• Advances in concrete construction
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• 제14권1호
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• pp.1-13
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• 2022

Due to the physical-chemical characteristics of some bottom ash (BA), there are technical, economic and environmental limitations to find a destination that will add value to it. In Brazil, this residue is eventually used for filling coal extraction pits or remains in sedimentation ponds, creating a susceptible panorama to environmental issues. The geopolymers binders are one of the alternatives to the proper use high amounts of these materials. In this work, geopolymeric binder pastes were produced with BA mixed to activators with different alkali contents (expressed as %Na₂O), as well as the incorporation of soluble silicates (Ms content). The production of binary geopolymeric pastes based on the use of two industrial wastes: fluid catalytic cracking (FCC) and aluminum anodizing sludge (AAS), was also assessed. The content in mass of BA/FCC and BA/AAS ranged from 100/0, 90/10; 80/20 and 70/30. Systems with soluble silicates as activator in a molar ratio SiO₂/Na₂O of 1.0 (Ms = 1.0) and Na₂O content of 15%, showed the best results of mechanical strength (42 MPa at day 28^th). The improvement is up to 5X when compared to NaOH based systems. For systems with partial replacement of BA of 10% of AAS and 20% of FCC (80/20), the presence of soluble silicates was also effective to increase compressive strength.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 말뚝기초 학술발표회
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• pp.65-84
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• 2000

Europe and US which have more restrictive regulations than Korea about the noise and vibration during construction are using Auger-cast Pile to reduce the problem relating with noise and vibration. However Auger-cast Pile has problems like difficult quality control and low bearing capacity. In Europe, Displacement in-situ concrete Pile has been used to sove that problems since 1990s, and Korea has performed the test construction in 1997 and it has been used as the real structural foundation since 1998. Test and real construction results verified that the allowable capacity of the pile(diameter = 410mm) is between 70 and 100ton. Though De Beer & Van Imps design method utilizing CPT result is used to calculate the bearing capacity of the Displacement in-situ Pile, Korea is dependant upon the SPT as the sounding test, so design method utilizing SPT result is necessary to promote the application of the pile. To find out reasonable design method using SPT result, rearing capacity of the pile constructed in sand and clay in Korea was calculated using Meyerhof, SPT-CPT translation method, Nordlund, Douglas and DM-7 method, and the calculation results were compared to the load test result. Analysis result shows that SPT-CPT translation method is more reliable than others and economical design can be possible because it considers efficiently the friction capacity of Displacement in-situ Pile.

• Journal of Welding and Joining
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• 제31권6호
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• pp.1-7
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• 2013

In nuclear power plants, lined carbon steel pipes or PCCPs (pre-stressed concrete cylinder pipes) have been widely used for sea water transport systems. However, de-bonding of linings and oxidation of PCCP could make problems in aged NPPs (nuclear power plants). Recently at several NPPs in the United States, the PCCPs or lined carbon steel pipes of the sea water or raw water system have been replaced with HDPE (high density polyethylene) pipes, which have outstanding resistance to oxidation and seismic loading. ASME B&PV Code committee developed Code Case N-755, which describes rules for the construction of buried Safety Class 3 polyethylene pressure piping systems. Although US NRC permitted HDPE materials for Class 3 buried piping, their permission was limited to only 10-year operation because of several concerns including the quality of fusion zone of HDPE. In this study, various requirements for fusion qualification test of HDPE and some regulatory issues raised during HDPE application review in foreign NPPs are introduced.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.814-822
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• 2022

The deployment of sensors for Structural Health Monitoring requires a complicated network arrangement, ground truthing, and calibration for validating sensor performance periodically. Any conventional sensor on a structural element is also subjected to static and dynamic vertical loadings in conjunction with other environmental factors, such as brightness, noise, temperature, and humidity. A structural model with strain gauges was built and tested to get realistic sensory information. This paper investigates different deep learning architectures and algorithms, including unsupervised, autoencoder, and supervised methods, to benchmark blind drift calibration methods using deep learning. It involves a fully connected neural network (FCNN), a long short-term memory (LSTM), and a gated recurrent unit (GRU) to address the blind drift calibration problem (i.e., performing calibrations of installed sensors when ground truth is not available). The results show that the supervised methods perform much better than unsupervised methods, such as an autoencoder, when ground truths are available. Furthermore, taking advantage of time-series information, the GRU model generates the most precise predictions to remove the drift overall.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.23-24
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• 2021

The use of recycled concrete aggregates (RCA) as a substitute for natural aggregates in new concrete produces both economic and environmental advantages. Most of the RCA applications for pavements have been primarily applied to support layers for roads and airfields. This paper summarizes a work completed at the University of Illinois in partnership with the O'Hare Modernization Program to examine the effect of coarse and fine RCA on the concrete's fresh and hardened properties for airfield rigid pavement applications. Ten different RCA concrete mixtures were prepared with the incorporation of different percentages of RCA fines as well as replacement of cement with high volume percentages of supplementary cementitious materials such as Class C fly ash and ground granulated blast furnace slag to improve the workability and long-term properties of RCA concrete. All the mixes on this stage included 100% recycled coarse aggregates and the Two-Stage Mixing Approach was used as a mixing procedure. Based on the results obtained in the research, mixes with high percentages of recycled fine and coarse aggregates could be used for construction of airfield concrete pavements in conjunction with supplementary cementitious materials

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.750-753
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• 2015

