• Structural Engineering and Mechanics
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• 제89권5호
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• pp.479-489
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• 2024

The cracking mechanism in ceramsite aerated concrete block (CACB) infill walls were studied in low seismic fortification intensity coastal areas with frequent occurrence of typhoons. The inter-story drifts of an eight-story residential building under wind loads and a seismic fortification intensity of six degrees were analyzed by using the PKPM software. The maximum inter-story drift ratio of the structure in wind load was found to be comparable to that under the seismic fortification intensity of six degrees. However, when accounting for the large gust wind speed of typhoon, the maximum inter-story drift ratio was much larger than that obtained under reference wind load. In addition, the finite element models of RC frames were employed by displacement loading to simulate two scenarios with and without window hole in the CACB infill walls, respectively. The simulation results show no signs of cracking in both the infill walls with window hole and those without window for the inter-story drift caused by seismic loads and the reference wind load. However, both types of infill walls experienced structural creaking when assessing the gust wind pressure recorded from previous typhoon monitoring. It is concluded that an underestimate of wind loads may contribute substantially to the cracking of frame CACB infill walls in low seismic fortification intensity coastal areas. Consequently, it is imperative to adopt wind pressure values derived from gust wind speeds in the design of CACB infill walls within frame structures. Finally, the future research directions of avoiding cracks in CACB filled walls were proposed. They were the material performance improving and building structure optimizing.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제63권8호
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• pp.1025-1032
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• 2014

The effective energy management method will provide the significant advantage to the residential customers under real time pricing plan since it can reduce the electricity charge by controlling the energy consumption according to electricity rate. The earlier studies for load management mainly aim to minimize the electricity charges and peak power but put a less emphasis on the human comfort dwelling in the residence. The discomfort and displeasure from the energy management only focusing on reduction of electricity charge will make the residential customer reluctant to enroll the real time pricing plan. In this paper, therefore, we propose optimal load control strategy which aim to achieve not only minimizing the electricity charges but also maintaining human comfort by introducing "the human comfort coefficient." Using the human comfort coefficient, the energy management system can reflect the various human personality and control the loads within the range that the human comfort is maintained. Simulation results show that proposed load control strategy leads to significant reduction in the electricity charges and peak power in comparison with the conventional load management method.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• 제23권6호
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• pp.392-399
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• 2011

Ground-coupled heat pump(GCHP) systems have been shown to be an environmentally-friendly, efficient alternative to traditional cooling and heating systems in both residential and commercial applications. Although some work related to performance evaluation of GCHP systems for commercial buildings has been done, relatively little has been reported on the residential applications. The aim of this study is to evaluate the cooling and heating performances of a vertical GCHP system applied to an artificial detached house($117\;m^2$) in Seoul. For this purpose, a typical design procedure was involved with a combination of design parameters such as building loads, heat pump capacity, borehole diameter, and ground thermal properties, etc. The cooling and heating performance simulation of the system was conducted with different prediction times of 8760 hours and 240 months. The performance characteristics including seasonal system COP, average annual power consumption, and temperature variations related to ground heat exchanger were calculated and compared.

• Wind and Structures
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• 제13권5호
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• pp.433-449
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• 2010

Wind tunnel model tests were conducted for a residential apartment block located within the complex terrain of The Hong Kong University of Science and Technology (HKUST). The test building is typical of medium-rise residential buildings in Hong Kong. The model study was conducted using modelling techniques and assumptions that are commonly used to predict design wind loads and pressures for buildings sited in regions of significant topography. Results for the building model with and without the surrounding topography were compared to investigate the effects of far-field and near-field topography on wind characteristics at the test building site and wind-induced external pressure coefficients at key locations on the building facade. The study also compared the wind tunnel test results to topographic multipliers and external pressure coefficients determined from nine international design standards. Differences between the external pressure coefficients stipulated in the various standards will be exacerbated when they are combined with the respective topographic multipliers.

• International conference on construction engineering and project management
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.401-407
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• 2022

Central heating, ventilation and air conditioning (HVAC) is one of the largest consumers of energy in the residential sector. This project explores the use of multiple HVAC units and/or Zoning in a single residence to reduce energy loads. The energy consumption data of a detached single-family home using two HVAC units, one primary for the main house and a secondary HVAC for a casita, was collected for the same month for two consecutive years, along with details related to the outdoor temperature and the square footage being air-conditioned by each HVAC. A regression algorithm was trained using the above details to find the relation between the parameters. Next, based on the occupancy and usage patterns, the HVAC was redesigned assuming more area under the secondary HVAC unit. The trained algorithm was then used to make energy usage predictions for the revised primary HVAC area, with the assumption that the secondary HVAC unit was turned off. The results were compared with existing energy usage data. It was determined that there were significant energy savings in the second scenario. It is expected that this study and its findings will help future research projects explore more ideas as alternatives to central HVAC, in improving the economic viability of existing options, and in developing a savings calculation tool that will help consumers make informed decisions on their best alternatives to central HVAC.

