• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1031-1040
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• 2023

Propagation characteristics in line-of-sight(LOS) paths in 3, 6, 10, and 17 GHz frequency bands were measured and analyzed in two different indoor corridors: second floors of Buildings D2 and E2. The measurement was designed to measure when the receiving antenna moved at 0.5 m intervals from 3 m to 30 m, while the transmission antenna was fixed. The analysis of the two indoor corridors was compared by applying basic transmission loss, root mean square (RMS) delay spread, and K-factor. For basic transmission loss, the loss coefficient of the floating intercept path loss model was higher in the indoor corridor of Building E2 than in that of Building D2. Similarly, the RMS delay spread in the time domain was greater in the indoor corridor of Building E2. However, the indoor corridor of Building D2 exhibited higher K-factor in the 3, 6, and 17 GHz bands with lower wave propagation in the 10 GHz band. Despite the 2 indoor corridors being identical, the propagation characteristics varied due to different internal structures and materials. The results provide measurement data for ITU-R Recommendations regarding various indoor environments.

• Journal of Navigation and Port Research
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• v.36 no.7
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• pp.545-552
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• 2012

Domestic marina facilities today consist mostly of composite-type marinas with particular spatial composition characteristics, due to the regulatory restrictions that keep their development in the public sector and the tepid growth of marine leisure-sports. To develop a marina club design appropriate for domestic conditions, this study establishes space program standards for designing Korean marinas based on a case analysis of existing marina clubs and a survey of floating marina clubs. It is possible for a current composite-type Korean marina club to have a spatial composition of 16~18% for marina-exclusive facility (mFA), 47~49% for commercial facility (cFA), 27~30% for public space (pFA) and 5~8% for management space (emFA). With this composition as a basis, space program estimation of a Korean marina club can be done through the process of estimating in order the marina-exclusive facility area, the floor area by each space and the total floor area, the first floor area, the deck area and the pontoon area. Since the space program established in this study can be utilized as a tool for designing a Korean marina club, it is expected to be helpful in designing marina clubs in the future.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1460-1463
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• 2010

Railway has been pointed to the efficiency of transportation, rapid transit, and comfortable train ride. the construction of railway near the downtown area and station building are increasing for maximization of utilization and convenience. but the heavy of transportation and rapid transit lead to increase noise and vibration. The noise and vibration of railway may cause the civil appeal, decline in the serviceability and insufficiency of environmental standard. In this study, floating slab vibration and repeated connection of devices to support joints and fatigue stress analysis of punching shear performance review was conducted to evaluate the safety.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.313-314
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• 2021

An old building over 30 years old continue to increase. Therefore, there will be more dismantling of old buildings in the future. Safety management of dismantling works is being strengthened. However, no consideration has been given to the effects of dismantling workers and their residents due to environmental hazards arising from the demolition process. Only spray and dust prevention measures are subject to inspection to minimize dust generation considering civil complaints around the site of dismantling work. In this paper, residential buildings, which account for the largest proportion of old buildings, were collected and identify total airborne bacteria and floating fungi among environmental hazards caused by non-structural dismantling work. Measurement results showed that workers during dismantling work are working in places with 4.8 times more total airborne bacteria than indoor air quality maintenance standards. Related research is needed for the health of dismantling workers.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.53-58
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• 2001

Floor impact sound has caused many acoustical complaints to the apartment building dwellers. The concrete floating floor construction is one of the most reasonable way to reduce floor impact sound. Recently, many damping materials are used in apartment buildings. In this study, to evaluate floor impact sound insulation performance, field tests were carried at five building floors with damping materials. The test results of impact sound insulation performance for five buildings showed good improvement in light weight impact sound after installation of damping materials, but heavy weight impact sound wasn't improved.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.141-144
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• 2008

Recently, railway has been pointed to the efficiency of transportation, rapid transit, and comfortable train ride. the construction of railway near the downtown area and station building are increasing for maximization of utilization and convenience. but the heavy of transportation and rapid transit lead to increase noise and vibration. the noise and vibration of railway may cause the civil appeal, decline in the serviceability and insufficiency of environmental standard. Therefore, the solution to avoid environmental matters becomes one of the most important factor in constructing railway. In this study, floating slab system which is one of the solution to avoid noise and vibration in railway has been introduced, and the concept of preliminary design and vibration absorber of floating slab system according to the isolator has been introduced.

