• Korean Journal of Construction Engineering and Management
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• v.6 no.4 s.26
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• pp.71-79
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• 2005

As construction projects have been extremely enormous, complex and special, risk factors have been increased consistently. Therefore, it is very important to identify and cope with the uncertain risk factors in such building constructions for successful project accomplishment. The purpose of this research is to approach practical affairs directly and show detail alternatives of risk factors by extracting the risk factors throughout construction process of curtain wall that is largely influenced on cost, quality, schedule ,safety and following activity. Also, extracting these risk factors make it possible to analyze quantitative risk and decide the priority raking of risk factors. Especially, this research is aimed to provide efficient management of scheduling risk that can make the risk minimize to practical workers who have different degree of knowledge and experience to the construction cite when the risk brings out suddenly.

• Journal of the Korean Solar Energy Society
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• v.29 no.6
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• pp.110-118
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• 2009

This research is an experimental study on BIPV Power performance of See-through a-si and Light-through applying external curtain wall. In case of See-through a-si Photovoltaic, appropriateness of facade applying standard($950\;{\times}\;980mm$) large($950\;{\times}\;1960mm$)area photovoltaic was examined. Transparent performance was also investigated through Power simulation according to angles and seasons of See-through a-si and Light-through Photovoltaic so that Power output was surveyed with using designed and manufactured Mock-up. When comparing See-through a-si to Light-through Photovoltaic for simulation Power output on angles based on full south aspect, which the result was that See-through a-si Power output according to Light-through Power output was the highest of 65.5% when applying a 90 degree angle. Monthly accumulated average Power output during winter seasons (December, January and February) applying a vertical plane on full south aspect was analyzed, which results in 66.37W/h of See-through a-si and 139.1 W/h of Light-through. See-through a-si Power output showed 47.7% in comparison with Light-through transparent. Also monthly, hourly average Power efficiency according to solar radiation during winter seasons (December, January and February) was that 4.7% of See-Through a-si and 9.8% of Light-through.

• Journal of the Korean Solar Energy Society
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• v.37 no.2
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• pp.47-57
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• 2017

CIGS thin film solar cells are technically suitable for BIPV applications than regularly used crystalline silicon solar cells. Particularly, CIGS PV has lower temperature coefficient than crystalline silicon PV, thus decrease in power generation is lowered in CIGS PV. Moreover, CIGS PV can decrease shading loss when applied to the BIPV system, and the total annual power generation is higher than crystalline silicon. However, there are few studies on the installation factors affecting the performance of BIPV system with CIGS module. In this study, BIPV curtain wall unit with CIGS PV module was designed. To prevent increase of temperature of CIGS PV module by solar radiation, ventilation was considered at the backside of the unit. The thermal specification and electrical performance of CIGS PV of the ventilated unit was analyzed experimentally. Non-ventilated unit was also investigated and compared with ventilated unit. The results showed that the average CIGS temperature of the ventilated curtain wall unit was $6.8^{\circ}C$ lower than non-ventilated type and the efficiency and power generation performance of ventilated CIGS PV on average was, respectively, about 6% and 5.8% higher than the non-ventilated type.

• Journal of Power System Engineering
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• v.20 no.6
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• pp.99-104
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• 2016

In this study, we researched the energy load according to the change of the inner window area ratio, the distance of the air gap and the azimuth of the curtain wall building, which installed the multistory double-skin facade(DSF). and we compared the results with the no double-skin facade situation as follows. With the DSF, it is better than other case, when the window area ratio is 40% and the air gap is 1.2m on the west, south-45-west, south-45-east and east. And it's best when the window area ratio is 40% and the air gap is 0.4m on the south. And on the east or south-45-east, the window area ratio is 40% and the air gap is 1.2m is better than other case with the DSF. On south, it is best when the window area ratio is 100% without DSF. On the south-45-west or west, it is best when the window area ratio is 40% without the DSF.

• Journal of Ocean Engineering and Technology
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• v.31 no.1
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• pp.47-59
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• 2017

This study conducted numerical simulations using LES-WASS-3D ver. 2.0 to analyze the seawater intrusion characteristics of the incident waves in a coastal aquifer. LES-WASS-3D directly analyzed the nonlinear interaction between the seawater and freshwater in a coastal aquifer, as well as the wave-current interaction in the coastal area. First, the LES-WASS-3D results were compared with the existing experimental results for the mean water level under wave action in the coastal aquifer and seawater penetration into the coastal aquifer. The mean water level, shape and position of the seawater-freshwater interface, and intrusion distance were well implemented in the results. This confirmed the validity and effectiveness of LES-WASS-3D. The overall seawater penetration distance increases in the coastal aquifer as a result of wave set-up and run-up in the swash zone caused by continuous wave actions, and it increases with the wave height and period. Furthermore, a numerical verification was performed by comparing the suggested existing structure and newly suggested curtain wall as a measure against seawater penetration. An existing underground dam showed a better effect with increased height. Additionally, the suggested curtain wall had a better effect when the embedded depth was increased.

• Journal of the Korea Institute of Building Construction
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• v.14 no.5
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• pp.433-442
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• 2014

The most design criteria and specifications in Korea utilized to ensure appropriate quality are based on process and prescriptive criteria determining materials, measure and methods. It has many problems including a loss of competitiveness resulting from inhibited creativity of the contractors. The performance-based specifications focused on final product are being proposed, but have difficulty in adapting to the architectural field. In this study the hybrid specification prototype for curtain wall construction was suggested. The specification framework was presented through analysis of linkage between the performance and prescriptive specification cases. Based on the survey with practitioners, the performance inspection process and the sample specification were developed by identifying the essential performance test timings. The applicability of the specification prototype was evaluated by interviews with experts. It was found that the prototype was active and a progressive supporting tool which could support to secure phased performance during construction as well as final performance.

