The application of AHP in the development of a taxonomy of merchant marine deck officers’ non-technical skills (NTS)

The importance of NTS has been realised in many safety critical industries. Recently the maritime domain has also embraced the idea and implemented an NTS training course for both merchant marine deck and engineering officers. NTS encompass both interpersonal and cognitive skills such as situational awareness, teamwork, decision making, leadership, managerial skills, communication and language skills. Well-developed NTS training allow ship’s officers to recognise quickly when a problem is developing and manage the situation safely and efficiently with the available team members. As a result, the evaluation and grading of deck officers’ NTS is necessary to assure safety at sea, reduce the effects of human error on-board ships, and allow ship board operations to be performed safely. This paper identifies the skills necessary for deck officers to effectively perform their duties on the bridge of a ship. To achieve this, initially, a taxonomy of deck officers’ NTS is developed through a review of relevant literature and the conducting of semi-structured interviews with experienced seafarers. Subsequently, NTS weighting data is collected from experienced seafarers to allow the weight of each element of the taxonomy to be established by the use of the Analytical Hierarchy Process (AHP)

A proposed Evidential Reasoning (ER) Methodology for Quantitative Assessment of Non-Technical Skills (NTS) Amongst Merchant Navy Deck Officers in a Ship’s Bridge Simulator Environment

Ship’s bridge simulators are very popular in the worldwide training and assessment of merchant navy deck officers. The examiners of simulator courses presently do not have a method to quantitatively assess the performance of a group or an individual. Some examiners use checklists and others use their gut feeling to grade competence. In this paper a novel methodology is established that uses the Evidential Reasoning algorithm to quantitatively assess the Non‐Technical Skills (NTS) of merchant navy officers. To begin with, interviews were conducted with experienced deck officers to develop the taxonomy and behavioural markers that would be used in the assessment process. A random selection of students studying towards their Chief Officer’s Certificate of Competency were recruited to have their NTS to be observed in a ship’s bridge simulator. The participant’s behaviour was rated against five criteria and the subsequent data was entered into the Evidential Reasoning algorithm to produce a crisp number. The results that were generated demonstrate that this approach provides a reliable method to quantitatively assess the NTS performance of merchant navy officers in a simulated bridge environment

A Cost Benefit Analysis Approach to Identify Improvements in Merchant Navy Deck Officers’ HELM (Human Element Leadership and Management) Training

A review of maritime accidents conducted over the last decade confirms that human error is the main contributing factor in these incidents. Well-developed Non-Technical Skills (NTS) can reduce the effects of human error. NTS include both interpersonal and cognitive skills such as situation awareness, teamwork, decision-making, leadership, managerial skills, communication and language skills. In a crisis situation good NTS allow a deck officer to recognise the problem quickly, take action to manage the situation, and utilise the available team members safely and effectively. This paper identifies the importance of NTS training for merchant navy deck officers. It also highlights room for improvement in the existing HELM training. Research has shown that at present the structure of HELM training is not very effective. The other safety critical domains? efforts into NTS developments are investigated and examples of best practice are adapted into the maritime domain?s NTS training. Suggestions are given for improvements to the HELM course based on proven successful methods in other safety critical domains (aviation and anaesthesia). A subsequent Cost Benefit Analysis for improving deck officers? NTS is also carried out through the use of Bayesian Networks and Decision Tree Modelling

Predators reduce extinction risk in noisy metapopulations

Background Spatial structure across fragmented landscapes can enhance regional population persistence by promoting local “rescue effects.” In small, vulnerable populations, where chance or random events between individuals may have disproportionately large effects on species interactions, such local processes are particularly important. However, existing theory often only describes the dynamics of metapopulations at regional scales, neglecting the role of multispecies population dynamics within habitat patches. Findings By coupling analysis across spatial scales we quantified the interaction between local scale population regulation, regional dispersal and noise processes in the dynamics of experimental host-parasitoid metapopulations. We find that increasing community complexity increases negative correlation between local population dynamics. A potential mechanism underpinning this finding was explored using a simple population dynamic model. Conclusions Our results suggest a paradox: parasitism, whilst clearly damaging to hosts at the individual level, reduces extinction risk at the population level

RADIOCARBON AND STABLE ISOTOPE EVIDENCE OF DIETARY CHANGE FROM THE MESOLITHIC TO THE MIDDLE AGES IN THE IRON GATES: NEW RESULTS FROM LEPENSKI VIR

