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The aim of this study is to design a guidance method to generate a smoother and feasible gliding reentry trajectory, a highly constrained problem by formalizing the control variables profile.

A novel accelerated fractional-order particle swarm optimization (FAPSO) method is proposed for velocity updates to design the guidance method for gliding reentry flight vehicles with fixed final energy.

By using the common aero vehicle as a test case for the simulation purpose, it is found that during the initial phase of the longitudinal guidance, there are oscillations in the state parameters which cause to violate the path constraints. For the glide phase of the longitudinal guidance, the path constraints have higher values because of the increase in the atmosphere density.

The violation in the path constraints may compromise the flight vehicle safety, whereas the enforcement assures the flight safety by flying it within the reentry corridor.

An oscillation suppression scheme is proposed by using the FAPSO method during the initial phase of the reentry flight, which smooths the trajectory and enforces the path constraints partially. To enforce the path constraints strictly in the glide phase, ultimately, another scheme by using the FAPSO method is proposed. The simulation results show that the proposed algorithm is efficient to achieve better convergence and accuracy for nominal as well as dispersed conditions.

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.

The main purpose of this paper is to select appropriate voltage vectors in the switching techniques and, by selecting the proper voltage vectors, be able to achieve a DC link with the same outputs and a symmetric multi-level inverter.

The proposed structure, a two-stage DC–AC symmetric multi-level inverter with modified Model Predictive Control (MMPC) method, is presented for Photovoltaic (PV) applications. The voltage of DC-link capacitors of the boost converter is controlled by MMPC control method to select appropriate switching vectors for the multi-level inverter. The proposed structure is provided for single-phase power system, which increases 65 V input voltage to 220 V/50 Hz output voltage, with 400 V DC link. Simulation results of proposed structure with MMPC method are carried out by PSCAD/EMTDC software.

Based on the proposed structure and control method, total harmonic distortion (THD) reduces, which leads to lower power losses and higher circuit reliability. In addition, reducing the number of active switches in current path causes to lower voltage stress on the switches, lower PV leakage current and higher overall efficiency.

In the proposed structure, a new control method is presented that can make a symmetric five-level voltage with lower THD by selecting proper switching for PV applications.

The purpose of this paper is to investigate the compliance of foreign investment projects with local environmental standards in Ethiopia. It examines the cause and impact of the environmental problems created by such projects as well as the necessary policy response, especially by examining the role of the applicable bilateral investment treaties (BITs) in enforcing local standards.

The research approach is fundamentally an empirical study with some doctrinal analysis. The empirical data (qualitative) was collected through interviews, focus group discussions and observation tools.

The investment projects selected for the case studies were not complying with the local environmental standards, which resulted in several environmental problems. The major cause for the overall environmental problems was not a legal gap in the local standards, but the failure of enforcing such standards by the government bodies and foreign investors. The applicable BITs also played no role in environmental protection as they do not impose environmental obligations along with enforcement mechanisms. Non-compliance with local standards can be mitigated if the applicable BITs impose environmental obligations along with workable enforcement mechanisms – as a treaty obligation has more binding force. The author argues that, in general, foreign investments are not environmental-friendly unless otherwise strictly regulated by combining local environmental standards and a BIT that imposes environmental obligations (along with enforcement mechanisms) on the foreign investors, host state and home state.

The existing literature does not deal with the environmental problems, the enforcement constraints and the role of the applicable BITs together in a single publication. They separately address these issues, which do not give a comprehensive understanding of the cause-and-effect relationship. This paper fills this gap by presenting comprehensive findings that combine the environmental problems and the associated enforcement constraints as well as the role of the applicable BITs in this regard. It also contributes to the ongoing debate concerning whether foreign direct investment is good or bad for the environment by producing empirical evidence from Ethiopia, the African continent.

The purpose of this paper is to study the traffic‐police enforcement process and develop models to improve enforcement effectiveness given substantial budgetary and resource constraints.

