Abstract
In the last decade, a growing number of studies have addressed the ongoing debate about whether corruption "sands" or "greases" the wheels of business at the firm level. This study revisits this debate and proposes a comprehensive theoretical framework to test whether corruption harms or boosts firm performance, as well as the extent to which this relationship is mediated by the countries' institutional settings, the size and strategic behaviour of the firms, and market competition. Based on a sample of 21,250 firms located in 117 emerging and developing countries, and resorting to instrumental variable (IV) estimations, three main results were found: (a) regardless of the proxy used for corruption and firm performance, the former clearly harms the latter; (b) corruption "greases the wheels" of business for African firms but it "sands the wheels" for firms in Latin America, the Caribbean, Eastern Europe, Central Asia, and Southern Asia; and (c) the negative impact of corruption on performance is mitigated for larger and exporting firms.

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Abstract
The great potential of Unmanned Vehicles (UV) for services is supported by the evolution of drones and their flexible ability to help us performing dangerous, boring and difficult tasks. The common communication solutions e.g., radio, consider a pilot and a vehicle in the same location. Besides, the alternatives based on Ground Control Stations (GCS) are difficult to configure, which makes it difficult for a common user and a developer to use and/or implement new services for drones. This work proposes a solution with a new messaging protocol to overcome the previous problems, allowing controlling a UV in a remote location after a simple configuration. The implementation of this approach is based on a cloud platform, responsible for UV and user management, and on TCP/IP WebSockets for the user to control remotely located vehicles, anytime and anywhere. This research starts with the analysis of the prior work regarding UV communication technologies and the available GCS. Minding the identified problems, we designed an architecture that represents a cloud platform and multiple users and UVs in different networks. To prototype this architecture, we developed the user interface, the platform and the UV control module. The functional assessment considers a generic simplified and controlled scenario, focusing on the real-time control and video stream. The results confirmed the possibility to control a UV in a different location, in real-time, with an average response time of 25ms. This work provides valuable insights regarding the communication in the fields of anytime and anywhere device control and vehicle-based services.

Abstract
Central areas of large cities offer in general many advantages to their inhabitants. Typically, a large number of products, services, and opportunities are available in those urban zones, thus increasing life quality. Unfortunately, these benefits are associated with increasing transportation activities that can cause serious problems, such as traffic congestion, excessive energy consumption, and pollution. This paper aims at presenting a new transport system that consists of transporting freight in long-haul passenger vehicles. Two mixed integer mathematical programming models are presented: one for total cost minimization and the other for the travel time minimization. The problem under study was considered as a multi-commodity network flow problem with time windows, multi transport-lines, and multiple vehicles. Three heuristics based on mixed integer programming (MIP) were designed to solve it: size reduction, LP-and-fix, and a combination of these two procedures. The proposed approaches were validated in a case study designed around the intercity passenger transport system, in Ceará, Northeast of Brazil. Several operational scenarios were evaluated, taking into account the available freight capacities. The developed MIP heuristics produced high-quality solutions, in reasonable computational times, with the LP-and-Fix algorithm outperforming the other approaches. © 2020 The Authors. Published by Elsevier B.V.

Abstract
This paper describes the functional principle of a non-isolated gate driver with truly differential inputs (TDI) and the benefits of its application in GaN HEMT high-voltage resonant half-bridge DC-DC converters (LLC). This innovative gate driver is able to overcome the driving issues associated with DC ground-shift or AC noise between controller and driver IC ground potentials, enabling its application even in high-side driving as a replacement of isolated gate drivers. Test results obtained in a GaN HEMT based 600 W/400 V/300 kHz half-bridge resonant converter are provided. © VDE VERLAG GMBH · Berlin · Offenbach.