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Several a posteriori error indicators and error estimators for frictionless contact problems are compared. In detail, residual based error estimators, error indicators relying on superconvergence properties and error estimators based on duality principles are investigated. Applications are to 2D solids under the hypothesis of nonlinear elastic material behaviour associated with finite deformations. A penalization technique is applied to enforce multilateral boundary conditions due to contact. The approximate solution of the problem is obtained by using the finite element method. Several numerical results are reported to show the applicability of the adaptive algorithm to the considered problems.

This paper outlines a dynamic domain decomposition‐based parallel strategy for combined finite/discrete element analysis of multi‐fracturing solids and discrete systems. Attention is focused on the parallelised interaction detection between discrete objects. Two graph representation models for discrete objects in contact are proposed which lay the foundation of the current development. In addition, a load imbalance detection and re‐balancing scheme is also suggested to enhance the parallel performance. Finally, numerical examples are provided to illustrate the parallel performance achieved with the current implementation.

This paper proposes that the quality of a company’s authorization system should be measured by two major considerations. First, the system should enhance the quality of customer service by reducing the waiting time at the point of sale. Second, it should reduce the risk of accepting transactions of bad credit. In this paper, a major credit card company is used to demonstrate how the credit authorization process can be improved using a quantitative approach. Opportunities for quality improvement were first identified through brainstorming sessions with top management, using quality improvement tools. A new sampling inspection scheme was then developed, based on analysis of the risk of requests for transactions in different industries. With the new inspection scheme, the total inspection cost was significantly reduced. A queuing model was then used to redesign the authorization process. Finally, a simulation model was used to test and evaluate the new process design. As a result of these improvements, it was determined that more than US$2.5 million was saved annually and authorization efficiency was improved by more than 40 per cent.

The total Lagrangian formulation and implementation of the element‐free Galerkin method (EFG) is presented for the analysis of contact‐impact problems with large deformations and for the simulation of metal forming processes. An integration scheme based on stress points is used, so no mesh is needed. A simple but general contact searching algorithm is used to treat the contact interface and an algorithm for the contact force is presented. Numerical results for Taylor bar impact are compared to finite element solutions and agree well. Solutions to upsetting, extrusion of metals with large material distortions are given to show the effectiveness of the algorithm. In particular, EFG is shown to be more capable of treating motions of the workpiece around corners of the punch than finite element methods.

Travel interests of tourists during pandemics and outbreaks are reduced due to the prevalence of fear. It induces lifestyle changes, which may hinder efforts to recover the tourism value chain during post-COVID-19 lockdowns. Subscribing to domestic travel and domestic tourism is deemed to mitigate fear and gradually reopen the tourism industry. Although a crucial initiative, evaluating the perceived degree of exposure of tourists to COVID-19 in tourist sites operating under domestic tourism has not been fully explored in the emerging literature, which forms the main departure of this work.

The problem domain is addressed by adopting multiple criteria sorting method – the VIKORSORT. To demonstrate such application, with 221 survey participants, 35 tourist sites in a province in the central Philippines struggling to revive the tourism industry are evaluated under six attributes that characterize tourists' exposure to COVID-19. To assess its efficacy, the performance of the VIKORSORT is compared to other distance-based multiple criteria sorting methods (i.e. TOPSIS-Sort and CODAS-SORT).

Results show that proximity and volume of tourist arrivals are considered on top of the priority list of attributes. The use of VIKORSORT yields the assignment of 27 sites to the “moderate exposure” class, and eight under the “high exposure” class, with no tourist site assigned to the “low exposure” class. Sorting the tourist sites reveals some observations that tourists prefer sites (1) with open spaces, (2) with activities having limited group dynamics, (3) that are nature-based, and (4) with tourist arrivals that are not relatively high, with enough land area to practice social distancing. In addition, the assignments of the VIKORSORT with TOPSIS-Sort and CODAS-SORT are consistent at least 90% of the time, demonstrating its efficacy in addressing multiple criteria sorting problems.

