• Analytical Science and Technology
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• v.23 no.2
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• pp.138-146
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• 2010

The Korean Ministry of the Environment revised a few sections of the regulations in the Law of indoor air quality management for the reinforcement or adjustment of the regulation criteria standard for releasing pollutants from building materials. Especially, in case of sealant, the contents covering liquid building materials, excess standards and testing methods have been added simultaneously in this revision, As a result it is impossible to compare original standards with revised standards directly. For this reason, this study reviewed revised test method of sealant pollutant emission rates in terms of impact and validity in comparison with the original test method. Through this study, the basic properties of revised pollutant emission control standards was assessed. Especially in sealant, since each product has a wide deviation of time required for complete drying, it is proved that there are a large number of products that are not hardened completely in test time. The result of our experiments on the revised test methods showed that this revised test methods yield emission rates that are two and half times less than those of the original testing method. To apply the revised test method of sealant to all the sealant products, It is necessary to extend the test period or improve specimen to fit the test method for quickly drying sealant products.

• Journal of the Korea Institute of Building Construction
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• v.15 no.2
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• pp.237-247
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• 2015

The project management information system (PMIS) has recently been developed by using the information technology(IT) in order to implement advanced information management technology to construction industry in Korea. The PMIS has been applied not only to domestic construction projects, but also to some overseas projects executed by Korean construction companies. This study was performed to develop the PMIS that is tailored to the US construction IT market. It has been monopolized by the US-based IT companies, but other companies are recently emerging with competitive technology and market strategy. As a preceding study, existing commercially available systems were analyzed, and the required features of the PMIS were identified by analyzing the core elements of contract, process and cost management about construction projects in the US. Then, the PMIS was developed based on the aforementioned analysis results. The system includes the document management module with an internal electronic approval system, the cost-plus-based automatic labor cost calculation module, and the progress management module to support the integrated project cost management. In addition, the functionality of the developed system was verified by experts about construction management in the US via questionnaire survey. The developed PMIS, in this study, is expected to be applied not only to the US construction IT market as a system specialized for the US construction industry, but also to other oversea markets in the future.

• Journal of the Korea Institute of Building Construction
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• v.16 no.4
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• pp.349-357
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• 2016

Recently, the quantity of risk in construction project has been inflated due to the fact that current construction projects have been large and complicated. Therefore, a study on the risk management methods is necessary that can predict and respond to the need in complicated modern construction projects. In this study, the objective is to analyze the cause of accident in actual construction sites and develop a risk assessment model based on insurance claims records. To reach the goal of this study, first, the frequency and severity of accidents are analyzed the causes of accidents based on the classification; progress rate, season, and total construction costs. Second, a risk assessment model is developed by utilizing a multiple regression analysis. The dependent variable is loss ratio of material damage and three categories; natural hazards, geographic information, and construction method & ability, are used as the independent variables. The model's adjusted R-square is 0.455. The contributions of this study will be used as a material for a quantitative risk analysis model development and review of the construction risk factors for future study.

• Journal of the Korea Institute of Building Construction
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• v.15 no.3
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• pp.265-271
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• 2015

This study is intended to produce a PC (Precast Concrete) member without a steam curing process in developing the high early strength concrete satisfying the condition of 10MPa in compressive strength at the age of 6 hours, and is intended to ensure economic feasibility by increasing the turnover rate of concrete form. Hence, high early strength cement with high $C_3S$ content and the hardening accelerator of powder type accelerating the hydration of $C_3S$ was used. And the properties of concrete were evaluated according to the hardening accelerator mixing ratio (0, 1.2, 1.6, 2.0). No big difference was found from the tests of both slump and air content. When 1.6 % or higher amounts of the hardening accelerator were mixed, the compressive strength of 10MPa was achieved at the age of 6 hours. From the test results of autogenous (drying) shrinkage and plastic shrinkage, it can be seen that there was a difference according to hydration reaction rate due to the addition of the hardening accelerator. However, it was shown that no problem arose with crack and durability. And it was shown that resistance to freezing-thawing, carbonation, and penetration were excellent.

• Journal of the Korea Institute of Building Construction
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• v.14 no.2
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• pp.156-162
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• 2014

This study aims to develop a rapidly hardening type of concrete to achieve the removal of form intensity (more than 10MPa) using the method of curing at room temperature in order to solve some economic environmental problems by omitting the steam curing process involved in producing PC (Precast Concrete). Therefore, this study evaluated a rapidly hardening cement containing a high amunt of C3S, which is very responsive in expressing early intensity, and a rapidly hardening type of concrete which uses some hardening accelerator to increase thehydration reaction of $C_3S$. The results of the experiment on concrete using some hardening accelerator are asfollows. In the slump flow experiment for identifying the liquidity and the air test, the desired values were met. The compression strength showed rapid expression response by 12 hours, and met the desired value within 6~9 hours. Its drying shrinkage value and Autogenous shrinkage value were measured as below ($-754.5{\times}10^{-6}$),and satisfied the requirements. In addition, in the Semi-Adiabatic Temperature Test, it was found that the concrete rose to its peak temperature within 24 hours and then its temperature dropped.

