• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.203-204
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• 2017

In case of developing a guide-rail type window cleaning robot, only the first prototype has been developed. In this study, it was considered that the size and the load of the window cleaning robot was not optimized, and through the structural analysis of the self-weight of the window cleaning robot, the stress concentration area was derived and the concentrated stress was quantified. Analysis showed that the upper rail shaft had a bending stress of 9.964Mpa and the bolt had a shear stress of 19.544Mpa. The results of this study will be used as basic data for designing future prototypes.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.06a
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• pp.142-143
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• 2020

A study was conducted on the production of LEFC using the Precast method, not the on-site construction. LEFC, Light Emotion Friendly Concrete, has the advantage of plastic rods being inserted to allow light to transmit, but because of the lack of adhesion to concrete, it leads to a decline in mechanical performance and durability. Therefore, it is necessary to apply precasting techniques to ensure homogeneous and superior quality of LEFC. In this study, wooden molds were used and plastic rods were arranged on porous acrylic plates. Prototyping was carried out with a UHPC mix proportioning to ensure flowability, self-consolidating performance and mechanical performance.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.618-623
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• 2008

Due to recent trends of the atypical plan shapes and the zoning construction in high-rise buildings, the building stability under construction is arising as an important issue for design and construction plan. To ensure the stability under construction, the differential column shortening and the lateral movements with unbalanced distributions of self-weight of structure members and the load flows before completion of member connections and lateral load resisting system should be checked by construction sequence analysis. This paper presents the scheme of zone-based construction sequence analysis, to check the stability of high-rise building under construction. This scheme is applied to the construction sequence analysis for real high-rise building under construction.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.3
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• pp.233-239
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• 2013

This study is interested in manufacturing the self-cleaning silicate concrete surface impregnant including tetra ethyl ortho silicate, lithium silicate for the repair of the exposed concrete surface and the color concrete requiring the advanced function in view of the concrete appearance. The concrete surface layer change and static contact angel was tested for the review of application. The result of this study shows that the effective silicate is tetra ethyl ortho silicate and lithium silicate. The adhesion in tension is satisfied with performance requirement of KS standard but the reinforcement of concrete substrate is slight. So, The self-cleaning silicate concrete impregnant of this study is more desirable for the improvement of durability rather than the reinforcement.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.3
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• pp.367-374
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• 2021

In this study, the applicability of mechanochemical process for the manufacture of self-healing admixtures and the effect of mechanochemical process on the self-healing performance were evaluated. The self-healing admixtures were adopted as a highly reactive materials(expansive agent, swelling material and crystal growth agent) for mechanochemical processes. The self-healing admixtures for the mechanochemical process application were evaluated by X-Ray Diffraction and Fourier Transform Infrared Spectroscopy analysis, water permeability performance was used to evaluate self-healing performance of mortar. As a result of the evaluation, the self-healing performance of the WM(With-Mortar)3 sample to which mechanochemical process increased by 4.1% compared to the WM1 sample that was not treated, and the average healing index was 94.3%.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.569-576
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• 2022

In this study, the healing performance of hybrid self-healing concrete was investigated by mixing bacterial pellets(BP) and solid phase capsules(SC), respectively, based on organic-inorganic self-healing material(MC). Constant water head permeability test was applied as a method of evaluating the healing performance, and the healing rate and the healed crack width calculated by the equivalent crack width were used as evaluation indicies. As a result of the water permeability test, when the initial crack width was 0.3 mm, the healing rates of MC-BP and MC-SC were 2.1~3.0 %pt higher than that of MC, and the healed crack width of hybrid concrete increased by 0.017~0.018 mm. In conclusion, it was found that the self-healing performance was not significantly improved even if the two types of healing materials are used together.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.241-242
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• 2022

Recently, related studies on the application of bacterial spores to self-healing concrete have been widely reported. Using the self-healing method of bacterial spores as a kind of pro-environment, the green method is very attractive, but because the living environment of bacterial spores is relatively harsh, it is necessary to have a way to separate the living environment of bacterial spores from the harsh external environment, And release bacterial spores when needed. Therefore, capsules are widely used in self-healing concrete. To enhance the self-healing effect, the capsules need to be evenly distributed in the concrete. Furthermore, we develop a CIP-based smart capsule with controllability. We determined the magnetic force of each capsule by mixing CIP in resin, then mass-fabricating the capsules for self-healing by a microfluidic method, and by measuring the kinetic distance of the capsules containing different amounts of cip under the action of a magnetic field strength. The results show that with the increase of the amount of cip, the active distance of the capsule also increases. When the cip is 8wt%, the active distance reaches 1.75cm. We believe this research can provide momentum for the development of self-healing capsule applications.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.51-59
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• 2009

Lean construction researchers and practitioners have established a new paradigm for managing construction projects. This paradigm stems from insights gained by viewing project delivery as one kind of production and, inspired by the success of the Toyota Production System, leveraging Toyota's 'lean thinking' in the context of such one-of production. Premises of lean construction are that (1) production systems are riddled with variation, (2) variation can be good or bad, but most of it is bad, (3) most of this variation-good or bad-is self-inflicted; consequently 'lean' passionately promotes good- and relentlessly eradicates bad variation. This paper surveys a few of many lean construction means to manage variation. Lean thinking encompasses a lot more than thinking about variation, but that is the lens used here through which construction project management is viewed. Pairing these premises with lean variation-management tools may help readers broaden the insights they can gain from reading the lean construction literature.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.315-316
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• 2012

The construction industry in the local areas business as the archetypal local one is effectuating industrial production, create employment and so on to perform a significant part in keeping local economy also reviving sluggish economy. The construction stagnation in market may cause severe economic depression in local which leads to having a crippling impact on local constructive industry, in terms of the phenomenon is on the interrelation between the local construction industry and local economy, with regard to local economy which is not covered by firm based industries is wield strong influenced over by construction industry. The object of this study is to research possible improvement factors on the preferential basis by only companies' efforts, therefore the policy of government or local self-governing body in support may be unnecessarily involved after grasping faced practical problems at regional construction companies from analysing the present condition of local construction marketplace and companies.

• Journal of Construction Engineering and Project Management
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• v.6 no.4
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• pp.15-23
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• 2016

The construction industry suffers from declining productivity and lack of trust between stakeholders and among the public. Increasing technical, regulatory, environmental and ethical challenges face the sector and necessitate a new type of leader. Authentic leadership is a relatively new construct that focuses on a leader demonstrating self-awareness, relational transparency, an internalized ethical and moral perspective and balanced processing. This study uses the Authentic Leadership Questionnaire to measure construction superintendent's levels of authentic leadership and compares them to effectiveness ratings. There is a correlation between higher authentic leadership scores and effectiveness and this study concludes that authentic leaders are more effective superintendents.