• Geomechanics and Engineering
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• v.28 no.6
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• pp.599-611
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• 2022

Tendon reinforced cemented soil is applied extensively in foundation stabilisation and improvement, especially in areas with soft clay. To solve the deterioration problem led by steel corrosion, the glass fiber-reinforced polymer (GFRP) tendon is introduced to substitute the traditional steel tendon. The interface bond strength between the cemented soil matrix and GFRP tendon demonstrates the outstanding mechanical property of this composite. However, the lack of research between the influence factors and bond strength hinders the application. To evaluate these factors, back propagation neural network (BPNN) is applied to predict the relationship between them and bond strength. Since adjusting BPNN parameters is time-consuming and laborious, the particle swarm optimisation (PSO) algorithm is proposed. This study evaluated the influence of water content, cement content, curing time, and slip distance on the bond performance of GFRP tendon-reinforced cemented soils (GTRCS). The results showed that the ultimate and residual bond strengths were both in positive proportion to cement content and negative to water content. The sample cured for 28 days with 30% water content and 50% cement content had the largest ultimate strength (3879.40 kPa). The PSO-BPNN model was tuned with 3 neurons in the input layer, 10 in the hidden layer, and 1 in the output layer. It showed outstanding performance on a large database comprising 405 testing results. Its higher correlation coefficient (0.908) and lower root-mean-square error (239.11 kPa) were obtained compared to multiple linear regression (MLR) and logistic regression (LR). In addition, a sensitivity analysis was applied to acquire the ranking of the input variables. The results illustrated that the cement content performed the strongest influence on bond strength, followed by the water content and slip displacement.

• Steel and Composite Structures
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• v.46 no.4
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• pp.497-512
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• 2023

Using light weight concrete as infill material in conventional cold-formed steel (CFS) shear wall systems can considerably increase their load bearing capacity, ductility, integrity and fire resistance. The compressive strength of the filler concrete is a key factor affecting the structural behaviour of the composite wall systems, and therefore, achieving maximum compressive strength in lightweight concrete while maintaining its lightweight properties is of significant importance. In this study a new type of optimum polystyrene lightweight concrete (OPLC) with high compressive strength is developed for infill material in composite CFS shear wall systems. To study the seismic behaviour of the OPLC-filled CFS shear wall systems, two full scale wall specimens are tested under cyclic loading condition. The effects of OPLC on load-bearing capacity, failure mode, ductility, energy dissipation capacity, and stiffness degradation of the walls are investigated. It is shown that the use of OPLC as infill in CFS shear walls can considerably improve their seismic performance by: (i) preventing the premature buckling of the stud members, and (ii) changing the dominant failure mode from brittle to ductile thanks to the bond-slip behaviour between OPLC and CFS studs. It is also shown that the design equations proposed by EC8 and ACI 318-14 standards overestimate the shear force capacity of OPLC-filled CFS shear wall systems by up to 80%. This shows it is necessary to propose methods with higher efficiency to predict the capacity of these systems for practical applications.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.218-219
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• 2022

The Korea Institute for Advancement of Technology and the Ulsan ICT Promotion Agency are building an electric smart ship using a full range of ICT with advanced technology, and are expected to demonstrate it in 2022. For the demonstration of onboard ship equipment, it needs to develop a demonstration procedure. There are 4 types of onboard equipment preferentially selected for the development of the demonstration test procedure which are an electronic chart display and information system, a ship RADAR system, a voyage data recorder, and a ship energy efficiency monitoring system. This paper describes the demonstration procedure based on the equipment standard for the electronic chart display and information system among 4 selected types of demonstration equipment, and also the verification test checklist and template is introduced.

• The Transactions of the Korea Information Processing Society
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• v.13 no.2
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• pp.1-12
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• 2024

Modern cities are actively adopting smart city services to address various urban challenges. Geospatial information acts as the foundational infrastructure of smart cities, promoting the sustainable development of urban areas. Consequently, as the standardization and utilization of geospatial information increase, the efficiency and sustainability of smart city operations improve. To achieve this, collaboration among diverse stakeholders is crucial for delivering optimal smart city services based on geospatial information. This paper defines smart city services, focusing on transportation and building-energy domains, based on the life cycle of geospatial information technology. Emphasis is placed on the importance of applying and utilizing geospatial information standards. Additionally, this paper proposes the Smart City based on Geospatial Information standards (SCGI) framework to provide insights into standardizing smart city services mapped to geospatial information standards. This research suggests a new paradigm for standardizing smart city services using geospatial information standards to offer customized solutions, thereby discussing the future development possibilities of smart cities.

• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.391-396
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• 2024

This study proposes a novel reverse N-Gram approach to overcome the limitations of traditional N-Gram methods and enhance performance in building an entity dictionary specialized for the healthcare sector. The proposed reverse N-Gram technique allows for more precise analysis and processing of the complex linguistic features of healthcare-related big data. To verify the efficiency of the proposed method, big data on healthcare and digital health announced during the Consumer Electronics Show (CES) held each January was collected. Using the Python programming language, 2,185 news titles and summaries mentioned from January 1 to 31 in 2010 and from January 1 to 31 in 2024 were preprocessed with the new reverse N-Gram method. This resulted in the stable construction of a dictionary for natural language processing in the healthcare field.

