• Wind and Structures
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• v.19 no.1
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• pp.15-33
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• 2014

This paper describes partial turbulence simulation and validation of the aerodynamic pressures on building models for an open-jet small-scale 12-Fan Wall of Wind (WOW) facility against their counterparts in a boundary-layer wind tunnel. The wind characteristics pertained to the Atmospheric Boundary Layer (ABL) mean wind speed profile and turbulent fluctuations simulated in the facility. Both in the wind tunnel and the small-scale 12-Fan WOW these wind characteristics were produced by using spires and roughness elements. It is emphasized in the paper that proper spectral density parameterization is required to simulate turbulent fluctuations correctly. Partial turbulence considering only high frequency part of the turbulent fluctuations spectrum was simulated in the small-scale 12-Fan WOW. For the validation of aerodynamic pressures a series of tests were conducted in both wind tunnel and the small-scale 12-fan WOW facilities on low-rise buildings including two gable roof and two hip roof buildings with two different slopes. Testing was performed to investigate the mean and peak pressure coefficients at various locations on the roofs including near the corners, edges, ridge and hip lines. The pressure coefficients comparisons showed that open-jet testing facility flows with partial simulations of ABL spectrum are capable of inducing pressures on low-rise buildings that reasonably agree with their boundary-layer wind tunnel counterparts.

• Journal of the Korea Concrete Institute
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• v.16 no.6 s.84
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• pp.867-873
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• 2004

It has been known that debonding failures between CFS(Carbon Fiber Sheet) and concrete in the strengthened RC beams are initiated by the peeling of the sheets in the region of combined large moment and shear forces, being accompanied by the large shear deformation after flexural cracks. These shear deformation effects are seldom occurred in small-scale model tests, but debondings due to the large shear deformation effects are often observed in a full-scale model tests. The premature debonding failure of CFS, therefore, must be avoided to confirm the design strength of full-scale RC beam in strengthening designs. The reinforcing details, so- called 'U-Shape fiber wrap at mid-span' which wrapped the RC flexural members around the webs and tension face at critical section with CFS additionally, were proposed in this study to prevent the debonding of CFS. Other reinforcing detail, so called 'U-Shape fiber wrap at beam end' were included in this tests and comparisons were made between them.

• Journal of the Earthquake Engineering Society of Korea
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• v.16 no.2
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• pp.47-60
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• 2012

Based on the Korean Building Standard Law, a building less than 3-stories and $1000m^2$ in area is defined as a small-level building and, as a result, this type of building has been excluded from the requirement to comply with seismic design. In order to prevent the loss of life and property under earthquake loadings, the small-scale building should satisfy the seismic performance specified in the current code through a seismic retrofit. In this study, a seismic retrofit scheme of a Buckling-Restrained Knee Brace (BRKB) was developed for non-seismic 2-story steel buildings, including small-scale buildings, using a fragility contour method. In order to develop an effective retrofit scheme of the BRKB for the building, a total of 75 BRKB analytical models were used to achieve the desired performance levels and analyzed using the fragility contour method. The seismic performance of the retrofitted building was evaluated in terms of the weight of the developed BRKB systems. This study shows that the fragility contour method can be used for rapid evaluation and is an effective tool for structural engineers.

• Journal of the Korea Institute of Building Construction
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• v.10 no.1
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• pp.81-89
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• 2010

Since 2004, the government has changedthe cost estimate system to one of an actual cost basis in order to calculate the optimum construction cost by reflecting changes in circumstance on the construction site in a timely manner. Currently, this is being applied to public construction work forover a billion won of actual cost data in estimation by contract unit cost. However, directly reflecting actual cost, which for large-sized construction work was originally an average unit cost, to a small building, entails the application of a low discount rate for the cost of materials, labor, etc. and therefore can frequently give rise to cases in which the actual cost of work performed exceeds the contract sum, which in turn causes problems such as decreased revenues, bad effectson business operation, productivity, etc. Therefore, to apply actual cost to small-sized construction work (less than a billion won), there should be a plan to modify unit cost in a manner that can reflect project scale, etc. in order to resolve the problem of unit cost application of actual cost to small-building construction projects. The unit cost modification model for proper actual construction cost in small-scale construction projects developed by this study will help to increase the relevant productivity and proper gain, preventing the aggravation of business operations. Organizations placing orders are also expected to be able to secure a more realistic construction cost in arranging the budget.

