• Journal of the Earthquake Engineering Society of Korea
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• v.24 no.1
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• pp.29-37
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• 2020

This study is to investigate the effect of a retrofitted reinforced concrete frame with non-seismic details strengthened by embedded steel moment frames with an indirect joint, which mitigates the problems of the direct joint method. First, full-scale experiments were conducted to confirm the structural behavior of a 2-story reinforced concrete frame with non-seismic details and strengthened by a steel moment frame with an indirect joint. The reinforced concrete frame with non-seismic details showed a maximum strength of 185 kN at an overall drift ratio of 1.75%. The flexural-shear failure of columns was governed, and shear cracks were concentrated at the beam-column joints. The reinforced concrete frame strengthened by the embedded steel moment frames achieved a maximum strength of 701 kN at an overall drift ratio of 1.5% so that the maximum strength was about 3.8 times that of the specimen with non-seismic details. The failure pattern of the retrofitted specimen was the loss of bond strength between the concrete and the rebars of the columns caused by a prying action of the bottom indirect joint because of lateral force. Furthermore, methods are proposed for calculation of the specified strength of the reinforced concrete frame with non-seismic details and strengthened by the steel moment frame with the indirect joint.

• Journal of the Earthquake Engineering Society of Korea
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• v.24 no.2
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• pp.77-86
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• 2020

Nonlinear static analysis and preliminary evaluation were performed in this study to evaluate the seismic performance of unreinforced masonry buildings subjected to various soil conditions based on the revised Korean Building Code. Preliminary evaluation scores and nonlinear static analyses indicated that all buildings were susceptible to collapse and did not reach their target performance. Therefore, retrofit of those building models was carried out through a systematic procedure to determine areas to be strengthened. It was possible to make most building models satisfy performance objectives through the reinforcement alone of damaged external shear walls. However, the application of a preliminary evaluation procedure to retrofit design was found to be too conservative because all the retrofitted building models verified with nonlinear static analysis failed to satisfy performance objectives. Therefore, it is possible to economically retrofit unreinforced masonry buildings through the fortification of external walls if a simple evaluation procedure that can efficiently specify vulnerable parts is developed.

• Korean Journal of Computational Design and Engineering
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• v.17 no.6
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• pp.456-465
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• 2012

Nowadays, AEC industry tries to adopt BIM for low-carbon and eco-friendly building development. With increasing environment policies, many of global construction projects require the adoption of BIM for its many advantages. The advantages can be maximized with Open BIM since it can produce optimal results for various purposes of energy performance assessment. However there are some troubles in representation and property information in the process of Open BIM based energy performance assessment. To examine such troubles, this study focuses on differences between IFC of Open BIM and IDF format of Energy Plus known as the most accurate and diverse energy performance assessment. Two issues the study addresses are form representation and property information. The study figures out the different definition of IFC and IDF, and suggests the way of interoperability. The interoperability test of IFC for building energy performance assessment hope to develop of Open BIM based energy assessment.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.279-283
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• 2009

Distributed generation(DG) of combined cooling, heat. and power(CCHP)has been gaining momentum in recent year as efficient, secure alternative for meeting increasing energy demands. This paper presents the energy performance of microturbine CCHP system equipped with an absorption chiller by modelling it in hospital building. The orders of study were as following. 1)The list and schedule of energy consumption equipment in hospital were examined such as heating and cooling machine, light etc. 2) Annual report of energy usage and monitoring data were examined as heating, cooling, DHW, lighting, etc. 3) The weather data in 2007 was used for simulation and was arranged by meteorological office data in Daejeon. 4) Reference simulation model was built by comparison of real energy consumption and simulation result by TRNSYS and ESP-r. The energy consumption pattern of building were analyzed by simulation model and energy reduction rate were calculated over the cogeneration. As a result of this study, power generation efficiency of turbine was about 30% after installing micro gas turbine and lighting energy as well as total electricity consumption can be reduced by 40%. If electricity energy and waste heat in turbine are used, 56% of heating energy and 67% of cooling energy can be reduced respectively, and total system efficiency can be increased up to 70%.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.4
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• pp.363-368
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• 2012

The result of the line simplification algorithm varies with the choice of algorithms, the change in tolerance and the selection of target objects. Three of the algorithms used in this study are Sleeve-fitting, Visvalingam-Whyatt, and Bend-simplify. They were applied to the three kinds of objects which were buildings, rivers, and roads with the five degrees of the tolerance. Through this experiments the vector displacement, the areal displacement, and the angular displacement were measured and the qualitative analysis was performed with the trend line of the errors. The experimental results show that errors were differ from tolerance values, and characteristics of line simplification algorithms based on changes of tolerance were understood.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.4
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• pp.1012-1017
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• 2008

