• Korean Journal of Construction Engineering and Management
• /
• v.9 no.5
• /
• pp.86-94
• /
• 2008

Productivity is one of key management indexes for evaluating soundness of a manufacturing organization and its efficiency. In many aspects of productivity management in the construction industry, however, intuition of an experienced field manager still plays a greater role while productivity data is not utilized efficiently for the construction management purposes, because the collection and analysis of the productivity-related information are not systematic. Lack of systematic method in collecting and analyzing the productivity data results in such problems. The existing WBS should therefore be improved to solve them. The authors developed a new WBS for productivity data collection and analysis by following the research direction that was determined by literature reviews, overseas cases, and interviews with field engineers. The new breakdown structure was then evaluated for its feasibility as a productivity analysis framework. It is expected that the productivity data collected by the WBS will be used for OLAP and mining for future productivity forecast.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.10
• /
• pp.176-182
• /
• 2018

In order to understand and track the trends of construction safety accident, this study shows the topic trends in the construction safety accident with LDA(Latent Dirichlet Allocation)-based topic modeling method for data analytics. Especially, it performs to figure out the main issue of construction safety accident with unstructured data analysis based on the topic modeling rather than a variety of structured data analysis for preventing to safety accident in construction industry. To apply this methodology, I randomly collected to 540 news article data about construction accident from January 2017 to February 2018. Based on the unstructured data with the LDA-based topic modeling, I found the 10 topics and identified key issues through 10 keyword in each 10 topics. I forecasted the topic issue related to construction safety accident based on analysis of time-series trends about the news data from January 2017 to February 2018. With this method, this research gives a hint about ways of using unstructured news article data to anticipate safety policy and research field and to respond to construction accident safety issues in the future.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1998.11a
• /
• pp.183-186
• /
• 1998

Axial magnetic field generated by special electrode construction in vacuum interrupters is used to extinguish electric plasma arcs. This investigation by FDM should prove to what extent the magnetic field might influence on the arc expansion. The calculated results show that the stronger magnetic field induced the lesser radius of arc plasma. This study will help to offer good data in design of vacuum interrupters.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1239-1243
• /
• 2007

Autonomous Station Control System is automatic route control system of large-scale station. The system has flexibility of system step-by-step construction and expandability. A method of step-by-step construction for Autonomous Station Control System has system expansion and subsystem software expansion. The system has autonomous controllability and autonomous coordinability for system step by step construction. With property for a basis, each of subsystem communicates data field. Also, Each subsystem has its own management system, Autonomous Data Manager to manage itself and coordinate with the others. This paper make clear test method for Autonomous Station Control System expansion and software expansion. The first test method of system increasing construction is single station construction test. The second of method is connecting test the neighbor's Autonomous Station Control System. The third of method is connecting test the Autonomous Line Management System. Also, the test method of software expansion take the case of route control subsystem.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2013.05a
• /
• pp.21-22
• /
• 2013

Construction industry has become higher, larger and more complicated. Construction projects demand precise planning and management prior and during actual operation. However, it has been analyzed that the process planning in the construction site has been made by the site engineer experience mostly that usually results in unreliable results. Numerous studies in this field have been conducted trying to solve such problems developing methodologies to suggest quantitative results. It has been analyzed that many studies have focused on limited data only and neglected suggesting an appropriate methodology for changing data applications. Therefore, this study suggests a methodology that effectively manages construction productivity by applying bayesian approach focusing on the high-rise curtain wall operations.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2021.11a
• /
• pp.240-241
• /
• 2021

For the sustainable development of the domestic construction project management field, each CM company should try to diversify in terms of service contract types and scope of work while having internationally competitive technical and service capabilities as follows. First, from the initiation of the service to the completion, the CMr should be able to establish and execute a plan to create specific outcomes. Second, CMr must have the capability to produce weekly or monthly cost, schedule, risk, and scope management reports. In addition, it should be possible to apply the cost plus sliding fee method or to systematically and continuously accumulate and process data generated during the construction process.

