• Journal of the Korean Society of Marine Environment & Safety
• /
• v.26 no.6
• /
• pp.732-741
• /
• 2020

Environmental regulations have recently been strengthened. Consequently, floating LNG(Liquefied Natural Gas) power plants are being developed, which are new power generation plants that generate electricity by utilizing LNG. A floating LNG power plant generates BOG(Boil-Off Gas) during its operation, and the system design of such a plant should be capable of removing or re-liquefying BOG. However, the design of an offshore plant differs according to the marine requirements. Hence, a process simulation model of the BOG re-liquefaction system is needed, which can be continuously modified to avoid designing the floating LNG power plant through trial and error. In this paper, to develop a model appropriate for the floating LNG power plant, a commercial process simulation program was employed. Depending on the presence of refrigerants, various BOG re-liquefaction systems were modeled for comparing and analyzing the re-liquefaction rates and liquid points of BOG. Consequently, the BOG re-liquefaction system model incorporating nitrogen refrigerants is proposed as the re-liquefaction system model for the floating LNG power plant.

• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.10
• /
• pp.87-95
• /
• 2021

This study aims to demonstrate the impact of BPR in reducing cost in international business organizations by analyzing the impact of decentralization, re-engineering organizational structures, re-engineering human resources, industrial process technology, improving total quality standards, and value engineering. The study population includes all the international business organizations operating in the Middle East, with the condition that they operate in at least four countries. The results showed that there is a significant effect of all dimensions of BPR in reducing costs in international business organizations operating in the Middle East. When studying the impact of the dimensions combined, the moral effect appeared at each processes (decentralization, re-engineering of human resources and industrial process technology), while the moral effect did not appear in (rebuilding organizational structures, improving total quality standards, and value engineering). This does not negate the importance of the impact of these dimensions, but rather shows a disparity between dimensions in reducing cost, when studying its combined effect. The study recommends that organizations should adopt modern management accounting methods, including value engineering, in order to identify and enhance activities that add value to the organization's operations, as well as identify and eliminate non-value adding activities, in order to reduce costs.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.25 no.4
• /
• pp.253-257
• /
• 2016

The effects of re-peening on the compressive residual stress and fatigue life of Al7075-T6 were investigated. The compressive residual stress induced on the surface of components by shot peening is known to increase the fatigue life. However, the fatigue load relaxes the compressive residual stress of components. Re-peening is a technique to again induce the relaxed compressive residual stress and increase the total fatigue life of components. In this study, the re-peening process was applied to fatigue-loaded specimens. The compressive residual stress and fatigue life were examined for re-peened specimens with fatigue ratios of 30%, 50%, and 70%. The results showed that the compressive residual stress of the specimens was relaxed under the fatigue load. The re-peening process significantly increases the compressive residual stress and total fatigue life.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.18 no.11
• /
• pp.109-114
• /
• 2019

Hydraulic pumps are widely used in fields such as machinery manufacturing, engineering and construction. Although the research on hydraulic engineering is mature, it is still necessary to examine various performance aspects in detail for specific applications. This paper will focus on the hydraulic pump used in special construction machinery that needs high temperature and high pressure resistance. It will analyze the theoretical design, structure and thermal characteristics of the pump system using the Fundamentals of Engineering (FE) method, and will measure the key tolerance parameters of the hydraulic pump to ensure the accuracy of the machining. Through this research, a good design method for the linear reciprocating type of hydraulic pump can be summarized.

• Journal of the Korea Convergence Society
• /
• v.11 no.10
• /
• pp.1-7
• /
• 2020

The manufacturing process of the resistive variable memory device, which is the based of neuromorphic device, maintained the continuity of vacuum process and applied plasma module suitable for the production of the ReRAM(resistive random access memory) and process technology for the neuromorphic computing, which ensures high integrated and high reliability. The ReRAM device of the oxide thin-film applied to the plasma module was fabricated, and research to improve the properties of the device was conducted through various experiments through changes in materials and process methods. ReRAM device based on TiO₂/TiOx of oxide thin-film using plasma module was completed. Crystallinity measured by XRD rutile, HRS:LRS current value is 2.99 × 10³ ratio or higher, driving voltage was measured using a semiconductor parameter, and it was confirmed that it can be driven at low voltage of 0.3 V or less. It was possible to fabricate a neuromorphic ReRAM device using oxygen gas in a previously developed plasma module, and TiOx thin-films were deposited to confirm performance.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.2090-2092
• /
• 2003

Adaptive algorithms are widely used for various applications. One challenging application is an echo canceller in the long distance telephony network. This paper proposes the new variable step-size algorithm for adaptive lattice structure for echo cancellation. The new algorithm is using power of the output signal and the error signal to controlled the step of adaptation process. By this technique, the proposed algorithm is an excellent and effective in good stability. Performance comparison of the proposed algorithm and the other algorithm is made through simulation results.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.21 no.2
• /
• pp.79-88
• /
• 2021

Scientific software requires a development process different from conventional application software due to its unique characteristics, such as expert-level deep domain knowledge requirements. In this study, we proposed a V & V development process based on RE (Reverse Engineering) and TDD (Test-Driven Development) for software development for science. We also configured a virtual scenario for the actual project, applied it, checked the procedure, and refined it. The development process of this study, suggested for the purpose of developing scientific software, will contribute to the development and application of the software that can provide high quality and high reliability. And This study is expected to serve as an opportunity for the development of scientific software and the spread of research.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.613-613
• /
• 2006

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.14 no.2
• /
• pp.19-24
• /
• 2015

Gears are produced through a variety of methods. In general, a metal piece is formed into the general shape of a gear through rough cuts. The gear then moves on to a more precise machine that removes more material. Grinders work via abrasion, rubbing a rough surface against a work piece at such high speeds that it literally scrapes unwanted material away from the item. Since the grinder is spinning so fast, the material is removed very quickly. This allows a grinder to remove a very small amount without taking any unwanted material with it. This study investigates the effect of grinding process parameters like grinding spindle speed and table transfer speed on the gear grade and grinding efficiency.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.19 no.4
• /
• pp.79-84
• /
• 2020

Induction bending via high-frequency heating is widely used for manufacturing pipe and section steel bends. It allows productivity improvement, unit cost reduction, delivery time compliance, and good mechanical properties. The recent increase in high-end vessels and offshore plants has raised the demand for high-frequency bending, which should improve the product quality and reduce the costs by simplifying the fabrication process; therefore, the characteristics and performance of this technique must be studied and proper design technology is required. During hot pipe bending via induction heating, the outward wall thickness of the pipe is thinned due to tensile stress and this thickness reduction cannot exceed 12.5%. This study focused on pipe bends with a bending curvature of 5D and their optimization design; in particular, the conditions that can both improve the productivity of the high-frequency bending process and keep the maximum thickness reduction below 12.5% were determined.