• Journal of the Korean housing association
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• v.18 no.1
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• pp.43-51
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• 2007

This study examines and analyzes view hindrance factors of high-storied apartment houses at small town like 'Eup' where county office locates and it is found that hindrance factors include designation of residential area and height, length and form of main building. On recognition of view, most subjects of research considered high-storied apartment houses hindered urban view and its regulation is needed. Apartment houses at small cities become main factors of hindering urban view because they were located randomly regardless of scale of city and surrounding situation, but there is no measure to control it. Accordingly, view control through enaction of regulations is urgently needed with establishment of guidelines such as height of large buildings including high-storied apartment houses, length of main building, location and regulation of exterior design.

• The Journal of Information Technology
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• v.5 no.4
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• pp.65-72
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• 2002

With the development of information technology and the rapid diffusion of Internet, the scale electronic commerce management is increasing year by year. Domestic small businesses also devote themselves to the creation of profits for the present and for the future, through active electronic commerce management. This paper aims to help small businesses to increase sales by presenting the direction for building a successful e-CRM of the horizontal B2B between small businesses.

• Journal of the Korea Institute of Building Construction
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• v.18 no.1
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• pp.81-87
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• 2018

Since February 2017, site managers in small architectural projects are required by the revised building act. In order to address issues for site managers and to improve project efficiency, system improving methods are surveyed and proposed in this study. The key inspection items in the existing surveillance guidance manual were investigated, and the checklist for site managers for a small to medium sized construction site was analyzed. This study also tries to propose using web-based site management systems for improvement of the utilization of checklists. It is expected that these on-site management systems, along with BIM technology, will be able to monitor the small size building construction project in real time and effectively monitor the various problems occurring on-site.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.202-203
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• 2021

The proportion of old buildings over 30 years old increased from 29.0% in 2005 to 37.8% in 2019. These old buildings were created during the absence of building-related safety standards such as fire safety performance. In the process of use, illegal changes and extensions were made, making them more vulnerable to safety. In the 1st Basic Plan for Fire Safety Policy, among the 12-Key Tasks, one is to ensure the safety of residential living spaces. Fire safety investigations are being conducted to prevent large-scale disasters such as multi-use buildings, but no investigation has been conducted at the regional district level where small-scale old buildings are concentrated. Therefore, in order to derive fire risk factors in the old building district where old buildings are concentrated, the composition characteristics of the buildings were first analyzed.

• Wind and Structures
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• v.26 no.6
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• pp.397-413
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• 2018

Excitation mechanism of interference effect between two tall buildings is investigated with wind tunnel experiments. Synchronized building surface pressure and flow field measurements by particle image velocimetry (PIV) are conducted to explore the relationship between the disturbed wind flow field and the consequent wind load modification for twin buildings in tandem. This reveals evident excitation mechanisms for the fluctuating across-wind loads on the buildings. For small distance (X/D < 3) between two buildings, the disturbed flow pattern of impaired vortex shedding is observed and the fluctuating across-wind load on the downstream building decreases. For larger distance ($X/D{\geq}3$), strong correlation between the across-wind load of the downstream building and the oscillation of the wake of the upstream building is found. By further analysis with conditional sampling and phase-averaged techniques, the coherent flow structures in the building gap are clearly observed and the wake oscillation of the upstream building is confirmed to be the reason of the magnified across-wind force on the downstream building. For efficient PIV measurement, the experiments use a square-section high-rise building model with geometry scale smaller than the usual value. Interference factors for all three components of wind loads on the building models being surrounded by another identical building with various configurations are measured and compared with those from previous studies made at large geometry scale. The results support that for interference effect between buildings with sharp corners, the length scale effect plays a minor role provided that the minimum Reynolds number requirement is met.

• Korean Journal of Construction Engineering and Management
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• v.20 no.1
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• pp.96-104
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• 2019

Recently, projects are being actively promoted to develop a new residential district centered around the metropolitan area, or to redevelop the residential area that was established long ago as unplanned land development. In this residential area, the owner can directly construct the building, and the way the building owner builds the residential house is called the direct construction of the owner. If the owner has the construction management (CM) capability while conducting direct management of the owner, the direct construction can be carried out by the CM method. This type of construction is called Owner-CM delivery method. However, it is very rare for small-scale construction in Korea to be implemented by the Owner-CM method. This may be due to the lack of knowledge and experience about the CM of the owner. In this study, we investigated the actual cases of the scheduling for the residential houses of similar size which were built at the same time in the residential housing complex developed near the metropolitan area. The purpose of this study is to derive the success factors of the scheduling in the small-scale construction from the cases carried out by the Owner-CM method. These success factors of the scheduling can be used as meaningful reference for the owners who want to build their own house in the future.