We propose a method for developing an in-pipe inspection robot based on multiple inertial sensors. Estimating the position of underground pipelines where satellite signals do not reach remains challenging. High-precision inertial sensors and high-tech mobile robots can be solutions, but their high price limits their general use. We developed an in-pipe inspection robot by combining various low-cost sensors with a microcomputer-based RC car platform. First, we fabricated a multi-inertial sensors module by combining commercial grade low-cost MEMS inertial sensors. The sensor values measured by the multi-inertial sensor are transmitted to the main computer through the MCU, and the attitude angle of the vehicle is finally calculated through the inverse variance weighted average. The travel distance of the robot is estimated by using hall sensors and neodymium magnets attached to the inside of the wheels. Also, we measured the pipe diameter using multiple ultrasonic sensors. We verified the estimation accuracy of each sensor through experiments and consequently estimated the 3D trajectory of the in-pipe robot.

This study aims to suggest the methodology to improve to estimate back-calculated fish growth parameters using weighted average. It is to contribute to correct errors in the calculation of back-calculated growth equation with unequal numbers of sample by age. If the numbers of sample were evenly collected by age, each back-calculated length at age was equal between arithmetic and weighted averages. However, most samples cannot be evenly collected by age in reality because of different catchability by fishing gear and limitation of environment condition. Therefore, the estimation of back-calculated length by weighted average method is essential to calculate growth parameters. There were some published growth equations from back-calculated length using a simple arithmetic average with different numbers of samples by age when searching for back-calculated growth equations from 91 relevant papers. In this study, the process of deriving growth equation was investigated and two different average calculations were applied to a fish growth equation, for example of Acheilognathus signifer. Growth parameters, such as L∞, k and t0, were estimated from two different back-calculated averages and the growth equations were compared with growth performance index. Based on the correction of back-calculated length using weighted average by age, the changes by female and male were -14.19% and -5.23% for L∞, and 59.28% and 18.91% for k, respectively. The corrected growth performance index by weighted average improved at 7.05% and 2.46% by female and male, respectively, compared to the arithmetic averages.

In this study, daily precipitation data and daily average temperature data of meteorological observatories in Daegu, Busan, Daejeon, Seoul, Mokpo, and Gwangju cities inland and offshore were analyzed by using moving average method. Were compared. Overall, summarizing changes in precipitation and temperature over the 24 seasons, precipitation and temperature in all six stations increased compared to the past 1960s. In the case of precipitation, precipitation increased at the end of July and early August, whereas precipitation in April, September and early October decreased. In the case of temperature, especially in February, the temperature increased, and in Mokpo, the temperature from August to December showed a general decline. Changes in precipitation and temperature due to seasons in the 24 seasons affect agriculture and our everyday life, and further research is needed to determine how these changes will affect agricultural water supply, crop growth and daily life. The results of this study can be useful.