• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1229-1234
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• 2005

Since the 20th century, the business of railway was invaded by the invention of airplanes and vehicles in the field of the transportation of passenger and commercial products, however, in the 21st century, the fervent development of a high speed railway made possible the huge capacity of transporting passengers and commercial freight, so the railway industry is facing a new era of railway revolution. The 200 years old railway tradition includes the history of railway bridges built in areas of river, valley and metropolitan region and in that, the number of constructions of railway bridges that is composed of cable-stayed bridges is increasing as one of the most optimal bridges considering the quality of materials and the span of continuous-welded long rail. Thanks to the minimized effects of the fixed load on the stiffening girder section by delivering the fixed load which is applied to the pylon with the composition of elastic supporting points by using cables and the effective structural system that can throughly resist extra loads in addition to fixed load, the long-extended span of a bridge becomes possible. In this structural system, the load that is applied to the stiffening girder section forms a now pattern and in the process of these load delivery, there will be a necessity to examine the concentration of stress occurred in the cable-anchor system of the cable.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.2
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• pp.101-106
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• 2010

Researches on air-ground robot cooperating system has been made recently. The cooperation among homogeneous robots focused on the architecture of the system, quality and influence of the communication. In contrast, the cooperation among heterogeneous robots such as aerial vehicle and ground vehicle robots has not been much handled. There are a couple of main points for those air-ground cooperating robots. One is using UAV (Unmanned Aerial Vehicle) as an extra sensor of UGV (Unmanned Ground Vehicle). This kind of application is usually used in situations such as guiding UGV to an appropriate path which could be better determined from the eye in the sky as UAV. The other main application of air-ground cooperating robot system is the localization. By combining sensor information from both UAV and UGV, the robot system as a whole can localize a target object or find features in the environment with better performance than UGV or UAV alone. Although these applications are recently studied in many different ways and devices, there are still a lot of possibilities in the field of air-ground cooperating robot systems. We introduce those research fields in this paper.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.552-557
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• 2006

Since the 20th century, the business of railway was invaded by the invention of airplanes and vehicles in the field of the transportation of passenger and commercial products, however, in the 21st century, the fervent development of a high-speed railway made possible the huge capacity of transporting passengers and commercial freight, so the railway industry is facing a new era of railway revolution. The 200 years old railway tradition includes the history of railway bridges built in areas of river, valley and metropolitan region and in that, the number of constructions of railway bridges that is composed of cable-stayed bridges is increasing as one of the most optimal bridges considering the quality of materials and the span of continuous-welded long rail. Thanks to the minimized effects of the fixed load on the stiffening girder section by delivering the fixed load which is applied to the pylon with the composition of elastic supporting-points by using cables and the effective structural system that can throughly resist extra loads in addition to fixed load, the long-extended span of a bridge becomes possible. In this structural system, the load that is applied to the stiffening girder section forms a flow pattern and in the process of these load delivery, there will be a necessity to examine the concentration of stress occurred in the cable-anchor system of the cable.

• Journal of Information Processing Systems
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• v.16 no.3
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• pp.699-717
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• 2020

Propagation time on permissionless blockchain plays a significant role in terms of stability and performance in the decentralized systems. A large number of activities are disseminated to the whole nodes in the decentralized peer-to-peer network, thus causing propagation delay. The stability of the system is our concern in the first place. The propagation delay opens up opportunities for attackers to apply their protocol. Either by accelerating or decelerating the propagation time directly without proper calculation, it brings numerous negative impacts to the entire blockchain system. In this paper, we thoroughly review and elaborate on several parameters related to the propagation time in such a system. We describe our findings in terms of data communication, transaction propagation, and the possibility of an interference attack that caused an extra propagation time. Furthermore, we present the influence of block size, consensus, and blockchain scalability, including the relation of parameters. In the last session, we remark several points associated with the propagation time and use cases to avoid dilemmas in the light of the experiments and literary works.

• Journal of Korean Classical Literature and Education
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• no.15
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• pp.89-111
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• 2008

In spite of importance of the experience education in Korean classic education, it has not made study in this field. Especially, is famous for typical Korean classic as a travel literature, but it was considered as a writing model or a novel. This study focuses on as the travel literature. For the experience education, it must be considered that literature appreciation is a core. So the experience education contents will contain what is selected, how to present, and how to teach. The resource of the experience education have to arouse educational meaning and interest in the classic literature. Concerning , there are two type of experience. First, the writer's experience. The writer, Yonam experienced a extra ordinary events. He wrote this event through other's points. This showed other's situation so it could make understand other's feeling and thought. Second, the reader's experience. A modern reader considers Korean classic as something difficult and strange. but if reader would have the point of view of others, he could understand more easily. Further, it will be expected that the reader can reflect on own's situation and conduct.

• Structural Engineering and Mechanics
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• v.51 no.4
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• pp.663-683
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• 2014

In order to study the dynamic failure mechanism and aseismic measure for high concrete gravity dam under earthquake, the comparative models experiment on the shaking table was conducted to investigate the dynamic damage response of concrete gravity dam with and without the presence of reinforcement and evaluate the effectiveness of the strengthening measure. A new model concrete was proposed and applied for maintaining similitude with the prototype. A kind of extra fine wires as a substitute for rebar was embedded in four-points bending specimens of the model concrete to make of reinforced model concrete. The simulation of reinforcement concrete of the weak zones of high dam by the reinforced model concrete meets the similitude requirements. A tank filled with water is mounted at the upstream of the dam models to simulate the reservoir. The Peak Ground Acceleration (PGA) that induces the first tensile crack at the head of dam is applied as the basic index for estimating the overload capacity of high concrete dams. For the two model dams with and without strengthening tested, vulnerable parts of them are the necks near the crests. The results also indicate that the reinforcement is beneficial for improving the seismic-resistant capacity of the gravity dam.