The formulation crosses the concepts of lean manufacturing and linear programming. Traffic police officers, automated machines and the back‐office are modeled in a similar manner to that of a manufacturing plant, working together to achieve ticket production as a function of quantity and quality, based on a preferential ranking of offence types.

Using data from the Israeli traffic police over a six‐year period, the case study shows that given available resources, it is possible to retain ticket quantity whilst significantly improving ticket quality as defined in the road safety literature. The case study shows a 24 per cent increase in quality ticket processing whilst taking into account the court summons constraint and maintaining throughput levels. This draws from changes in the method of ticket‐production, production of warnings rather than tickets in certain cases and the application of new technologies.

The results are limited by the current lack of data and require a cost‐benefit analysis in order to further develop certain parameters.

The application of the approach improves the holistic planning of traffic enforcement activities as well as providing specific details, such as the number and distribution of ticket production.

This research merges three disciplines; operations research, road safety and operations management, generating a methodology for the planning and control of traffic police ticket issuance, which has not been analyzed in the literature to date.

The social protests on the streets of indebted sovereigns in crises across the Eurozone have made debt restructuring an imperative. Further delay in achieving this expeditiously and equitably significantly exacerbates the social costs of crises from which current and future generations will struggle to recover. This article examines the feasibility of the drastic and widespread debt restructuring needed to resolve the problem in the face of existing private law sanctions that protect individual creditor rights. It relies on an analysis of US policy in the transition to a securitized market and of key sovereign debt cases to reveal the historical contingency of private law protections. It concludes by showing that the effectiveness of private law protections have always been constrained by the overriding imperative to achieve debt sustainability with negotiated and consensual workouts. This can be achieved in the Eurozone with statutory constraints on enforcement action pending the settlement of debt workouts as suggested in a recent proposal.

The purpose of this paper is to apply agent-based modeling and simulation concepts in evaluating different approaches to solve ambulance-dispatching decision problems under bounded rationality. The paper investigates the effect of over-responding, i.e. dispatching ambulances even for doubtful high-risk patients, on the performance of equity constrained emergency medical services.

Agent-based modeling and simulation was used to evaluate two different dispatching policies: first, a policy based on maximum reward, and second, a policy based on the Markov decision process formulation. Four equity constraints were used: two from the patients’ side and two from the providers’ side.

The Markov decision process formulation, solved using value iteration method, performed better than the maximum reward method in terms of number of patients served. As the equity constraints conflict with each other, at most three equity constraints could be enforced at a time. The study revealed that it is safe to over-respond if there is uncertainty in the risk level of the patients.

Further research is required to understand the implications of under-responding, where doubtful high-risk patients are denied an ambulance service.

The need for good triage system is apparent as over-responding badly affects the operational budget. The model can be used for evaluating various dispatching policy decisions.

Emergency medical services have to ensure efficient and equitable provision of services, from the perception of both patients and service providers.

The paper applies agent-based modeling to equity constrained emergency medical services and highlights findings that are not reported in the existing literature.

By distinguishing between types of institutional constraints based on their susceptibility to bribery, this study aims to highlight the different mechanisms through which institutions influence bribery and export intensity. This work highlights the susceptibility of institutional constraints as a key consideration in understanding how bribery influences institutions and has implications for export intensity.

This study utilizes firm-level data from World Bank Enterprise Surveys using a fractional logit estimation method.

An analysis of firm-level data from 26 emerging economies shows support for a positive relationship between permit constraints and firm-level bribery payments. In addition, results provide partial support for a negative relationship between firm-level bribery payments and export intensity. Finally, this study finds partial support for the strengthening impact of financial constraints on the negative relationship between bribery payments and export intensity. However, contrary to our expectations, results indicate that tax rate constraints can weaken the relationship between bribery payments and exports.

This work contributes to international business literature by analyzing how home market institutions influence firms' export intensity. In addition, the study contributes to corruption research by highlighting the importance of heterogeneous susceptibility of formal institutional constraints to bribery. The focus on bribery responds to calls for work on firm misbehavior in international business.