• International Journal of High-Rise Buildings
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• v.11 no.1
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• pp.1-14
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• 2022

Debates on what is the first skyscraper have been ongoing from time to time since the construction of the Home Insurance Building in Chicago in 1885, which is generally recognized as the first built skyscraper. This paper attempts to verify this assertion through a detailed investigation after identifying the criteria that characterize a skyscraper. By considering and examining several competing buildings for the title of "first skyscraper" in terms of their levels of satisfying these criteria, the paper reconfirms that the Home Insurance Building in Chicago indeed qualifies as the first skyscraper and is the harbinger of future skyscrapers. By introducing technological and associated architectural innovations in this pioneering building, its designer William Le Baron Jenney paved the way for the construction of future skyscrapers. In traditional construction, heavy masonry walls especially at lower levels did not allow large window openings in exterior walls that would permit ample daylight. For the Home Insurance Building, originally built with 10 stories, Jenney created a metal-framed skeletal structure that carried the building's loads, making the building lighter and allowed for large windows permitting ample natural light to the building's interior. The exterior iron columns were encased in relatively small masonry piers mainly for fireproofing, weather-protection and façade aesthetics. Relying on the structural framing on the building's perimeter, the exterior masonry thus turned into a rudimentary "curtain wall" system, heralding the use of curtain wall construction in future skyscrapers. This building's innovative structural system led to what is known as the "Chicago Skeleton," and eventually produced remarkable skyscrapers all over the world.

• KIEAE Journal
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• v.17 no.1
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• pp.69-75
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• 2017

Purpose: Heat transfer analysis of recently developed 'slim type double-skin system window' were presented. This window system is designed for curtain wall type façade that main energy loss factor of recent elegant buildings. And the double skin system is the dual window system integrated with inner shading component, enclosed gap space made by two windows when both windows were closed and shading component effectively reflect and terminate solar radiation from outdoor. Usually double-skin system requires much more space than normal window systems but this development has limited by 270mm, facilitated for curtain wall façade buildings. In this study, we estimated thermophysical phenomena of our double-skin curtain wall system window with solar load conditions at the summer season. Method: A fully 3-Dimentional analysis adopted for flow and convective and radiative heat transfer. The commercial CFD package were used to model the surface to surface radiation for opaque solid region of windows' frame, transparent glass, fluid region at inside of double-skin and indoor/outdoor environments. Result: Steep angle of solar incident occur at solar summer conditions. And this steep solar ray cause direct heat absorption from outside of frame surface rather than transmitted through the glass. Moreover, reflection effect of shading unit inside at the double-skin window system was nearly disappeared because of solar incident angle. With this circumstances, double-skin window system effectively cuts the heat transfer from outdoor to indoor due to separation of air space between outdoor and indoor with inner space of double-skin window system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5B
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• pp.547-558
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• 2008

With the advent of super cargo ship due to the explosive increase in the amount of cargo shipped via seas, some mega ports are under construction in South Korea, to accommodate the super cargo ship, and some of them already enter their final phase. To sustain the harbor tranquility, mega ports usually comprise huge vertical type breakwaters which are intrinsically vulnerable to the attack of long waves. In this rationale, we present the chamber type breakwater with a circular curtain wall - Eco-breaker 2, to alleviate the reflection of long waves and numerically investigate the hydraulic characteristics of Eco-breaker 2. As a wave driver, we use the Navier-Stokes eq., the most robust wave driver, using SPH (Smoothed Particle Hydrodynamics) and LES (Large Eddy Simulation). For the verification of numerical results, we also carried out hydraulic model test. It is shown that Eco-breaker 2 can effectively alleviate the reflection of long waves with its inherited large organized eddies encompassing the water chamber and some region off the curtain wall of varying size. It is also shown that the scope and strength of large organized eddies strongly depends on the incident wave period, and the reflection coefficient can be lowered to 0.18 by tuning the size of water chamber such that resident time at the chamber is just short of the half period of incident waves. Based on these results, we present the specification of Eco-breaker 2 to boost its use on the development of water environment friendly harbor worldwide.

• Journal of Korean Institute of Architectural Sustainable Environment and Building Systems
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• v.12 no.6
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• pp.531-542
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• 2018

Building energy demands have highly risen in modern society; thus, It is necessary to reduce building energy demands especially commercial buildings adopting a curtain wall architecture. Curtain wall architectures have a high ratio of windows which is a vulnerable in heat insulations as cladding. In order to complement insulation performance of windows in these buildings, there are various methods adopted often such as installing blinds, wing wall and films. There are two suggestions of this paper. 1) WWR (Window-to-Wall Ratio) makes a impaction of energy demands in buildings. 2) Another one is an efficiency of blind systems which are installed in buildings in order to reduce cooling demands. It is also critical to make fundamental model for low-energy building construction by processing a lot of simulation As a result by this study, 1) an external blind system is more useful for reducing cooling energy demands rather than an internal blind system. 2) Buildings which have a large window require more amount of cooling demands. In case of WWR 45%, it needs more cooling energy rather than WWR 15% model's 3) Adopting blind system would reduce energy demands. WWR 45% model with external blind systems reduces about 4% of cooling energy demands compared to same model without any blind systems.4) it is necessary to study an efficiency of blind systems combined with renewable energy and it will be possible to reduce more energy demand in building significantly.