• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.11
• /
• pp.1596-1602
• /
• 2021

Battery-operated IoT devices in IoT systems require low power consumption. In general, IoT devices enter a sleep state synchronously to reduce power consumption. A problem arises when an IoT device has to handle asynchronous user requests, as the duty cycle must be reduced to enhance response time. In this paper, we propose a new low-power-consumption scheme, called Repetitive Wake-up scheme for IoT systems of asynchronous environments such as indoor lights control. The proposed scheme can reduce power consumption by sending wake-up signals from the smartphone repetitively and by retaining the IoT device in sleep state to the smallest possible duty cycle. In the various environments with IoT devices at home or office space, we showed that the proposed scheme can reduce power consumption by up to five times compared to the existing synchronous interlocking technique.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2015.10a
• /
• pp.322-323
• /
• 2015

Traditional rotation type large beacon was characterized by frequent failure, long repair time and high cost etc. These problems are caused by traditional light sources(metal halide lamps or tungsten halogen lamps). In order to solve these problems, IALA standards-based(efficiency and reliability) large LED beacon technologies are needed. we developed by applying a LED. The object of the this project, to design a reflective optics and the high power LED lighting engine module. And to develop a rotational speed control system for controlling flash pattern of beacon. As a result, to develop of LED beacon for landfall mark that distance to reach the light 20NM to 27NM.