• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2004.11a
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• pp.249-254
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• 2004

The pressing of car body parts is one of the most important sheet metal drawing processes. The corrosion protection oil applied by the steel mills plays a part in every sheet metal forming operation and also makes up the largest proportion of lubricants used. The idea to combine the corrosion protection properties of a corrosion preventive oil with the lubricity of a drawing oil lead to the development of the Anticorit prelubes. Applied at the finishing lines of the steel mills, they finally serve as lubricant in the press shops. A prerequisite for the suitability of a prelube-type oil is the absolute compatibility with all single processes from the coil to the Body in White. The use of prelubes in steel mills reduces the number and quantity of spot lubricants for additional press shop oiling dramatically. But their true benefits can only be fully achieved if the compatibility principle is applied throughout the manufacturing chain. Therefore, modem prelubes systems are modular, even different viscosities can be part of the same concept. This results in a far-reaching multifunctionality of the Anticorit prelube system for all applications.

• Advances in Computational Design
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• v.7 no.3
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• pp.189-210
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• 2022

Deployable structures have the ability to shift from a compact state to an expanded functional configuration. By extension, reconfigurability is another function that relies on embedded computation and actuators. Linkage-based mechanisms constitute promising systems in the development of deployable and reconfigurable structures with high flexibility and controllability. The present paper investigates the deployment and reconfigurability of modular linkage structures with a pin and a sliding support, the latter connected to a linear motion actuator. An appropriate control sequence consists of stepwise reconfigurations that involve the selective releasing of one intermediate joint in each closed-loop linkage, effectively reducing it to a 1-DOF "effective crank-slider" mechanism. This approach enables low self-weight and reduced energy consumption. A kinematics and finite-element analysis of different linkage systems, in all intermediate reconfiguration steps of a sequence, have been conducted for different lengths and geometrical characteristics of the members, as well as different actuation methods, i.e., direct and cable-driven actuation. The study provides insight into the impact of various structural typological and geometrical factors on the systems' behavior.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2288-2297
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• 2023

Current designs of both large reactor units and small modular reactors utilize a nuclear fuel with increasing enrichment. This increasing demand for better nuclear fuel utilization is a challenge for nuclear fuel handling facilities. The operation with higher enriched fuels leads to reduced reserves to legislative and safety criticality limits of spent fuel transport, storage and final disposal facilities. Design changes in these facilities are restricted due to a boron content in steel and aluminum alloys that are limited by rolling, extrusion, welding and other manufacturing processes. One possible solution for spent fuel pools and casks is the burnup credit method that allows decreasing very high safety margins associated with the fresh fuel assumption in spent fuel facilities. This solution can be supplemented or replaced by an alternative solution based on placing the neutron absorber material directly into the fuel assembly, where its efficiency is higher than between fuel assemblies. A neutron absorber permanently fixed in guide tubes decreases system reactivity more efficiently than absorber sheets between the fuel assemblies. The paper summarizes possibilities of fixed neutron absorbers for various nuclear fuel and fuel handling facilities. Moreover, an absorber material was optimized to propose alternative options to boron. Multiple effective absorbers that do not require steel or aluminum alloy compatibility are discussed because fixed absorbers are placed inside zirconium or steel cladding.

• Journal of Engineering Education Research
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• v.26 no.1
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• pp.37-44
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• 2023

Recently, the Internet of Things is attracting attention as an important key technology of the 4th Industrial Revolution, and SW education using physical computing is suggested as a good alternative to supplement the problems raised by beginners in programming education. Among the many teaching tools that can be used for physical computing education, MODI is a modular manufacturing tool that anyone can easily assemble like Lego. MODI is a teaching tool that can improve learners' achievement by linking a self-linked block-type code editor called MODI Studio to lay the foundation for programming in a relatively small amount of time and immediately check the results in person. In this paper, a physical computing education method using MODI was designed to be applied to basic programming courses for programming beginners and applied to after-school classes for middle school students. As a result, it was found that students' interest and satisfaction were much higher in physical computing classes using MODI than in text-based programming classes. It can be seen that physical computing education that allows beginners to see and feel the results in person is more effective than grammar-oriented text programming, and it can have a positive effect on improving basic programming skills by increasing students' participation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.2
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• pp.97-102
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• 2012

