Optical fiber connection navigation system using visible light communication in central office
An optimized optical-fiber-connection system for central offices is described. This system employs visible-light communication to reduce costs while maintaining the functions and usability of an earlier system. Little skill is needed to realize optical-fiber connection.
Visible Light Communication System Using Low-speed Image Sensor and Two-dimensional Optical Scanner
Visible light communication (VLC) is an optical wireless communication scheme that has potential uses in indoor navigation and in cooperation among vehicles. To receive data efficiently using commercial devices (e.g., smartphones), we proposed a VLC system using a low-speed image sensor and a one-dimensional optical scanner (polygon mirror and MEMS mirror) at a receiver (Rx). In this system, when a rapidly blinking light is incident to the Rx, the light is converted to a dotted and dashed line by an optical scanner, enabling the Rx to receive multiple bits modulated at a high frequency within one frame. However, a scanned signal overlaps with a scanned noise on the image-sensor under the condition that the signal and noise sources exist in the same scanning direction. In this paper, we address this signal-to-noise interference problem by using a two-dimensional optical scanner (galvo mirror). In our improved VLC system, the Tx emits a rapidly blinking light to the Rx. The Rx measures the positional relationship between the signal and noise sources prior to the communication. Then the Rx scans the incoming light using a galvo mirror, whose scanning direction is established to minimize the signal-to-noise interference. The performance of our improved system was evaluated in experiments. The experimental results suggested that the improved system could reduce interference between signal and noise while providing superior communication quality.
The effect of educational intervention on family planning knowledge, attitudes, and practices among married women in a military barrack in northern Nigeria.
Army barracks in Nigeria have low contraceptive prevalence rates (CPRs) and many children per family. The aim of this interventional study, involving 963 married women, is to determine the impact of health education on family planning knowledge, attitudes, and practices among married barrack women. The intervention group attended a 50-minute health talk and demonstrations on family planning methods. In the intervention group, the mean knowledge score rose significantly, from 5.5 points to 7.8 points post-intervention (t = -16.7281, p = 0.0000, df = 460). In addition, the CPR increased significantly, from 11.8% at baseline to 22.4% post-intervention (McNemar's chi2 = 125.41, p = 0.0000). Such significant changes were not noted in the control group. We conclude that health education is an effective intervention for improving knowledge about and attitudes towards contraceptives and their use among married women in military barracks in Nigeria. Intense and sustained health education is therefore recommended in addressing the low CPR in Nigeria.