• Fire Science and Engineering
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• v.23 no.1
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• pp.40-47
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• 2009

Applying fire resistive coating to steel members is one of the general methods to secure fire resistance performance of steel members. And intumescent coating system is currently one of methods giving fire resistance to steel members. Intumescent coating system for fire resistance, however, has undesirable weaknesses that fire resistance performance of steel members is being deteriorated due to cracks and falling-offs of the coverings as time goes after completion of the coverings to the members. So it is necessary to understand changes of the durability and the fire resistance performance of intumescent coating system over a time elapse and to reflect such change properly into the building design and construction. This research is performed to present the test method of durability and the maintenance of intumescent coating system through theoretical investigation of the test method of durability and the guide of maintenance & management of intumescent coating system of several countries, including the Britain, United States, Japan.

• International Journal of Highway Engineering
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• v.8 no.4 s.30
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• pp.159-179
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• 2006

By using the current road design method that is based on the regulation about structure and facilities standard of the road and the route plan guide of a national road and the alignment optimization road design method which is studied in the inside and outside of country, this study operate the route plan of the sample study and compare and analysis the route character, consequently the current design method has local optimization that is formed the plan by the stage and the section. Alignment optimization road design has the system optimal route search. But cost function has limite that caused by construction parameter that is not included in cost function. So we design a road route included cost function in main fields. As a result, we obtain a realistic and economically road route. The alignment optimization road design model has to be made up some problems, like the change of vertical gradient in the tunnel section, though this defects it has a lot of merits as a geometric design tool, especially in the feasibility study and the scheme design.

• International Journal of Highway Engineering
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• v.15 no.2
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• pp.47-55
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• 2013

PURPOSES : This study aimed to evaluate the feasibility of AASHTO86 design method for Bonded Concrete Overlay. METHODS : The Feasibility of AASHTO86 design method for Bonded Concrete Overlay is investigated based on the following study : i) Sensitivity analysis of designed service life of Bonded Concrete Overlay by major design input for AASHTO86 guide. ii) Comparison of actual Bonded Concrete Overlay life and predicted Bonded Concrete Overlay life by AASHTO86. iii) Finding the stress component influence the potential distress of Bonded Concrete Overlay based on 3-d FEM analysis. iv) Exploring the limitation of AASHTO86 in the aspect of design input. RESULTS : Sensitivity analysis showed that the condition of existing pavement significantly on the Bonded Concrete Overlay life. Also the overlay thickness affect the Bonded Concrete Overlay life. The comparison of actual Bonded Concrete Overlay life and predicted Bonded Concrete Overlay life showed relatively good agreement when the early distress sections are excluded in comparison. Bonding stress occurred at the interface may be larger than the bond strength used in the specification of Bonded Concrete Overlay construction. CONCLUSIONS : Bonded Concrete Overlay life predicted by the AASHTO86 may not be reliable. Number of points to improve the reliability in the design of Bonded Concrete Overlay are suggested in this study.

• New & Renewable Energy
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• v.16 no.2
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• pp.35-46
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• 2020

Recently, turbines operating in hydro power plants are required to undergo renovation and modernization due to their age exceeding 30 years. In the process of renovation or modernization, a performance test of the scaled-down model is necessary to verify the performance of the real-size model. This model test method, with criteria that is similar to that of a real turbine, is the most economical and important method. Furthermore, the shapes of the runner and guide vane can be modified or replaced easily. However, during the process of modernization, the components with the spiral casing and draft tube are impossible to repair or replace because of the buried ground. Thus, in this study, numerical analysis is conducted to investigate the hydraulic performance based on the difference between the two-dimensional computer-aided design (CAD) shape and the real three-dimensional scan shape of the spiral casing and draft tube.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.3
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• pp.91-98
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• 2011

Road signs are part of the traffic facilities intended to guide drivers to their destinations in a safe and comfortable manner. Due to the creation of new routes, changes to the old routes, and the deterioration of road signs, road signs do require efforts to do ongoing field investigations and put the results in a database. The purpose of this study was to propose methodologies to do field investigations and build a database for road signs efficiently. For that purpose, a mobile mapping system was designed for field investigations. The designed mobile mapping system was comprised of three cameras to produce image information about road signs, GPS/IMU/DMI to obtain information about the position and attitude of a vehicle, and a laser scanner to generate information about the locations of road signs and routes. Also proposed in the study was a procedure to automatically detect the areas of road signs in the road signs images and recognize their characters.

