• Journal of computational fluids engineering
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• v.15 no.3
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• pp.39-45
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• 2010

The turbulent flows in a tunnel mock-up($10L{\times}0.5W{\times}0.25H$ m3 : scale reduction 1/20) with rectangular cross section were investigated. The instantaneous velocity fields of Re = 49,029, 89,571 were measured by the 2-D PIV system which is consisted of double pulsed Nd:Yag laser and the tracer particles in the straight-duct mock-up where the flows were fully developed. The mean velocity profiles were taken from the ensemble averages of 1,000 instantaneous velocity fields. Simultaneously, numerical simulations(RANS) were performed to compare with experimental data using STREAM code. Non-linear eddy viscosity model (NLEVM : Abe-Jang-Leschziner Eddy Viscosity Model) was employed to resolve the turbulent flows in the duct. The calculated mean velocity profiles were well compared with PIV results. In the log-law profiles, the experimental data were in good agreement with numerical simulations all the way to the wake region except the viscous sub-layer (near wall region).

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.663-668
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• 2002

In this paper, insulating effects and strength development of concrete placed at mock up model structure are discussed using anti freezing agent and insulating forms. According to test results, concrete containing 8% of anti freezing agent shows lower freezing temperature, earlier setting time and higher strength development than plain concrete. As for the temperature history of mock up structures, when plain concrete is placed at euro form, the temperature drops to -4${\circ}$ before early 24 hours, and when concrete containing anti freeze agent at euro form, it to -3${\circ}$ before early 24 hours. Nevertheless, when concrete containing anti freeze agent is placed at insulating form, it does not go below zero, and the concrete containing anti freeze agent enhances higher strength development.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.6 s.261
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• pp.635-643
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• 2007

As many engineers and technicians are involved in the design process of large scale and/or complex products, there are a lot of miss matches and interferences due to designers' faults and several kinds of CAD systems. Recently, CAD systems are applied to verify and check the assembly process. Digital Mock-Up(DMU) system, a tool to build a virtual mock-up in the design stage, has been used to prevent the interferences and miss matches during precision design processes. Using the virtual assembly tool, engineers are able to design precision and interference free parts without physical mock-ups. Instead of a single CAD source, several CAD systems are used to design a complex product. Several organizations are involved in the distributed design environment for heterogeneous multi-CAD assembly. XML and the lightweight CAD file are proposed for the multi-CAD assembly. XML data contains hierarchy of the heterogenenous multi-CAD assembly. STEP PDM schema and STEP ISO 10303-28 formations are applied to construct the XML data. The lightweight CAD file produced from various CAD files through ACIS kernel and InterOp not only contains mesn, B-Rep and topological data, but also is used to visualize CAD data and to verify dimensions. Developed system is executed on the desktop computers. It does not require commercial CAD systems to visualize 3D assembly data. Real-time interference and fitness checks, dimensional verification, and design and assembly verification are performed on the developed system. Assembly of heterogeneous models for a car is conducted to verify the effectiveness of the developed DMU system on the Internet.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1417-1420
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• 2006

In this paper, floor impact is studied by using 1-D wave model and predicted insertion loss is compared to the measurements done in the mock-up. A mock-up is built by using 6t steel plate, and two identical cabins are made where 25t or 50t panel is used to construct wall and ceiling inside the steel structure. Various floating floor structures are studied, in which mineral wool thickness, height, and stiffness changes are investigated. It is shown that the wave model and measurements are in good agreements in general, although there occur significant discrepancies in the low frequency range below 200 Hz.

• Journal of the Earthquake Engineering Society of Korea
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• v.21 no.5
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• pp.237-244
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• 2017

This study proposes a numerical model to explain the closely placed double modes in the vibration of a layered stone pagoda system. The friction surface between the stones is modelled as the Timoshenko finite element while each stone layer is modelled as a rigid body. It is assumed that the irregular asperity on the friction surface enables the stone to be excited. This results in the closely placed modes that are composed of natural modes and self-excited modes. To examine the validity of the proposed model, a set of modal testing and analysis for a layered stone pagoda mock-up model has been conducted and a set of closely placed double modes are extracted. Applying the extended sensitivity-based system identification technique, the various system parameters are identified so that the modal parameters of the proposed numerical model are the same with those of the experimental mock-up. For a horizontal impulse excitation, the simulated acceleration responses are compared with measurements.

