• International Journal of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.143-153
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• 2021

Recently, by applying the 4th industrial revolution technologies such as A.I., IoT, and big data to general residential infrastructure, various application services of residential-based are provided to residents through linkage and utilization between technologies. Accordingly, smart housing system is increasing as advanced living spaces that can improve the quality of life and convenience of residents. Such a smart housing is expected to be an item that can create new demands and markets in the construction industry since it provides a new paradigm that combines construction technology and IT by combining IT technology with existing construction industry. Based on this, it is expected that it will be possible to gradually develop large-scale markets such as smart buildings and smart cities. In this paper, therefore, we propose an artificial intelligence multiplex smart housing system as an intelligent platform that can autonomously manage and control the size of places and spaces, used for various purposes based on smart housing technology by using artificial intelligence systems.

• Steel and Composite Structures
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• v.19 no.6
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• pp.1561-1580
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• 2015

No significant improvement has been observed on the seismic performance of the ordinary steel reinforced concrete (SRC) columns compared with the reinforced concrete (RC) columns mainly because I, H or core cross-shaped steel cannot provide sufficient confinement for core concrete. Two improved SRC columns by constructing with new-type section steel were put forward on this background: a cross-shaped steel whose flanges are in contact with concrete cover by extending the geometry of webs, and a rotated cross-shaped steel whose webs coincide with diagonal line of the column's section. The advantages of new-type SRC columns have been proved theoretically and experimentally, while construction measures and seismic behavior remain unclear when the new-type columns are joined onto SRC beams. Seismic behavior of SRC joints with new-type section steel were experimentally investigated by testing 5 specimens subjected to low reversed cyclic loading, mainly including the failure patterns, hysteretic loops, skeleton curves, energy dissipation capacity, strength and stiffness degradation and ductility. Effects of steel shape, load angel and construction measures on seismic behavior of joints were also analyzed. The test results indicate that the new-type joints display shear failure pattern under seismic loading, and steel and concrete of core region could bear larger load and tend to be stable although the specimens are close to failure. The hysteretic curves of new-type joints are plumper whose equivalent viscous damping coefficients and ductility factors are over 0.38 and 3.2 respectively, and this illustrates the energy dissipation capacity and deformation ability of new-type SRC joints are better than that of ordinary ones with shear failure. Bearing capacity and ductility of new-type joints are superior when the diagonal cross-shaped steel is contained and beams are orthogonal to columns, and the two construction measures proposed have little effect on the seismic behavior of joints.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.952-955
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• 2005

In the early 90's, we had serious shortage of construction engineers in Korea. The shortage was acute especially in construction quality control and supervision area, which were gaining social attention due to the road bridge and the department store collapse that took the hundreds of lives in the early 90's in Seoul, Korea. In order to meet the high demand of construction engineers, the engineering license regulations were changed in 1995. Engineers who did not pass the written exam but have equivalent working experience are given engineering license to practice engineering legally. Since year 2000, while the severe engineer-shortage has been resolved, the opposite situation has occurred: there is serious over-supply of construction engineers. Policy makers and engineering practitioners are agreed to bring back the old-fashioned written exam engineer licensing system like before 1995, i.e., no more written exam exemption. However, the engineers who obtained license without taking written exam may not want to go back to old policy which would take their license. It is required to provide appropriate grace period before the new policy takes effect to minimize the impact of the changes. This paper forecasts the supply-demand of construction engineers providing the basis for the most appropriate policy changes.

• Construction Engineering and Management
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• v.11 no.6
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• pp.66-69
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• 2010

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.213-214
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• 2016

This paper intends to analyze the roles of regulations and certifications within the construction market that affect the effective recycling and application methods of construction waterproofing industries. Certifications, eco-labels, green certification patents, and new excellent technologies obtained in construction waterproofing industries are studied. In accordance to the study results, it was determined that, a total of 38 items obtained eco-labels with effective recycling as the theme, 10 items with green certifications, and 8 items with New Excellent Technologies.