• Korean Journal of Construction Engineering and Management
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• v.20 no.2
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• pp.3-12
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• 2019

Despite the importance and function of productivity information, in the Korean construction industry, the method of collecting and analyzing productivity data has not been organized. Also, in most cases, productivity management is reliant on the experience and intuitions of field managers, and productivity data are rarely being utilized in planning and management. Accordingly, this study intends to develop a prediction model for interior finishes of apartment using deep learning techniques, so as to provide a foundation for analyzing the productivity impacting factors and predicting productivity. The result of the study, productivity prediction model for interior finishes of apartment using deep learning techniques, can be a basic module of apartment project management system by applying deep learning to reliable productivity data and developing as data is accumulated in the future. It can also be used in project engineering processes such as estimating work, calculating work days for process planning, and calculating input labor based on productivity data from similar projects in the past. Further, when productivity diverging from predicted productivity is discovered during construction, it is expected that it will be possible to analyze the cause(s) thereof and implement prompt response and preventive measures.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.28 no.6
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• pp.243-249
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• 2018

Ceramic tiles, which were manufactured through high-temperature firing process at over $1000^{\circ}C$, are widely used as interior and exterior materials for building construction due to their excellent durability and aesthetic of surface glaze. In recent years, the introduction of digital ink-jet printing in ceramic tiles for architectural use has been rapidly proceeding, and studies on the materials such as ceramic ink, ceramic pigment, glaze have been actively conducted. In this study, the effect of microstructure change of surface glaze on the printing properties of ceramic inks was investigated by micronization of kaolin, which is the raw material of surface glaze. Black ceramic ink was used for ink-jet printing on the surface glaze of ceramic tile to evaluate the printability by measuring the size and roundness of the printed ink dot. The relationship between microstructure change of surface glaze and printability of ceramic ink was also investigated by analyzing the surface roughness and internal micropore distribution of surface glaze.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.19-26
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• 2021

The lattice structure is attracting attention from industry because of its excellent strength and stiffness, ultra-lightweight, and energy absorption capability. Despite these advantages, widespread commercialization is limited by the difficult manufacturing processes for complex shapes. Additive manufacturing is attracting attention as an optimal technology for manufacturing lattice structures as a technology capable of fabricating complex geometric shapes. In this study, a unit cell was formed using a three-dimensional coordinate method. The relative density relational equation according to the boundary box size and strut radius of the unit cell was derived. Simple cubic (SC), body-centered cubic (BCC), and face-centered cubic (FCC) with a controlled relative density were designed using modeling software. The accuracy of the equations for calculating the relative density proposed in this study secured 98.3%, 98.6%, and 96.2% reliability in SC, BCC, and FCC, respectively. A simulation of the lattice structure revealed an increase in compressive yield load with increasing relative density under the same cell arrangement condition. The compressive yield load decreased in the order of SC, BCC, and FCC under the same arrangement conditions. Finally, structural optimization for the compressive load of a 20 mm × 20 mm × 20 mm structure was possible by configuring the SC unit cells in a 3 × 3 × 3 array.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6A
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• pp.765-778
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• 2008

Performance Profiles are essential to predict the performance variation over time for the bridge management system (BMS) based on risk management. In general, condition profiles based on experts opinion and/or visual inspection records have been used widely because obtaining profiles based on real performance is not easy. However, those condition profiles usually don't give a good consistency to the safety of bridges, causing practical problems for the effective bridge management. The accuracy of performance evaluation is directly related to the accuracy of BMS. The reliability of the evaluation is important to produce the optimal solution for distributing maintenance budget reasonably. However, conventional methods of bridge assessment are not suitable for a more sophisticated decision making procedure. In this study, a method to compute quantitative performance profiles has been proposed to overcome the limitations of those conventional models. In Bridge Management Systems, the main role of performance profiles is to compute and predict the performance of bridges subject to lifetime activities with uncertainty. Therefore, the computation time for obtaining an optimal maintenance scenario is closely related to the efficiency of the performance profile. In this study, the Response Surface Method (RSM) based on independent and important design variables is developed for the rapid computation. Steel box bridges have been investigated because the number of independent design variables can be reduced significantly due to the high dependency between design variables.

• Journal of Korea Entertainment Industry Association
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• v.13 no.5
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• pp.67-72
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• 2019

Animation is a comprehensive audio-visual art, animation literature, painting, music, architecture, photography and other art forms are integrated. China's animation industry has made some achievements in the new century, but on the whole, with the globalization of China, China's animation industry has been influenced by Japan and the United States. China has a history and culture of five thousand years, with profound social deposits and cultural foundation. Of the four ancient civilizations in the world, the Chinese civilization is the only one that has survived. China has too many stories to tell. From the development history of Chinese and foreign animation, we can see that many Chinese traditional cultural elements are used for reference. Since the 1980s, Chinese animation has been on the road of national revival. Chinese animation has begun to draw close to traditional culture in terms of themes, characters and scenes, and integrate Chinese traditional cultural elements. The theme of big fish and begonia is to repay kindness by sacrificing one's own life for the sake of justice and friendship. This fearless spirit of sacrificing one's life for justice is the concentrated embodiment of the fine qualities of the Chinese nation over the past several thousand years. Kun to save chun and give up his life, chun in order to repay rather give up half of his life, and qiushui in order to help their beloved, also would rather give up all of their own. These three protagonists are very distinctive personality characteristics, are to "righteousness" and give up their most precious things. At the same time, big fish and begonia combines many traditional Chinese cultural elements to form an animated film with Chinese characteristics.