• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.49-50
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• 2023

Asbestos is a building material that has been actively used because of its excellent durability and heat resistance until 2009, when it was found to be a first-class carcinogen and prohibited in Korea. Currently, asbestos dismantling is an essential process in demolition of old buildings. Workers are likely to be exposed to asbestos in the process of dismantling and removing them, which causes various occupational diseases, suggesting related laws and work standards to ensure the safety of asbestos dismantling process. Accordingly, prior studies have been conducted to analyze the level of asbestos exposure and influencing factors occurring during work, but most of them are mainly concerning health issue while research on process risks considering field characteristics and safety aspects of the work processes is still insufficient. Therefore, this study aims to derive the process risks affecting the safety of workers based on the survey results of asbestos dismantling companies, and further proposed a cost calculation model taking those risks into account.

• KIEAE Journal
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• 제15권1호
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• pp.69-75
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• 2015

Building has required the repair money to improve or maintain the decent living condition continuously after construction. It needs to grasp the building deterioration to decide the scope and contents before it is repaired. Under various conditions such as physical, social and financial constraints, the repair plan would be prepared. Among constraints, the cost is indispensible to specify the repair time, repair scope and target. The required cost would be planned to preparation over the years. In this paper, it aimed at providing the repair strategy of the public rental housing in repair time, using the cumulative cost model which is $3^{rd}$ function. In the $3^{rd}$ function, the inflection point should exist in the line. And there are two types in the cumulative model, First, if the maximum cost be shown, the repair time would be provided. Second, if the maximum cost not be shown, the cumulative function should be proportionally increased and the repair strategy is properly provided with a short cycle. In results of this study, 11 items would provide the repair time. These cumulative function would be repaired about 4 years after constructed, and after about 4 years, the cumulative function would be continuously increased.

• Advances in Computational Design
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• 제3권4호
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• pp.385-404
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• 2018

The study investigated an area of sustainable structural design that is often overlooked in practical engineering applications. Specifically, a novel method to simultaneously optimise the cost and embodied carbon performance of steel building structures was explored in this paper. To achieve this, a parametric design model was developed to analyse code compliant structural configurations based on project specific constraints and rigorous testing of various steel beam sections, floor construction typologies (precast or composite) and column layouts that could not be performed manually by engineering practitioners. Detailed objective functions were embedded in the model to compute the cost and life cycle carbon emissions of the different material types used in the structure. Results from a comparative numerical analysis of a real case study illustrated that the proposed optimisation approach could guide structural engineers towards areas of the solution space with realistic design configurations, enabling them to effectively evaluate trade-offs between cost and carbon performance. This significant contribution implied that the optimisation model could reduce the time required for the design and analysis of multiple structural configurations especially during the early stages of a project. Overall, the paper suggested that the deployment of automated design procedures can enhance the quality as well as the efficiency of the optimisation analysis.

• 한국건축시공학회지
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• 제12권4호
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• pp.401-414
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• 2012

The adoption of Green Frame is expected to provide economic benefits, since construction costs are reduced by the in-situ production of precast concrete column and beam. The cost reduction can ultimately be realized by saving transportation costs and the overhead and profit of PC plants. The cost structure of Green Frame, which is built up using composite precast concrete members, is similar to that of a bearing-wall structure, but the difference in construction process has resulted in some cost differences for a few items. In particular, production and installation is the principal work involved in Green Frame made by precast concrete members, while form and concrete work is the principal work for a bearing-wall structure. As such, the rental time and fee for a tower crane should be compared through time analysis. To verify reliability, this study focused on developed residential projects to estimate the construction costs. Through this analysis, it was found that the costs of Green Frame were 1.57% lower than the costs of bearing-wall structure. The results of this study will help in the development of a management plan for the structural work of Green Frame.

• 한국지열·수열에너지학회논문집
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• 제9권2호
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• pp.25-31
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• 2013

It has become very important for unused energy to be used for building air conditioning. Economic evaluation on energy system by using river water as a heat source, which is one of the unused energy, was carried out. The floor area of the building and the distance between heat source equipment and river was assumed $50,000m^2$ and 200 m. General heat source system using absorption chiller-heater was used for comparing to the energy saving system, and payback period method using initial cost and running cost of two systems, was used to perform economic evaluation. According to development of high capacity of water source heat pump which is appropriate for using river water, initial cost for the system has been reduced. Payback period was about 3.2 years, and this period might be shortened if nation's economic support enact.

