• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.22 no.6
• /
• pp.495-501
• /
• 2012

In this study, the natural frequencies and mode shape of an external mounting pod were verified using the modal analysis and modal testing technique for a pod mounted on an aircraft. The procedure associated with the FE model building of an external mounted pod to predict the dynamic behavior of aircraft structures is described. The simplified FE model reflecting the results of the modal testing of a pod is built through the optimization and will be applied to the structural dynamic model of an aircraft which is used to verified the stability of vibration and flutter of an aircraft.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2022.04a
• /
• pp.133-134
• /
• 2022

This study proposed vision artificial intelligence-based automated supervision technology for external insulation and finishing system, and basic research was conducted for it. The automated supervision technology proposed in this study consists of the object detection model (YOLOv5) and the part that derives necessary information based on the object detection result and then determines whether the external insulation-related adhesion regulations are complied with. As a result of a test, the judgement accuracy of the proposed model showed about 70%. The results of this study are expected to contribute to securing the external insulation quality and further contributing to the realization of energy-saving eco-friendly buildings. As further research, it is necessary to develop a technology that can improve the accuracy of the object detection model by supplementing the number of data for model training and determine additional related regulations such as the adhesive area ratio.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.85-85
• /
• 2022

The world's most extensive and active deltas, Louisiana's wetlands, are deteriorating rapidly due to multiple stressors such as the discharge of the Mississippi River, sea-level rise, and coastal retreat, the substantial but spatially and temporally variable impacts. However, the ecological and anthropogenic histories, the mode of environmental changes on a multi-millennial timescale have not been thoroughly documented. This study, a palynology-based multiproxy analysis, investigates hydrological, geological, geochemical, and anthropogenic impacts on southern Louisiana wetlands and a variety of external forcing agents influencing ecological succession. Sediment cores extracted from a small pond on a mangrove-dominate island near Port Fourchon, Louisiana, USA yielded a 4,000-year record. The site has been transformed from freshwater to saline water environments, to a mangrove dominant island over the late Holocene. The multivariate principal component analysis identified the relative strength of external drivers responsible for each ecological shift. The Mississippi River delta cycle (lobe switching) was the dominant driver of ecosystem changes during the late Holocene, while relative sea-level rise, tropical cyclones, climate, and anthropogenic effects have been the main drivers late in the site's history.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2023.11a
• /
• pp.25-26
• /
• 2023

The internal core material and external color of a sandwich panel have a significant impact on the performance of the sandwich panel. For use on roofs and walls, the internal core material and external color must be considered. Therefore, the surface and back side temperatures were measured for each exterior color and inner core material type. For the internal core materials, urethane foam and Expanded Poly Styrene(EPS), which are core materials mainly used in sandwich panels, were selected. As colors, black and ivory were selected according to brightness, and a total of five colors were selected: red, blue, and green, which are the three primary colors of light. As a result, there were differences in surface and temperature depending on the external color and type of internal core material. Regardless of the color, the temperature was measured lower for panels with urethane foam than for panels with an internal core of EPS. This is believed to have been influenced by the difference in thermal conductivity of urethane foam being 0.023W/(m·K) and that of EPS being 0.032W/(m·K). In addition, panels with a black exterior color were found to have higher surface and back temperatures than panels of other colors, and ivory-colored panels had lower back temperatures regardless of the core material. This is proportional to the brightness and light-absorbing characteristics.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2002.05a
• /
• pp.387-392
• /
• 2002

In many years, post-tensioning method has been used for structural reinforcement of RC structures due to easy installation and good quality control. This study presents practical application results for the effectiveness of structural post-tensioning reinforcement of the FCM bridge girders, cement silos and building girders. For the FCM bridges deflected excessively at the end of girders, for cement silos cracked vertically at silo surface and for building girders deflected due to heavy load from roof, the external post-tensioning method was used for uplifting deflected girders and closing cracks with increasing resisting capacity of the structures. It was demonstrated that all the items were rehabilitated nearly to the initial construction status according to the field test results.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.05a
• /
• pp.272-273
• /
• 2017

As businesses put a greater emphasis on outward appearances, the demand for external window cleaning has been on the rise. However, with the conventional labor-intensive window cleaning method, it is hard to meet this demand. Therefore, this study proposes a Life Cycle Cost (LCC) analysis model for a guiderail-type cleaning robot, and estimate the LCCs of the conventional method and the cleaning robot. The findings of this research are expected to serve as a guide for future development of a cleaning robot.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2005.11a
• /
• pp.191-195
• /
• 2005

Till now, the roles of a tradition market were a circulation of the necessities of life, a employment market of local society, a center of community, and a main structure of local economy. Recently, these tradition market is on the decline because it couldn't cope with the internal and external changes. It is recognized that these phenomenon is a factor of economy unbalance. So, to activate the local economy, tradition market should be promoted. Therefore, external changes such as the increase of competition intensity and the changes of consume pattern, internal changes such as the deterioration of facility and old fashioned management were analysed. The activation plan of traditional market were suggested through the decision index for the tradition market in this study.

• Proceedings of the SAREK Conference
• /
• 2008.11a
• /
• pp.61-66
• /
• 2008

Recently a certain level is required in natural ventilation for improving on the 'quality' aspect in housing. It is simulated the external flow around building which affact natural ventilation using CFD. Natural ventilation is estimated on the specific household which considered topography and not considered.

• Journal of the Korea Institute of Building Construction
• /
• v.9 no.3
• /
• pp.109-116
• /
• 2009

The magnesium sulfate solution digestion test carried out for resistance of concrete containing waste glass powder on magnesium sulfate attack. Moreover, it yielded S.D.F index was used for the criteria of quantitative assessment to the resistance of magnesium sulfate for the purpose of evaluation of chemical deterioration on concrete. Furthermore, to evaluate for micro-cracks within concrete and external corrosion, the weight variation of specimens and the dynamic elasticity were compared and analyzed and also the applicability was examined using the analysis of product of hydration through out observing external deformation and micro-structural deformation.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2019.11a
• /
• pp.130-131
• /
• 2019

As part of recent low-energy policies, thermal insulation standards for buildings are being tightened every year. In addition, the conventional styrofoam insulating material has a problem that the thickness of the heat insulating material to achieve a standard heat permeability is rapidly increased. Due to the thick insulation, there is a high risk of spreading vulnerable structures such as fire due to lack of space between buildings. On the other hand, the method of using the insulation as a formwork is known to be excellent cost saving effect through the reduction of the formwork usage and the simplification of the external insulation work. In order to solve this problem, this study aims to fabricate a multi-layered insulator that combines high-performance phenolic foam insulation and styrofoam insulation and evaluate the deflection characteristics for use as formwork.