The results of the measurements using an optical surface roughness meter are shown according to the angle changes of 0, 0.5, 1, 1.5, 2, and 3°. Through the experiment, it can be seen that the measurement value is 3.140 at 0°, 3.148 at 0.5°, 3.140 at 1°, 3.151 at 1.5°, 5.078 at 2°, and 4.790 at 3° setting. In addition, the test statistic (P) value is 0.000, which is smaller than the significance level of 0.005, so it was confirmed through the experiment that a measurement error occurs according to the angle change when measuring the surface roughness.

In this paper, we deal with the design of a model predictive control (MPC) for precise speed servo control of DC motor systems. The proposed controller is designed in the form of optimal control that calculates and outputs the optimized control input under constraints for each sampling. In particular, MPC designs the control inputs in advance for each sampling and predicts the outputs using them. Thus, it shows excellent control performance even in the case of disturbance or model uncertainty. The effectiveness of the proposed controller was demonstrated through computer simulations using MATLAB/Simulink and DC motor experimental system using real time controller. Moreover, the effectiveness of the proposed controller was confirmed by comparing its control performance with PID controller, which was tested under the same experimental condition as the MPC.

This study focuses on analyzing the energy-saving effects of the recirculation aquaculture system using seawater source heat pumps and solar power generation. Based on the thermal load analysis conducted using the transient system simulation tool, the annual energy consumption of the recirculation aquaculture system was analyzed and the energy-saving effects of utilizing the photovoltaic system was evaluated. When analyzing the heat load, the sea areas where the fish farms are located, the type of breeding tank, and the circulation rate of breeding water were taken into consideration. In addition, a method for determining the appropriate capacity for each operation time was examined when applying the energy storage system instead of the existing diesel generator as an emergency power, which is required to maintain the water temperature of breeding water during power outage. The results suggest that, among the four seas considered, Jeju should be estimated to achieve the highest energy-saving performance using the solar power generation, with approximately 45% energy savings.

In this study, data on indication errors within the range of 0 to 10 mm were measured using a dial gauge, which is widely used as a comparative measuring instrument in the field. Using Minitab, a statistical program, measurement conditions were determined during calibration of measuring instruments. Since the P value of the test statistic for the indication error is 0.000 to 0.003, the alternative hypothesis (H1) that no significant difference occurs due to a change in the measurement point at the significance level of 0.05 was adopted.

This study deals with the application of an artificial neural network (ANN) model to predict power consumption for utilizing seawater source heat pumps of recirculating aquaculture system. An integrated dynamic simulation model was constructed using the TRNSYS program to obtain input and output data for the ANN model to predict the power consumption of the recirculating aquaculture system with a heat pump system. Data obtained from the TRNSYS program were analyzed using linear regression, and converted into optimal data necessary for the ANN model through normalization. To optimize the ANN-based power consumption prediction model, the hyper parameters of ANN were determined using the Bayesian optimization. ANN simulation results showed that ANN models with optimized hyper parameters exhibited acceptably high predictive accuracy conforming to ASHRAE standards.

The CMM is the most widely used measuring device in the field. The three-dimensional measurement method is divided into a method of scanning the shape of a product and a touch method. In this study, the accuracy of the dimension and shape of each measurement point touch method was analyzed based on the measured value with the touch method CMM using the inner and outer diameter measurement specimens. Through the experimental results, it was possible to obtain the closest value to the true value at more than 30 measurement points.

In this study, the change in the mold opening stroke of important functional parts according to the 20, 50, 80, and 100% increase in the injection speed of a hydraulic 150 ton hydraulic injection molding machine was studied to verify the accuracy of the injection speed and mold opening stroke and the reproducibility of the standard deviation. The null and alternative hypotheses were confirmed by conducting hypothesis verification according to the experimental condition change using the experimental design method.

In this study, measurement errors of the X and Y axes were verified by using an 80-100 mm gauge block, an NPL type angle measuring device, and a spelling on a contact-type 3D measuring device surface plate. In addition, the measurement specimen was repeatedly measured 10 times at 10° intervals from 0° to 40° to confirm the average value and standard deviation. After confirming the statistical test value (P) through ANOVA analysis of the statistical program, the correlation between angle change and error was confirmed.

This study was evaluated based on the items of KS B 6389. The study on the calculation of angular error and measurement uncertainty of HRc hardness measurement using statistical techniques using Rockwell measurement specimens with different hardness values ​​was analyzed, and the results were derived according to the change in the angle of the indenter part of the hardness tester and the specimen. As a result of the experiment, the test statistic P values ​​for angle changes such as 0°, 1°, and 2° were all 0.000 using the HRc 30 and 40 measurement specimens, so it was confirmed through the experiment that a significant difference occurred between them. In addition, the extended uncertainty value was calculated as 0.612 at the 95.45% confidence level, and the fact that the hardness test value came out smaller than the existing test value as the inclination angle increased was verified through experiments.

In this study, using a 100mm gauge block in a contact-type three-dimensional measuring machine surface plate, an NPL-type angle measurement, and a steel ruler, the specimen was measured at 0°, 5°, 10°, 20°, 30°, and 40° along the X and Y axes. After setting the measurement conditions, the average value and standard deviation were confirmed by repeating measurements for each yield 10 times. After checking the statistical test value (P) through ANOVA, the correlation between the angle change and the error was checked.

In this experiment, the error according to the measurement method was analyzed for the length, angle, radius of curvature, and diameter of the measurement system analysis using a profile projector device used in the field. One-way analysis was performed on each data tested 30 times using a statistical technique. Through the experiment, it was found that an error occurred in each data when measuring the angle according to the measurement method, and the null hypothesis that no error occurred when measuring the length, inside dia and radius was established.

Due to industrial development, the importance of GD&T tolerance is growing day by day. Roundness measurement means the size deviated from the ideal circle. Roundness evaluation methods include LSCI, MZCI, MCCI, and MICI. In this experiment, measurement deviations according to roundness measurement methods such as radius method, diameter method, and three-point method were studied using the same roundness specimen. The measurement method was measured 20 times each by the measurer, and the average value and dispersion of each data obtained through the experiment were confirmed. Through the experiment, it was confirmed that the diameter method, the three-point method, and the radius method were measured and spread out in the order of magnitude. In addition, the interrelationship according to each measurement method was confirmed using the experimental design method. The test statistic value (P) was greater than 0.05 through hypothesis testing, and the null hypothesis was rejected and the alternative hypothesis was adopted in the experiment.

The purpose of this study was to establish the optimum experimental conditions by investigating the relationship between the nine experimental conditions using Taguchi technique. Through experiments, we found that the weight, thickness, and length of the sample were most affected by the angle at which the sample was installed, while the width had the largest influence on the sample's x-axis and the inner diameter. It was confirmed. Therefore, through this experiment, it was confirmed that the installation angle of the product had the greatest influence on the error occurrence of the product during 3D printer processing.