• Journal of the Korean Solar Energy Society
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• v.39 no.2
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• pp.45-55
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• 2019

More than 76% of the detached houses in Korea are over 20 years old. These old detached houses have poor energy efficiency. According to the 2017 Housing Census (Statistics Korea), more than 50% of low-income families live in detached houses. Therefore, the improvement of energy efficiency in old detached houses is needed from the viewpoint of energy welfare. The general method of building energy modelling for the verification of energy efficiency is based on the construction year data of "Building Design Criteria for Energy Saving" due to the cost and time involved in collecting the thermal performance data of buildings. There is poor accuracy with the deterioration of long-term aging of building materials. Also, the selection of alternatives for energy performance improvement is based on the items to be applied, not a performance improvement goal. It is difficult to calculate energy performance that reflects variations in various parameters with dynamic energy simulations. In this study, the influence of long-term aging is used to accurately predict the energy performance of old detached houses. The building energy modelling method is called ENERGY#, which is a static analysis method based on ISO13790. Energy performance is evaluated by a combination of input variables including building orientation, insulation of walls and roof, thermal performance of windows and window/wall ratio, and infiltration rate. Finally, this study provides a way to determine alternatives that meet energy performance improvement goals.

• Wind and Structures
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• v.28 no.5
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• pp.271-284
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• 2019

This paper describes the application of a novel virtual prototyping methodology to wind turbine blade design. Numeric modelling data and experimental data about turbine blade geometry and structural/dynamical behaviour are combined to obtain an affordable digital twin model useful in reducing the undesirable uncertainties during the entire turbine lifecycle. Moreover, this model can be used to track and predict blade structural changes, due for example to structural damage, and to assess its remaining life. A new interactive and recursive process is proposed. It includes CAD geometry generation and finite element analyses, combined with experimental data gathered from the structural testing of a new generation wind turbine blade. The goal of the research is to show how the unique features of a complex wind turbine blade are considered in the virtual model updating process, fully exploiting the computational capabilities available to the designer in modern engineering. A composite Sandia National Laboratories Blade System Design Study (BSDS) turbine blade is used to exemplify the proposed process. Static, modal and fatigue experimental testing are conducted at Clarkson University Blade Test Facility. A digital model was created and updated to conform to all the information available from experimental testing. When an updated virtual digital model is available the performance of the blade during operation can be assessed with higher confidence.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.77-85
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• 1997

Researches in the field of Computer Graphics and Geographical Information Systems(GIS) have extensively studied the method of photo-realistic landscape modelling, because it have become a commom requirement in applications such as flight simulators, mission rehearsal, and construction planning. A common approach to the display of terrain uses a Digital Elevation Model(DEM). DEM is an evenly spaced array of the terrain elevation data and can be obtained from stereo satellite data. With the DEM data, the process of 3D terrain modelling consists of three steps. The first step is to extract the meaningful data (such as peak, pit, passes...) from DEM data based on LOD(Level Of Detail) criteria. The second is to construct the 3D surface by TIN, which represents a surface as a set of non-overlapping continuous triangular facets of irregular size and shape. The third is a rendering of 3D terrain model. The goal of this research is a construction of 3D terrain with TIN. To do this, we are going to app]y Radial Sweep Algorithm. Radial Sweep Algorithm for generating TIN works quickly and efficiently. However, it does not solve the problem caused by the approximated nature of triangulated surface. To solve this problem, this research derive improved radial sweep algorithms with the optimal triangle definition.

• International Journal of High-Rise Buildings
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• v.13 no.1
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• pp.97-102
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• 2024

In this paper, we would like to share our ongoing research on global population and demographic shifts and the corresponding need for diverse responses. As population growth varies worldwide, the pressing issue is the current global housing shortage. The USA alone lacks 4 million homes, underlining the urgency for new construction and renewal of existing. Our focus is primarily on new building processes, which must also incorporate elements of renewal for future sustainability. Our research addresses several key questions: How will roles for construction professionals change? What should be the primary goal of the design process? What types of technologies are currently available, and which aspects of the process can be enhanced with AI? A significant part of our study is exploring sustainable building methods that reduce embodied carbon and increase speed of construction. Our goal is to extend the transition from smart homes to cities, analyzing the evolution towards smart communities and cities. A critical aspect of our research is the 'kit of parts concept, involving prefabrication and modular construction. This approach is essential for both rebuilding and new projects, potentially lowering costs in manufacturing and design for long term. Lastly, we present a detailed comparison of the construction industry with manufacturing.

