48 research outputs found
Localization Techniques for Water Pipeline Leakages: A Review
Pipeline leakages in water distribution network (WDN) is one of the prominent issues that has gain an interest among researchers in the past few years. Time and accuracy play an important role in leak localization as it has huge impact to the human population and economic point of view. The complexity of WDN has prompt numerous techniques and methods been introduced focusing on the accuracy and efficacy. In general, localization techniques can be divided into two broad categories; external and internal systems. This paper reviews some of the techniques that has been explored and proposed including the limitations of each techniques. Â
Pump power distribution in bidirectional pumped dual-stage L-band EDFA
Bidirectional pumped dual-stage L-band EDFA utilizing a single power splitter and pump laser has been presented in this paper. A power splitter has been used to distribute the pump power bidirectionally to pump two EDFs with different length. An average gain of 18.6 dB with average NF of 8.6dB has been attained when the signal is equal to 0 dBm ranging from 1570 nm to 1605 nm signal. By using a single pump simultaneously with low gain ripple of less than 0.7 dB throughout the L-band transmission window
Load and Household Profiles Analysis for Air-Conditioning and Total Electricity in Malaysia
Load profile of household air-conditioning (AC) and total electricity consumption is essential to increase the stability of the energy demand on the grid. Therefore, field measurements on time series data of total and AC electricity consumption from 20 households were conducted from March 2016 to August 2017. The questionnaire survey was carried out simultaneously to grasp the profile of each family. The average total daily and AC consumption were 14.5 kWh/day and 3.9 kWh/day, respectively. The average hourly electricity consumption for total was 0.6 kWh/hour, meanwhile for AC was 0.2 kWh/hour. About 20% of the total peak demand was contributed by the consumption of AC. The indoor air temperature was measured in the bedroom (BR) when AC was switched ON and OFF with an average of 27 ∘C and 29 ∘C, respectively. However, the indoor air temperature in the living room (LR) was 2∘C and 1∘C higher if compared to BR for both conditions. Based on the questionnaire survey, 92% of the occupants preferred a temperature setting below than the level recommended by the Malaysian standard i.e., 24 ∘C. These results might be beneficial to understand the occupant behavior of electricity demand in Malaysia for designing smart grid energy systems in the future
Short-Term Measurements of Household Electricity Demand During Hot Weather in Kuala Lumpur
The aim of this study was to conduct short-term measurements on household electricity demand under hot weather conditions in a residential area in Kuala Lumpur. The measurements included total and air conditioner (AC) electricity consumption of 10 households in an apartment building as well as outdoor air temperatures, which were collected from March to May 2016. Results indicated that the average AC electricity consumption contributed to a major portion of total household electricity consumption, which ranged from 19.4 to 52.3% during the measurement period. Additionally, 1-minute interval time series data indicated household energy consumption more accurately than 30- or 60-minute interval
Performance Improvement for Hybrid L-band Remote Erbium Doped Fiber Amplifier/Raman using Phase Modulator
We have demonstrated the performance improvement of L-band hybrid remote Erbium-doped fiber amplifier by introducing a phase modulator to suppress the stimulated Brilloiun scattering (SBS) effect in the transmission. The transmission gain has improved by 12.65dB while the noise figure has reduced by 47.1dB when 0dBm signal power is generated at 1590.05nm wavelength. Furthermore, the optical signal-to-noise ratio has improved from 7.81dB to 29.72dB when the signal power is varied from -30dBm to 0dBm. By implementing a phase modulator to the input signal somehow able to produce better performance regarding gain, noise figure and optical signal-to-noise ratio, especially at the higher signal power as the gain, has been transferred to the Stokes signal and the amplified signal
Investigation of Multiwavelength Laser Performance based on Temperature Variation of PMF and different SOAs