• Journal of Construction Engineering and Project Management
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• v.5 no.2
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• pp.16-23
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• 2015

In this paper, a survey related to excavation construction activities among national and international construction companies was conducted to evaluate site productivity in construction industry. To analyze the respective productivity levels of each construction company, a benchmarking measures analysis that featured calculations of the performance ratio (PR) and performance management index (PMI) was performed. As a result of these analyses, it has been found that the work performed by local companies was marked by lower productivity and that of international companies was characterized by good productivity. Further analysis of construction workforce resources P% revealed that a construction company's productivity is largely dependent on production capacity and consumption resources, which means that the retention of skilled workers and utilization of high-quality resources yields the highest level of productivity. These results suggest that for a local construction company to be competitive in the construction work market, it must retrain skilled craftspeople, foremen, engineers, and project managers, and strengthen its building capability by leveraging new equipment and technologies.

• Steel and Composite Structures
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• v.23 no.4
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• pp.453-464
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• 2017

The square tubed-reinforced concrete (TRC) column is a kind of special concrete-filled steel tube (CFST) columns, in which the outer thin-walled steel tube does not pass through the beam-column joint, so that the longitudinal steel reinforcing bars in the RC beam are continuous through the connection zone. However, there is a possible decrease of the axial bearing capacity at the TRC column to RC beam connection due to the discontinuity of the column tube, which is a concern to engineers. 24 connections and 7 square TRC columns were tested under axial compression. The primary parameters considered in the tests are: (1) connection location (corner, exterior and interior); (2) dimensions of RC beam cross section; (3) RC beam type (with or without horizontal haunches); (4) tube type (with or without stiffening ribs). The test results show that all specimens have relatively high load-carrying capacity and satisfactory ductility. With a proper design, the connections exhibit higher axial resistance and better ductility performance than the TRC column. The feasibility of this type of connections is verified.

• Structural Engineering and Mechanics
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• v.78 no.1
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• pp.87-102
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• 2021

Long span cross-rope suspension structure is an innovative structural system evolved from typical Cross-Rope Suspension (CRS) guyed tower, a type of supporting system with short span suspension cable supporting overhead power transmission lines. In mountainous areas, the span length of suspension cable was designed to be extended to hundreds or over one thousand meters, which is applicable for crossing deep valleys. Vortex Induced Vibration (VIV) of overhead power transmission lines was considered to be one of the major factors of its fatigue and service life. In this paper, VIV and its controlling by Stockbridge damper for long span CRS was discussed. Firstly, energy balance method and finite element method for assessing VIV of CRS were presented. An approach of establishing FE model of long span CRS structure with dampers was introduced. The effect of Stockbridge damper for overall vibration of CRS was compared in both theoretical and numerical approaches. Results indicated that vibration characteristics of conductor in long span CRS compared with traditional tower-line system. Secondly, analysis on long span CRS including Stockbridge damper showed additional dampers installed were essential for controlling maximum dynamic bending stresses of conductors at both ends. Moreover, factors, including configuration and mass of Stockbridge damper, span length of suspension cable and conductor and number of spans of conductor, were assessed for further discussion on VIV controlling of long span CRS.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.517-524
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• 2004

The leading cause of bridge failures is scouring bed material from around bridge foundations. Many advanced countries such as U.S.A., U.K., the Netherlands and New Zealand have developed and revised their own bridge scour manuals fit for their field conditions. In Korea, researches for reducing bridge failures during floods have concentrated on analysis, laboratory test and countermeasure of bridge scour during the last ten years. however no comprehensive manual for evaluating bridge scour and for identifying the conditions of bridge foundations has been provided yet. In this study, a new bridge scour manual is developed for the accurate evaluation of bridge scour, which reflects domestic field conditions with various streambed materials. The SRICOS method and the Erodibility Index Method are suggested for fine-grained soils and weathered rocks, respectively. In addition, bridge scour analysis algorithms are developed for field engineers to estimate bridge scour depth and to evaluate the susceptibility of bridge scour with ease.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.836-841
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• 2012

The repair of road pavement and manhole has been resulted long construction times and traffic jams, environmental pollution from construction wastes, and budget waste due to excessive construction costs. In order to resolve such problems, we have developed the new construction method using C-ring, which can fix and raise the manhole securely. This technology is the method by driving in a wedge after inserting C-ring and expanding it in order to raise manhole to the regular height. This has been approved by the test reports of KOLAS(Korea Laboratory Accreditation Scheme), and was confirmed safety, durability and reliabilty in result. In this paper we approved this technology was able to short working times to around 20% and construction costs to around 50% with compare other construction methods. Also, environmental pollution and civil complaints will be prevented because there will be no longer any noises, vibrations, dust, or construction wastes.