• 국제초고층학회논문집
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• 제9권4호
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• pp.351-360
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• 2020

Monitoring civil structures periodically is necessary for ensuring the fitness of the structures. Cracks on inner and outer surfaces of the building plays a vital role in indicating the health of the building. Conventionally, human visual inspection techniques were carried up to human reachable altitudes. Monitoring of high rise infrastructures cannot be done using this primitive method. Also, there is a necessity for more accurate prediction of cracks on building surfaces for ensuring the health and safety of the building. The proposed research focused on developing an efficient crack classification model using Transfer Learning enabled EfficientNet (TL-EN) architecture. Though many other pre-trained models were available for crack classification, they rely on more number of training parameters for better accuracy. The TL-EN model attained an accuracy of 0.99 with less number of parameters on large dataset. A bench marked METU dataset with 40000 images were used to test and validate the proposed model. The surfaces of high rise buildings were investigated using vision enabled Unmanned Arial Vehicles (UAV). These UAV is fabricated with TL-EN model schema for capturing and analyzing the real time streaming video of building surfaces.

• 한국산업융합학회 논문집
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• 제25권1호
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• pp.71-78
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• 2022

With the advent of cutting-edge technology, renewable energy is significantly considered as alternative resources to supply electric power. However, many barriers such as energy intermittency, high initial installation cost, and low-efficiency generation challenged building new infrastructure with clean energy. Efforts reducing greenhouse gas emissions and reliance on fossil fuels resulted in the decentralization of power generation like distributed energy resource (DER). This paper is to introduce and evaluate the feasibility of building-integrated photovoltaics (BIPV) in a high-rise building in Ulsan. To optimize BIPV, a variety of methods to minimize efficiency decrease and maximize electric power generation after installing BIPV on the building's facade are suggested. The variables causing power losses are analyzed. By utilizing System Advisor Model (SAM), actual power generated from solar panels is measured by Thin-film PV, Mono-crystalline PV, and Poly-crystalline PV.

• KIEAE Journal
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• 제10권5호
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• pp.159-164
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• 2010

High-rising buildings are a sort of solution to recent cities. Till now real estate development was concentrated in new development on vacant lots, and it resulted urban sprawl. Generally large cities are confronted with the exodus of industry and population from city. High-rising buildings solve many problems associated with this problem. The purpose of this research is to identify the effect of super high-rise mixed use building project process on apartment price. For this study, the hypothesis is that price of apartments is influenced by project process of super high-rise mixed use building. The study concerned 4 variations of project process that is building permits stage, sale stage, construction starting stage and stage of moving into building. The target projects of buildings are selected by number of floor(over 40 floors) and construction time. And 48 apartment complex are selected around super high-rise mixed use building. This study uses hedonic price function to analysis effect of project process of super high-rise mixed use building. A price of apartments is defined as a dependent variable. Characteristics of residence, complex, district and super high-rise building are defined as independent variables. The results are as follows; first, there is no error in price model of this study. Second, it is found that apartment price was influenced negatively by building permit stage and sale stage of super high-rise mixed use building. But that was influenced positively by construction starting stage and stage of moving into building of that. Third, as the project process of super high-rise mixed use building was proceeded, price of apartments was increased.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.345-353
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• 2012

Recently rapid urbanization facilitates development of high-rise building complex including apartment and office building in urban area. Many problems related with high-rise building are reported. Especially, unpleasant strong winds in pedestrian area are frequently encountered around the high-rise building. CFD simulation methods are used to analyze the wind environment of pedestrian level in high-rise building block. However the results show differences between CFD and measurement. The reason for the difference is that conventional CFD simulation couldn't consider the effect of trees, shrubs and plants which affect the wind environment. Canopy model is a solution to solve the limitation of CFD analysis. In this paper, the canopy model to predict wind environment of pedestrian level by CFD simulation will be proposed and the validity will be analyzed by comparison of measurement and CFD prediction.

• Wind and Structures
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• 제34권5호
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• pp.395-405
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• 2022