This is the published version, also available here: https://journals.uair.arizona.edu/index.php/radiocarbon/article/view/4269.A previous radiocarbon dating and stable isotope study of directly associated ungulate and human bone samples from Late Mesolithic burials at Schela Cladovei in Romania established that there is a freshwater reservoir effect of approximately 500 yr in the Iron Gates reach of the Danube River valley in southeast Europe. Using the d15N values as an indicator of the percentage of freshwater protein in the human diet, the 14C data for 24 skeletons from the site of Lepenski Vir were corrected for this reservoir effect. The results of the paired 14C and stable isotope measurements provide evidence of substantial dietary change over the period from about 9000 BP to about 300 BP. The data from the Early Mesolithic to the Chalcolithic are consistent with a 2-component dietary system, where the linear plot of isotopic values reflects mixing between the 2 end-members to differing degrees. Typically, the individuals of Mesolithic age have much heavier d15N signals and slightly heavier d13C, while individuals of Early Neolithic and Chalcolithic age have lighter d15N and d13C values. Contrary to our earlier suggestion, there is no evidence of a substantial population that had a transitional diet midway between those that were characteristic of the Mesolithic and Neolithic. However, several individuals with Final Mesolithic 14C ages show d15N and d13C values that are similar to the Neolithic dietary pattern. Provisionally, these are interpreted either as incomers who originated in early farming communities outside the Iron Gates region or as indigenous individuals representing the earliest Neolithic of the Iron Gates. The results from Roman and Medieval age burials show a deviation from the linear function, suggesting the presence of a new major dietary component containing isotopically heavier carbon. This is interpreted as a consequence of the introduction of millet into the human food chain

Wigner Crystallization of a two dimensional electron gas in a magnetic field: single electrons versus electron pairs at the lattice sites

The ground state energy and the lowest excitations of a two dimensional Wigner crystal in a perpendicular magnetic field with one and two electrons per cell is investigated. In case of two electrons per lattice site, the interaction of the electrons {\em within} each cell is taken into account exactly (including exchange and correlation effects), and the interaction {\em between} the cells is in second order (dipole) van der Waals approximation. No further approximations are made, in particular Landau level mixing and {\em in}complete spin polarization are accounted for. Therefore, our calculation comprises a, roughly speaking, complementary description of the bubble phase (in the special case of one and two electrons per bubble), which was proposed by Koulakov, Fogler and Shklovskii on the basis of a Hartree Fock calculation. The phase diagram shows that in GaAs the paired phase is energetically more favorable than the single electron phase for, roughly speaking, filling factor $f$ larger than 0.3 and density parameter $r_s$ smaller than 19 effective Bohr radii (for a more precise statement see Fig.s 4 and 5). If we start within the paired phase and increase magnetic field or decrease density, the pairs first undergo some singlet- triplet transitions before they break.Comment: 11 pages, 7 figure

Hydrodynamics of the quantum Hall smectics

We propose a dynamical theory of the stripe phase arising in a two-dimensional electron liquid near half-integral fillings of high Landau levels. The system is modelled as a novel type of a smectic liquid crystal with the Lorentz force dominated dynamics. We calculate the structure factor, the dispersion relation of the collective modes (magnetophonons), and their intrinsic attenuation rate. We find strong power-law renormalizations of the elastic and dissipative coefficients by thermal fluctuations familiar from the conventional smectics but with different dynamical scaling exponents.Comment: Replaced with the published versio

An agent-based approach to assess drivers’ interaction with pre-trip information systems.

This article reports on the practical use of a multi-agent microsimulation framework to address the issue of assessing drivers’ responses to pretrip information systems. The population of drivers is represented as a community of autonomous agents, and travel demand results from the decision-making deliberation performed by each individual of the population as regards route and departure time. A simple simulation scenario was devised, where pretrip information was made available to users on an individual basis so that its effects at the aggregate level could be observed. The simulation results show that the overall performance of the system is very likely affected by exogenous information, and these results are ascribed to demand formation and network topology. The expressiveness offered by cognitive approaches based on predicate logics, such as the one used in this research, appears to be a promising approximation to fostering more complex behavior modelling, allowing us to represent many of the mental aspects involved in the deliberation process

Cyclotron resonance of correlated electrons in semiconductor heterostructures

The cyclotron resonance absorption of two-dimensional electrons in semiconductor heterostructures in high magnetic fields is investigated. It is assumed that the ionized impurity potential is a dominant scattering mechanism, and the theory explicitly takes the Coulomb correlation effect into account through the Wigner phonons. The cyclotron resonance linewidth is in quantitative agreement with the experiment in the Wigner crystal regime at T=4.2K. Similar to the cyclotron resonance theory of the charge density waves pinned by short-range impurities, the present results for the long-range scattering also show the doubling of the resonance peaks. However, unlike the case of the charge density waves, our theory gives the pinning mode independent of the bulk compressibility of the substrate materials.Comment: 6 pages, 5 figure