Military equipment such as large radar system is difficult to transport because protecting each of inner components is mandatory. Therefore, a large radar system is basically transported by military vehicle and consider safety about transportation vibration during design procedure. However, in this paper, a large radar system which includes a large radar and cooling unit is transported by a commercial truck, not military, using different mounting methods so that analyzing acceleration is necessary in terms of verifying safety about transportation vibration. In addition, PSD data which is measured during a variety of transport environment explains that air suspension can absorb vibration efficiently and input vibration is small compared to the MIL-STD-810H, as such most amount of vibration from road can be damped and small energy would be transferred to upper equipment through load path, chassis to equipment. Furthermore, specific mounting method fasten a large radar system effectively. As a result, using a commercial truck with mounting methods during transportation large radar system is totally safe from transportation vibration.

The importance of cutting forces in machining has been emphasized for monitoring and optimizing cutting conditions, leading to various method to detecting cutting forces researched. Cutting forces can be directly measured using dynamometer or indirectly estimated using AE sensors and accelerometers, etc. However, these external sensors demand high costs and have accuracy limitations due to environment issues. To compensate for these drawbacks, utilizing internal signals of machine tool has been developed. Among these, using internal electrical signals of machine tool is representative. In commercial machine tools, cutting forces are often estimated through current measurements. However, due to the characteristics of the spindle motor, electrical properties such as slip, power factor, and efficiency vary with the load, resulting in relatively lower accuracy. This study introduces current-based method considering characteristics of motor and power-based method for estimating cutting forces and compare accuracy of those methods with the measurements from dynamometer respectively.

In this paper, we propose an autonomous stair-driving system for the stable traversal of stairs by a tracked mobile robot operating in indoor disaster environments. Before developing the system, we conduct dynamic simulations to analyze the requirements for the robot to climb stairs. Simulations are performed under various initial conditions, and based on a detailed analysis of the results, we derive the necessary conditions for the robot's ascent. Using these requirements, we design the autonomous stair-driving system, which includes three main components: stair approach, stair alignment, and stair traversal. First, during the approach stage, we present a strategy for recognizing stairs using an object detection algorithm and generating control inputs for the stair approach motion. Next, in the alignment process, we outline an image processing sequence that extracts the edge contour of the stairs and a method for generating control inputs from the combined contour. Finally, in the traversal sequence, we describe the strategy for driving up the stairs. Additionally, we introduce an integrated ROS system to ensure the sequential execution of each strategy. We also verify the effectiveness of the individual strategies and demonstrate the capability of the proposed system through experiments using mock-up stairs and tracked robots.

Most temperature indicators that use thermocouples as sensors include an internal thermometer for compensating room temperature variations. This thermometer measures ambient temperature, which is then converted to a thermoelectric voltage. This voltage is added to the electromotive force measured in the thermocouple sensor and then converted back to temperature. Although precise calibration of the indicator can be conducted in a controlled room-temperature environment, additional uncertainty arises due to room temperature compensation during actual measurements. To address this issue, we calibrated temperature indicator at the ice point. In this experiment, the indicator was placed in an environment where the temperature varied between 8 and 38oC, demonstrating its dependency on ambient temperature. In a second set of experiments, we shorted the thermocouple input terminal to verify whether the indicator correctly indicated the ambient temperature. This study proposed a method to assess additional uncertainty that must be considered when using a thermocouple connected to an indicator calibrated with an external ice point in a laboratory. It also highlights additional steps and factors to consider during the calibration of temperature indicators that employ internal temperature compensation.

A circular flexure hinge is a core element for force transmission and relative motion of precision stages used in semiconductor processes. When designing a circular flexure hinge, calculation formulas for axial and rotational compliance are essential. However, in the case of axial compliance, results of the existing calculation formulas have significant differences from reliable finite element analysis results. In this study, calculation formulas for axial compliance of the circular flexure hinges were derived based on stress distribution phenomenon. Comparison with finite element analysis results confirmed that the newly developed calculation formulas were more accurate than existing ones. It is anticipated that these enhanced formulas will lead to more precise designs, ultimately reducing both time and costs in research and industry.