• Fire Science and Engineering
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• v.28 no.6
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• pp.82-89
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• 2014

Disasters that destroy homes and infrastructure and cause significant financial damage are becoming more common as population centers grow. In addition, several natural disasters have resulted in a major loss of life and created countless refugees due to damage to housing. After major catastrophic disasters, it is very important that the government agencies respond to post-disaster housing issues and provide resources such as temporary housing before the full rehabilitation and reconstruction of destroyed and damaged housing. To provide affordable temporary housing for residents who may lose their homes as the result of a catastrophic disaster including storms, government agencies must develop a post-disaster housing prototype. In general, government agencies should explore several different forms of factory-built single-story, single family housing, such as modular homes, panelized homes, and precut homes. In urban cities including New York and Seoul, it is very important to provide housing which supports the demand for higher-density living spaces than single-family homes or trailers typically available due to the high population density and the desire to resettle as many residents as possible in their former neighborhoods. This study identified the urban post-disaster housing prototypes that may provide higher density housing with high quality living spaces, high air quality, and energy efficiency as well as rapid deployment. A case study of "Urban Post-Disaster Housing Prototype Program in New York" was conducted through a detailed interview process with a designer, engineer, contractor, the Office of Emergency Management (OEM) in New York, the U.S. Army Corps of Engineers (USACE), and temporary occupants. An appropriate disaster housing program that can provide living spaces for victims of disasters that keeps residents in their community and allows them to live and work in their neighborhoods was developed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.379-387
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• 2016

The goal of this research is to identify the planning techniques of high-rise housing estates applying a smart green city concept in order to understand the necessity of integrating 'planning & building' planning techniques and 'smart system' planning techniques and to analyze the current status of application. For the research, firstl, the definition of smart green city was established and high-rise housing estates planning was categorized according to a three space hierarchy, seven planning directions and 17 major features through literature review. Second, 28 'planning & building' planning techniques and 'smart system' planning techniques were derived through literature review and FGI analysis. Last, four cases in Multi-functional Administrative City were analyzed for the current status of application of planning techniques. In conclusion, planning techniques in 'Transportation Network', 'Environment-friendly layout planning of housing', 'Revitalization of green transportation', 'Utilization of new & renewable energy', 'Crime prevention and accident reduction', 'Use of high performance, and efficiency facility' main feature were identified as important planning techniques for Smart Green City and its implications were estimated.

• Journal of the Korea Institute of Building Construction
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• v.19 no.2
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• pp.175-184
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• 2019

This paper presents a modeling prototype that optimizes construction processes implementing information communication technology (ICT). Using "IAMB", each and every actual steps of the construction process may be defined visually and explicitly by elaborating ICT to improve productivity and management efficiency. It contributes to identify the features on what parts of construction task are covered by ICT, and the effects of ICT on process performance. After analyzing 10 real project cases, ICT application types are classified into four categories according to ICT type, job functions that ICT applied, and the project phase in which ICT used. As a reuslt, it was confirmed that the positive outcomes on the construction process were beneficial to mostly the general contractors and mainly obtained by automated information processing, external consignment and consistent information use. Negative effects, which were occurred by mainly manual manipulation and duplication of information handling, were accrued to general contractors minimally, but to subcontractors maximally. Expert focus group commends that several important issues should be considered when implementing ICT.

• Journal of the Korea Institute of Building Construction
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• v.21 no.5
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• pp.459-468
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• 2021

Blocking electromagnetic waves on the exterior walls of buildings effectively reduces the intensity of electromagnetic fields in buildings, which leads to attenuation of electromagnetic disturbances, so there is a great interest in developing technologies. In this study, SiC by-products and graphite generated in the semiconductor field were selected and mixed into mortar after pretreatment such as pulverization to evaluate their physical properties and electromagnetic wave shielding performance. Considering the economic efficiency of each shielding material, only 10% volume of the outermost side of the experiment was mixed with each shielding material to evaluate the shielding performance. The shielding performance was predicted when the experiment was manufactured by mixing the shielding material with the entire volume of the experiment using the shielding effect evaluation formula. The results of the experiment showed that the shielding performance was up to 20 dB when SiC grains were mixed with shielding materials, the shielding performance was up to 18 dB when graphite powder was mixed with shielding materials, and the shielding performance was up to 28 dB when SiC powder was mixed with shielding materials, and the shielding performance was close to 30 dB, which is known to have a shielding rate of 99.9%.

• Journal of the Korea Institute of Building Construction
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• v.21 no.6
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• pp.653-664
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• 2021

As the construction standards for energy-saving eco-friendly housing have recently been strengthened, the proportion of window work has increased with the demand for high-efficiency housing. Windows have high frequency of use, and there is the potential for many defects to occur depending on the characteristics of construction. According to a government agency's survey of defects in public rental apartment housing, defects in the windows work accounted for the highest portion of complaints received. Accordingly, related previous studies were considered, and it was found that the existing studies in Korea lacked research that reflected the construction characteristics of window work and the importance of maintenance. In addition, existing overseas studies considered both the constructor and the resident's position, considering the cost aspect together, and showed a trend of structuring the relationship between defects and causes. Therefore, this study will analyze the causes of defects that can occur in the construction phase of the windows work, reflect the construction characteristics, and derive major factors that consider the importance of maintenance based on the possibility of recurrence after repairing defects. Ultimately, this research will contribute to preventing defects in the construction phase and reducing maintenance costs by presenting a highly effective defect management plan through selecting the major factors for each defect type that can be intuitively judged by analyzing the causal relationship between defect types and causes.