• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.05b
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• pp.199-202
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• 2009

Turn-key and CMF(CM for Fee) have been selected as procurement paths of large public projects in Korea. However, recently, researches and discussions on CMR(CM at Risk) have been popular as the Korean government seeks for alternative procurement paths to enhance the performance. In the CMR projects, the part who is responsible for construction management should predict and control the potential risks for guaranteeing benefits. In this research, CMR projects in which a general contractor plays the role as CMr is mainly analyzed. We give attentions to risk management during construction process given that subcontractors, main parts in this phase, work in various ways and thus more chances for faults exist. In this case, CMr manages risks to control the procedure of project. So, potential risk factors can constitute the database, and that database can be matched to following activity. And construction manager can forecast measures of risk using the result of matching. This chain of activities increase efficiency in roles of CMr on CMR(CM at Risk). Furthermore this study will propose one of the solution of Construction Management Module.

• Journal of Construction Engineering and Project Management
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• v.6 no.4
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• pp.7-14
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• 2016

While the idea of the existence of a set of key factors for success in planning, designing and construction of projects is not new, it remains one of the most important issues in the field of construction management. This is due to project success factors are inputs to project management practice which can lead directly or indirectly to project success. This study identifies the success factors which can be used for improving the highway projects performance in Egypt during the project pre-construction and construction phases. Through a detailed literature review 35 success factors are identified. Furthermore, the AHP is adopted to prioritize the studied factors through the application of questionnaire survey. The study establishes that implementing an effective quality control and assurance systems, allow sufficient time for feasibility studies, design, drawing and tender preparation, effective cost control system and frequency of project budget updates, preparing adequate designs and drawings and determining sufficient time to implement the desired scope of work are the most important success factors for enhancing the highway projects performance in Egypt.

• Advances in Computational Design
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• v.7 no.4
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• pp.345-369
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• 2022

Infectious disease emergency hospitals are usually temporarily built during the pneumonia epidemic with higher requirements regarding diagnosis and treatment efficiency, hygiene and safety, and infection control.This study aims to identify how the Building Information Modeling (BIM) + Industrialized Building System (IBS) approach could rapidly deliver an infectious disease hospital and develop site epidemic spreading algorithms. Coronavirus-19 pneumonia construction site spreading algorithm model mind map and block diagram of the construction site epidemic spreading algorithm model were developed. BIM+IBS approach could maximize the repetition of reinforced components and reduce the number of particular components. Huoshenshan Hospital adopted IBS and BIM in the construction, which reduced the workload of on-site operations and avoided later rectification. BIM+IBS integrated information on building materials, building planning, building participants, and construction machinery, and realized construction visualization control and parametric design. The delivery of Huoshenshan Hospital was during the most critical period of the Coronavirus-19 pneumonia epidemic. The development of a construction site epidemic spreading algorithm provided theoretical and numerical support for prevention. The agent-based analysis on hospital evacuation observed "arched" congestion formed at the evacuation exit, indicating behavioral blindness caused by fear in emergencies.

• Journal of the Korea Institute of Construction Safety
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• v.2 no.2
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• pp.76-81
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• 2019

It becomes easy to acquire operating qualification of remote control tower crane and illegal retrofits is increased, remote control tower crane models are increasingly being used in smaller construction sites. However, as the problems caused by tower crane operators who have shortages of operating experience grow, safety accidents is increasing and worker is exposed to risk of accident. In this study, the cause of the accident was derived by analyzing the cause of the remote control tower crane accident. And then, the significance of accident causes was analyzed by AHP technique. The result of this study is that tower crane operators and construction workers do not comply with work rules.

• International Journal of Control, Automation, and Systems
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• v.1 no.4
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• pp.484-494
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• 2003

In this paper, we describe a hydraulic system design and vehicle dynamic modeling for development of tire roller traction, an essential aspect in the system analysis of tire rollers. Generally, tire rollers are one of the most useful types of machines employed in road construction, technically applied to many construction fields. We also conceptualize a new hydraulic and driving system as well as define the motion equations for dynamic and hydraulic analysis. First, we design the hydraulic circuit of the steering control and driving machine system, which can be employed to advance the performance of the lateral control, creating a prototype of construction equipment. Second, we formulate the hydraulic steering system model and hydraulic driving system model through tire roller system development technology. Finally, we validate the acquired performance results in actual tire roller equipment using the data acquisition system. These results may perhaps facilitate the establishment of priorities and design strategies for incremental introduction of tire roller technology into the vehicle and construction field.

