Residential electricity demand can be influenced by the behavior of users. Therefore, it is essential to know users’ behaviors to reduce electricity consumption or for energy saving. This research aims to analyze users’ behaviors concerning the use of light-emitting diodes (LED) lamps in the residential sector in Makassar, Indonesia. Moreover, the drivers of users’ behaviors in terms of usage and habitual behavior are also identified by two composed regression models. Some options for both models were compared by using statistical tests to get better models. A questionnaire was developed, and the survey was done on respondents that have 900 VA and greater of installed power capacity in their homes to get data for analysis. The main finding of this research shows that the user’s perception of energy saving was quite good. Both proposed models, namely LED usage model and habit model, were well §validated with R adj 2 a value above 39% for both models. Six considered variables can explain usage behavior better than the habit of users. Among the significance variables, the factor of the technology aspect has the highest effect on the usage of LED lamps and the general perception factor for the user’s habit. Presented results may give useful information in designing programs for consumers in Makassar, such as energy conservation programs or home energy management systems.

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Cogging torque in permanent magnet machine application effects to some undesirable vibration and noises. To minimize the cogging torque in permanent magnet machine’s the most important issue recently. Influence the number of edge points in the magnet of one and two steps of magnet edge slotting was studied in this paper’. For purpose of study, the structure of permanent magnet machine with 18 slot / 8 pole has been chosen, and the magnetic flux of all magnets was radial. The finite element of 2D based on FEMM 4.2 software was implemented to analysis the magnet flux distribution in air gap. Simulation results showed that by improvement of edge point at magnet edge of the two steps of slotting in magnet edge could reduce the cogging torque of permanent magnet significantly when compared with the initial structure. Employing the numerical simulation, both of the machine structures were analysed. It has been found that, the cogging torque reduction of edge points with 8 points has the highest reduction around 98.84 % compared with initial structure of the permanent magnet machine.

A new technique in reducing the cogging torque by combining the magnet edge shaping and dummy slot in stator core of fractional slot number in permanent magnet machine was studied in this paper. The cogging torque is the most issue in permanent magnet application, since it effects to reduce the machine performance. A permanent magnet machine of fractional slot number with 24 slot/20 pole was presented in the paper. Firstly, the permanent magnet machine with conventional both of magnet structure and stator structure has been investigated as the basic reference of initial structure. Secondly, the magnet edge shaping with conventional stator core was investigated. Thirdly, in proposed structure, the combination of magnet edge shaping with dummy slot in stator was employed. The three different structures of the permanent magnet machine then analysed and compared. By implementation of magnet edge shaping combined with dummy slot in stator core has increased the interaction between magnet and stator core. This leads to increase the cogging torque frequency and reduce the peak value the cogging torque of the machine. Using the FEMM, the cogging torque value of the permanent magnet machine was analysed and computed. It was found that cogging torque reduction of the proposed structure as much as 99.47 % compared with the initial structure.