We demonstrated a multiwavelength performance based on bidirectional Lyot filter at different temperature of polarization maintaining fiber (PMF) and semiconductor optical amplifiers (SOAs). The multiwavelength fiber laser (MWFL) based on bidirectional Lyot filter is not investigated thoroughly on its channel spacing tunability due to birefringence change. A channel spacing of this MWFL is tunable due to birefringence change of the PMF. The birefringence value of is changed by heating the PMF, that leads to narrower channel spacing. From the experimental data, the temperature coefficient based on PMF length of 53.2 m and 10.6 m is 0.49 ×10-3 nm/°C and 1.35 ×10-3 nm/°C, respectively, thus shorter PMF is more sensitive to temperature. We also investigated the multiwavelength performance at different SOAs. When the SOA from Qphotonics is changed to the SOA from Alphion, the extinction ratio is reduced from 15 dB to 8 dB. In terms of flatness value, the Qhotonics’s SOA has a flatter multiwavelength spectrum with only 1 dB of peak power difference from 1538 nm until 1541 nm as compared to 2.5 dB when using Alphion’s SOA
Characterization of Wideband Semiconductor Optical Amplifiers based on OptiSystem and MATLAB
A study about different types of semiconductor optical amplifiers (SOA)s - linear, nonlinear and in-line SOAs modelling is carried out. The SOA key performance characteristics covered in this paper include optical gain, power, and amplified spontaneous emission (ASE) noise figure. These characteristics definition are included in this work together with the tabulation of each SOA specification parameter operating in the operational conventional (C-) band. The first modelling of SOA wideband travelling wave (TW) component is done through a simple configuration using OptiSystem software. Next, the second modelling method is simulated through numerical steady-state model using MATLAB software. Each graphical result is explained and discussed according to the operational characteristic theories of SOA along with the evaluation for the best performance among the types of SOAs. The contrasted result among them had shown that linear SOA has the most ideal and competitive characteristics, as compared to the nonlinear and in-line SOAs, especially a better choice as gain medium in the multiwavelength fiber laser (MWFL) application
Time series data measurement on electricity consumption for selected domestic appliances in typical terrace house of Malaysia
This paper describes the pattern of electricity consumption from total and selected domestic appliances at a typical terrace house in Malaysia. The measured appliances can be classified into four groups on the basis of pattern of use which are ‘standby’ (TV), ‘active’ (massage chair, charger of hand phone, laptop and power bank, washing machine, air-conditioners, iron, standing fan, shower heaters, rice cooker, toaster, microwave), ‘cold’ (refrigerator) and ‘cold and hot’ (water dispenser). The major contribution of monthly electricity consumption comes from ‘cold’ appliances that consume 118.8 kWh/month followed by ‘active’ appliances that consume 87.8 kWh/month and ‘cold and hot’ appliance with 52.5 kWh/month. ‘Standby’ appliances shown a small contribution to the total electricity with 0.9 kWh/month. The amount of energy consumed depends on time-of-use, power characteristics of particular appliances as well as occupancy period
Effect of semiconductor optical amplifiers types on multiwavelength fiber laser performance
This paper demonstrates a multiwavelength fiber laser (MWFL) using different types of semiconductor optical amplifiers (SOAs) in conjunction with Lyot filter as comb filter. Three different SOAs were compared; linear, non-linear and booster optical amplifier (BOA). The multiwavelength generation using BOA had produced the best performance with extinction ratio (ER) of 52dB and peak power of -13.2dBm
Investigation of Multiwavelength Performance Based on Different SOAs
We investigated multiwavelength fiber laser (MWFL) performance using different types of semiconductor optical amplifiers (SOAs) utilizing Lyot filter as comb filter. The lasing performances of linear SOA (LSOA), nonlinear SOA (NLSOA) and booster optical amplifier (BOA) at different current settings were observed. Among the three SOAs, LSOA has the best lasing performance due to the lowest peak power difference with the highest number of lasing lines, a high ER value of 42 dB and considerable high peak power of -14.1 dBm at 550 mA. The multiwavelength laser is stable within 60 minutes at power fluctuation of less than 0.2 dB. The output spectra at 550 mA for all the SOAs are 70 nm to 80 nm wavelength difference from the ASE spectra