• Journal of Drive and Control
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• v.17 no.4
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• pp.113-124
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• 2020

Most of the work of construction equipment and agricultural machinery is done in off-road conditions. Autonomous driving required in these conditions uses GPS sensors, and PID controllers to control their speed and position. The hydrostatic steering, which is composed of a PSU, hydraulic hoses, and cylinders, rather than a mechanical coupling is used in these equipments. The PSU plays a key role in hydrostatic steering. Precise control of the position under various conditions requires detailed behavioral analysis of the basic components and operation. Two Gerotor PSU is now a commonly used safer option. The components of the PSU can be divided into mechanical and hydraulic actuating elements by its behavior. Since the system is combined by mechanical and hydraulic elements, the modelings are performed using Amesim, which is one of the most effective for the multi-domain dynamic system analysis. To confirm the validity of the model, input torque and pressures are checked with varying steering speed. The opening and the steering speed of normal and newly designed control valve set is investigated with the effect of centering spring force and friction. Finally, simulation results with fully detailed model with two gerotors are analyzed and compared with simple model.

• Safety and Health at Work
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• v.9 no.1
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• pp.115-124
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• 2018

Background: Substantial empirical research has shown conflicting results regarding the influence of organizational external factors on construction risk management, suggesting the necessity to introduce a moderator into the study. The present research confirmed whether rules and regulations matter on the relationships between organizational external factors and construction risk management. Methods: Based on discouragement and organizational control theory, this research examined the effects of organizational external factors and rules and regulations on construction risk management among 238 employees operating in construction companies in Abuja and Lagos, Nigeria. A personally administered questionnaire was used to acquire the data. The data were analyzed using partial least squares structural equation modeling. Results: A significant positive relationship between organizational external factors and construction risk management was asserted. This study also found a significant positive relationship between rules and regulations and construction risk management. As anticipated, rules and regulations were found to moderate the relationship between organizational external factors and construction risk management, with a significant positive result. Similarly, a significant interaction effect was also found between rules and regulations and organizational external factors. Implications of the research from a Nigerian point of view have also been discussed. Conclusion: Political, economy, and technology factors helped the construction companies to reduce the chance of risk occurrence during the construction activities. Rules and regulations also helped to lessen the rate of accidents involving construction workers as well as the duration of the projects. Similarly, the influence of the organizational external factors with rules and regulations on construction risk management has proven that most of the construction companies that implement the aforementioned factors have the chance to deliver their projects within the stipulated time, cost, and qualities, which can be used as a yardstick to measure a good project.

• Journal of Drive and Control
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• v.15 no.2
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• pp.46-51
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• 2018

Many research studies have been carried out related to saving energy and environmental pollution in the field of construction machinery. The best solution for reducing the related environmental pollution is to reduce fuel consumption by upgrading the energy efficiency of machinery used in this field. An efficiency upgrade in the field of construction machinery would mean minimizing the pressure loss in hydraulic pipe lines or achieving optimal operating conditions while responding to a load. One way to achieve this is to make an equivalent circuit, like an electrohydrostatic actuator, or to improve the spool type valve using the 4/3 way method. This study deals with an electrohydraulic proportional flow control valve. SimulationX software is used as a simulation tool for analyzing the dynamic characteristics. The analysis results, including the performance and characteristics of design parameters, are discussed and the validity of the theoretical analysis is also evaluated.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.705-711
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• 2022

Roadway lighting is an integral element of a highway system. Luminaires on roadways provide viewing conditions for drivers and pedestrians during nighttime in order to improve safety. It is time-consuming and labor-intensive to manually measure roadway illuminance at predetermined spots with a handheld illuminance meter. To improve the efficiency of illuminance measurement, a remote-control electrical cart and a drone were utilized to carry an illuminance meter for the measurements. The measurements were performed on the marked grid points along the pavement. To measure the illuminance manually, one person measures illuminance at each grid point with the handheld meter and another person records the illuminance value. To measure the illuminance with the remote-control cart, the illuminance meter is attached to the cart and it measures illuminance values continuously as the cart moves along the grid lines. With the drone, the meter records the illuminance continuously as the drone carries the meter and flies along the grid line. Because the drone can fly at different heights, the measurements can be done at different altitudes. The illuminance measurements using the cart and the drone are described in detail and compared with manual measurements in this paper. It is shown through this study that automated measurements can greatly improve the efficiency of roadway illuminance data measurements.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.4
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• pp.433-441
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• 2004

This paper presents a strategy for the quality assurance of the continuous preflex composite girder bridge through the camber management of the girder during construction. The construction stages which require welding, balanced preflexion loads at the ends, etc. may cause unexpected large deformation to the preflex girder. Furthermore, these defects can be detected by measurements and analyses of the girder behavior which is sometimes time consuming. In the present study, preflex girder's camber data at equally spaced nodes in each construction stage are obtained and analyzed for the quality control of thee span continuous preflex girder composite bridge.