July 1st adjustment criterion to November 30

Wind Driven Optimization Technique for Estimation of Solar Photovoltaic Parameters

In order to increase the efficiency of the solar photovoltaic (PV) system, accurate electrical modeling of the system under different environmental conditions is necessary. The double diode electrical model of solar PV is known to be more accurate than its single diode model counterpart since it takes into account the effect of recombination. However, because of its nonlinear characteristics, the parameters of the double diode model have to be identified using ptimization algorithms. In this paper, the Wind Driven Optimization (WDO) algorithm is proposed as a potential new method for identifying the parameters of a twelveparameter double diode model (12p-DDM) of the solar PV. The accuracy and flexibility of the proposed method are verified using three different sets of data: (i) experimental data at the controlled environmental condition, (ii) data sheet values of different solar PV modules and (iii) real-time experimental data at the uncontrolled environmental condition. Additionally, the performance of the WDO is compared to other well-known existing optimization techniques. The obtained results show that the WDO algorithm can provide optimized values with reduced Mean Absolute Error in Power (MAEP) and reduced Root Mean Square Error (RMSE) for different types of solar PV modules at different environmental conditions. We show that the WDO can be confidently recommended as a reliable optimization algorithm for parameter estimation of solar PV model