The continuing trend of built environment set forth by the rise of modernization and industrialization has led every country in achieving their respective economic development. Along side this trend is an issue that needs to be addressed - the environmental impacts of the built industry. Construction and maintenance of buildings are said to consume 40% of the world's energy, 65% of electricity, and 40% of raw materials, creating drastic pollutants harmful not only to the environment but also to human. Figures have been released and analyzed proving the contributions of built environment with environmental depreciation. Said figures earned concerns not just from different private and non-profit organizations but also the governments of every country, thus, steps towards sustainable development are being implemented. As a response, the "green" was added in the built environment. Later on, the now emerging concept of "National Green Building Code" found its role in the policy of various states in protecting the people in accord with the nature. This paper appreciates the initiatives of various countries and non-profit organizations in their drive to pursue sustainable green built environment in general, and specifically proposes an establishment of an "incentives grant framework" as an additional legislative policy to be included in the draft of the National Green Building Code of the Philippines.

• International Journal of Concrete Structures and Materials
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• 제6권3호
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• pp.145-153
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• 2012

The aim of this study is to explore the possibility of re-cycling a waste material that is now produced in large quantities, while achieving an improvement of the mechanical properties and durability of the mortar. This study examines the mechanical properties and the durability parameters of mortars incorporating plastics bag wastes (PBW) as fine aggregate by substitution of a variable percentage of sand (10, 20, 30 and 40 %). The influence of the PBW on the, compressive and flexural strength, drying shrinkage, fire resistance, sulfuric acid attack and chloride diffusion coefficient of the different mortars, has been investigated and analyzed in comparison to the control mortar. The results showed that the use of PBW enabled to reduce by 18-23 % the compressive strength of mortars containing 10 and 20 % of waste respectively, which remains always close to the reference mortar (made without waste). The replacement of sand by PBW in mortar slows down the penetration of chloride ions, improves the behavior of mortars in acidic medium and improves the sensitivity to cracking. The results of this investigation consolidate the idea of the use of PBW in the field of construction.

• 토지주택연구
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• 제9권4호
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• pp.1-9
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• 2018

Since year 2000, French housing and rent prices rose at a rapid rate and the housing market has been overheated. Face to this phenomena, the French government enacted a new law Alur which is a legislatif tool to control the private housing rent price for the cities, where the tension of the housing market is very high. This new law has impacted the housing market in two major ways. First, for the 38 cities designated by this law, the rent price's increase rate can not rise above the IRL, which is the rent reference index. Secondly, this law also permits local authorities to control the housing rent's price following the concrete price guidance. Especially in Paris, the city applicated this method for private rental housing since 2015. This city classified its own area by 14 zones. Based on the market surveys of each sector, local authority made a guidance for private housing rent's price. The guideline is consisted of average prices, maxima and minima price by types, which is classified by the construction year, number of rooms and furnished or not. Therefore, this study aims to understand french housing rent's price control system and draw implementation for korean housing rent policies. This research is meaningful for it introduces recent foreign regislations which could be helpful to control the housing market in Korea.

• 복식문화연구
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• 제26권4호
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• pp.583-597
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• 2018

The purpose of this study is to classify and analyze the deconstruction phenomena expressed in contemporary knit fashion design, and to analyze the inner meaning of deconstruction based on certain characteristics. As a method of study, literature data for theoretical backgrounds, prior studies, and internet data were analyzed. The scope of this study was restricted to knitwear published in the world's four major collections (Milan, Paris, New York and London) from 2014 F/W to 2018 S/S. Based on prior studies, four concepts of deconstruction were derived: "$Diff{\acute{e}}reance$", "Intertextuality", "Intermeaning of Meaning", "Dis De Phenomenon". The results of the study were as follows: first, "$Diff{\acute{e}}reance$" refers to a transcendence of time and space. These expressions are discursive, unrealistic, and convey freedom through intent that deviates from rules and norms. Second, "Intertextuality" indicates a mixture of different texts, such as styles, materials, and items. These expressions deliver novelty with amusement, and can be entertaining depending on audience expectations. Third, "Intermeaning of Meaning" is accidental category - depending on how the wearer wears the clothing. -; accordingly, free and spontaneous creativity is an emerging trend in fashion. Fourth, the clothing was expressed in deformed and distorted form by the construction and destruction of the structure, a technique we describe as the "Dis De Phenomenon". In this concept, the sense of free design of young emotion appears along with the sense of purity and shock due to intentional inconsistency.

• Architectural research
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• 제4권1호
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• pp.25-31
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• 2002

For more than a hundred years, art and architectural historians, architects, and engineers interested in structure have attempted to interpret Gothic architecture, one of the most technologically complex and sophisticated structural systems in history. Indigenous Gothic, however, such as non-vaulted Gothic in the Lower Languedoc region of southern France, has been largely ignored. This study intends to analyze the Gothic non-vaulted nef unique (aisleless) structures of Lower Languedoc which have never been scientifically tested, and to provide as comprehensive an explanation as possible of the way in which these non-vaulted buildings work. In order to achieve this goal, this paper is to examine, by means of finite element computer analysis, a selected example of an existing building. The church of Notre-Dame de Lamourguier, the earliest surviving example of a Gothic nef unique with wide-span diaphragm arches in Lower Languedoc, is selected. Thus, hypothetical models of diaphragm arch buildings and an existing building as a complete structural system were scientifically analyzed in order to provide a comprehensive explanation of how the non-vaulted nef unique system works. The result of the analysis, allows us better to understand the structural behavior of this type of masonry arcuated system and the processes involved in the design and construction of medieval buildings.