• Explosives and Blasting
• /
• v.15 no.2
• /
• pp.53-72
• /
• 1997

It is impossible to precat the behavior of ground soil and structure accurately during underground construction in urban area or excavation in soft ground area because of difference between the assumed design condition and the actual site condition. Therefore, it must be managed by measuring system and correct the difference by real data. Large scale under ground construction in urban area like a seoul subway project has needed for Intelligent Construction technique, a field of the Engineering Contractor. The automated measuring system is developed for the technique. It is described that the procedure and the method of measuring work with application of the automated measuring system.

• Journal of Construction Engineering and Project Management
• /
• v.8 no.1
• /
• pp.10-21
• /
• 2018

Many construction projects involve a plethora of safety-related problems that can cause loss of productivity, diminished revenue, time overruns, and legal challenges. Incorporating data collection and analytics methods can help overcome the root causes of many such problems. However, in a dynamic construction workplace collecting data from a large number of resources is not a trivial task and can be costly, while many contractors lack the motivation to incorporate technology in their activities. In this research, an Android-based mobile application, Preemptive Construction Site Safety (PCS2) is developed and tested for real-time location tracking, trajectory prediction, and prevention of potential collisions between workers and site hazards. PCS2 uses ubiquitous mobile technology (smartphones) for positional data collection, and a robust trajectory prediction technique that couples hidden Markov model (HMM) with risk-taking behavior modeling. The effectiveness of PCS2 is evaluated in field experiments where impending collisions are predicted and safety alerts are generated with enough lead time for the user. With further improvement in interface design and underlying mathematical models, PCS2 will have practical benefits in large scale multi-agent construction worksites by significantly reducing the likelihood of proximity-related accidents between workers and equipment.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.60 no.5
• /
• pp.55-67
• /
• 2018

The objectives of this study were to monitor organic farming upland compared with conventional upland field and to evaluate nutrient loads reduction of surface cover effect with long-term historical climate data. APEX(Agricultural Policy Environmental eXtender) model was validated with experimental data and used for assessing surface cover scenarios for 30-year simulation periods. The validated values of RMSE(Root Mean Square Error), RMAE(Root Mean Absolute Error), $R^2$ and E(Nash-Sutcliffe efficiency) for runoff were 1.17-1.37 mm/day, 0.28-0.45 mm/day, 0.88-0.90 and 0.82-0.94 in two treatments, respectively. Those for water quality (nitrogen) were 0.05-0.16 kg/ha, 0.52-0.75 kg/ha, 0.67-0.72 and 0.32-0.70 in two treatments, respectively, and therefore the validated model showed good agreement with the observed runoff and nitrogen load for the study period. When decreasing the surface cover rate of organic farming field to 75%, 50%, 25%, and 0% (conventional field), average annual runoff increased by 7%, 15%, 23% and 31%, respectively. Under same condition of decreasing the surface cover rate, average annual nitrogen loads increased by 1.4 times, 1.7 times, 2.0 times, and 2.3 times compared with organic farming field, respectively. This study showed that it is possible to present an appropriate surface cover ratio to maintain conventional production and minimize nonpoint sources pollution for organic farming system, although long-term monitoring is needed to determine its effects on environmental concerns, crop competition, and other uncertainty.

• Composites Research
• /
• v.19 no.1
• /
• pp.43-48
• /
• 2006

High performance fiber reinforced cement composites have better performances than traditional cement based materials, therefore, have been expected as new construction applications such as the materials for construction & bridge structure, repair and rehabilitation applications, anti-collapse applications, anti-noise applications etc. However, they have lots of the problems such as material design, fabrication method and structural analysis. Also, the most serious problems of High performance fiber reinforced cement composites have been expensive initial cost, lack of long-term exposure data. As a result, it is needed that the efforts for lowering the initial cost and accumulation of long-term exposure. There has been hardly assessment results of life cycle cost for HPFRCC in construction field, but some papers showed that total life cycle cost could be profitable if the initial cost could be reduced.