• International Journal of High-Rise Buildings
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• v.10 no.1
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• pp.17-28
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• 2021

In Harbin, a network of underground commercial spaces has been developed to occupy spaces that were originally created as civil defense shelters. With the gradual extension of the local metro rail system, the existing underground commercial space is no longer an isolated regional development, but a space that represents "three-dimensional city" and coordinated development taking place in many Chinese cities. Based on the analysis of the unique development process taken in underground space of Harbin, this paper summarizes three characteristics of its early model of "fragmented development" of underground space. By conducting a comprehensive field research and survey, the researchers analyzed 472 questionnaires related to the development trend, and proposed multi-level synergistic elements for the renewal and development of underground commercial space. The paper concludes by discussing the trend of "three-dimensional and collaborative development," suitable for the development needs of the new era, and the corresponding development strategies for the renewal of underground space.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.49-53
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• 2005

This paper presents a multi-scale hybrid simulation for the design of a catalytic multi-tubular reactor with high performance. The multi-tubular reactor consists of shell and a large number of tubes in which various catalytic chemical reactions occur. To consider fluid dynamics in the shell-side and kinetics in the tube-side at the same time, commercial CFD package and process simulation tool are coupled. This hybrid approach allowed us to predict many kinds of meaningful results such as tube center temperature profile, heat transfer coefficients on the tube wall, temperature rise of cooling medium, pressure drop through shell and tube side, concentration profile of each chemical species along the tube, and so on., and to achieve the optimal reactor design.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.413-419
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• 2000

An efficient method for calculating the nonlinear stiffness of the Progressive Multi-Leaf Spring is developed and evaluated. It utilizes the interaction between the main and help spring that induces the nonlinearity. The main and the help springs are modeled as multi-leaf cantilever beams, and, then, they are integrated as one by connecting the two models for each side of the Progressive Multi-Leaf Spring at the center-bolt. The results from the developed model are evaluated by use of the commercial FEA program, ABAQUS. The nonlinear spring coefficients calculated by FEM analysis yield the numbers very close to the numbers calculated for the spring coefficients by used of the developed method. From the comparative evaluations, the developed method is accurate enough and very efficient in calculation time for evaluating the nonlinear spring property of the Progressive Multi-Leaf Spring.

• Journal of Power System Engineering
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• v.11 no.2
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• pp.44-50
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• 2007

The oxidation behavior of commercial pure titanium is investigated in the temperature range of $727^{\circ}C{\sim}950^{\circ}C$ in mixed gases. The weight change is measured by TGA during oxidation in mixed gases. The oxidation behavior indicated by weight gain or the growth of oxide layer is based on the linear rate law at high temperatures. The structure of the oxide scale formed during oxidation is analysed by optical microscopy, electron probe microanalyzer, scanning electron microscope and x-ray diffraction. Oxide scales have a $TiO_2$ structure, and are constituted with multi-layered or two layered porous external one and a dense internal one. Ti-O solid solution region is formed at the interface of metal and scale layer. The formation of oxide scale is influenced by the oxidation temperature, time, crystal structure and the condition of atmosphere.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.277-280
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• 2008

Multi layer bellows are being manufactured for commercial vehicle because of the characteristic of high durability compared with single iaγor bellows used to passenger vehicle. Finite Element Method (FEM) study and optimization about single layer bellows are actively progressed, but FEM study about multi layer bellows which have gap between layer is rarely processed. Therefore, this article presents finite element modeling of multi layer bellows for the improvement of simulation reliability. For the shape optimization of multi layer bellows, design of experiment and Taguchi method are used.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2007.05a
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• pp.193-198
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• 2007

The propose of this study analyze an expression method of a surface in commercial buildings, and it is to show an example of a surface design in Manhattan. In particular, I focus on the following three categories : representation element of surface image : materials and structure method, the property of transparency, and an electronic surface and media screen. Unlike the past era in which surface design in commercial buildings was viewed just as a mean ornament, it has become more important in the presently era because diverse expression technologies in surface design makes architects express there creative ideas. Besides, the diversity of surface design expands the concept of cultural space as it provides various graphic element that human desire for multi-cultures. So diversity of surface will accelerate.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.124-130
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• 2012

An injection mold cooling circuit for an automotive front bumper was optimally designed in order to simultaneously minimize the average of the standard deviations of the temperature and the difference in mean temperatures of the upper and lower molds for uniform cooling. The temperature distribution for a specified design was evaluated by Moldflow Insight 2010, a commercial injection molding analysis tool. For efficient design, PIAnO (Process Integration, Automation and Optimization), a commercial PIDO tool, was used to integrate and automate injection molding analysis procedure. The weighted-sum method was used to handle the multi-objective optimization problem and PQRSM, a function-based sequential approximate optimizer equipped in PIAnO, to handle numerically noisy responses with respect to the variation of design variables. The optimal average of the standard deviations and difference in mean temperatures were found to be reduced by 9.2% and 56.52%, respectively, compared to the initial ones.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.19 no.2 s.72
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• pp.115-124
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• 2006

The 1st and 2nd tension forces of the PSSC(Prestressed Steel and Concrete) grider constructed with commercial rolling beams and concrete are optimally designed. The design variables are the 1st and 2nd tension forces due to multi-step prestressing and live load. The objective function is set to the maximum live load. Design conditions are allowable stresses at the top and bottom of slab, beam and infilled concrete due at the several construction stages. A Matlab based optimization program is developed. The results show that the tendon position as well as concrete compression strength have significant influence on the beam strength.

• Journal of Korean Society of Rural Planning
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• v.13 no.4
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• pp.23-30
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• 2007

The purpose of this paper is to estimate economic value of multi-functionality roles including landscape and so on, which grassland in Jeju possesses, using Dichotomous Choice Contingent Valuation Method (DC-CVM). Grassland is life cultural heritance of regional residents in Jeju. It has functions like development of favorable landscapes, maintenance of cultural heritage, and recreation/relaxation. Expectation from regional visitors shows that the existence and inheritance value of grassland is higher than we expected. According to the research that we had done from the people that had agreed to contribute grassland. moreover the public commercial value of grassland was not only $397{\sim}419$ billion won but also it will increase an economic gain in every year in Jeju. Therefore, preserving grassland that has multi-functional roles and values can lead to huge economic value in the future in Jeju. Moreover, farm households which are located in the grassland conservation area would be supported $15{\sim}31$ billion won in every year for grassland conservation but it is only $4{\sim}8%$ of the economic value of grassland i.e. $3,971{\sim}4190$ billion won. Thus, grassland preservation policy and plan can raise green-tour commercial value of Jeju area as a long-term inside measurement. Those will have to be propelled continuously.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.3
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• pp.363-370
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• 2016

This paper proposes a Ku-band multi-mode coupler and its monopulse tracking system, which can be applied to a unmaned aircraft vehicle(UAV) platform. In general, the carrier-to-noise(C/N) level of the beacon signal from a Ku-band commercial satellite is relatively weak compared to that of a military satellite because the Ku-band satellite has been designed for commercial services. Therefore, this paper proposes a coupler and its multi-mode monopulse tracking system satisfying the tracking accuracy under a low C/N environment and analyzes the tracking accuracy. After that, we perform a real satellite tracking test and compare the accuracy of the test with the analysis result before validating the performance of the architecture of the proposed satellite tracking system.