• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.1
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• pp.95-100
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• 2021

This paper introduces model-based meta reinforcement learning as a control for the manipulator of an underwater construction robot. Model-based meta reinforcement learning updates the model fast using recent experience in a real application and transfers the model to model predictive control which computes control inputs of the manipulator to reach the target position. The simulation environment for model-based meta reinforcement learning is established using MuJoCo and Gazebo. The real environment of manipulator control for underwater construction robot is set to deal with model uncertainties.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.601-612
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• 2005

In mountainous area, Two parallel tunnels have been usually recognized as a road tunnel which has benefits in aspects of cost and stability. However, Design and construction of 2-Arch road tunnel are growing recently due to environmental destruction, compensation of land and difficulty of route separation. As studies are mainly undergoing on only guaranteeing stability and developing a waterproofing-drainage system to avoid water leakage through comprehension for characteristics of 2-arch tunnel behaviors, there is a tendency to evaluate quantity of support by empirical method with a tunnel which has a complicated cross-section and lack of construction ability. In this study, therefore, we made a plan of tunnel cross-section which had shown good construction ability and developed the waterproofing-drainage system which is able to solve the water leakage problem fundamentally by analyzing precedented 2-arch tunnels and investigating their sites in and out of nation. We also determined fixed quantity of support by a large-scale model test and numerical analysis. We want to contribute to 2-arch tunnel design hereafter introducing design procedure and method applied here.

• Journal of Soil and Groundwater Environment
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• v.17 no.6
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• pp.119-128
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• 2012

The applicability and accuracy of Revised Universal Soil Loss Equation (RUSLE) model on the estimation of soil loss at impacted area of shooting range was tested to further the understanding of soil erosion at shooting ranges by using RUSLE. At a shooting range located in northern Kyunggi, the amount of soil loss was estimated by RUSLE model and compared with that estimated by Global Positioning System-Total Station survey. As results, the annual soil loss at a study site (202 m long by 79 m wide) was estimated to be 2,915 ton/ha/year by RUSLE and 3,058 ton/ha/year by GPS-TS survey, respectively. The error between two different estimations was less than 5%, however, information on site conditions should be collected more to adjust model coefficients accurately. At the study shooting range, sediments generated by rainfall was transported from the top to near the bottom of the sloping face through sheet erosion as well as rill erosion, forming a gully along the direction of the storm water flow. Coarser fractions of the sediments were redeposited in the limited area along the channel. Distribution characteristics of explosive compounds in soil before and after summer monsoon rainfall in the study area were compared with the erosion patterns. Soil sampling and analyses results showed that the dispersion of explosive compounds in surface soil was consistent with the characteristics of soil erosion and redeposition pattern of sediment movements after rainfalls.

• Korean Journal of Construction Engineering and Management
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• v.13 no.4
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• pp.78-88
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• 2012

As worldwide efforts to reduce global warming gases, the construction Industry is endeavoring to diminish carbon dioxides emissions. Especially, by introducing the LCA methodology to the industry, A variety of related studies to measure the emission of carbon dioxides have been conducted. However, when the conventional LCA methodology is applied to the construction projects, some limitations have been reported. To overcome the restrictions derived from the industry characteristics, this research suggested the Activity-based LCA model by applying the Activity-based Costing (ABC), which breaks down the whole life cycles into more detailed stages. By implementing the newly developed model, forecasting accuracy of $CO_2$ emission was elevated, and the critical control points on carbon dioxides were established. Through the case study of aluminium curtain-wall system, this research verified the usefulness of the Activity-based LCA.

• Korean Journal of Optics and Photonics
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• v.28 no.5
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• pp.203-212
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• 2017

A scientific model refers to a conceptual system that can describe, explain, and predict a particular physical phenomenon. The co-construction of the scientific model is attracting attention as a new teaching and learning strategy in the field of science education and various studies. The evaluation and modification of models compared with the predicted models of data from the real world is the core of modeling strategy. However, there were only a limited data provided by the teacher in many studies of modeling comparing the students' predictions of their own models. Most of the students were not given the opportunity to evaluate the suitability of the model with the data in the real world. The purpose of this study was to develop a scientific model co-construction program that can evaluate the model by directly comparing the predicted models with the observed data from the real world. Through a collaborative discussion between teachers and researchers for 6 months, a 5-session scientific model co-construction program on the subject 'image formation by convex lenses' for second grade middle school students was developed. Eighty (80) students in 3 classes and a science teacher with 20 years of service from general public co-educational middle school in Gyeonggi-do participated in this 2-week program. After the class, students were asked about the helpfulness and difficulty of the class, and whether they would like to recommend this class to a friend. After the class, 95.8% of the students constructed the scientific model more than the model using the construction rule. Students had difficulties to identify principles or understand their friends, but the result showed that they could understand through model evaluation experiment. 92.5% of the students said that they would be more than willing to recommend this program to their friends. It is expected that the developed program will be applied to the school and contribute to the improvement of students' modeling ability and co-construction ability.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.654-655
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• 2015

