• Structural Engineering and Mechanics
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• v.74 no.1
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• pp.129-143
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• 2020

This study proposes a new shape memory alloy-tuned mass damper (SMA-TMD) and investigates the effectiveness of this damper in reducing and controlling the vibrations of a transmission tower-line system under various seismic excitations. Based on a practical transmission line system and considering the geometric nonlinearity of this system, the finite element (FE) software ANSYS is used to create an FE model of the transmission tower-line system and simulate the proposed SMA-TMD. Additionally, the parameters of the SMA springs are optimized. The effectiveness of a conventional TMD and the proposed SMA-TMD in reducing and controlling the vibrations of the transmission tower-line system under seismic excitations is investigated. Moreover, the effects of the ground motion intensity and frequency ratio on the reduction ratio (η) of the SMA-TMD are studied. The vibration reduction effect of the SMA-TMD under various seismic excitations is superior to that of the conventional TMD. Changes in the ground motion intensity and frequency ratio have a significant impact on the η of the SMA-TMD. As the ground motion intensity and frequency ratio increase, the η values of the SMA-TMD first increase and then decrease. Studying the vibration reduction effects of the SMA-TMD can provide a reference for the practical engineering application of this damper.

• Journal of the Korean Geosynthetics Society
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• v.3 no.4
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• pp.3-12
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• 2004

In this paper, a mechanism of the soil structure reinforced by geosynthetics is discussed. The reinforcing mechanism is interpreted an effect arising from the reinforcement works so as to prevent the dilative deformation (negative dilatancy) of soil under shearing. A full-scale in-situ model test was carried out in Kanazawa of Japan(1994) and in the laboratory test the strength and the characteristics of deformation conducting a constant volume shear test are examined. The parameters needed in the FEM are also applied by using the experimental data. The elasto-plastic finite element simulation is carried out, and the results are quantitatively compared with that of experiment. As a results, it is known that the theoretical predictions could be explained effectively the experimental results which are obtained by a full-scale in-situ model test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1489-1494
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• 2013

Tsunami happens rarely enough to allow a false sense of security, but when they do occur, there may be just minutes or hours for people to reach a safe location. Natural disasters like tsunami are inevitable and it is almost impossible to fully recoup damages caused by the disasters. However, it is possible to minimize the potential risk by developing early warning strategies. GIS modelling with its geoprocessing and analysis capability can play a crucial role in efficient mitigation and management of disaster. This study aims at developing integrated spatial information system processing model supporting tsunami evacuation action planning using geo-information technology such as GIS. The integration process classified into four phases. And in each phase, required input data and GIS processes are decided. The main effort in minimizing casualties in tsunami disaster is to evacuate people from the hazard area before tsunami strikes by means of either horizontal or vertical evacuation. The study provides essential spatial information for local decision making related with people's evacuation in tsunami-prone areas based on a modeling approach transferable to other coastal areas.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.973-977
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• 2003

Land is the only immovable property that can be used, as a means for agricultural production as well as a means for mortgage for financing industrial or commercial enterprises. Spatial technologies play a key role in managing our land, water and natural resources. Cadastral data is a major component for the development of Land Information System. Therefore, systematic land registration system based on accurate and scientific cadastral map are found inevitable for poverty alleviation, good governance and women empowerment through security of their rights on property, as well as the planning and development of a sustainable environmental protection within Metropolitan city. Digital cadastral parcel is the fundamental spatial unit on which database is designed, created, maintained and operated. Availability of accurate and updated cadastral maps is a primary requisite for successful planning, policy formulating and maintenance of city utility services, which need cadastral and utility information together. Flawed cadastral maps can put land, revenue and taxation system at stake. Kathmandu the capital city of Nepal still is lacking utility maps combining cadastral information with the utility. There is an urgent need to have an effective, accurate and easy to access land revenue and utility services system within the urban areas which could be achieved after the production of reliable base maps and land registration system to guarantee land allocation and property rights which can well be achieved by digital conversion and correction of base cadastral maps. This paper highlights the drawbacks of the conventional cadastral maps and the possible advantages of digital cadastral maps over these. Also the problems, issues and implications during digital conversion and creating database of the same will be discussed.

• Journal of Advanced Navigation Technology
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• v.19 no.2
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• pp.98-102
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• 2015

In this paper are This paper is about the efficient use operational management plan for the metropolitan public Jamsil heliport. First, understand the general operations and facilities to Jamsil heliport and raised the issue for them. And, in cases such as urban offshore heliport Jamsil heliport in New York and Texas (USA), for example, which was presented for comparative analysis and Jamsil heliport in London (UK). Operations, research is seen against a facility to install and manage a couple of airfield operations based on the subject by presenting the alternatives, thereby causing the principal operating facilities, infrastructure and security facilities even suggest ways to enhance the standards. Unlike other countries, Jamsil heliport location characteristics were excluded from the study on the safety aspects related to flight operations and for this I'm a military airport facilities coexist in the neighborhood.