In this study, we developed and evaluated a simple device for removing ionic impurities that affect the performance of a polymer electrolyte membrane fuel cell (PEMFC) in a marine environment. In such environments, PEMFCs may experience performance degradation due to the presence of Na+ and Cl- in the air. To address this issue, the decontamination device was designed with both heating and cooling components. This device was positioned between a humidifier containing NaCl solution and a humidifier containing deionized water, both connected on the cathode side. The decontamination device effectively removed impurities (Na+ and Cl-) during experiments. As a result, the electrochemical performance of the fuel cell with the decontamination device improved compared to that of the fuel cell without it. Notably, the activation resistance and electrochemical surface area were significantly enhanced, and the ohmic resistance also improved when compared to the fuel cell without the decontamination device.

In this study, the effect of flow rate ratio (R) and total flow rate (Q) on the surface temperature of thermal barrier coatings (TBC) was investigated using a newly developed small-scale methane-oxygen burner rig. Subsequently, the failure mode of electron beam physical vapor deposition (EB-PVD) TBC was examined, and the relationship between surface temperature and coating life was established. The surface temperature of the TBC was found to be strongly dependent on both the flow rate ratio and the total flow rate. Specifically, surface temperature exhibited a proportional relationship with total flow rate, while it showed an inverse relationship with flow rate ratio. The failure mode of the EB-PVD TBC involved a gradual increase in delamination from the rim to the center of the coin-shaped specimen, and this failure mode was found to be independent of surface temperature. Additionally, it was determined that the surface temperature of EB-PVD TBC has a perfectly inverse linear relationship with coating life. This finding implies that the derived linear regression line from the burner rig test can be directly used to predict coating life for any untested surface .temperature.

This paper shows results of research on transparent electrode manufacturing processes using thermal imprinting and IPL technique. By using an IPL process instead of the existing heat sintering process, the sheet resistance value was reduced to about 1/ 10. Additionally, sintering time could be reduced from 1 hour to 1 ms. As a result of measuring the transmittance to determine the excellence of the transparent electrode produced in this way, it was confirmed that it had a high transmittance of 94.4% compared to the substrate with a very high bending stability compared to the existing ITO transparent electrode. These results show that the transparent electrode manufacturing method proposed in this study is very useful.

A robotic focal plane system using robotic fiber positioners enables multi-object spectroscopy for hundreds to thousands of galaxies by utilizing a dense array of positioners that are closely packed at the focal plane of a telescope. While this dense arrangement increases the number of observations, it also introduces the potential for collisions between adjacent positioners. A fiber positioner is designed similarly to a SCARA robot. It is driven by two series of BLDC motors. Each positioner is manufactured with an outer diameter of 16 mm. It operates within an annular workspace with an outer diameter of 33.6 mm and an inner diameter of 12.8 mm. As these positioners are arranged with a spacing of 16.8 mm, target assignment and motion planning are critical to avoid collisions caused by overlapping workspaces. To address this, we proposed an optimized step choice algorithm using a motion planning method based on optimization with the sequential quadratic programming algorithm. Simulation results demonstrated that paths for all positioners within a tile were successfully generated with a success rate of up to 93.75% across 80 tiles.

Additive manufacturing, a key enabler of Industry 4.0, is revolutionizing the automatic landscape in manufacturing. The primary challenge in manufacturing innovation centers on the implementation of smart factories characterized by unmanned production facilities and automated management systems. To overcome this challenge, the adoption of 3D printing technologies, which offer significant advantages in standardizing production processes, is crucial. However, a major obstacle in complete automation of additive manufacturing is an inadequate placement of support structures at critical locations, which remains the leading cause of print failures. This study proposed a novel algorithm for accurate detection of island regions known to be critical areas requiring support structures. The algorithm can compare loops on two consecutive layers derived from STL files. In contrast to conventional GPU-based image comparison methods, our proposed CPU-based algorithm enables high-precision detection independent of image resolution. Experimental results demonstrated the algorithm's efficacy in enhancing the reliability of 3D printing processes and optimizing automated workflows. This research contributes to the advancement of smart manufacturing by addressing a critical challenge in the automation of additive manufacturing processes.