Recently, the use of wireless fan is increased by the development of wireless communication and convenience. Moreover, it makes an issue of security threat and vulnerability of wireless tan. Therefore, the IEEE established new standard such as 802.11i in 802.11 to supplement security vulnerability of wireless tan. But the security threat that does not solve, still remains. In this paper, we proposed that the location detection algorithm, that is used Kalman-Filter, Lateration and RSSI, and the mechanism that detects security status of AP and unauthorized AP by using beacon-frame of AP in building. Finally, we confirmed performance of proposed algorithm is good in comparison of established algorithm.

• Korean Journal of Computational Design and Engineering
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• v.19 no.2
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• pp.129-137
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• 2014

Due to the increase of carbon dioxide and building regulations, BIM is considered a way of low-carbon and eco-friendly building development for its many advantages. The advantages can be maximized with Open BIM since it can produce optimal results for various purposes of energy performance assessment. However there are some problems in data interoperability in the process of Open-BIM based energy performance assessment. To solve such problems, this study focuses on space boundary information interoperability between IFC of Open BIM and IDF format of Energy Plus known as the most accurate and diverse energy performance assessment. The study analyzes the analogous study then figures out the problems of IFC based energy performance analysis, and suggests the way of interoperability. Finally, the development of automation program makes this way much more effective. The study of IFC data interoperability is useful for improving the reliability of Open-BIM based energy assessment.

• KIEAE Journal
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• v.12 no.2
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• pp.25-32
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• 2012

This paper focused on the daylighting performance of residential high-rise buildings in South-Korea. the purpose of this study is to estimate the visual environment of sunlight coming into opening according to sky conditions, orientation of windows and each space of Apartment buildings. Season of the year, weather, and time of day combine with predictable movement patterns of the sun to create highly variable and dynamic daylighting conditions. Daylighting design is usually based on the dominant sky condition and the micro-climate for the building site. There are three common sky conditions: clear sky, overcast sky, and partly cloudy sky. The clear sky includes sunshine and is intense and brighter at the horizon than at the zenith, except in the area around the sun. Daylight received within a building is directly dependent upon the sun's position and the atmospheric conditions. Easily used charts, diagrams, and software programs allow study of solar geometry for any geographic location and time of day. on the other hand, the overcast sky is characterized by diffuse and variable levels of light and has dense cloud cover over 90% of the sky. This paper was calculated by a Desktop Radiance program. The space dimensions were based on a unit module of real constructed apartment having divided into five sections such as living room, room1, room2, room3 and kitchen.

• KIEAE Journal
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• v.17 no.4
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• pp.83-88
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• 2017

Purpose: The objective of this study is to develop a predictive model for calculating the amount of cooling load for the different setback temperatures during the setback period. An artificial neural network (ANN) is applied as a predictive model. The predictive model is designed to be employed in the control algorithm, in which the amount of cooling load for the different setback temperature is compared and works as a determinant for finding the most energy-efficient optimal setback temperature. Method: Three major steps were conducted for proposing the ANN-based predictive model - i) initial model development, ii) model optimization, and iii) performance evaluation. Result:The proposed model proved its prediction accuracy with the lower coefficient of variation of the root mean square errors (CVRMSEs) of the simulated results (Mi) and the predicted results (Si) under generally accepted levels. In conclusion, the ANN model presented its applicability to the thermal control algorithm for setting up the most energy-efficient setback temperature.

• Journal of Korean Association for Spatial Structures
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• v.15 no.3
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• pp.51-60
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• 2015

Recently, the concept of damped outrigger system has been proposed for tall buildings. But, structural characteristics and design method of this system were not sufficiently investigated to date. In this study, the dynamic response control performance of outrigger damper has been analyzed. To this end, a simplified analysis model with outrigger damper system has been developed. An artificial wind of 1000 seconds with 0.1 second time steps was generated by using a Kaimal spectrum. Analysis results show that outrigger damper system is more effective up to 20-23% in the control of dynamic response compared to conventional outrigger system. The increase of outrigger damper capacity usually results in the improved control performance. However, it is necessary to select that proper stiffness and damping values of the outrigger damper system because, the outrigger damper having large capacity is result in heavy financial burden.