• Journal of the Korea Concrete Institute
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• v.25 no.4
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• pp.389-400
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• 2013

Little investigations have been carried out to study the shear behaviors of RC beams with recycled aggregates. So, this experiment investigates the shear performance and suggests the possible application of Recycled Concrete Aggregate (RCA) for building structures. In general, shear strength of reinforced concrete beam without stirrups is dependent on the compressive strength of concrete, the longitudinal steel ratio, and the shear span-to-depth ratio. In this study, total 28 recycled aggregate concrete beams without shear reinforcement were tested by two-point load and all beams were singly reinforced. The variables studied in this investigation are shear span-to-depth ratios (a/d=2, 3 and 4), RCA replacement ratios (0, 15, 30 and 50%) and longitudinal steel ratios (0.80, 1.27 and 1.84%). The designed concrete compressive strength with a 30 MPa is used. This research will play an important role toward the establishment of the structural design standard for RCA concrete.

• Cartoon and Animation Studies
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• s.33
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• pp.449-467
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• 2013

Contemporary 21st century, the rapid development of technology has achieved due to the emergence of various digital devices, a variety of media to the diversification of the limits of visual representation is reduced. Therefore, the combination of technology and art, visual arts, giving limits of getting it free to the public will feel fresh new visual impact. Such a new approach to light of a combination of technology and art, a variety of fine art and motion picture of the visual arts, such as has been recognized as a new genre. Of the resolution of the projector by utilizing the current reality and unreality beyond the boundaries of the building or structure in the city, as a schematic design of the screen projected structure and mapping of the art technology in an attempt to integrate recent has been studied in various ways. The projected structure design and the mapping of the art technology in an attempt to incorporate recent research has been diverse. In this study, as a new technology of a projection mapping to study the technique of looking for the definition of mapping practices to maximize the effectiveness of Visual Perception 3D animation was applied to a case study. A combination of 3D animation and project mapping in the future the fusion of art and technology to meet the zeitgeist with new possibilities of visual art to create synergies that is expected.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.6
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• pp.625-633
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• 2015

In this study, a coupled probabilistic framework is developed to assess wind risk on apartment buildings by using the convolution of wind hazard and fragility functions. In this framework, typhoon induced extreme wind is estimated by applying the developed Monte Carlo simulation model to the climatological data of typhoons affecting Korean peninsular from 1951 to 2013. The Monte Carlo simulation technique is also used to assess wind fragility function for 4 different damage states by comparing the probability distributions of the window system's resistance performance and wind load. Wind hazard and fragility functions are modeled by the Weibull and lognormal probability distributions based on simulated wind speeds and failure probabilities. The modeled functions are convoluted to obtain the wind risk for the different damage levels. The developed probabilistic framework clearly shows that wind risk are influenced by various important characteristics of terrain and apartment building such as location of building, exposure category, topographic condition, roof angle, height of building, etc. The risk model presented in this paper can be used as tools to predict economic loss estimation and to establish wind risk mitigation plan for the existing building inventory.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.365-369
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• 2016

Red sorrel (Rumex acetosella L.), as one of exotic weeds in Korea, was dominated in grassland and reduced the quality of forage. Improving current pasture productivity by precision management requires practical tools to collect site-specific pasture weed data. Recent development in unmanned aerial vehicle (UAV) technology has offered cost effective and real time applications for site-specific data collection. To map red sorrel on a hill pasture, we tested the potential use of an UAV system with digital cameras (visible and near-infrared (NIR) camera). Field measurements were conducted on grazing hill pasture at Hanwoo Improvement Office, Seosan City, Chungcheongnam-do Province, Korea on May 17, 2014. Plant samples were obtained at 20 sites. An UAV system was used to obtain aerial photos from a height of approximately 50 m (approximately 30 cm spatial resolution). Normalized digital number values of Red, Green, Blue, and NIR channels were extracted from aerial photos. Multiple linear regression analysis results showed that the correlation coefficient between Rumex content and 4 bands of UAV image was 0.96 with root mean square error of 9.3. Therefore, UAV monitoring system can be a quick and cost effective tool to obtain spatial distribution of red sorrel data for precision management of hilly grazing pasture.

• Explosives and Blasting
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• v.35 no.1
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• pp.43-52
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• 2017

Mountain and hill areas occupy by more than 70% in South Korea and Rock drilling should be applied in order to reduce noisy & vibration from massive civil engineering business such as road expansion, high-way construction, subway construction and construction of site renovation such as a newly-built & re-development of apartment, newly-built of high-rising building in downtown area. As Blasting noise & vibration such as vibration, noise, fly rock etc caused by blasting operation from large small scale construction occurs, neighboring residents who demand the compensation file a civil complaint so that the business reach a deadlock. As the excavation method for these areas, There are blasting of micro-vibration, mechanical excavation method(Rock splitter, Breaker etc), similar blasting method(plasma, gel fragmentation etc) to date. In this study, we are trying to find the feature & performance which get improved economic feasibility & construct ability through improving sympathetic detonation of New KINECKER-I used in blasting of micro-vibration & formulation and would provide convenience for use by introducing standard blasting pattern & construction method. Also, checked and confirmed all the blasting with connecting cap has been cleary detonated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.6
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• pp.877-886
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• 2019