This work provides an integrative approach in evaluating tourist sites in view of tourism recovery during pandemics. The findings offer crucial insights for the primary stakeholders (i.e. government, tourist operators, and tourists) in planning, resource allocation decisions, and policy formulation. Policy insights are offered, as well as avenues for future works.

The stiffening international competition facing the Swedish chemical industry has led to a transition from commodity chemicals to speciality chemicals. Emphasis on speciality chemicals places demands on the flexibility of production systems. Analyses the issues regarding flexible production in the chemical industry in terms of the means of achieving flexibility and factors affecting flexibility, based on a study designed as a case study of two production units in a Swedish chemical company. Demonstrates the multi‐dimensional nature of the problems surrounding flexibility, and that technical and social factors interact to achieve a state of flexibility. Controlled by skilled employees, new technology may be a powerful means of achieving flexibility. Shows that technological factors may be associated with heavy restrictions that can be only partly offset by the social system.

We link counterproductive work behavior (CWB) (particularly workplace bullying) and organizational citizenship behavior to individual narcissism and organizational culture. We link counterproductive work culture in turn to organizations' leader(s), enumerating multiple roles an executive may play: actor, target, ignorer, enabler, rewarder, or, ultimately, champion of change. Both positive (citizenship) and negative (counterproductive) behaviors are associated with narcissism, a complex, multifaceted set of personality characteristics, primarily based on the individual's cognitive interpretation of self and the world. Theoretical interpretations of reactive CWB (stressor-emotion-control theory) and instrumental CWB (theory of planned behavior) support the development of coaching and counseling interventions. Cognitive behavioral theory (CBT)-based prescriptive executive coaching is proposed as a promising mechanism for redirecting narcissistic organizational players from counterproductive to citizenship schemas and behaviors.

The purpose of this paper is to explore some key factors that influences ethnic entrepreneur’s decision in starting-up a new business in Aberdeen, Scotland.

The authors set out to investigate the motives, drivers and attitudes of ethnic minorities in seeking entrepreneurial opportunities. The authors conduct in-depth face-to-face interviews with 25 ethnic entrepreneurs from a variety of nationalities and cultures originating mainly from the Indian subcontinent region. This includes entrepreneurs from India, Bangladesh, Pakistan, Sri Lanka and some others. The motivations varies according to their culture, traditions, religion and other environmental factors influencing on their decision to start-up.

The results reveal some interesting influential factors that lead to the successful start-up decision. These include a positive mindset, self-efficacy, strong determination, knowing of the market and local business culture and good financial management.

This paper is based on empirical research and new data have been collected specifically for this research. The authors hope the new findings from this research work will enhance the understanding about ethnic minority businesses in the context of Aberdeen, Scotland.

This paper presents a general procedure for solving 3D contact problems with implicit finite element codes. Emphasis is put on generality and robustness. Bodies in contact can be 3D solids or shells. Material and geometric nonlinearities can be dealt with (elasto‐plasticity, elasto‐visco‐plasticity, nonlinear elasticity, large displacements, strains and rotations). Different kinds of interaction are supported (tied, slip, friction). Advantage is taken of the solution history in order to improve the efficiency of the search algorithm. Numerical examples illustrate the general character of the proposed algorithm.

The numerical solution of contact problems via the penalty method yields approximate satisfaction of contact constraints. The solution can be improved using augmentation schemes. However their efficiency is strongly dependent on the value of the penalty parameter and usually results in a poor rate of convergence to the exact solution. In this paper we propose a new method to perform the augmentations. It is based on estimated values of the augmented Lagrangians. At each augmentation the converged state is used to extract some data. Such information updates a database used for the Lagrangian estimation. The prediction is primarily based on the evolution of the constraint violation with respect to the evolution of the contact forces. The proposed method is characterised by a noticeable efficiency in detecting nearly exact contact forces, and by superlinear convergence for the subsequent minimisation of the residual of constraints. Remarkably, the method is relatively insensitive to the penalty parameter. This allows a solution which fulfils the constraints very rapidly, even when using penalty values close to zero.