All minutes are not equal: travel time and the effects of congestion on commute satisfaction in Canadian cities

Despite decades of research, it is unclear under which circumstances travel is most onerous. While studies have found that some individuals derive positive utility from aspects of commuting, others have shown that traffic congestion can entail important time, monetary, and mental stress costs. Moreover, responses to traffic congestion-related stressors differs by individual characteristics. In response, this research captures how exposure to traffic congestion events, the duration of this exposure, and individual trait susceptibility to congestion affect the utility of commuting. Working through the lens of individual satisfaction with the duration of their commute, we show that not every minute of travel is valued the same by car commuters in Canadian cities. Results suggest a complex relationship between travel time, congestion, and individual predisposition to congestion-related stress. While improvements in travel time matter for increasing commute satisfaction, it is reductions in travel in congested conditions that matter most, particularly among those susceptible to congestion-related stressors.     

Optimal allocation of fleet’s spare parts for system reliability

Allocation of fleet’s spare parts is rarely studied due to its complexity. However, this task is extremely important because the warship’s service level highly relies on the maintenance logistics’ level. In this study, the readiness ratio is proposed as a critical index in measuring the system’s reliability. A well-established mathematical model adopting the optimization method of spare part allocation is also introduced. The objective is to minimize the number of each spare part while satisfying the fleet’s system reliability. The fault tree analysis (FTA) is applied to analyze the system’s failure logic and stratify the units on ship. As a result, the strategy of spare part sharing can be introduced in detail. The solution algorithm is developed, and the simulation experiments to obtain the key parameters are conducted. The proposed model and algorithm are applied to an actual fleet of two warships, and results show that the method above is feasible and can be directly applied into practice.     

Singapore’s Vehicle Quota System and its impact on motorcycles

Singapore’s Vehicle Quota System, implemented in 1990, uses uniform-price auctions to allocate Certificates of Entitlement (COE) or registration rights in five categories presently. Four of these are restricted to small and big cars, commercial vehicles and motorcycles. The fifth one is unrestricted as it allows successful bidders to register a vehicle in any restricted category of their choice. Owners are incentivised via another policy to deregister their vehicle by the tenth year expiry of the COE instead of revalidating it. Each deregistration results in a new COE. Currently, 10% of the COEs from each restricted category is channelled to the unrestricted category. However, hardly any of the expensive COEs in the unrestricted category has been used to register motorcycles. The sharp decline in the number of motorcycle COEs since 2014 has led to a surge in auction premiums at about twice the price of an entry-level motorcycle. The auction process before 2014 is shown to be exemplary with the COE premium driven by its inertia and a host of exogenous factors. After 2014 however, it appears to be unresponsive to the historically low quota levels. This undesirable auction trait needs to be remedied by a reformulation of the COE quota in order to help those most in need of a motorcycle to earn a living. Measures announced in the February 2017 Singapore Budget trudge in that direction.     

Network concentration indices for less-than-truckload transportation

An efficient and service-oriented transportation network is a necessary resource for successful less-than-truckload operations. The design and evaluation of transportation networks are mainly driven by quantitative particularly cost-oriented measures, such as transport and transshipment costs. This type of measurement, however, simply cannot represent the manifold performance of a transportation network. In particular, incorporating network concentration into network design decisions overcomes the shortcomings of purely cost-oriented decisions because spatial network concentration is at the root of many aspects of network performance (e.g., congestion and network vulnerability). This paper suggests modifications to the network concentration index and the hubbing concentration index from the passenger airline context for less-than-truckload road transportation. The modified indices enable information to be conveyed by network concentration into less-than-truckload network design decisions and provide a suitable perspective to include service-oriented aspects into network design.     