• Journal of the Korean Society of Industry Convergence
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• v.27 no.1
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• pp.161-172
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• 2024

Approximately 89% of all capsizing accidents involve small vessels, and despite their relatively high accident rates, small vessels are not subject to ship stability regulations. Small vessels, where the provision of essential basic design documents for stability calculations is omitted, face challenges in directly calculating their stability. In this study, considering that the majority of domestic coastal small vessels are of the Chine-type design, the goal is to establish the major hull form characteristic data of vessels, which can be identified from design documents such as the general arrangement drawing, as input data. Through the application of a deep learning approach, specifically a multilayer neural network structure, we aim to infer hydrostatic curves, operational draft ranges, and more. The ultimate goal is to confirm the possibility of directly calculating the initial stability of small vessels.

• Journal of Environmental Science International
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• v.13 no.8
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• pp.733-737
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• 2004

FThe aim of this study was to carry out a preliminary test of the air quality modelling system (HIRES-AIRCHEM) developed at The University of New South Wales, particularly with regard to the forecast ozone distribution. This was achieved by assimilating the New South Wales State Environment Protection Authority (EPA) emissions inventory, consisting of road and non-road sources, and running the system over the Sydney metropolitan area for the four day period 25-28 February 1998. During this period ozone readings exceeded the EPA's goal of 8pphm on several occasions. The model forecasts of ozone distribution verified well with the EPA's ozone readings. This result has important implications for possible future use of the system as a tool for routinely predicting and assessing air quality.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.1
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• pp.91-99
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• 2003

This paper describes the development of a pc-based machinery space simulator for training and research, relevant to STCW-95. The detailed mathematical modelling process for the actual machinery is discussed and a method to perform effective education and training for the simulator is suggested. The method includes scenario, procedure, exercise and evaluation. The procedure guides the trainee through a sequence of steps designed to meet a specific goal, showing the trainee what must be done and explaining why The exercise enhances understanding for efficient engine management and enable user to perform research for the machinery. The evaluation shows exercise results and feeds back to instructor how to guide the under-performed trainee.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.7
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• pp.140-147
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• 1996

Machining accuracy of machine tools spindles using the hydrostatic bearing, largely depends on the static stiffness and the thermal deformation of the spindle unit. In this paper, the modelling and static, thermal analysis of the hydrostatic spindles were performed for the relationship between the design variables like the bearing span, overhang, bearing stiffness and static stiffness at spindle. The goal of optimization is the mazimum, static stiffness at spindle nose with lower temperature rise in hydrostatic bearing. Temperature rise of hydrostatic bearing is minimized with the variables of spindle diameter and oil supply pressure. Finally, validity of the proposed algorithm is verified by improving the static, thermal performance of the existing hydrostatic spindles.

• Smart Structures and Systems
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• v.15 no.4
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• pp.949-961
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• 2015

The goal of this study is to present numerical modeling and analytical testing in order to evaluate an innovative space truss typed temporary structure, which is used to maintenance and repair of road tunnels. The present space truss structure has merits to use UL-700 high strength steel tube as members and to carry out maintenance and repair works of road tunnels without blocking cars and transportations. Numerical modeling and analytical testing of the space truss are investigated by using commercial engineering software, i.e., ABAQUS 6.5-1, and then it is verified that the truss structure has both structural safety and effective function for maintenances and repairs of road tunnels.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.212-215
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• 2003

The aim of this study was to test the air quality modelling system (HIRES-AIRCHEM) of The University of New South Wales particularly with regard to forecast ozone distribution. This was achieved by assimilating the New South Wales State EPA emissions inventory consisting of road and non-road sources and running the system over the Sydney metropolitan area for the four day period 25-28 February 1998. During this period ozone readings exceeded the EPA＇s goal of 80ppb on several occasions. The model forecasts of ozone distribution verified well with the EPA＇s ozone readings. This result has important implications for possible future use of the system as a tool for routinely assessing air quality.