Nowadays many robot approaches to robust control problems are applicable only to linear systems for nonlinear systems; we may not be able to easily compute the solution to the optimal control problem as analytical solutions may not be available problem is that statically-stable wheeled mobile robots can easily become dynamically unstable. If the center of gravity is too high or the robot accelerates/decelerates too rapidly or is on a sloping surface so the power supply are necessary for input to actuator robot. This paper presents mode control solutions in power supply for support Omni mobile robot. The performance compare between Continuous Conduction Mode (CCM) and Discontinuous Conduction Mode (DCM) in Power supply. The experiment on the 5V/50W 100 KHZ prototype CCM and DCM converter which have been designed and builted with similar circuit layouts and component. Aspects to be compared are stability voltage and ripple factor. The both operation mode are discussed based on the simulation and experimental result.

This research was to influence of electrode force affecting the complete of the resistance spot welding. The specimen was mild steel sheet metal has 1 mm. thickness. Then applied the force to the specimen are 1.0 2.0 3.0 4.0 and 5.0 kN. The welded specimens were tested by tensile shear testing according to JIS Z 3136: 1999 and Macro structure testing according to JIS Z 3139: 1978.The results showed that electrode force had affected on tensile shear and nugget size at 95% confidential (P value > 0.05). The low electrode force had increase the nugget heating because it had a high resistance (Q=I2Rt) and increase the gab between specimen. When the resistance increasing so the current flow will difficult to passed that fusion zone will had a high heating. It will affected to nugget seize heat affected zone and mechanical properties decreasing. The electrode forces are complete 2.0 kN. Tensile shear 6.39 kN and Nugget Size 5.83 mm. This data can be applied to be used as process monitoring of resistance spot weld quality.

However recognized as more sustainable and safer way for crop production organic agriculture is still facing many technical difficulties. One of the problems is concerning the management of posthavest disease caused by fungal pathogens. Since the applications of synthetic fungicides are prohibited thus organically produced crops are more vulnerable to be attacked by pathogens. Therefore the development of novel reliable and more compliant technologies for diseases management are required. The aim of this study was to demonstrate the potential use of plant essential oils as biofumigant to control of fungal diseases of tomato during storage. We selected three essential oils including clove oil cinnamon oil and ajowan oil for this study. The in vitro test for antifungal activity showed that the volatile headspace of the three oils exhibited potent effect on the test pathogens which includes Botrytis cinerea Fusaruim oxysporum and Aspergillus niger. Then ajowan oil which showed highest inhibitory effect was further evaluated for its effectiveness when applied as biofumigant. Results from the experiment indicated that fumigation with ajowan oil can reduce the occurrence gray mold decay of tomato (caused by B. cinerea) significantly. The rate of control was up to 100 % during fifteen days of storage at 20 ºC. These results support the idea of using the essential oil as biofumigant for protection of postharvest tomato from fungal diseases. However further comprehensive studies are still required especially on the issues concerning the reliability and eco-efficiency of this method at trial and commercial level.

The purpose of this research was to develop new mixed fiber from waste cocoon and other plant fibers. It was found that waste cocoon has qualitative properties to produce new mixed fiber when mixed with five kinds of plant fibers namely cotton yarn linen yarn pineapple yarn ramie yarn and hemp yarn. The processes included boiling waste cocoon in wetting agent water and Sodium Carbonate for 30 minutes at 90 ºC and dehydrating it. After that short cocoon yarn was obtained. Then mix it with the five kinds of plant fibers with the ratio of 50:50 in carding at silk card and undergo mixing and spinning process. Qualitative test result of new mixed fiber from waste cocoon used as weft yarn and five kinds of plant fibers used as warp yarn in industrial weaving showed that fiber from waste cocoon mixed with hemp yarn has the best breaking strength of 194 CN/tex followed by waste cocoon mixed with ramie yarn of 149 CN/tex waste cocoon mixed with linen yarn of 146 CN/tex waste cocoon mixed with pineapple yarn of 145 CN/tex and waste cocoon mixed with cotton yarn of 143 CN/tex. Meanwhile fiber from waste cocoon mixed with heft yarn has the best mean elongation of 2.30 cm followed by waste cocoon mixed with cotton yarn of 2.32 cm waste cocoon mixed with ramie yarn of 2.77 cm waste cocoon mixed with linen yarn of 3.42 cm. and waste cocoon mixed with pineapple yarn of 3.43 cm. Thus the research results indicated that fiber from waste cocoon mixed with hemp yarn is good for producing home textile as it has the highest breaking strength while fiber from waste cocoon mixed with pineapple yarn is good for producing clothes.

Genetic algorithms are applied to the multiple products and multiple periods inventory lot-sizing problem with supplier selection under storage capacity. The objective of this research is to calculate the optimal inventory lot-sizing for each supplier and minimize the total inventory cost which includes joint purchase cost of the products transaction cost for the suppliers and holding cost for remaining inventory. It is assumed that demand of multiple products is known over a planning horizon. The problem is formulated as a mixed integer programming and is solved with genetic algorithms. Finally numerical example is provided to illustrate the solution procedure. The results determine what products to order in what quantities with which suppliers in which periods.