In construction industry, while requiring advanced knowledge of technicians through a long experience, there is a problem with the tacit knowledge is not carried on the inner organization. Recent technological developments allow sharing and application of the tacit knowledge while technology tools use the CoP(Community of Practice) that mainly interacts between people. Clearly, the most consideration in stimulating CoP is the circulation of knowledge, namely the willingness to share and use knowledge with others. It is then important to explain why individuals factors to share and use knowledge with others when they have a choice. In this paper, we would like to report to find out about factors whether people are actually sharing and using the knowledge obtained in CoP. The results help to analyze which factors are influenced to be a successful CoP in construction industry. The implications for theory and future research direction are discussed.

• Journal of Korean Society of Disaster and Security
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• v.9 no.2
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• pp.43-52
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• 2016

Notwithstanding industrial accident decrease generally, Construction industry is on the rise recently. Most accident occurs in the small scale like as multiflex housing, remodeling, neighbourhood facility more than safety supervisor appointed large scale construction site. By the size of business place, 81.6% of total accident occurs mostly in small scale site that is bellow 120 billion won and 50 manpower. This paper aimed that small scale housing company achieve a zero hazard practising and understanding the safety adminstration standar d model easily and it applied firstly after investigating the operation condition of construction site safety control in small scale company propelling the complex style multiflex housing business.

• Journal of the Korean Solar Energy Society
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• v.32 no.1
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• pp.32-39
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• 2012

New and renewable energy systems(solar thermal system, photovoltaic system, geothermal system, wind power system) are environmentally friendly technologies and these in South Korea are very important measures to reduce greenhouse-gas(GHG) and to push ahead with Green Growth. The purpose of this paper is to analyze GHG mitigation potential by distribution of solar thermal system in housing sector with bottom-up model called 'Long-range Energy Alternative Planning system'. Business as usual(BAU) was based on energy consumption characteristic with the trend of social-economic prospects and the volume of housing. The total amount of GHG emission of BAU was expected to continuous increase from 66.0 million-ton $CO_{2e}$ in 2007 to 73.1 million-ton $CO_{2e}$ in 2030 because of the increase of energy consumption in housing. The alternative scenario, distribution of solar thermal system in housing sector had GHG mitigation potential 1.54 million-ton $CO_{2e}$ in 2030. The results of this study showed that new and renewable energy systems made a contribution of reducing the use of fossil fuel and the emission of greenhouse-gas in building.

• Journal of the Korean Society of Safety
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• v.19 no.4 s.68
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• pp.86-93
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• 2004

Through this study we have reviewed the implementation model, certificate criteria and the formation of KOSHA 18001 Safety and Health Management System and have compared and examined with OHSAS 18001 Certificate. In the course of the 1st questionnaires which have been participated by the concerned Safety and Health Staffs(such as Project Mannager, Site Supervisior, Safety Engineers) of the local construction sites, actual condition of application for KOSHA 18001 has been scrutinized and examined. And as a result, we presented the improved model by digging out the problems. The improved model has been applied for about eight months in local construction sites and the effectiveness has been carefully compared and examined before and after the application of the improvement model through the 2nd questionnaires by the relevant staffs (such as Project Manager, Site Supervisor, Safety Engineer and Project Engineers of the Coordinated Sub-Contractors).

• Journal of the Korean Society of Safety
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• v.19 no.2
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• pp.75-87
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• 2004

This study suggests a safety management model for construction management (CM) suitable to domestic conditions so that inefficiency resulted from the operation of construction projects by public and private indtitutes according to different systems can be eliminated for the securing of systematic and efficient safety managment. Based on the suggested safety management model, this study also develops a safety management information system that can efficiently and consistently manage and maintain a large quantity of information, and give necessary supports in a speedy way in the managing of construction projects.