• International Journal of Aeronautical and Space Sciences
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• v.17 no.2
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• pp.268-283
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• 2016

Aircraft manufacturing companies have to consider multiple derivatives to satisfy various market requirements. They modify or extend an existing aircraft to meet new market demands while keeping the development time and cost to a minimum. Many researchers have studied the derivative design process, but these research efforts consider baseline and derivative designs together, while using the whole set of design variables. Therefore, an efficient process that can reduce cost and time for aircraft derivative design is needed. In this research, a more efficient design process is proposed which obtains global changes from local changes in aircraft design in order to develop aircraft derivatives efficiently. Sensitivity analysis was introduced to remove unnecessary design variables that have a low impact on the objective function. This prevented wasting computational effort and time on low priority variables for design requirements and objectives. Additionally, uncertainty from the fidelity of analysis tools was considered in design optimization to increase the probability of optimization results. The Reliability Based Design Optimization (RBDO) and Possibility Based Design Optimization (PBDO) methods were proposed to handle the uncertainty in aircraft conceptual design optimization. In this paper, Collaborative Optimization (CO) based framework with RBDO and PBDO was implemented to consider uncertainty. The proposed method was applied for civil jet aircraft derivative design that increases cruise range and the number of passengers. The proposed process provided deterministic design optimization, RBDO, and PBDO results for given requirements.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.3
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• pp.447-453
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• 2010

Response-based approach is getting more preferred in determining the design sea-state for offshore structures because traditional environment-based approach is known to yield a much conservative design condition. This paper introduces the inverse first-order second-moment (IFOSM) method as a response-based approach, which is expected to give a more feasible design condition at the cost of reasonable number of motion analyses. The IFOSM method is based on the theory of probability and adopts an optimization scheme to determine the design point. Both the design maximum response and design sea state can be obtained straightforwardly from the optimum. The IFOSM method has been applied to a turret-moored FPSO's design problem and showed its effectiveness in practical use.

• Earthquakes and Structures
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• v.19 no.3
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• pp.175-188
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• 2020

The Hengda Group super high-rise building in Jinan City uses the frame-core tube structural system. With a height of 238.3 m, it is above the B-level height limit of 150 m for buildings within 7-magnitude seismic fortification zones. Therefore, it is necessary to apply performance-based seismic design to this super high-rise building. In this study, response spectrum analysis and comparative analysis of the structure are conducted using two software applications. Moreover, elastic time-history analysis, seismic analysis under an intermediate earthquake, and elastic-plastic time-history analysis under rare earthquakes are performed. Based on the analysis results, corresponding strengthening measures are implemented at weaker structural locations, such as corners, wall ends connected to framed girders, and coupling beams connected to framed girders. The failure mode and failure zone of major stress components of the structure under rare earthquakes are analysed. The conclusions to this research demonstrate that weaker locations and important parts of the structure satisfy the requirements for elastic-plastic deformation in the event of rare earthquakes.

• International Journal of Advanced Culture Technology
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• v.11 no.2
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• pp.56-63
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• 2023

I proposed the architectural guideline for educational environment based on design thinking approach to integrate and enhance learners' activities and achievements. The physical environment of design education learning space should be applied by teaching methods and learning activities, especially for STEAM-based convergent education, the architectural space conditions should support the design process based on design thinking. The learning environment conditions influence design education with physical design factors and learners' communication, and the flexible environment based on design thinking, which is crucial for design education. The 3 steps of design thinking experiences also allow students to learn the context of ideas, skills and outcomes. Therefore, I argued that the learning surrounding based on design thinking needs flexible and mobile, connected, integrated, organized, and team-focused environments to support learners' understanding, participation, and collaboration, and to achieve the design process based on research findings. For spaces for convergent learning environments based on design thinking, common design principles should be reviewed, such as coexistence with technology, safety and security, transparency and spatial extension, multi-purpose space and outdoor learning.

