Firefly algorithm is among the nature-inspired optimization algorithms. The standard firefly algorithm has been successfully applied to many engineering problems. However, this algorithm might be stuck in stagnation (the solutions do not enhance anymore) or possibly fall in premature convergence (fall into the local optimum) in searching space. It seems that both issues could be connected to exploitation and exploration. Excessive exploitation leads to premature convergence, while excessive exploration slows down the convergence. In this study, the classical firefly algorithm is modified such that make a balance between exploitation and exploration. The purposed modified algorithm ranks and sorts the initial solutions. Next, the operators named insertion, swap and reversion are utilized to search the neighbourhood of solutions in the second group, in which all these operators are chosen randomly. After that, the acquired solutions combined with the first group and the firefly algorithm finds the new potential solutions. A multi-echelon supply chain network problem is chosen to investigate the decisions associated with the distribution of multiple products that are delivered through multiple distribution centres and retailers and demonstrate the efficiency of the proposed algorithm.
Advanced technology in agriculture has enabled the manipulation of the artificial light spectrum in plant development such as improving yield and plant growth. Light manipulation using light-emitting diodes or LEDs can inhibit, delay, or even promote flowering. Some studies have shown that far-red (FR) light can stop flowering, but studies have not fully explored the best method involving intensity and duration to induce plant growth. This paper presents results on LED light manipulation techniques, particularly FR light, on plant flowering control and plant elongation. The light manipulation technique on the combination of colors, photoperiods, and intensities proved that it can stop flowering, and stimulate and control the growth of plants during cultivation. The system was monitored using an Internet-of-Things (IoT) remote monitoring system, and it performed data mining. The results showed that plants that were grown under artificial sunlight (T5) and normal light (T1) treatments were superior compared to others. The FR light delayed flowering until 50 days of planting and accelerated the plant growth and increased the fresh weight by 126%. The experiment showed that a high variable intensity at 300 µmol m−1s−1 showed a great performance and produced the largest leaf area of 1517.0 cm2 and the highest fresh weight of 492.92 g. This study provides new insights to the researchers and the farming community on artificial light systems in improving plant factory production efficiency and in determining the best plant cultivation approach to create a stronger indoor farming management plant.
1 March 2019 in International Journal of Japanese Sociology
Being the most demanding, challenging and exciting engineering and technological advances has provided escalated interests amongst the engineers at large to venture into the oil and gas (O&G) industry. Although claimed as the most expensive industry in the world via the utilisation of critical equipments, the O&G industry is still recording notorius failures in its project management especially due to turbomachinery issues, the heart equipment of any O&G project. Therefore, it is important for this paper to review turbomachinery project as one of the long lead items during project executions that is also proven to be the most costly and expensive equipment. This paper therefore discusses the gaps in turbomachinery studies via literature review in highlighting its application in O&G projects. It is found that the main components of turbomachinery are driver and driven equipment, which are applied for mechanical equipment, Electric Power Generation and heat generation for Combined Cycled Configuration. Important variables for turbomachinery selection include: (1) process requirement; (2) site location; (3) driver selection; (4) equipment sparing philosophy; (5) efficiency and reliability; (6) operability and maintainability; and (7) cost. It is hoped that this paper would lead to the successful project management of turbomachinery in the O&G industry.