• Journal of the Korea Society of Computer and Information
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• v.11 no.4 s.42
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• pp.221-230
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• 2006

Changing drastically, the life in a modern city has forced citizens to gradually shorten their average period of settlement, which has weakened the identity of city habitation, thus causing serious crimes and damaging the security of city greatly. Haying a highly composite structure with not only macro, but micro characteristics, city is grasped as a very composite phenomenon shown in the social, economic and spatial constitution relationships, including the personal motives of criminals. Accordingly, this study puts stress on the necessity of any crime prediction program to predict the occurrence of crimes by analyzing the occurrence patterns of sharply increasing intra-city crimes of violence on a typical, time and spatial basis and clarifying their structural dynamic relationships in a both macro and micro manner. Moreover, the deduction of various factors closely related to crime occurrence will contribute to elucidating the occurrence structure of city crimes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.2
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• pp.558-579
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• 2021

The cloud storage provides flexible data storage services for data owners to remotely outsource their data, and reduces data storage operations and management costs for data owners. These outsourced data bring data security concerns to the data owner due to malicious deletion or corruption by the cloud service provider. Data integrity verification is an important way to check outsourced data integrity. However, the existing data verification schemes only consider the case that a verifier launches multiple data verification challenges, and neglect the verification overhead of multiple data verification challenges launched by multiple verifiers at a similar time. In this case, the duplicate data in multiple challenges are verified repeatedly so that verification resources are consumed in vain. We propose a duplicate data verification algorithm based on multiple verifiers and multiple challenges to reduce the verification overhead. The algorithm dynamically schedules the multiple verifiers' challenges based on verification time and the frequent itemsets of duplicate verification data in challenge sets by applying FP-Growth algorithm, and computes the batch proofs of frequent itemsets. Then the challenges are split into two parts, i.e., duplicate data and unique data according to the results of data extraction. Finally, the proofs of duplicate data and unique data are computed and combined to generate a complete proof of every original challenge. Theoretical analysis and experiment evaluation show that the algorithm reduces the verification cost and ensures the correctness of the data integrity verification by flexible batch data verification.

• Tunnel and Underground Space
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• v.29 no.1
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• pp.1-11
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• 2019

This study investigated use cases of machine learning technology in domestic medical, manufacturing, finance, automobile, urban sectors and those in overseas mining industry. Through a literature survey, it was found that the machine learning technology has been widely utilized for developing medical image information system, real-time monitoring and fault diagnosis system, security level of information system, autonomous vehicle and integrated city management system. Until now, the use cases have not found in the domestic mining industry, however, several overseas projects have found that introduce the machine learning technology to the mining industry for improving the productivity and safety of mineral exploration or mine development. In the future, the introduction of the machine learning technology to the mining industry is expected to spread gradually.

• The Journal of Korean Institute of Information Technology
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• v.16 no.12
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• pp.57-68
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• 2018

A system to prevent disasters by collecting and analyzing environmental information such as road surface sedimentation, sinkholes, collapse risk of bridges, temperature and humidity around tram station is continuously monitored by monitoring the condition of road surface when constructing tram which is one of the urban railways. In this paper, we propose a wireless network security management system for tram roads based on LPWA that can recognize risk factors of road surface, bridge and tram station of tram in advance and prevent risk. The proposed system consists of a sensor node that detects the state of the tram road surface, a gateway that collects sensor information, and a safety management system that monitors the safety and environmental conditions of the tram road surface, and applies the low power long distance communication technology. As a result of comparing the proposed system with the LTE system in the field test, it was confirmed that there is no significant difference between the sensor information value and the critical alarm level in the monitoring system.

• Journal of the Society of Disaster Information
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• v.17 no.2
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• pp.218-225
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• 2021

Purpose and Method: Financial field among the various changes due to the nationalization of fire fighting officials is the main point and to stably settle according to the purpose, improvement of special account for fire fighting officials is suggested by analyzing the facts and related acts. Results: To use the fire fighting project budget entirely in fire fire fighting project by the purpose of the installation of special account for fire fighting officials, dual budgeting standard for labor cost should be revised. In the reserve cost budgeting standard "Within 1/100 of the total budget rule" total budget includes the labor cost, as a result reserve cost budget will keep increase, so reserve cost budget should be fixed by the project budget instead of the total budget. Conclusion: To use the fire fighting budget by the purpose of the installation of special account for fire fighting officials, improvement on budgeting standard is necessary to increase quality of the fire service and stably operate the fire fighting organization.