• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.307-310
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• 2010

Ubiquitous society to build basic infrastructure in the power supply and power equipment safety is important. U-City in order to prevent the disaster of U-IT Power Equipment Performance Module and the security for the safety of the U-City is necessary. In this paper, the power unit of U-IT module, temperature sensor, humidity sensor, equipped with sensors arranged throughout the fire, and home distribution boards, Home Network Wall-Pad, Blocker, MPNP black boxes, arc detection, arc safety equipment, outlet of the modular performance evaluation and security measures will be studied. U-IT power devices and sensors to analyze the information conveyed by proactive risk and ensure safety, access control, authentication, security safeguards, such as U-IT integrated management system for electrical safety and strengthen the security, safety and security with a U-City will contribute to the construction and operation.

• Journal of Korean Society of Steel Construction
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• v.26 no.4
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• pp.263-275
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• 2014

In this study, connection of steel reinforced concrete(SRC) column and composite beam which consists of H-section and U-section members were tested under cyclic loading. An essential point of the composite beam is the structural performance of welded joint between the H-section and the U-section members. To improve the structural performance of joint of two beam members, vertical stiffeners, trapezoidal stiffeners, and top bars were used. Five full-scaled specimens were designed to study the effect of a number of parameters on cyclic performance of connections such as H-section beam size($H-500{\times}200{\times}10{\times}16$, $H-600{\times}200{\times}11{\times}17$), the presence of stiffeners and top bars, and the presence of no weld access hole(WAH) method. Based on the test results, deformation capacity of the specimens with H-500 series beam and H-600 series beam were 4% and 3% rotation angle, which is the requirement for the Special Moment Frame and Intermediate Moment Frame(IMF), respectively. Test result showed that deformation capacity of connection with stiffeners and top bars is greater than that of connection without stiffeners and top bars. Finally, energy dissipation capacity and strain profile of specimens were summarized.

• Journal of Korean Association for Spatial Structures
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• v.18 no.4
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• pp.123-130
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• 2018

U-flanged truss beam is composed of u-shaped upper steel flange, lower steel plate of 8mm or more thickness, and connecting lattice bars welded on the upper and lower sides. The hybrid beam with U-flanged steel truss is made in the construction site through pouring the concrete, and designated as U-flanged truss hybrid beam. In this study the structural experiments on the 4 hybrid beams with the proposed basic shapes were performed, and the flexural capacities from the tests were compared with those from the theoretical approach. The failure modes of each specimen were quite similar. The peak load was reached with the ductile behavior after yielding, and the failure occurred through the concrete crushing. The considerable increasement of deformation was observed up to the concrete crushing. The composite action of concrete and steel member was considered to be reliable from the behavior of specimens. The flexural strength of hybrid beam has been evaluated exactly using the calculation method applied in the boubly reinforced concrete beam. The placement of additional rebars in the bottom instead of upper side is proposed for the efficient design of U-flanged truss hybrid beam.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.367-372
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• 2006

Government is not only the biggest owner in public sector, but also the leader responsible for improving and fostering construction industry. Delivery systems and award methods are enacted as laws via government's strong will for construction innovation. In addition to establishing relationships between government and contractor, delivery systems and award methods affect every aspect of industry. Therefore, the government should keep trying to remove inefficiency and achieve Best Value. This paper analyzes the delivery systems and award methods of advanced countries to extract lessons for Korean industry focusing on leading parties, direction, and change in owner's awareness of their respective innovative movements for construction. The prerequisites for improvement in delivery systems and award methods are suggested as partnership between public and private sectors, consistent innovation, enhancement in efficiency, and reinforcement of owner's capability.

• Korean Journal of Construction Engineering and Management
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• v.12 no.4
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• pp.106-116
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• 2011

It is very important to collect and manage labor information in the construction industry that is labor-intensive. Although research and cases that utilize RFID are increasing for more effective labor management, labor management is limited to the checking-in and -out information management at the entrance of a construction site due to high expense of an RFID reader. Labor and safety information is still managed based on the redundant process that is hand-written in a book and re-input of information by using a personnel-computer. Therefore, the objective of this paper is to develop more effective and efficient process for labor information record and management. This paper presents a prototype application that supports integrated labor information management by incorporating QR-code into RFID-based labor management system and verifies the application through a pilot test and comparison with the existing labor management syste.

