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The purpose of this paper is to calculate the probability of collision of flying aircraft crossing on straight paths in any direction.

The probability of deviations from the intended flight paths is used to calculate the probability of collision that is integrated over time to cover whole events.

The probabilities of collision are calculated in terms of the r.m.s. position errors and encounter geometry, that is aircraft velocities and flight path angles and crossing angles.

The method does not apply to aircraft flying in parallel tracks at the same velocity in air corridors: that case has been covered elsewhere, as well as the case of climbing or descending aircraft.

International Civil Aviation Organization (ICAO) specifies as target level of safety (TLS) a probability of collision not exceeding 5×10⁻⁹ per hour. To meet the ICAO TLS standard, it is necessary to calculate collision probabilities for all stages of flight.

A low collision probability is a safety metric; the value does depend on a realist choice of probability distribution.

Calculates the probability of collision for crossing flights, corresponding to a common scenario on air traffic management.

Most of the existing approaches for flight collision avoidance are concerned with local traffic alone for which the separation is based on the pairwise analysis of aircraft trajectory trends, which is not efficient with regard to some flight path requirements along waypoints. The purpose of this paper is to deal with the global collision avoidance problem which aims at separating aircraft taking into consideration the global traffic in a given area instead of considering them pairwise. It aims to model the concept of global collision avoidance and propose a validated algorithm for the purpose in the framework of free‐flight.

The collision avoidance procedure computes online the appropriate speed and heading for each aircraft, at each sampling time‐instant, to generate a collision‐free flight trajectory along scheduled waypoints. The method accounts for automatic assignment of priority indexes that are updated from one control time horizon to the next. The paper considers here the case of aircraft flying at the same altitude, but the proposed method is easily extendable to the general 3D situation. Owing to the predictive features that are inherent to collision avoidance, the collision‐free trajectories are generated using model predictive control approach. A simulation example is presented in the end and its results show the suitability of the proposed approach.

Since the model predictive control approach is used, the collision avoidance procedure is anticipative; therefore, the avoidance capability depends only on the prediction horizon rather than on the control horizon.

The computation of the trajectory guidance information (speed and heading) at each time‐step is fast, therefore the proposed method is well suited for online processing requirements in real world applications.

The paper provides a flexible modelling framework and a computationally effective algorithm, both based on model predictive control concepts, to cope with global collision avoidance for flight safety enhancement in the framework of free‐flight.

This paper aims to assess the implications in safety levels by the integration of remotely piloted aircraft system (RPAS). The goal is to calculate the number of RPAS that can jointly operate with conventional aircraft regarding conflict risk, without exceeding current safety levels.

This approach benchmarks a calculated level of safety (CLS) with a target level of safety (TLS). Monte Carlo (MC) simulations quantify the TLS based on the current operation of conventional aircraft. Then, different experiments calculate the CLS associated with combinations of conventional aircraft and RPAS. MC simulations are performed based on probabilistic distributions of aircraft performances, entry times and geographical distribution. The safety levels are based on a conflict risk model because the safety metrics are the average number of conflicts and average conflict duration.

The results provide restrictions to the number of RPAS that can jointly operate with conventional aircraft. The TLS is quantified for four conventional aircraft. MC simulations confirm that the integration of RPAS demands a reduction in the total number of aircraft. The same number of RPAS than conventional aircraft shows an increase over 90% average number of conflicts and 300% average conflict time.

The methodology is applied to one flight level of en-route airspace without considering climbing or descending aircraft.

This paper is one of the most advanced investigations performed to quantify the number of RPAS that can be safely integrated into non-segregated airspace, which is one of the challenges for the forthcoming integration of RPAS. Particularly, Europe draws to allow operating RPAS and conventional aircraft in non-segregated airspace by 2025, but this demanding perspective entails a thorough analysis of operational and safety aspects involved.

Given that many subordinates work for leaders who mistreat them, the purpose of this paper is to examine whether leader–member exchange (LMX) influences the relationship between leaders’ dark triad (DT) traits and follower perceptions of abusive supervision. Drawing on theories of idiosyncratic and deviance credits, the authors posit that high LMX weakens the positive relationship between leaders’ DT traits and the perception of abusive supervision.