CPV system in the desert areas or areas near the equator, as is suitable for high-temperature region. As compared to silicon solar cells, CPV system have a high proportion of a BOS (balance of system). Solar cells because of its low proportion when designing a module technology is applied in a variety of ways. Applied to the CPV system is classified into two kinds of optical technology. One of those using fresnel lens uses refraction of light energy. The other is a mirror reflection of the structure using sprays. Both of these two ways to condense the sun to collect solar cell is a form of light. And goals by using a small solar cell materials is to produce more energy. In this paper, suitable for a domestic environment, with the aim CPV Manufacturing Technology, built on a variety of modular process technology to the development of a prototype performance analysis was carried out. In particular, silicone coated on the glass by the method of implementation of the Fresnel lens SOG(Silicon on glass) by applying the lens to absorb the solar spectrum was broad. In addition to, for the analyze to characteristics of the CPV module, developed CPV module performance and generating characteristics studied. These related technology through research and development of high-performance multi-junction solar cells, modules, development of concentrating solar power systems to facilitate the growth of the market is considered to be.

• Design & Manufacturing
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• v.17 no.4
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• pp.14-23
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• 2023

The electric vehicle market is developing rapidly around the world. Also, parts of electric vehicles require precision.In order to produce high-precision motor cores,Press equipment must also have good precision. Drive motor cores are an important technology for electric vehicles. It uses a large high-speed press to mass-produce drive motor cores. Because it's a large high-speed press, there are many reasons why the precision is not good. One of the causes is vibration and noise. Recently, as environmental demands have become stricter, regulations on noise and vibration have been strengthened. It is important for press machines to reduce vibration first for sound insulation and dust proofing. This is because the "breakthrough" phenomenon occurs in the press. Dynamic precision is the precision under the load of the press, Design considering strain and stiffness shall be made. Vibration and noise may occur due to SPM of high-speed press,And vibration and noise can cause structural deformation of the press. Structural deformation of the press can affect the precision of the product.Noise and vibration also cause problems for workers and work environments. Problems with vibration and noise occur during press processing, and vibration and noise lead to damage to the mold or defects in the product. Reliability in high-quality technology must be secured with low noise and low vibration during press processing. Modular shape and deformation energy effects were analyzed through finite element analysis. In this study, a study on vibration and noise countermeasures was conducted through finite element analysis of a large high-speed press.

• Journal of the Korean Vacuum Society
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• v.10 no.2
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• pp.145-154
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• 2001

A new type of modular mirror manipulator with independent adjustability was developed for the EPU6 beamline under construction at the Pohang Accelerator Laboratory. The mirror manipulator was designed so that the angular displacements of roll and pitch rotations do not introduce translational displacements and are independent with each other by positioning the mirror center to the center of a newly devised spherical joint. Manipulating its roll and pitch micrometers, the rotation angles of a dummy mirror were measured at an accuracy of 5 $\mu$rad using a gravity-referenced inclinometer. While the designed angular resolution was 3.937 $\mu$rad/$\mu\textrm{m}$, measured angular resolutions were 3.94 $\mu$rad/$\mu\textrm{m}$ for roll rotation and 3.85 $\mu$rad/$\mu\textrm{m}$ for pitch rotation. The effect of roll rotation on pitch angles was measured to be -3.18% and the effect of pitch rotation on roll angles was measured to be -5.21%. As the mirror manipulator was designed with emphases on independent adjustability and standardization, it results in eases of manufacturing, installation and adjustment as well as reductions of development period and design cost of mirror manipulators for various types of mirrors.

• Journal of the Korea Institute of Building Construction
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• v.23 no.2
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• pp.175-185
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• 2023

Upon analyzing labor productivity in the construction industry across OECD countries, it was found that in 2019, labor productivity per employee in the South Korean construction industry was lower than that of major developed countries when adjusted for purchasing power parity(PPP). Specifically, when benchmarked against other countries at a base of 100, South Korea scored 76.9 in the United States, 88.4 in Japan, and 85.1 in the OECD average. Notably, South Korea ranked 25th in labor productivity per employee in the construction industry among 35 OECD countries in 2019, indicating a low standing. A comparative analysis of the construction market size and labor productivity in the construction industry across OECD countries revealed that larger construction markets did not necessarily correlate with higher labor productivity. To enhance labor productivity in the construction industry, this study proposed the active implementation of smart construction technology at construction sites and the promotion of on-site assembly work using off-site construction(OSC) technology, rather than traditional on-site labor. Moreover, it was recommended that the development of modular construction methods and technologies be expanded. In the future, if off-site production methods and modules are further developed through advanced robotics and factory automation, labor productivity is anticipated to increase due to the restructuring of production methods, such as manufacturing.