• Journal of Energy Engineering
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• v.16 no.3
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• pp.93-102
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• 2007

This paper presents a scenario evaluation model of the AHP (Analytic Hierarchy Process) to evaluate dismantling scenarios considering quantitative and qualitative considerations. And decommissioning information producing modules which can obtain a dismantling schedule, quantify radioactive waste, visualize a radioactive inventory, estimate a decommissioning cost, and estimate a worker's exposure was developed to assess qualitatively decommissioning information. The digital mock-up (DMU) system was developed to verify dismantling processes and find error of scenarios in virtual space. It combines and manages the decommissioning information producing modules, the decommissioning DB, and the dismantling evaluation module synthetically. By using AHP model and DMU system, the thermal column in KRR-1 was evaluated on plasma arc cutting scenario and nibbler cutting scenario using the developed decommissioning DMU system.

• Journal of the Korea Society of Computer and Information
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• v.20 no.1
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• pp.49-62
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• 2015

In this study we have proposed the prototype of design support device for architectural design assessment using the building information modeling(BIM) data and the augmented reality(AR) technology. The proposed system consists of novel hardware composition with the transparent display, the mock-up model and the digital architectural model in the new shape of frame. The removal of background and the correction of viewer point in the capture video are proposed in order to use the transparent display in AR application. The BIM data formats are reviewed to be converted for using in AR application. Also the proposed system can be expanded to multi-user collaboration system from two user system through the suggested hardware and software compositions. The results of this study will be applied to use the mock-up model and digital architectural model in order to carry out the design assessment process efficiently and economically in the architectural design field.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.10
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• pp.1062-1067
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• 2015

Floating architecture is a type of building that is geographically located on a sea or a river. It floats under the influence of buoyancy, and does not have an engine for moving it. Korea is a peninsula surrounded by sea except on the north side, so floating architectures have been mainly focused on two points: solving the issue of small territory and providing various leisure & cultural spaces. Floating architectures are expected to save energy effectively, if they use sea water heat, which is known to be clean energy with infinite reserves. To use sea water heat as the heat source and/or heat sink, this study proposes a model in which a sea water heat exchanger is embedded in the concrete structure in the lower part of the floating architecture that is submerged under the sea. Based on the results of performance evaluations of the sea water heat exchanger using CFD (computational fluid dynamics) analysis and mock-up experiments under various conditions, it is found out that the temperature difference between the inlet and outlet of the heat exchanger is in the range of $3.06{\sim}9.57^{\circ}C$, and that the quantity of heat transfer measured is in the range of 3,812~7,180 W. The CFD evaluation results shows a difference of 5% with respect to the results of mock-up experiment.

• KIEAE Journal
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• v.6 no.2
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• pp.67-74
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• 2006

As sustainable design technologies, advanced daylighting systems with lightshelves have been developed and are currently under monitoring the daylighting performance. This study aims to evaluate the comparative daylighting performance of sloped lightshelf and conventional glazing window with mock-up model, reconstructed as a prototype of Korean office building, sized $12.0m{\times}7.3m{\times}3.7m$ ($w{\times}d{\times}h$) and $1.8m{\times}4.8m$($w{\times}h$) for the south facing side-window was installed on the rooftop of engineering building, Kyung Hee University in Korea. It has an identical configuration of reference room and the test room. For the test room, the sloped type lightshelf system was designed as 10mm transparency sheet glass, tilt angle degree $29^{\circ}$, and total sized 1.28m (interior length 0.88m, exterior length 0.49m). It consisted of daylighting collector, entrance glazing and reflector. To assess daylighting performance, the totally 37 measuring points for illuminance and 2 view points of luminance were monitored in every 30 minutes from 12:00 to 15:00. For the detailed analysis, photometric sensors of each room were installed at work-plane (8 points), wall (7 points), ceiling (3points), and exterior horizontal illuminance (1 point). Luminance of window, rare of the room was measured under clear sky. It is to be monitored by Agilent data logger, photometric sensor Li-cor and the Radiant Imaging ProMetric 1400. Comparisons with a light factor, increase-decrease ratio, uniformity, and luminance are discussed.

• KIEAE Journal
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• v.15 no.1
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• pp.83-88
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• 2015

This study aims to develope the light-weight PV blinds with windows and to investigate the shading analysis by the control conditions. For the study, the polycarbonate characteristics and coating methods are analyzed and the PV blind design for a small office is suggested. Also, the mock-up model of a suggesting system was made. The field tests were controled based on a solar altitude under clear sky conditions. As results, it is necessary to use a polycarbonate instead of a tempered glass for a light-weight PV. The shading effects of blind systems are high in slat angle $30^{\circ}$ and low in $0^{\circ}$. Also, the shading ratio is more affected by solar latitude than solar altitude. The shading change rate is relevantly constant on the solar altitude.