Data were collected from 326 full-time employees. A moderated regression was performed to determine whether high LMX weakened the relationships between each DT trait (Machiavellianism, narcissism and psychopathy) and the perception of abusive supervision.

Results suggested that high LMX indeed weakened the positive relationships between two leader DT traits – narcissism and psychopathy – and the occurrence of abusive supervision. Hence, employees who perceived their LMX relationship to be high were less likely to report the occurrence of abusive supervision when their leader was also perceived to be high in narcissism or psychopathy. A post hoc analysis suggested different results for mixed-sex dyads.

The present study suggests a potential strategy for reducing the detrimental effects of a DT leader, namely, forming a high-quality relationship between leader and follower.

This study addresses the call for more research into the boundary conditions under which leader characteristics may affect followers. Drawing on past research that treats LMX as a boundary condition, the authors frame LMX as an important buffer between DT leader characteristics and the perception of abusive supervision. Results suggest a potential exchange of deviance credits in cases where LMX is high rather than low.

Testing business processes is crucial to assess the compliance of business process models with requirements. Automating this task optimizes testing efforts and reduces human error while also providing improvement insights for the business process modeling activity. The primary purposes of this paper are to conduct a literature review of Business Process Model and Notation (BPMN) testing and formal verification and to propose the Business Process Evaluation and Research Framework for Enhancement and Continuous Testing (bPERFECT) framework, which aims to guide business process testing (BPT) research and implementation. Secondary objectives include (1) eliciting the existing types of testing, (2) evaluating their impact on efficiency and (3) assessing the formal verification techniques that complement testing.

The methodology used is based on Kitchenham's (2004) original procedures for conducting systematic literature reviews.

Results of this study indicate that three distinct business process model testing types can be found in the literature: black/gray-box, regression and integration. Testing and verification approaches differ in aspects such as awareness of test data, coverage criteria and auxiliary representations used. However, most solutions pose notable hindrances, such as BPMN element limitations, that lead to limited practicality.

The databases selected in the review protocol may have excluded relevant studies on this topic. More databases and gray literature could also be considered for inclusion in this review.

Three main originality aspects are identified in this study as follows: (1) the classification of process model testing types, (2) the future trends foreseen for BPMN model testing and verification and (3) the bPERFECT framework for testing business processes.

Looks at the eighth published year of the ITCRR and the research, from far and near, involved in this. Muses on the fact that, though all the usual processes are to the fore, the downside part of the industry is garment making which is the least developed side. Posits that the manufacture of clothing needs to become more technologically advanced as does retailing. Closes by emphasising support for the community in all its efforts.

Discusses the 6th ITCRR, its breadth of textile and clothing research activity, plus the encouragement given to workers in this field and its related areas. States that, within the newer research areas under the microscope of the community involved, technical textiles focuses on new, ‘smart’ garments and the initiatives in this field in both the UK and the international community at large. Covers this subject at length.

This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming and powder metallurgy are briefly discussed. The range of applications of finite elements on the subjects is extremely wide and cannot be presented in a single paper; therefore the aim of the paper is to give FE users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An appendix included at the end of the paper presents a bibliography on finite element applications in material processing for the last five years, and more than 1100 references are listed.

Stress computation in finite element materially non‐linear analysis is an important problem that has perhaps been receiving less attention than it deserves. Not only does it consume a significant share of total computer time, but also inaccuracies and ‘savings’ thereupon may well jeopardize the gains aimed at by sophisticating elsewhere the numerical strategy. A well established algorithm for stress computation is reviewed in detail, illustrating a number of computational hazards and proposing simple solutions.

For several years, the classic car market has been attracting considerable media and public attention, but the research literature is virtually nonexistent. The purpose of this paper is to address the factors that determine the values of classic car models and explain the remarkable price differences among them.

The paper develops and tests a set of research hypotheses about the effects of model characteristics on market values in the context of a generalized hedonic price model that also accounts for heterogeneity among classic car brands.

It is demonstrated that classic car model values reside at several levels and are determined by observable characteristics pertaining to aesthetics, rarity, engineering and performance. In addition, we show that classic car marques play a critical role in the determination of model values and account for considerable variation in values, even after controlling for observable model attributes

This is one of the first empirical studies to address classic car model value formation. The findings reveal how measurable, observable factors determine classic car model values and augment our understanding of a very interesting but understudied market.