• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.7-8
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• 2014

Latex-modified concrete using ready mix concrete (R-LMC) was developed for application of building construction project (specifically, the rooftop of a parking garage unable to use heavy equipments for bridge deck overlay) due to three major outstanding properties of R-LMC; bond strength, resistance of cracks at early age, and resistance of freezing and thawing. However, R-LMC at the placement stage is required to be sufficiently cured because R-LMC is very sensitive to rate of evaporation of surface moisture. This study focused on effects of different curing methods and climate condition on cracks on the surface of hardened R-LMC considering the chart of rate of evaporation of surface moisture from concrete provided by American Concrete Institute in manual for placement of latex modified concrete.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.6
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• pp.936-942
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• 2022

While indoor vehicle navigation is an essential component in large-scale parking garages of major cities, technical limitations and challenging propagation environments considerably degrade the accuracy of existing localization techniques. This paper proposes a proximity detection scheme using low-cost beacons where a handheld mobile device within a moving vehicle autonomously detects its approximate position and moving direction by only observing Received Signal Strength (RSS) values of beacon signals. The proposed approach essentially exploits the differential RSS technique of multi-directional beams to reduce the impact of the environment, vehicle, and mobile device. A low-cost multi-directional beacon prototype is developed using Bluetooth technology. The localization performance is evaluated using 96 beacons in an underground parking garage within an area of 394.8m×304.3m. Experimental results show that the 90th percentile of the average proximity detection error is 0.8m. Furthermore, our proposed scheme provides robust proximity detection performance with various vehicles and mobile devices.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.61-65
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• 2008

A 4-story reinforced concrete structure built above an underground parking garage shows some slab deflections, and the deflections of the concrete floor slabs are proposed to be alleviated by the application of light-weight topping material in conjunction with localized strengthening of the slabs. The application of light-weight concrete topping on the existing slab has been simulated and its performance to anticipated loads has been analyzed. The application of light-weight topping material imposes additional weight on the exiting floor slabs. This added weight on the existing slabs causes over-stressing of the slabs. This over-stressing can be alleviated by enhancing the load carrying capacity of the existing slabs. Additional load carrying capacity in the existing slabs can be developed by localized strengthening of the slabs utilizing techniques such as the application of fiber-reinforced composites on the bottom surface of the slabs, and application of fiber-reinforced composites adequately complements the capacity of the existing slabs to bear the additional load imposed by light-weight leveling material. Additional moments in the beam and columns induced by the application of the light-weight topping material were tabulated and compared with capacity. The moment D/C ratios of the beam and columns are well the range of acceptable limits, and the beam and columns are not overstressed by the application of the surcharge.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.797-800
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• 2003

In the current study, the authors propose a method for extracting license plate regions by means of a neural network trained to output the plates center of gravity. The method is shown to be effective. Since the learning pattern presentation positions are defined by random numbers, a different pattern is submitted to the neural network for learning each time, which enables it to form a neural network with high universality of coverage. The article discusses issues of the optimal learning surface for a license plate revered by the learning pattern, the effort of suppression learning of the number and headlight sections, as well as the effect of learning pattern enlargement/reduction and of concentration value conversion. Results of evaluation tests based on pictures of 595 vehicles taken at an underground parking garage demonstrated detection rates of 98.5%.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37A no.9
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• pp.780-785
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• 2012

In the current study, the authors propose a method for extracting license plate regions by means of a neural network trained to output the plates center of gravity. The method is shown to be effective. Since the learning pattern presentation positions are defined by random numbers, a different pattern is submitted to the neural network for learning each time, which enables it to form a neural network with high universality of coverage. The article discusses issues of the optimal learning surface for a license plate covered by the learning pattern, the effect of suppression learning of the number and headlight sections, as well as the effect of learning pattern enlargement/reduction and of concentration value conversion. Results of evaluation tests based on pictures of 595 vehicles taken at an underground parking garage demonstrated detection rates of 98.5%.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.1 no.3
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• pp.105-109
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• 2008

In the current study, the authors propose a method for extracting license plate regions by means of a neural network trained to output the plate.s center of gravity. The method is shown to be effective. Since the learning pattern presentation positions are defined by random numbers, a different pattern is submitted to the neural network for learning each time, which enables it to form a neural network with high universality of coverage. The article discusses issues of the optimal learning surface for a license plate covered by the learning pattern, the effect of suppression learning of the number and headlight sections, as well as the effect of learning pattern enlargement/reduction and of concentration value conversion. Results of evaluation tests based on pictures of 595 vehicles taken at an underground parking garage demonstrated detection rates of 98.5%.

• Korean Institute of Interior Design Journal
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• v.27 no.1
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• pp.58-67
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• 2018

This study aims to analyze the cases of storage space outside housing unit and propose the activation plan. The issue of storage in residential complex has continued to be reported. This is more salient due to the recent preference trend for small houses, the constant increase of living goods and the limitation of the available space inside housing unit. Although more apartment houses are trying to have individual storage in the exterior space to address these issues, there is still a paucity of the related studies and more studies are required. In this study, we conducted on-site investigation and user interview of each case to propose active usage of the storage space outside housing unit. Result of this study shows that the most crucial factor to improve is 'accessibility' in order to activate the storage space. Storage room should be located close to each household or the individual parking space. The second factor is the size and the structure of the storage room. The sufficient space for keeping and taking large objects out are required. The front of the storage room should have a clogged structure to insure privacy. The third is the provision of suitable support programs such as the system that occupants can check remotely what items are in their storage rooms, garage sale, laundry service, auto cleaning system and rental program. Those programs are required for efficient management and activation of space. Another requirement is to improve environmental factors which include maintenance of optimal temperature and humidity, automatic ventilation system, control of individual lights, and security enhancement. Based on the results of the survey, we provide basic data which can be used for practical space planning to activate exterior storage space of the housing unit. Further surveys are required to develop this study by obtaining more data for generalization.

• Environmental Analysis Health and Toxicology
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• v.24 no.3
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• pp.203-211
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• 2009

A lesser degree of research is available with respect to indoor radon characteristics associated with occupants' exposure. The present study evaluated the radon levels in several public-access buildings or underground facilities, and their temporal variation in underground facilities. Radon measurements were conducted in 2005 and 2006, utilizing a continuous radon detector. A solid alpha detector (RAD7) was utilized to measure indoor radon levels. The mean radon concentrations obtained from the building or facilities were in a descending order: platforms of Daegu subway line 2, 2005 (32 $Bq/m^3$), hot-air bathroom (14 $Bq/m^3$), basement of office building (14 $Bq/m^3$), underground parking garage (14 $Bq/m^3$), underground shop (12 $Bq/m^3$), nursery (10 $Bq/m^3$), platforms of Daegu subway line 2, 2006 (9.0 $Bq/m^3$), platforms of Daegu subway line 1, 2006 (8.9 $Bq/m^3$), supermarket (7.9 $Bq/m^3$), hospital (7.3 $Bq/m^3$), and second-floor of office building (5.7 $Bq/m^3$). In general, underground-level facilities exhibited higher radon levels as compared with ground-level facilities. It was suggested that ventilation is an important parameter regarding the indoor levels of a subway. There was a decreasing or increasing trend in hourly-radon levels in a subway, whereas no trend were observed in a basement of office building. In addition, the radon levels in the subway lines 1 and 2 varied according to the platforms. The radon levels in the present study were much lower than those of previous studies. The average annual effective dose (AED) of radiation from indoor radon exposure was estimated to be between 0.043 and 0.242 mSv/yr, depending on facility types. These AEDs were substantially lower than the worldwide average AED (2.4 mSv/yr).