• Journal of Cadastre & Land InformatiX
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• v.48 no.1
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• pp.229-244
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• 2018

The purpose of this study is to analyze the factors affecting the influence of the size and composition of the floating population on goodwill and Rent. First, the conceptual difference between location value and rent is clearly distinguished. Second, the value of land price is divided into fixed land value and floating land value. The empirical analysis utilized consulting data from 188 shops in Seocho and Gangnam-gu in 2013 ( restaurants, resting restaurants, drinking places, general stores, entertainment and sports). The results using linear regression analysis are as follows. Goodwill and rent have a positive correlation, but the evaluation system and factors are different. Especially the influence of the floating location factor is larger than the rent. And the fixed location factors such as building deterioration bus stops, were found to be significant influencing factors in the rents, but they did not affect goodwill. This result implies that the value of location of goodwill should be taken into consideration of a temporal and spatial concept. Since, in order to resolve disputes between the landlord and the tenant, it is necessary to accumulate data continuously and to study the objective evaluation system in the future.

• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.221-230
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• 2016

Multi-functional floating wetland island (mFWI) was developed in order to prevent algal bloom and to improve water quality through several unit purification processes. A test bed was applied in the stagnant watershed in an urban area, from the summer to the winter season. For the advanced treatment, an artificial phosphorus adsorption/filtration medium was applied with micro-bubble generation, as well as water plants for nutrient removal. It appeared that the efficiency of chemical oxygen demand (COD) and total phosphorus (T-P) removal was higher in the warmer season (40.9%, 45.7%) than in the winter (15.9%, 20.0%), and the removal performance (suspended solid, chlorophyll a) in each process differs according to seasonal variation; micro-bubble performed better (33.1%, 39.2%) in the summer, and the P adsorption/filtration and water plants performed better (76.5%, 59.5%) in the winter season. From the results, it was understood that the mFWI performance was dependent upon the pollutant loads in different seasons and unit processes, and thus it requires continuous monitoring under various conditions to evaluate the functions. In addition, micro-bubbles helped prevent the formation of anaerobic zones in the lower part of the floating wetland. This resulted in the water circulation to form a new healthy aquatic ecosystem in the surrounding environment, which confirmed the positive influence of mFWI.

• KIEAE Journal
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• v.7 no.2
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• pp.71-76
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• 2007

For the many years the children's running noise has caused perpetual frictions between neighbors in apartment houses. For this reason the government established a regulation to reduce the floor impact noise, as a result almost all apartment houses have been enforced to use the floor structure with 210mm thickness concrete slab and 120mm thickness of floor heating system since July 2005. If do not want to apply this kind of system, a system which obtain the certification from the institution appointed by government must be applied. In this reason a lot of construction material companies and construction companies have been trying to develop the system with 180mm thickness concrete slab for the purpose of reducing the cost. To develop the optimized floor system, actual size test building were constructed and the materials related with reducing floor impact noise were composited and tested in the test building. Through this procedure the most effective system was found.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.283-284
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• 2018

The rear side surface of tiles act have protrusions that helps secure the adhesion between the tile and the mortar for tile setting. Conventional height of the rear side usually ranges between 1 to 1.5 mm, and the molding method is classified in between press type and compression type during the manufacturing process, with most tiles being produced by the former method. In sites where adhesion failures were observed, tiles were taken to examine the cause of defect. It was determined that height was irregular at the rear side surface. Based on these findings, an experiment was conducted to determine the correlation between the rear surface and the bonding strength of tiles.