• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1505-1515
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• 2016

The age of autonomous vehicles has come according to development of high performance sensing and artificial intelligence technologies. And importance of the vehicle's surrounding environment sensing and observation is increasing accordingly because of its stability and control efficiency. In this paper we propose an integrated platform for efficient networking, analysis and monitoring of multiple sensing data on the vehicle that are equiped with various automotive sensors such as GPS, weather radar, automotive radar, temperature and humidity sensors. From simulation results, we could see that the proposed platform could perform realtime analysis and monitoring of various sensing data that were observed from the vehicle sensors. And we expect that our system can support drivers or autonomous vehicles to recognize optimally various sudden or danger driving environments on the road.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.36 no.5
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• pp.147-154
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• 2020

Currently, there are no specific repair methods for RC structures damaged by fire, and repair methods are applied when durability deteriorates due to aging. In addition, a number of recent studies have been reported that have conducted fire resistance assessment of the repair materials themselves, assuming exposure to high-temperature environments such as fires. However, researches that evaluate the fire resistance performance of the repair materials by applying existing repair materials to the actual fire damaged reinforced concrete structures are very rare. Therefore, in this study, a number of existing repair materials were applied to fire-damaged concrete column to compare and evaluate the fire resistance performance with the original cover concrete.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.778-780
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• 2004

This paper presents a computing system, called MEDICOS. that enables Multidisciplinary Design Optimization (MDO) technology for engineering design on distributed environments. In MDO, various legacy softwares have to be Integrated, so dynamic configuration and seamless coordination between these legacy softwares must be supported. MEDICOS is designed to address these issues by the Linda shared memory model-based design and the agent-based wrapper technology. A prototype system for engineering designs is developed and tested with designing a super high temperature vacuum furnace.

• Advances in nano research
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• v.14 no.6
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• pp.495-506
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• 2023

We study the bending wave, shear wave and longitudinal wave characteristics in the double nanobeams in this paper for the first time, in the process of research, based on the Reddy's higher-order shear deformation theory and considering shear layer stiffness, linear stiffness, inter-laminar stiffness, the pore volume fraction, temperature variation, functionally graded index influence on wave propagation, based on the nonlocal strain gradient theory and Hamilton variational principle, the wave equation of the double-nanometer beams are derived. Since there are three different motion states for the double nanobeams, which includes the cases of "in phase", "out of phase" and "one nanobeam fixed", the propagation characteristics of shear-, bending-, and longitudinal- waves in these three cases are discussed respectively, and some valuable conclusions are obtained.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.3
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• pp.303-311
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• 1996

The microflora changes of 10 water-controled treatments combined with livestock manures(pig, chicken) and bulking agents(sawdust, paper sludge) were investigated. The B/F values of the P-1 and C-1(65%, $H_2O$) treatments were 3571 and 5400 respectively, but those of the P-4 and C-4(50%, $H_2O$) treatments showed very low values, 667 and 334, respectively. The B/F values tended to increase with higher water content of the treatments. In the composting processes, the successions of microflora, adapting the compost environments, took place via fluctuating temperature. In the high temperature period, the numbers of mesophilic bacteria and fungi decreased, but that of the spore forming bacteria increased. However, the number of mesophilic bacteria inereased during the cold period. The B/F values of compost ranged 25-300, which indicates a decrease in the quantity of bacteria. The time required for the temperature of compost to reach $60^{\circ}C$ showed different patterns. There was no pathogenic microorganism in the treatments which reached a high temperature in a short period of time, but, in the treatments which reached a high temperature over a Long period of time, the pathgenic microorganism was not still alive.

• Journal of Korea Foundry Society
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• v.41 no.2
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• pp.127-131
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• 2021

Based on its good compatibility with high-temperature environments, the Ti-48Al-2Cr-2Nb alloy is used for high-temperature materials of industrial equipment. In this study, a Ti-48Al-2Cr-2Nb alloy turbocharger turbine wheel was fabricated by a vacuum centrifugal casting method. The conditions that prevent misrun defects of the turbocharger turbine wheel blade from centrifugal casting using alumina molds were investigated. The microstructure of the alloy prepared by vacuum centrifugal casting was studied by means of optical microscopy (OM), with a micro-Vickers hardness analyzer (HV), by X-ray diffraction (XRD) and by SEM-EDS. The HV and SEM-EDS examinations of the as-cast Ti-48Al-2Cr-2Nb alloy showed that the thickness of the oxide layer (α-case) was typically less than 50 ㎛. At a high preheating temperature of 1,100℃, a moderate RPM of 260, and with an alumina mold with a large gate size, there were almost no misrun defects. Therefore, it was confirmed that a Ti-48Al-2Cr-2Nb alloy turbocharger turbine wheel with fewer misrun defects could be achieved through a high preheating temperature, a moderate RPM, a large gate size and an alumina mold to suppress the formation of alpha-case components.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.9
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• pp.871-877
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• 2015