• Steel and Composite Structures
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• v.48 no.6
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• pp.611-623
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• 2023

This work considered an optimal control formulation in the sense of Caputo derivatives. The optimality of the fractional optimal control problem. The tumor immune interaction in fractional form provides an excellent tool for the description of memory and hereditary properties of inter and intra cells. So the interaction between effector-cells, tumor cells and are modeled by using the definition of Caputo fractional order derivative that provides the system with long-time memory and gives extra degree of freedom. In addiltion, existence and local stability of fixed points are investigated for discrete model. Moreover, in order to achieve more efficient computational results of fractional-order system, a discretization process is performed to obtain its discrete counterpart. Our technique likewise allows the advancement of results, such as return time to baseline that are unrealistic with current model solvers.

• Korean Institute of Interior Design Journal
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• v.24 no.6
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• pp.202-211
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• 2015

This study attempts to deduce the necessity and validity of complexation, and suggests complexation through complexation suitability evaluations as follows. First, the concept and current state of leisure facilities for the elderly and elementary facilities and architectural complexation were investigated through theoretical considerations. Second, the target schools for complexation of 'elementary school-leisure facility for the elderly' were selected. The aspects of facility introduction of an elementary school, teacher support facility, convenience facility for the disabled, safety and security facilities as well as school facility accessibility were investigated on the basis of the data attained from theoretical considerations. Third, the feasibility of complexation of leisure facilities for the elderly was reviewed, based on the investigated data on complexation-targeted elementary school. Regarding school building and support facilities, with a focus on leisure programs for the elderly, the availability and number of rooms, extra numbers of regular classrooms and the room condition were assessed on the basis of the analysis of operational perspective of each facility. The convenience facilities for the disabled were examined by classifying them into interventional facility in consideration of facilities for the elderly, pursuant to the provisions in the convenience promotion assurance act for the disabled, elderly and pregnant women. Safety and security facilities were evaluated in an effort to assess the safety issue of the elderly and children. The result of the evaluation of the 6 elementary schools in Seong-buk county based on the above-mentioned four measurement standards shows that they scored 107~124 points out of the total 155 points, with the average of 118.5 points. This is more than the medium score and shows the possible complexation of the elementary school facilities as the leisure facilities for the elderly, and at the same time it may lead each school to find out the elements conducive to enhancing the complexation as a result of the evaluation. Through the evaluation data, I expect that we contribute to promoting the process of the evaluation of the appropriateness of complexation and the efficient complexation.

• Journal of the Korean Ceramic Society
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• v.41 no.12 s.271
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• pp.929-932
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• 2004

It is known that small amount of MgO in excess is often added to develop pure perovskite single phase of PMN-based composite, however, extra MgO precipitates in grains and inhibits densification of PMN. In this study PMN-PT-BT (PBT) powder was prepared by a conventional mixed oxide method using $(MgCO_3)_4{\cdot}Mg(OH)_2{\cdot}5H_{2}O$ instead of MgO. The precursor was heated at $500^{\circ}C/1h$ and its surface was modified with MgO sol. This effect was investigated in the aspects of sintering and dielectric properties. Small amount of added MgO sol ($0.5{\sim}1.0wt\%$) enhanced sintering substantially below $1000^{\circ}C$. The PBT with $0.5wt\%$ MgO sol sintered at $900^{\circ}C/2h$ had density of $7.62\;g/cm^3$, room temperature dielectric constant of 14800, loss of dielectric constant of $1.1\%$, which were comparable to those of the PBT sintered at $1000^{\circ}C/2h$. It was noticeable that the extra MgO precipitated mostly on triple points and grain boundaries and resulted in inhibition of grain growth.

• Land and Housing Review
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• v.6 no.4
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• pp.221-229
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• 2015

Large trees in the apartment complex are playing an important role to decide the quality of external environment. They are planted with the object of utilizing themselves as a landmark of the complex and enhancing space symbolism. Since planting large trees would require high maintenance costs and generate defect, it would cause decline in quality of external environment. This study researches on large trees in artificial ground of the apartment complex. This study analyzes actual condition of planting and tries to provide improvement direction of planting. In order to conduct this research, three target areas (over R30) and 265 trees are selected. Based on the drawings and specifications this study researches on the plan of landscape design, changes of field design, actual condition of completion, present condition of planting, minimum soil depth of growth and development and types of extra action for soil depth. The result shows that 85% of drawings and specifications for large trees in the apartment complex are deep-rooted tree species. On average large trees with R 35 are planted in artificial ground and there is lack of on average 65cm minimum soil depth of growth and development. Reviewing changes of field design is conducted in such limited size as mainly R30 and R40 and there is no extra plan for lack of soil depth. The plan for securing additional soil depth is done by 85% of mounding. However, since there is only 10% of satisfaction, the inappropriateness in securing additional soil is pointed out. This research also points out that the size of large trees, root characteristics and location-allocation for planting are pivotal factors for securing minimum soil depth of growth and development. This research also provides improvement direction in case of planning planting.