• Wind and Structures
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• 제30권4호
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• pp.379-392
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• 2020

The paper presents a Life-Cycle Cost-based optimization framework for wind-excited tall buildings equipped with Tuned Mass Dampers (TMDs). The objective is to minimize the Life-Cycle Cost that comprises initial costs of the structure, the control system and costs related to repair, maintenance and downtime over the building's lifetime. The integrated optimization of structural sections and mass ratio of the TMDs is carried out, leading to a set of Pareto optimal solutions. The main advantage of the proposed methodology is that, differently from the traditional optimal design approach, it allows to perform the unified design of both the structure and the control system in a Life Cycle Cost Analysis framework. The procedure quantifies wind-induced losses, related to structural and nonstructural damage, considering the stochastic nature of the loads (wind velocity and direction), the specificity of the structural modeling (e.g., non-shear-type vibration modes and torsional effects) and the presence of the TMDs. Both serviceability and ultimate limit states related to the structure and the TMDs' damage are adopted for the computation of repair costs. The application to a case study tall building allows to demonstrate the efficiency of the procedure for the integrated design of the structure and the control system.

• Animal cells and systems
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• 제3권2호
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• pp.167-172
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• 1999

We report for the first time the life history of a 'social' spider, Philoponella prominens, living in a temperate region. Philoponella prominens hibernated as immatures or subadults for 7-8 months in 1995 and 1996 from September-October to April-May in central Korea. When they emerged from their winter hibernation, a majority began their lives as commensals in the webs of other species. As the mating season approached, however, commensal spiders switched to become colonial or solitary. The mating season began in early June and lasted until early August. Newly-hatched spiderlings began to appear in the field in late June. They formed a colony by building their webs connected to the mother's by using pan of the mother's web as supporting substrates. As the season progressed, however, some of the colonial spiderlings became commensal or solitary individuals. Our field observations suggest that Philoponella prominens form colonies or commensal associations to reduce the web-building cost.

• 한국CDE학회논문집
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• 제16권4호
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• pp.292-299
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• 2011

Han-ok has a long history and cultural traditions. It has green and healthy and culture but high construction costs, thermal insulation performance of residential and vulnerable to fires and have a weakness for maintenance. However, modernized resident housing, Han-ok is required to improve in terms of environmental aspect due to its weakness for insulating and inconvenience for modem era. Also Han-Ok's building is criticized as a huge dependence on subjective building experiences. This is pointed to be the biggest problem, Han-ok has. Traditionally it does not have a scientific and specific manual for construction. In this research, process simulation was adopted to develop Han-Ok's environmental improvements. In terms of LCC (Life Cycle Cost) aspect, however, Han-Ok's environmental characteristics are examined to suggest an appropriate Han-Ok construction method. Also the result of this research would be utilized to base the information database for efficient constructing and its management in new Han-Ok constructing industry.

• 국제초고층학회논문집
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• 제9권2호
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• pp.113-125
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• 2020

Beginning in the late 19th century, construction of skyscrapers spread throughout Chicago, New York City, and then the world as demand of space in buildings and increase of cost of land. With this change curtain wall systems have evolved to be more visually complex; these unique profiles of the skyscraper became powerful images and symbols of our cities. A curtain wall is defined as usually aluminum-framed wall containing in-fills of glass and metal panels. The framing is attached to the building structure and does not carry the floor or roof loads of the building.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.66-67
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• 2014

Design and construction of freeform building technologies are being implemented to reduce time and cost due to the development of materials and equipments. However, production of freeform concrete segments takes much more time and manpower than typical due to disposable mold and various shape. Therefore, manufacturing technology of freeform concrete segments need to be developed for securing economic and constructive feasibility. The objective of this study is development of efficient casting technology for freeform concrete segments in a short time. This technology includes details about the fluidity of concrete and the sectional shape of freeform concrete segments. And problem of cost and time can be solved. Also, mold can be reusable and freeform concrete segments will be produced quickly and accurately. After this study, productivity study for validation will continue through prototype development and example application.