Over 700 bike-sharing systems are currently in operation worldwide, and the number of systems has grown quickly in recent years. Rwanda's bike-sharing system has only recently begun operations and has encountered numerous challenges. The current study used an Ordinal Priority Approach (OPA) to examine these challenges and provide an acceptable strategy for overcoming them. Five strategies have been established. These strategies are prioritized using four criteria. The results indicate that “theft” and “damage of some bikes when being returned” are the most critical challenges while the first alternative “improving the current bike infrastructure to better serve the bike share system” is the appropriate strategy to overcome these challenges for a successful operation of the bike share system. Taking into account the findings, recommendations were provided to help local administrative bodies handle these challenges.

Due to the wear of the brake linings of the rear brake, as well as due to the stretching of the steel rope of the handbrake control during the exploitation of the vehicle, the transmission mechanism of the handbrake increases the predefined clearances, that is, the free travel of the control lever increases. This free travel can increase to the extent that it compromises the normal functioning of the braking system. For this reason, all parking brake systems contain backlash adjustment mechanisms. On most vehicles, this adjustment is done manually, which means that the vehicle is periodically taken out of service for servicing. For this reason, the application of various mechanisms for self- adjustment of the handbrake, during the actual exploitation of the vehicle, began. This paper presents the process of design and construction of an innovative mechanism for continuous self-adjustment of the handbrake, without withdrawing the vehicle from operation.

Construction projects are of a particular nature and are affected by many factors, which exposes them to risks due to the long implementation period and the multiplicity of phases from the project idea phase through the implementation phase to the final delivery of the project, which leads to increased uncertainty and increased likelihood of these risks. This paper examines the risks in construction projects in Libya, and their impact on project objectives. This research identified risks in construction projects based on previous studies and a number of interviews with experts in construction projects, as well as field visits to project sites. On this basis, a questionnaire was prepared to locate and identify the risks that construction projects may face and was distributed to a number of local companies affiliated to the Libyan state operating in the construction sector. After the compilation of the questionnaire, the risks were analyzed qualitatively and quantitatively to determine the impact of each risk and the probability of its occurrence. The results of the study showed that 28% of the risks are certain and high, and 53% of the risks affect the project implementation time to a high degree. The results also showed a strong correlation between the probability of occurrence of the risks. Grey theory was used to weigh and rank the most important risks, and the most important of these was the insufficient manpower, material and equipment criterion.

Lightweight is one of the primary design goals for the innovative development of wheel hubs. A new type of automobile wheel rim is proposed in this paper. The wheel rim is divided into wheel rim face and rib. The thickness of the wheel rim surface is studied by parameter optimization. The rib layout is designed based on honeycomb features by considering processing technology and load-bearing performance of wheel hub. A novel wheel rim named “honeycomb wheel rim” is given. The mechanical performances are analyzed and the results show that the weight of new wheel rim was reduced by 12.61%, and the stiffness and strength can meet the design requirements.

Optimizing the supply chain of agricultural products is an important way to revitalize the rural economy. The perishable products are agricultural products with special properties and great potential. Game theory is an effective research tool for maximizing revenue management in competition and cooperation. Therefore, this study reviews the literature on the pricing and procurement of perishable products in the past three years under the game theory. Firstly, this study summarizes the common game models of supply chain through the review of multi-objective models. Secondly, it summarizes the literature on pricing and purchasing, and explores the strategies of product management, benefit maximization and supply chain coordination. Finally, based on some cutting-edge results, this study proposes promising research directions in the future. This study is helpful to summarize the application of game theory in supply chain management, help rural agricultural products to achieve maximum benefit, and solve the problem of supply and demand optimization.