• Journal of Educational Research in Mathematics
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• v.9 no.1
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• pp.263-278
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• 1999

Computer with various powerful functions has profound potential for mathematics instruction and learning. As computer technology progress, its applicability to mathematics education become more comprehensive. Not only its functional development but various psychological positions also changed the way computer technology utilized in mathematics education. In behaviorist's perspective, computer viewed as a teaching machine and constructivist viewed computer as microworld where students could explore various mathematical contents. Both theoretical positions emphasized individual aspect of learning because behaviorist tried to individualize learning using computer and constructivist focused on the process of individual construction. But learning is not only a individual event but also a social event. Therefore we must take social aspect into account. This is especially important when it comes to computer based learning. So far, mathematics loaming with computer weighed individual aspect of loaming. Even in microworld environment, learning should be mediated by teacher and collaborative learning activities. In this aspect, the roles of teacher and peers are very important and socio-cultural perspective sheds light on the computer based learning. In socio-cultural perspective, the idea of scaffold is very important in learning and students gradually internalize the social dimension and scaffolding is gradually faded. And in the zone of proximal development, teacher and more competent peers guide students to formulate their own understanding. In sum, we must take following points into account. First of all, computer should not be viewed as a medium for individualized teaming. That is, interaction with computer should be catalyst for collaborative activities with peers. So, exploration in computer environment has to be followed by small group activities including small group discussion. Secondly, regardless of the role that computer would play, teacher should play a crucial role in computer based learning. This does not mean teacher should direct every steps in learning process. Teacher's intervention should help student construct actively. Thirdly, it is needed to conceptualize computer in learning situation as medium. This would affect learning situation and result in the change of pre-service and in-service teacher training. Computer to be used effectively in mathematics classroom, researches on assessment of computer based learning are needed.

• Journal of the Speleological Society of Korea
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• no.90
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• pp.35-56
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• 2009

The purpose of this paper is to analyze the implementation of the karst infrastructure systems for the u-cave. IT based u-cave represents spatial information derived fields, such as geographical distribution of the cave boundaries, physical configuration of the cave locations and formation characteristics of the karst history. These three aspects relate to karst infrastructure systems, cave monitoring center and spatial database implementation. In terms of the IT based u-cave infrastructure implementation systems, the u-cave depends on IT contents and spatial features. uIT contents are strongly related to IT839 strategy due to the national agenda is "u-Korea". Cave should contribute to u-cave construction through the spatial analyses methods including USN, RFID, LiDAR, ELD, and GIS technologies. For these methods various cave functions will guide to u-cave's distribution, location, and characteristics of karst. The infrastructure consists of landforms and speleothem facilities, underground related facilities, environmental protection systems, and cave planning. These six units of the cave infrastructures have spatial databases that consist of spatial configuration, such as 4-D in order to draw the spatial distribution of the limestone and lava caves. IT based u-cave system infrastructure implementation should deal with IT convergence to generate fusion affects.

• Fire Science and Engineering
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• v.33 no.5
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• pp.86-93
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• 2019

Previous studies related to evacuation guidance systems are focused on the system construction, and research on manual of the standard evacuation map is insufficient. Therefore, this research is a basic study to establish the standard evacuation map, and analyzed the decision-making time according to the type and size for each component of the evacuation map. Experimental elements were derived through the review of previous studies and legal regulations. After that, decision-making time was analyzed according to the type and size of the component display method. An experiment was conducted to analyze the decision-making time according to the type and size of the component display method. Afterwards, through the statistical test, the evacuation map guidelines for smartphones were proposed.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.39 no.5
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• pp.45-55
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• 2002

In this paper, we describe an outdoor augmented reality system using GPS tracking for position and attitude information. The system consist of a remote mobile operation unit and a ground operation unit. The remote mobile operation unit includes a real-time image acquiring device, a GPS tracking device, and a wireless data transceiver; the ground operation unit includes a wireless transceiver, a virtual image generating device, and an image superimposing device. The GPS tracking device for measurement of position and attitude of the remote mobile operation unit was designed by TANS Vector and RT-20 for DGPS. The wireless data transceiver was for data transmission between the remote mobile operation unit and the ground operation unit. After the remote mobile operation unit was installed on a vehicle and a helicopter, the system was evaluated to verify its validity in actual applications. It was found that the implemented system could be used for obtaining real-time remote information such as construction simulation, tour guide, broadcasting, disaster observation, or military purpose.

• Journal of Korean Society of Archives and Records Management
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• v.20 no.1
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• pp.207-212
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• 2020

This paper introduces the process in which the Center for Freedom of Information, founded for the public's right to know by disseminating public information, was created . Building archives with scarce resources and capacities has resulted in a number of troubles and frustrations, and the need for reorientation. However, through the contributions of many people empathizing with the unique needs and meanings of citizen-led archives, difficulties were overcome, and archives were built. This paper summarizes the specific difficulties and capabilities required in this process, especially the knowledge and assistance needed in the field of records management. Although much research is necessary, the archives serve as an example of remembering and reconstructing the past when the 1997 Crisis Archives had shaken all the foundations of people's lives, and a tool to guide decision-making.