Deep-sea equipment such as underwater robots and unmanned submersible vehicles, include various machine components and sensors, and it is important that their reliabilities be tested before use in the fields. This is necessary because they are affected by complex extreme-environment conditions, such as high pressures, extreme temperatures, and tidal forces that are present in the deep sea. We require test equipment that can conduct empirical tests in conditions that mimic these complex oceanic environments. In this study, we propose specifications that should be met, and a design plan for the primary components, which should limit their use to a maximum water pressure of 2.0 MPa, water temperature of $5{\sim}60^{\circ}C$, and a maximum flow velocity of 2 m/s. in work-in type underwater combined environment test equipment and. We present test system development procedures to verify the reliability of products and systems used in deep-sea environments.

• Journal of the Korea Society for Simulation
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• v.27 no.2
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• pp.25-33
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• 2018

When developing military equipment, it should be designed considering the temperature condition so that the operator can operate in a stable environment. The shelter for storing various military equipments is operated in various environments. The storage temperature and operating requirements of the test equipment and repair accessories shall be $-32^{\circ}C$ to $50^{\circ}C$ and the inside of the shelter shall be designed to meet the storage temperature and operating requirements. In this study, thermal analysis of a 2.5 ton military shelter operating under high temperature and solar heat conditions is performed considering MIL-STD-810G. The thermal analysis was applied by using the concept of heat resistance and heat circuit, and the solar thermal test was performed on the actually manufactured military shelter in order to verify the analysis results.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.1026-1036
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• 2014

Real-time monitoring for environmental factors (temperature, salinity, chlorophyll-a, etc.) and fugacity of carbon dioxide ($fCO_2$) was conducted at an oyster Crassostrea gigas farm in Goseong Bay, south coast of Korea during 2-4th of November, 2011. Surface temperature and salinity were ranged from $17.9-18.7^{\circ}C$ and 32.7-33.8, respectively, with daily and inter-daily variations due to tidal currents. Surface $fCO_2$ showed a range of $390-510{\mu}atm$ and was higher than air $CO_2$ during the study period. Surface temperature, salinity and $fCO_2$ are showed significant correlations with chl.-a and nutrients, respectively. It means when chl.-a value is high in surface water of the oyster farm, active biological production consume $CO_2$ and nutrients from environments and produce oxygen, suggesting a tight feedback between biological processes and environmental reaction. Thus, factors affecting the surface $fCO_2$ were evaluated using a simple mass balance. Temperature and biological productions by phytoplankton are the main factors for $CO_2$ drawdown from afternoon to early night, while biological respiration increases seawater $CO_2$ at night. Air-sea exchange fraction acts as a $CO_2$ decreasing gear during the study period and is much effective when the wind speed is higher than $2-3m\;s^{-1}$. Future studies about organic carbon and biological production/respiration are required for evaluating the roles of oyster farms on carbon sink and coastal carbon cycle.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.3
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• pp.157-163
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• 2022

An automatic mooring system for a ship consists of a vacuum suction pad and a mechanical part, enabling quick and safe mooring of a ship. In the development of a mooring system, the design of a vacuum suction pad is a key to secure enough mooring forces and achieve stable operation of a mooring system. In the vacuum suction pad, properly designing its rubber seal determines the performance of the suction pad. Therefore, it is necessary to appropriately design the rubber seal for maintaining a high-vacuum condition inside the pad as well as achieving its mechanical robustness for long-time use. Finite element analysis for the design of the rubber seal requires the use of an appropriate strain energy function model to accurately simulate mechanical behavior of the rubber seal material. In this study, we conducted simple uniaxial tensile testing of Chloroprene Rubber (CR) to explore the strain energy function model best-fitted to its experimentally measured engineering strain-stress curves depending on various temperature environments. This study elucidates the temperature-dependent mechanical behaviors of CR and will be foundational to design rubber seal for an automatic mooring system under various temperature conditions.