Tornado-induced damages to high-rise buildings and low-rise buildings are quite different in nature. Tornado losses to high-rise buildings are generally associated with building envelope failures while tornado-induced damages to low-rise buildings are usually associated with structural or large component failures such as complete collapses, or roofs being torn off. While studies of tornado-induced structural damages tend to focus mainly on low-rise residential buildings, transmission towers, or nuclear power plants, the current rapid expansion of city centers and development of large-scale building complexes increases the risk of tornadoes impacting tall buildings. It is, therefore, important to determine how tornado-induced load affects tall buildings compared with those based on synoptic boundary layer winds. The present study applies an experimentally simulated tornado wind field to the Commonwealth Advisory Aeronautical Research Council (CAARC) building and estimates and compares its pressure coefficient effects against the Atmospheric Boundary Layer (ABL) flow field. Simulations are performed at the Wind Engineering, Energy and Environment (WindEEE) Dome which is capable of generating both ABL and tornadic winds. A model of the CAARC building at a scale of 1:200 for both ABL and tornado flows was built and equipped with pressure taps. Mean and peak surface pressures for TLV flow are reported and compared with the ABL induced wind for different time-averaging. By following a compatible definition of the pressure coefficients for TLV and ABL fields, the resulting TLV pressure field presents a similar trend to the ABL case. Also, the results show that, for the high-rise building model, the mean and 3-sec peak pressures are larger for the ABL case compared to the TLV case. These results provide a way forward for the code implementation of tornado-induced pressures on high-rise buildings.

• Wind and Structures
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• 제8권5호
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• pp.309-324
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• 2005

Aerodynamic damping often plays an important role in estimations of wind induced dynamic responses of super high-rise buildings. Across- and along-wind aerodynamic damping ratios of a square super high-rise building with a height of 300 m are identified with the Random Decrement technique (RDT) from random vibration responses of the SDOF aeroelastic model in simulated wind fields. Parametric studies on effects of reduced wind velocity, terrain type and structural damping ratio on the aerodynamic damping ratios are further performed. Finally formulas of across- and along-wind aerodynamic damping ratios of the square super high-rise building are derived with curve fitting technique and accuracy of the formulas is verified.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.573-578
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• 2009

Previous research on super high rise buildings focused mostly on the use of public space from building plan perspective, survey of residents' satisfaction evaluation, construction technology and structural technology. But little research is done on the economic analysis of landmark factors. The purpose of this study is to find landmark factors that can be quantitatively measured, collect data on super high rise residential buildings in Seoul. Find the intrinsic values of the landmarks, and analyze how these values differ in areas with different densities, i.e. in 3 Gangnam-gus & Yeongdeungpo-gu and in other areas. It is expected that the results of this study can be used to set an appropriate price of super high rise building in consideration of its landmark value in different area

• 국제초고층학회논문집
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• 제1권3호
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• pp.221-228
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• 2012

Shanghai Tower is a super high-rise building of 632 m height with 'mega frame-core- outrigger truss' structure system. Due to the complexity and irregularity of structure, shaking table test was carried out to investigate its seismic performance. A 1/40 scaled test model was designed, built and tested on shaking table under earthquake of small, moderate and large levels. The experimental results showed that the structure can meet the requirements of Chinese codes and reach scheduled performance objectives. Elastic and plastic time-history analysis on the structure were carried out and the results were compared to experimental results. Based on the research results some suggestions were proposed to contribute favorable effect on the seismic capacity of the structure.

• KIEAE Journal
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• 제13권1호
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• pp.151-157
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• 2013

Since high-rise building construction sites are usually located in crowded city areas, sufficient spaces for the inventories of key materials are rarely available. This spatial constraints have been one of the critical challenge that may cause productivity loss and increasing costs of the high-rise building construction projects. The proper material inventory management is certaing a key to the success of high-rise building construction projects as it handles difficulty of securing material stock yards, changes in demands, uncertain delivery time through integrating the construction schedules and actively responding to the key materials attributes. In this light, this research analyzes the latest inventory model, (Q,r) model, in accordance with the high rise building characteristics. This research suggests an optimal inventory management of re-bar considering various demands and lead times. The case study is also presented with regard to the re-bar inventory management.

• Structural Engineering and Mechanics
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• 제78권3호
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• pp.305-317
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• 2021

An AMD control system is usually built based on the original model of a target building. As a result, the fact leads a large calculation workload exists. Therefore, the orders of a structural model should be reduced appropriately. Among various model-reduction methods, a suitable reduced-order model is important to high-rise buildings. Meanwhile, a partial structural information is discarded directly in the model-reduction process, which leads to the accuracy reduction of its controller design. In this paper, an optimal technique is selected through comparing several common model-reduction methods. Then, considering the dynamic characteristics of a high-rise building, an improved balanced truncation (BT) method is proposed for establishing its reduced-order model. The abandoned structural information, including natural frequencies, damping ratios and modal information of the original model, is reconsidered. Based on the improved reduced-order model, a new reduced-order controller is designed by a regional pole-placement method. A high-rise building with an AMD system is regarded as an example, in which the energy distribution, the control effects and the control parameters are used as the indexes to analyze the performance of the improved reduced-order controller. To verify its effectiveness, the proposed methodology is also applied to a four-storey experimental frame. The results demonstrate that the new controller has a stable control performance and a relatively short calculation time, which provides good potential for structural vibration control of high-rise buildings.