A study of the role of seafarers in combating piracy off the coast of Nigeria

Piracy off the coast of Nigeria portends grave danger to the economic, security, and sociopolitical development of the country. It also threatens both international and regional trade as well as the stability of the West African sub-region. Despite Nigerian government’s attempts to curb piracy caused by poverty, unemployment, including corrupt and weak maritime regulatory and security institutions, attacks by pirates have continued to occur off the country’s coast. Consequent upon the adverse effects of piratical attacks on their day to day activities, seafarers can facilitate the suppression of piracy off the Nigerian coast. This paper uses statistics, provisions of international instruments and domestic legislations, the United Nations Security Council resolutions, soft laws, and opinions of researchers to examine the nature, causes, and effects of piracy on seafarers in Nigeria. The author argues that seafarers are necessary partners to curb piracy off the coast of Nigeria through enforcing maritime security conventions and other related instruments as well as testifying against pirates during trials. In conclusion, this paper contends that acts of piracy adversely affect crew members’ life, health, family, job, and finance thereby providing an overwhelming motivation for seafarers to play a role in suppressing piracy off the Nigerian coast.     

Design of Wind Turbine Blade for Solar Chimney Power Plant

Aiming at the global efficiency of solar chimney power plant (SCPP), we design a wind turbine generation device to elevate its electricity generating efficiency. Based on wind power utilization theory, a new method is proposed to design a type of wind turbine blade for SCPP. The lift and resistance coefficients on different Reynolds numbers of NACA4418 airfoil, which is suitable for experimental solar electricity generation system, are determined by Profili-V2.0 airfoil design software, a program written in Matlab to calculate chord length of the airfoil. The optimization is conducted by class-shape-transformation (CST) parameterization method and Xfoil software. An airfoil design program is designed on the basis of blade element theory and attack angle with the highest lift coefficient to iteratively determine the inflow angle and setting angle. Prandtl’s tip-loss factor is applied to correct the setting angle, after the airfoil data are input into AutoCAD to build an airfoil model which is then imported into Solidworks to draw blades. A new way is put forward to design wind turbine blades in SCPP.     

Improving operational safety during icebreaker operations

The study presented in this paper aims at investigating what safety measures that can be taken to improve the operational safety during icebreaker operations in the Baltic Sea. During icebreaker operations, the icebreaker and the assisted vessel operate in close proximity to each other, a distance which can be even smaller if weather and ice conditions are severe. This poses a severe threat to the operation, since the extremely short distance between the vessels leaves no room for error. The results, which are based on data collected through individual interviews and questionnaires, indicate several possible improvements. Firstly, on a regulatory level, the introduction of an ice navigation certificate for deck officers would set a minimal level of formal competency. Secondly, on a knowledge level, more ice navigation training and better language skills work in favour for the safety. Thirdly, on a technical level, having an electronic chart with target tracking capability increases the efficiency and safety of the passage through ice. In addition to these results, this study shows a need to further research the communication and language situation during icebreaker operations.     

Optimization of CMOS repeater driven interconnect RC line using genetic algorithm

In this work, optimization of complementary metal oxide semiconductor (CMOS) repeater driven interconnect resistive-capacitive (RC) line is carried out using genetic algorithm (GA). This work is aimed at powerdelay- product (PDP) minimization of RC interconnect at 180 nm technology node. The algorithm simultaneously optimizes the values of supply voltage, number of repeaters and repeater width for delay and PDP minimization. The accuracy of results obtained is verified by simulations from Cadence virtuoso tool. For delay minimization, comparison of GA results with previous results of the literature shows an improvement of 44.4% in the value of the optimal number of repeaters required. This improvement is obtained by increasing the repeater size, which also increases power dissipation, so a tradeoff has also been achieved in terms of PDP minimization. The comparison of PDP results obtained in this work, with the results at 70, 100, and 130 nm technologies from literature shows improvement in optimal number of repeaters required. The results of algorithm and simulations are in good agreement and demonstrate the validity of proposed algorithm.     

Enhancing the Efficiencies of Organic Photovoltaic and Organic Light-Emitting Diode Devices by Regular Nano-Wrinkle Patterns

Organic photovoltaic (OPV) cells and organic light-emitting diodes (OLEDs) are energy harvesting and generation devices that have attracted great attention these years because of their low costs, thin film structures, flexibility and environment-friendly manufacturing processes. For such thin film devices, photon management methods that increase the light absorption of OPV cells and the light extraction from OLEDs are highly desirable. Here, we report the experimental efforts to fabricate geometrically tunable and spontaneously formed nano-wrinkle structures with large areas, and the theoretical results on photon management with the nano-wrinkles.