The size of the subway entrance should be calculated according to the user's demand, but Korea has the same size for each entrance by applying a uniform value. Recently, the installation of mobile convenience facilities such as escalators, elevators, etc. is mandated by the traffic weakness promotion law, but it is inconvenient to use the existing stations because it is mainly arranged in the place where it can be installed regardless of user demand. This study aims to establish a model for estimating the size of mobile convenience facilities by predicting the use demand of each station entrance so that the location and size of mobile facilities can be reflected in the design or construction of the station. To this end, a multiple regression model was established to forecast daily demand by utilizing the demand for getting on and off by station and the building association area for each purpose around the railway station. The actual data of Dongdaemun and Jonggak Stations were used to verify the estimated model. In addition, the escalator installation scale was compared / analyzed by doorway using domestic and overseas escalator equations. As a result, it was more accurate to estimate the usage demand for a single station. Also, Jonggak Station has an up and down escalator installed at exit 1, but it was analyzed that it is appropriate to install at exit 4. This study is an advanced form of the essay model for estimating the users of the entrance and exit users of urban railway stations published in 2018. In addition, it seems to be the basis of the current escalator installation criteria.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.18-23
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• 2017

The shipyard quay process struggles to control workers and maintain a secure working environment because of the presence of at least 1,000 people. Therefore, safety accidents such as an explosion or a fire are likely to occur. With the recent increase in safety accidents at shipyards, the requirements for safety and process monitoring have been strengthened. Major shipyards are conducting researchto monitor the process in real time and to detect the work environment for safety. In this paper, we propose a safe and accurate evacuation route based on the information of the dangerous area and the user's location based on a mobile application to reduce the casualty accidents in the presence of many personnel in a concentrated area. To do this, we analyze the trend of the fire escape system on the ground building, compare various algorithms for escape route calculation, select appropriate algorithms for this study, and perform programming. A basic experiment was conducted to confirm the results. The proposed method is expected to be used in large ship construction sites, passenger ships and large public facilities to reduce accidents in the case of a safety accident.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8147-8156
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• 2015

This study analyzes the Pattern Language of Insadong-gil in street environmental design analysis for street vitalization. The urban public spaces, such as pedestrian streets, parks and plazas, have been increased with rapid urbanization and industrialization. But the fact is the satisfied spaces with the behavior patterns of users is little. This is because of the too much slanted thought toward formal supply and management of spaces without enough consideration for people and spatial quality of public spaces. The purpose of this study is to find out the factors to make the street more vital and diverse and to give the characteristic of region through the research on Insadong street with the pattern language of Christopher Alexander. So, throughout the value recognition of the changing urban street environment that has been changed by age selected spatial characteristic of public spaces. By selecting a suitable pattern language for each spatial characteristics provide the basis for street environmental design analysis. For this study, look at the relationship between pattern language focused on Insadong street, pattern language as the vitalization factor of street were analyzed 16 elements, including Pedestrian Street(100), Building Fronts(122), Activity Nodes(30) etc. This study focuses on street environmental design analysis of Insadong-gil through the Pattern Language, it propose the criteria and guidelines that will help enable street vitalization.

• Journal of the Korea Concrete Institute
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• v.18 no.1 s.91
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• pp.29-36
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• 2006

Steel reinforced concrete(SRC) columns, which have been widely employed in high-rise buildings, exhibit a time-dependent behavior because of creep and shrinkage of concrete. This long-term behavior may cause a serious serviceability problem in structural systems, so it is very important to predict the deformation due to creep and shrinkage of concrete. However, it was found from the previous experimental studies that the long-term deformation of SRC columns was quite dissimilar from that of RC columns. A new method is required to quantitatively predict the long-term deformation of SRC columns. In this study, the causes of the discrepancy between the behaviors of RC and SRC columns are investigated and discussed. SRC columns exhibit a time-dependent relative humidity distribution in a cross section differently from that of reinforced concrete(RC) columns owing to the presence of a inner steel plate, which interferes with the moisture diffusion of concrete. This relative humidity distribution may reduce the drying shrinkage and the drying creep in comparison with RC columns. Therefore it is suggested that the differential moisture distribution should be taken into account in order to reasonably predict column shortening of SRC columns.

• Journal of the Korea Concrete Institute
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• v.18 no.2 s.92
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• pp.257-266
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• 2006

Flat-plate building systems are utilized extensively for construction of apartments, hotels and office buildings because of short construction period, low floor-to-floor height and flexibility in plan design. Recently, to increase lateral seismic resistance of flat-plate building systems, wall-columns are used frequently. Therefore, to estimate strength of flat-plate column connection accurately, the effect of column section shape on the behavior of flat-plate column connection should be considered properly, In the present study, a numerical analysis was performed for interior connections of continuous flat-plate to analyze the effect of column section shape. For the purpose, a computer program for nonlinear FE analysis was developed, and the validity was verified. Through the parametric study, the variations of shear stress distribution around the connection were investigated. According to the result of numerical analysis, as the length of the cross section of column in the direction of lateral load increases, the effective area and the maximum shear strength providing the torsional resistance decrease considerably. Therefore, these effects should be considered properly to estimate the strength of flat-plate connection accurately.