• Journal of Korean Association for Spatial Structures
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• v.18 no.3
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• pp.57-66
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• 2018

Recently various composite beams in which concrete is filled in the U-shaped steel plate have been developed for saving story height and reducing construction period. Due to the high flexural stiffness and strength, they are widely being used for the building with large loads and long spans. The semi-slim AU composite beam has proven to take highly improved stability compared to the existing composite beams, because it consists of the closed steel section by attaching cap-type shear connectors to the upper side of U-shaped steel plate. In this study the finite element analyses were performed to evaluate the safety of the AU composite beam with unconsolidated concrete which were sustained through the closed steel section during the construction phase. The analyses were performed on the two types of cross section applied to the fabrication of AU composite beams, and the results were compared to the those of 2-point bending tests. In addition, the flexural performance according to the space of intermittent cap-type shear connectors and the location of reinforcing steel bars for compression was comparatively investigated. Through the results of analytical studies, it is preferable to adopt the yield moment of AU composite beam for evaluating the safety in the construction phase, and to limit the space of intermittent shear connectors to 400 mm or less for the construction load.

• Korean Journal of Construction Engineering and Management
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• v.8 no.3
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• pp.142-149
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• 2007

A ubiquitous environment in construction should be developed integrating hardware and software systems. The objective of this paper is to study the feasibility of applying the RFID technology to the concrete pour process, and improve the effectiveness of data exchange A pilot system of u-CPS (Ubiquitous Concrete Pour System) has been developed to test the feasibility. The pilot can automatically generate the data for concrete pour work such as departure time, arrival time, concrete pour time. Construction managers can keep track of the progress of concrete pour work using the information. A case study was done for a building construction using the pilot system, the result of which demonstrated that the RFID-base system can help improve the effectiveness of data communication during the concrete pour process.

• Journal of the Korean Society of Safety
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• v.37 no.6
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• pp.102-107
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• 2022

South Korea will soon be a super-aged society, as more than 20.6% of its population will be 65 years and older by 2025. As of 2022, 17.5% of the total population in South Korea is 65 years and older, which exceeds the set threshold for an aged society, where more than 14% of the population is 65 years and older. The proportion of older subway construction workers has increased. Aging workers and their work stress negatively impact their workability. A previous study demonstrated that the stress index measured using the uBioMacpa measurement device (Macpa stress index) had a significant correlation with work stress in South Korea. The device tests vascular health and measures stress levels via Macpa signal analysis. In this study, the pulse waves of subway construction workers were measured using uBioMacpa to identify their stress levels. The stress levels were analyzed by age, years of service, job position, employment type, and work type. Herein, these statistics could not be easily represented by a normal distribution; therefore, the Kruskal-Wallis test, a nonparametric statistical method, was used for the analysis of data. The results showed that age, job position, employment type, and working type affected the Macpa stress index and the stress levels of workers increased with age. In terms of job position, technical engineers were more stressed than other workers because of their poor working environment. In terms of employment type, daily-wage workers were more stressed than other workers. In terms of working type, tunneling, waterproofing, and construction scored the highest Macpa stress indexes without any significant difference, whereas earthworks scored the lowest. Based on the analysis of Macpa stress index, safety and health management plans were proposed to reduce the stress levels of workers. Moreover, a manual for efficient stress management must be developed for subway construction workers.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.506-513
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• 2009

The Construction Industry Institute (CII) developed the Project Definition Rating Index (PDRI), as a part of their Front End Planning best practices, which helps project managers assess and measure project scope definition risk elements. U.S. Green Building Council are seeing the benefits of sustainable building and Leadership in Energy and Environmental Design certification by positively impacting life cycle costs, building marketability, and organizational productivity. However, there have been no efforts to integrate these two planning tools in construction industry. By applying a supplemental tool which combines the PDRI with the LEED rating system, construction industry can develop and implement a tailored instrument that leads to total project success in sustainability. The objective of this research is to assemble a new front end planning mechanism for green buildings by incorporating the current PDRI and LEED systems.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1553-1558
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• 2009

Give high priority to the technologies that can be directly applicable to the U-City development projects which are in progress by many central and local governments. Create a real world product at the end of R&D phase by testing prototypes in test-beds or test-labs. Recently, new construction technologies have been developed, but they are rarely being applied to the construction filed. In this paper, the basic design was examined so that various technologies can be selected through a test-bed, analyzed for the real situation, and applied to actual construction sites. Improve productivity of regional and urban construction exercises and improve competitiveness of related products and services using IT-based telemetering/GIS technology.