Advanced Materials Research Vols. 488-489

Abstract: Sadness, one of the negative emotions, may cause undesirable impact to the daily life. Therefore, it is desirable to automatically detect sadness emotion in human-machine interactions in order to adopt measures to impair the negative effects caused by it. Speech is one of the means used by human to express emotions, therefore, it is reasonable to detect sadness emotion using speech samples. In this paper, we analyzed relevant speech features, and proposed an improved Back Propagation (BP) network for sadness recognition. The experimental results show that the improved BP network proposed has better performance than traditional BP networks in detecting sadness emotion.

Abstract: We consider the problem of stochastic optimization, where the objective function values are not available and need to be simulated to get their estimates. When the function values are available one can use the simulated annealing algorithm. In this paper, we modify an algorithm that uses the hill climbing feature of simulated annealing with fixed temperature to search the feasible solution set. The proposed algorithm uses indifference zone approach of ranking and selection method to compare the current optimal solution and the potential solution that guarantee the optimal solution with a pre specified level of confidence. The algorithm is tested on a (s, S) inventory problem and compared to other competing algorithm. The numerical results show that the proposed method outperforms the competing method and indeed locate the optimal solution quickly.

Abstract: Low cost electrochemical etching method was utilized to prepare macroporous silicon on p-type silicon substrate in dilute HF solution. By optimizing the substrate resistivity, the etching current density, and the etching time, excellent macroporous silicon was obtained on 15 Ω•cm p-type silicon substrate with the pore diameter of about 2 μm, the pore depth of about 30 μm, and the surface pore density up to ~107/cm2. Such macroporous silicon gave out an excellent antireflective performance with the reflectance lower than 4% in a wide spectral range of 400-1000 nm. The low reflectance combined with the deep pore morphology provides an attractive potential to fabricate radial p-n junction solar cells on such macroporous silicon.

Abstract: Ga doped Z_nO (GZO) films of different concentrations (1, 2 and 4 mol%) have been deposited on glass substrates by RF magnetron sputtering. The grown layers at room temperature have been subjected to structural, optical and electrical characterization. It has been found that 2 mol% Ga doped ZnO has best structural, optical and electrical properties which has been used as anode layer for the fabrication of Organic Light Emitting Diode (OLED). The Zn0.98Ga0.02O film was then deposited at a lower working pressure of 0.015 mbar to obtain a good carrier concentration. The OLED structure has been fabricated with best GZO as anode layer, [N, N*-Diphenyl N, N*-Di-p-Tolylbenzene-1] as hole emitting layer and (Alq3) as electron transport layer. The fabricated OLED device has been subjected to current-voltage characteristics.

Abstract: Management Information System (MIS) is an Integration information systems engineering of computer technology and network communications technology. It can be more accurate, timely, comprehensive, detailed record of the data, while further processing of all kinds of information. In this paper, MFC, GPS and GE (Google Earth) technology is used in managing Old and Valuable Trees information, to solve a series of existing problems of labor management. At the same time of improving the efficiency of information management, it can achieve the implementation of monitoring and tree information Virtual Tour by combination in GPS the point marked and Google Earth software.

Abstract: The application of electrophoretic deposition (EPD) technique for deposition of thick and thin film deposition has been extended not only on to electrically conducting materials but also to non-conducting material. The review encompasses the fundamental aspects of EPD technique and specific factors influencing the EPD process on non-conducting substrate. Important EPD processing parameters, during EPD on non-conducting substrate discussed are types of substrate, counter-electrode substrate and substrate additive. The parameters were discussed based on the up-to-date comprehensive overview of the current research progress in the field of EPD on non-conducting material.

Abstract: This study elucidates the significance of thermal transient measurement based on structure function evaluation particularly on high power LEDs. The metal core printed circuit boards (MCPCBs) were redesigned with reference to the product datasheet. Aluminium nitride was employed as the dielectric material of the MCPCBs and thermal performance of copper and aluminium substrate with different substrate thickness has been reported in this paper. It was observed that the aluminium based MCPCBs performed better heat dissipation compared to the copper based MCPCBs. In addition, when two different thicknesses of the MCPCB substrates were compared, it was observed that the thicker substrate performed a lower thermal resistance compared to the thinner substrate MCPCB. The junction to board thermal resistance was determined using the standard transient dual interface method.

Abstract: Proper heat management is necessary for better performance of the LEDs. In the present study, the thermo-optical properties of the LED with different type of PCBs were analyzed. The measurement was done with two different testing conditions to identify the effect of increasing drive current at constant ambient temperature and increasing ambient temperature at constant drive current on the the LEDs with different PCBs. In both the conditions, the thermal behaviors of the LED are affected much due to different type of boards. As the drive current increases, the junction temperature and RthJA of the LED with MCPCB reduces around 3.7K/W and 15.3K/W compare with the LED with FR4. The change in magnitude of chromaticity coordinates of LED with FR4PCB and MCPCB calculated as 0.154 and 0.132 respectively. At a lower ambient temperature, the LEDs with FR4 and MCPCB record the RthJA as 71.2K/W and 50.6K/W respectively. However, these values were lowered around 15% at higher ambient temperatures for both the LEDs. As ambient temperature increases, the shift in chromaticity coordinates for the LEDs with MCPCB and FR4 was obtained as 0.0163 and 0.0165. The influence of the different type of PCB’s performance on LEDs was observed in the increasing drive current condition rather than the increasing ambient temperatures.

Abstract: Due to environmental concern, lead-free solder are taking the place of eutectic Sn-Pb solder in electronic packaging industry. Among various lead free alloys, Sn–Ag–Cu (SAC) alloys are leading lead-free candidate solders for various applications because it is offered better properties. This study investigates the interfacial reactions during reflow soldering and isothermal aging between Sn-3.0Ag-0.5Cu (SAC305) and Sn-3.0Ag-0.5Cu-0.05Ni (SACN30505) on electroless nickel/ immersion palladium/immersion gold (ENEPIG) surface finish. The substrates were subjected to isothermal aging at 125°C for up to 2000 hours with solder size diameter of 500μm. The results indicated that after reflow soldering, (Cu, Ni)6Sn5 IMC is formed between solder and substrate while after aging treatment a new IMC was formed between (Cu, Ni)6Sn5 and substrate known as (Ni, Cu)3Sn4. Moreover, after soldering and isothermal aging, Ni-doped (SACN) solder represents a thicker IMC compared to SAC solder. Aging time of solder joints results in an increase of IMC’s thickness and changes their morphologies to become more spherical, dense and with larger grain size. In addition, the results also revealed that the thickness of intermetallics formed is proportional to the aging duration.

Abstract: By conventional production-line process, n-type Al-doped rear junction solar cell could be easily fabricated without any other equipment and process. Since the properties of n-type silicon material are different to that of p-type silicon material and the junction is placed at the back, the process parameters should be optimized theoretically to assess the efficient potential. By modeling cells using PC1D software, the effect of some process parameters on the properties of n-type base solar cells were studied, including base resistivity, bulk lifetime, front surface field and recombination rate of front surface. The key parameters were identified and the potential industrial efficiency was calculated.