Physical Responsibility Versus Financial Responsibility of Producers for E-Wastes

Extended producer responsibility (EPR) is a legislative mandate that requires a producer to be accountable for the whole life cycle of its product—from product design to final disposal. The EPR system is imposed to solve the problem of the growing e-waste in different areas of the world. Different countries have different system designs and approaches in EPR, depending on the country’s legislation, customer demand, incentives, and resources; it can either be a physical responsibility or a financial responsibility. Physical responsibility is when the producers are responsible for the physical movements of the e-wastes necessary, while financial responsibility is when the producers are financially supporting all the costs needed to successfully fulfil the EPR goals. In this study, we will determine which type of EPR system is better by doing a comparison on its social welfare value using a social welfare model. This study uses a notebook computer as an example, and based on our analysis, we conclude that the physical responsibility is better if and only if the rate of return of e-waste is equal to or greater than a certain percentage. Otherwise, the financial responsibility model outperforms the physical responsibility model. A sensitivity analysis is also carried for each parameter used in the two models for determining the significance.

Miniature DC-DC Boost Converter for Driving Display Panel of Notebook Computer

This paper proposes a miniature DC-DC boost converter to drive the display panel of a notebook computer. To reduce the size of the circuit, the converter was designed to operate at a switching frequency of 1 MHz. The power conversion efficiency improved using a passive snubber circuit that consisted of one inductor, two capacitors, and two diodes; it reduced the switching losses by lowering the voltage stress of the switch and increased the voltage gain using charge pumping operations. An experimental converter was fabricated at 2.5 cm × 1 cm size using small components, and tested at input voltage 5 V ≤ VIN ≤ 17.5 V and output current 30 mA ≤ IO ≤ 150 mA. Compared to existing boost converters, the proposed converter had ~7.8% higher power conversion efficiency over the entire range of VIN and IO, only ~50% as much voltage stress of the switch and diodes, and a much lower switch temperature TSW = 49.5 °C. These results indicate that the proposed converter is a strong candidate for driving the display panel of a notebook computer.

Design of GPU Based Non-coherent Signal Tracking Module for Real-time GNSS SDR

In this paper, we design and implement GPU-based non-coherent GPS signal tracking module for real-time SDR. When using CPU and GPU simultaneously, the signal tracking module should be designed considering the memory bottleneck between the two processors. The basic non-coherent module, which accumulates the 1msec correlation value 20 times, is changed to accumulate M(20/N) times of Nmsec units. From the experiments using real GPS signals, the computational performance of N=20 is improved by 80% compared to N=1. Therefore, the implemented SDR using notebook computer can tracks more channels simultaneously in the real time.