• Design Convergence Study
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• v.15 no.4
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• pp.59-70
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• 2016

Due to the newly emerging market for telepresence robots and the research in the area, designers and developers lack guidelines for specifying the physical characteristics of telepresence robots. On the basis of the previous literature, we attempted to make a distinction between two robot height approaches for telepresence robot designs: floor- versus desk-based robot designs. This research investigated the effects of these robot height approaches on consumer acceptance. We predicted that there would be difference between floor-based robots and desk-based robots regarding consumers' evaluation of and intent to purchase social robots. A study using two types of robots was conducted with sixty university students. The results showed that participants perceived desk-based robots as more useful than floor-based robots. In addition, the participants evaluated desk-based robots more positively than floor-based robots. Purchase intention and willingness to pay also showed similar results as evaluation. The implications for the design of telepresence robots in terms of increasing acceptance of robots are discussed in detail.

• Korean Institute of Interior Design Journal
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• no.40
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• pp.158-164
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• 2003

The rapid development of information technology has much influence on architectural design. Collaboration beyond time and space has been possible by networking the work environment and digital products. Thus, the virtual design studio on architectural design is getting more important than ever before. This research investigates a virtual design studio methodology for effective collaboration. The building design process and the communication model are studied and possible modes of design collaboration are defined. This paper proposes an internet-based Virtual Reality(VR) communication tool as well as new design methodology that we call the 'Hybrid Design Methodology'. We expect that this design methodology will dramatically increase design feedbacks, and thus results in better design alternatives. There are two issues involved in developing the collaborative virtual design studio: 1) an intuitive interface that presents collaborative relations, and 2) three-dimensional computer-mediated communication tool using sketch as a modeling method. Further research issues identified at the end of the research include developing algorithms that translate mapping images to polygons for the drafting phase in the design process.

• Educational Technology International
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• v.10 no.2
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• pp.29-61
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• 2009

The purpose of this study was to design an inquiry supporting tool on wiki based collaborative learning and to investigate the effect of the inquiry supporting tool. Eight design principles were selected and more specified design strategies were made from the literatures. The first system with the first-round design principles was developed and implemented in an actual classroom. After the first field study, researcher found a few drawbacks of the system. The second system was implemented in the classroom again. Finally developed wiki-based inquiry supporting tool system is unique in that it allows instructors to design their own CSCL inquiry activities, and it has intuitive menu tabs showing inquiry learning processes.

• International journal of advanced smart convergence
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• v.8 no.4
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• pp.113-120
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• 2019

Recently, the artificial intelligence(AI) is used in various environments in life, and research on this is being actively conducted in education. In this paper, we designed a Design-Based Research(DBR)-based AI programming education program and analyzed the application of the program for the improvement of understanding of AI in elementary school. In the artificial intelligence education program in elementary school, we should considerthat itshould be used in conjunction with software education through programming activities, rather than creating interest through simple AI experiences. The designed education program reflects the collaborative problem-solving procedures following the DBR process of analysis - design - execution - redesign, allowing the real-world problem-solving activities using AI experiences and block-type programming language. This paper also examined the examples of education programs to improve understanding of AI by using Machine Learning for Kids and to draw implications for developing and operating such a program.

• Korean Journal of Computational Design and Engineering
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• v.14 no.3
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• pp.137-149
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• 2009

For recent years, there has been significant research achievement on the feature-based multiresolution modeling technique along with widely application of three-dimensional feature-based CAD system in the areas of design, analysis, and manufacturing. The research has focused on several topics: topological frameworks for representing multiresolution solid model, criteria for the LOD, generation of valid models after rearrangement of features, and applications. This paper surveys the relevant research on these topics and suggests the future work for dissemination of this technology.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.6
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• pp.33-41
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• 2015

Scaled model of a dual-mode ramjet engine with large backward-facing step, as a component of the rocket-based combined cycle engine, was designed. Design parameters were derived for this engine with the consideration of application for the rocket-based combined cycle engine. Design methodology was established for these design parameters. The design was partially verified through numerical study. Flow characteristics of the dual-mode ramjet engine with large backward-facing step was investigated experimentally. The design methodology for relevant design parameters established in this study was verified as feasible.