• Structural Engineering and Mechanics
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• 제89권6호
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• pp.627-634
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• 2024

This research deals with the process of conducting a reinforced concrete slab loading test of a Residential Complex Project at the Shatt Al Arab District which is located in southern Iraq. The purpose of the test which represents a destructive test is to evaluate the structural behavior of the slab condition state during and after the examination of the test process in order to ascertain the ability of the slab ceiling to withstand the loads generated during the use of the building. The test was carried out accordant to ACI 437.2-13 code. The reason for this test is the postponed 8 years of building project construction. Concrete blocks were used to simulate and conduct a loading test of 30-tons for 3 days. The central point has been installed to measure the slab deflection that occurred during the test. The results showed that both the total deflection and residual deflections were lesser than the permissible values according to the ACI 437.2-13, the RC slab behavior was mainly linear structural behave, and that the purpose of the examination was achieved. Finally, a new method was introduced to the assessment of the slab condition at the support which is found in good condition.

• Journal of the Computational Structural Engineering Institute of Korea
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• 제15권3호
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• pp.441-451
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• 2002

Recently, Increasing residential-commercial buildings are composed of upper wall and lower frame type. As structural fragility, a large numbers of researchers have tried to develope the efficient analysis methods. But these studies were too theoretical and were not considered the lateral load which was required in analysing the transfer level in addition to being used nonlinear program which was difficult to use for practical design. thus, results of these studies we not appropriate to apply practical design, therefore, in this paper, the procedure of the current design practice were compared with that of used FEM method and presented new modeling method. in particular, an efficient analytical model which can be used in practical design of residential-commercial buildings for vortical and seismic loads was proposed and the usefulness of proposed model was verified.

• Journal of the Computational Structural Engineering Institute of Korea
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• 제36권2호
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• pp.85-92
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• 2023

Unlike a completed building, a building under construction may be at risk in terms of safety if a load exceeds the value considered in the design stage owing to various factors, such as a load action different from that in the design stage and insufficient concrete strength. In addition, if an earthquake occurs in a building under construction, greater damage may occur. Therefore, this study studied example models with various sizes of 5, 15, 25, and 60 floors for typical building types and analyzed the effects of seismic load on buildings under construction using construction-stage models according to frame completeness. Because the construction period of the building is much shorter than the period of use after completion, applying same earthquake loads as the design stage to buildings under construction may be excessive. Therefore, earthquakes with a return period of 50 to 2,400 years were applied to the construction stage model to review the seismic loads and analyze the structural performances of the members. Thus, we reviewed whether a load exceeding that of the design stage was applied and the return period level of the earthquake that could ensure structural safety. In addition, assuming the construction period of each example model, the earthquake return period according to the construction period was selected, and the design appropriateness with the selected return period was checked.

• Wind and Structures
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• 제9권3호
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• pp.217-230
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• 2006

This paper describes a procedure to develop fragility curves for woodframe structures subjected to lateral wind loads. The fragilities are cast in terms of horizontal displacement criteria (maximum drift at the top of the shearwalls). The procedure is illustrated through the development of fragility curves for one and two-story residential woodframe buildings in high wind regions. The structures were analyzed using a monotonic pushover analysis to develop the relationship between displacement and base shear. The base shear values were then transformed to equivalent nominal wind speeds using information on the geometry of the baseline buildings and the wind load equations (and associated parameters) in ASCE 7-02. Displacement vs. equivalent nominal wind speed curves were used to determine the critical wind direction, and Monte Carlo simulation was used along with wind load parameter statistics provided by Ellingwood and Tekie (1999) to construct displacement vs. wind speed curves. Wind speeds corresponding to a presumed limit displacement were used to construct fragility curves. Since the fragilities were fit well using a lognormal CDF and had similar logarithmic standard deviations (${\xi}$), a quick analysis to develop approximate fragilities is possible, and this also is illustrated. Finally, a compound fragility curve, defined as a weighted combination of individual fragilities, is developed.

• Journal of Power Electronics
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• 제18권2호
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• pp.573-587
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• 2018

Recently evolved power electronics' based domestic/residential appliances have begun to behave as single phase non-linear loads. Performing as voltage/current harmonic sources, those loads when connected to a three phase distribution network contaminate the line current with harmonics in addition to creating a neutral wire current increase. In this paper, an enhanced performance three phase four leg shunt active power filter (SAPF) controller is presented as a solution for this problem. The presented control strategy incorporates a hybrid predictive fuzzy-logic based technique. The predictive part is responsible for the SAPF compensating current generation while the DC-link voltage control is performed by a fuzzy logic technique. Simulations at various loading conditions are carried out to validate the effectiveness of the proposed technique. In addition, an experimental test rig is implemented for practical validation of the of the enhanced performance of the proposed technique.