This paper proposes the bidirectional resonant converter with duty cycle voltage control using for CCTV with solar energy. The converter designed at 20 KHz for 20 W with 92.85 % of efficiency is operated at zero voltage switch mode for reducing the losses of converter. The modes of operation divide in two modes for operating bidirectional current. The first part is buck mode which has 5 volt at the output voltage and second is boost mode which has 8 volt at the output voltage. The two operation modes of converter will be discussed in this paper.

This thesis presents an application of particle swarm optimization technique (PSO) to optimal economic dispatch analysis in power system with contingency criteria for management power system operation cost power loss and bus voltage. The objective of optimal economic dispatch for contingency in power system compared with the results of analysis power system in normal case. The study result show that when contingency occur in power system operation cost are rising. In the other hand system stability are decrease.

The conductor of an order is the largest ideal of the ring of integers of a field which is contained in the order. In this paper we characterize conductors in quartic number fields whose norm is a power of unramified prime.

The purpose of this research is to study the construction safety measure for working at height. The safety measure for working at height in this research is developed by referring to the Ministerial Regulations prescribing the standard for administration and management of occupational safety health and environment for construction work 2008. The average of safety is low in five high rise construction projects in Bangkok metropolitan. So all parties involved in contractors need to focus on safety measure for working at height.