Electricity-saving strategies are an essential solution to overcoming increasing global CO₂ emission and electricity consumption problems; therefore, the determinant factors of electricity consumption in households need to be assessed. Most previous studies were conducted in developed countries of subtropical regions that had different household characteristic factors from those in developing countries of tropical regions. A field survey was conducted on electricity consumption for Malaysian households to investigate the factors affecting electricity consumption that focused on technology perspective (building and appliance characteristics) and socio-economic perspective (socio-demographics and occupant behaviour). To analyse the determinant factors of electricity consumption, direct and indirect questionnaire surveys were conducted from November 2017 to January 2018 among 214 university students. Direct questionnaire surveys were performed in order to obtain general information that is easily answered by respondents. On the other hand, some questions such as electricity consumption and detailed information of appliances must be confirmed by the respondents’ parents or other household members through an indirect questionnaire survey. The results from multiple linear regression analyses of the survey responses showed that appliance characteristic factors were the main variables influencing electricity consumption and house characteristics were the least significant. Specifically, air conditioners, fluorescent lamps, and flat-screen TVs emerged as appliances with the most significant effect on electricity consumption. Occupant behaviour factors had a more significant influence than socio-demographic factors. The findings in this study can be used by policymakers to develop electricity-saving strategies in Malaysia.

A dual-stage erbium doped fiber amplifier (EDFA) having a flat gain wavelength response throughout L-band transmission window is presented. By applying pump power distribution technique, the pump power is distributed to two different stages with different length of EDF depending on the coupling ratio. By controlling these two parameters, gain of 19.1 dB with small gain variation of less than 0.5 dB and a noise figure of less than 10.5 dB are achieved in this architecture using bidirectional pumping. However, when another 3 dB power coupler is added to split the pump power equally at the second stage in bidirectional, a better noise figure of less than 7.5 dB was obtained. Comparison with a conventional single-stage optical amplifier was made in order to validate the performances of this dual-stage EDFA.

We demonstrate a Sagnac-interferometer-based multiwavelength fiber laser with an intensity-dependent loss (IDL) mechanism in the L-band region using a semiconductor optical amplifier (SOA) as the gain medium. The IDL mechanism flattens and stabilizes the multiwavelength spectrum. We also investigate the effect of rotation angles of polarization controllers (PCs) at different polarization devices on multiwavelength performance. At best settings, 31 lasing lines within 3 dB uniformity were generated with an extinction ratio (ER) of 17 dB. Adjusting the half-wave plate of PC1 and PC2 from 0° to 90° shifted the multiwavelength output by 0.01 nm and 0.072 nm, respectively. PC2 adjustment also affects the multiwavelength flatness as compared to PC1. Furthermore, the number of lasing lines and the ER were directly influenced by the SOA current.