• Journal of the Korean Society for Railway
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• v.16 no.3
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• pp.202-206
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• 2013

A submerged floating railway is an innovative tunnel infrastructure passing through the deep sea independent of wave and wind so that high speed trains can run on it. It doesn't depend on water depth and is cost effective due to modular construction on land. The construction period can be reduced drastically. This paper introduces the concept design of a submerged floating railway, and for securing safety, proposes a method to analyze the structural behavior of the body in case of collision with a submarine. The theory of a beam with an elastic foundation was used to calculate the equivalent mass of the body so that the perfect elastic collision could be applied to calculate the collision velocity. The maximum deformation and bending moment was analyzed based on energy conservation. To verify the results, a collision analysis using a finite element analysis code was made. Comparing the results confirmed that this simplified collision analysis method gives enough accurate deformation and bending moment to be used for actual estimation in the initial design stage.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.4
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• pp.469-475
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• 2021

In order to effectively maintain and manage river facilities, on going data collection of associated objects is important. However, the existing data acquisition methods of using a total station, a global navigation satellite system, or a terrestrial laser scanner have limitations in terms of cost/time/manpower when acquiring spatial information data on river facilities distributed over a wide and long area, unlike general facilities. In contrast, a mobile mapping system (MMS), which acquires data while moving its platform, acquires precise spatial information data for a large area in a short time, so it is suitable for use in the maintenance of linear facilities around rivers. As a result of applying a MMS to a research area of 4 km, 184,646,099 points were acquired during a 20-minute data acquisition period, and 378 cross-sections were extracted. By comparing this with computer-drawn river plans, it was confirmed that efficient levee management using a MMS is possible.

• Journal of Digital Convergence
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• v.19 no.10
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• pp.1-13
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• 2021

This study postulates that Government as a Platform(GaaP) could be a next generation government model, drawing activation strategy from success factors of webtoon platform by NAVER. It suggests success factors of Naver webtoon case based on three main components of platform strategy. First, in the aspect of platform infrastructure, Naver webtoon was established based on powerful portal site by parent company Naver and improved platform accessibility through using webtoon without login. Second, in the aspect of stakeholder engagement, Naver webtoon has offed webtoon at no cost and it has taken an intermediary role for supporting the stakeholders with PPS. Third, in the aspect of outputs production, Naver webtoon offered real time feedback from webtoon users that could affect webtoon production and established incubating system that allow users to create their webtoon. And due to PPS, it makes possible to various create second outputs based on webtoon, which can contribute to activating webtoon ecosystem.

• International Journal of Computer Science & Network Security
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• v.21 no.12
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• pp.235-247
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• 2021

Today, the cloud computing has become a major demand of many organizations. The major reason behind this expansion is due to its cloud's sharing infrastructure with higher computing efficiency, lower cost and higher fle3xibility. But, still the security is being a hurdle that blocks the success of the cloud computing platform. Therefore, a novel Multi-tenant Decentralized Information Flow Control (MT-DIFC) model is introduced in this research work. The proposed system will encapsulate four types of entities: (1) The central authority (CA), (2) The encryption proxy (EP), (3) Cloud server CS and (4) Multi-tenant Cloud virtual machines. Our contribution resides within the encryption proxy (EP). Initially, the trust level of all the users within each of the cloud is computed using the proposed two-stage trust computational model, wherein the user is categorized bas primary and secondary users. The primary and secondary users vary based on the application and data owner's preference. Based on the computed trust level, the access privilege is provided to the cloud users. In EP, the cipher text information flow security strategy is implemented using the blowfish encryption model. For the data encryption as well as decryption, the key generation is the crucial as well as the challenging part. In this research work, a new optimal key generation is carried out within the blowfish encryption Algorithm. In the blowfish encryption Algorithm, both the data encryption as well as decryption is accomplishment using the newly proposed optimal key. The proposed optimal key has been selected using a new Self Improved Cat and Mouse Based Optimizer (SI-CMBO), which has been an advanced version of the standard Cat and Mouse Based Optimizer. The proposed model is validated in terms of encryption time, decryption time, KPA attacks as well.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.65-73
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• 2019

A spiral steel pipe has been more used widely as a structural member as well as transport pipeline because the pipe can be manufactured continuously, consequently more economical than the conventional UOE pipe. As improved pipe manufacture technology makes spiral pipes to have high strength and to have larger diameters, the spiral pipes have been recently used as long distance transport pipeline with a large diameter and strain-based design is thus required to keep structural integrity and cost effectiveness of the spiral pipe. However, design codes of spiral pipe have not been completely established yet, and structural behaviors of a spiral pipe are not clearly understood for strain-based design. In this paper, the effects of residual stresses due to the spiral pipe manufacture process are investigated on the flexural behavior of the spiral pipe. Finite element analyses were conducted to estimate residual stresses due to the manufacturing process for the pipes which have different forming angle, thickness, and strength, respectively. After that, the results were used as initial conditions for flexural analysis of the pipe to numerically investigate its flexural behaviors.

• Journal of Advanced Navigation Technology
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• v.22 no.6
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• pp.577-584
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• 2018

GNSS based transport infrastructure cluster is to broadcast satellite navigation correction information and integrity information capable of precise positioning for land transport users. This makes it possible to do lane-level positioning reliably. However, in order to provide the lane-level positioning and correction information service nationwide, new station sites selection and to build GNSS stations have a heavy cost and a burden for a considerable period of time. In this paper, we propose the cluster design criteria and national-wide network-based precise positioning for land transportation (NETPPI-LT) cluster design for a cluster-based precise positioning. Furthermore, it is analyzed the precise positioning pre-performance of this cluster design based on the spatial error and verified its suitability as the precise positioning pre-performance of the cluster design.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.83-90
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• 2018

LoRa (Long Range) is a long-distance, low-power communication technology. Broader range of communication than NFC technology allows communication without having to install multiple APs and reduces the cost of initial infrastructure deployment. MQTT (Message, Queuing, Telemetry, Transport) protocol is also low power and lightweight protocols. It can increase module persistence and reduce maintenance costs when used with LoRa. In this paper, we developed a system for compiling various environmental information in a factory using LoRa and MQTT. Environmental sensor data from long distances can be monitored by the management system and the facilities in each workshop can be controlled. Performance tests have also shown that the use of LoRa and MQTT is effective in terms of long-distance and power consumption.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.537-546
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• 2019

In this paper, a system that integrates a home concentrate unit(HCU) in a smart electricity meter to collects water, gas, hot water, and heating usage required for AMI has been proposed. The collected data could be transmitted to the in house display(IHD) and server to provide a more economical AMI system. The developed system is less expensive in the network configuration than the existing system, which could reduce the operating cost, and be easy to install. By applying the developed system, the usage of electricity, water, gas, hot water and heating could be measured and these make it easier to apply AMI system. The main contents of the development are the smart electricity meter and embedding of HCU into the smart electricity meter, and transferring these data to IHD and server to structure the AMI system. The each developed unit has been networked to structure the AMI system to perform the actual meter reading operation and show the result.

• Journal of Korea Port Economic Association
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• v.35 no.1
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• pp.77-96
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• 2019

Logistics and transportation are increasingly playing a crucial role in international trade relations. Logistics services provide sectoral connections within the local economy. The efficient logistics services facilitate the flow of products; besides ensuring safety and speed of movement, they can reduce the cost of cross-border trade. The Logistics Performance Index (LPI) evaluates the efficiency of customs, quality of transportation service, and infrastructure for overland and maritime transport in each country it covers. The objective of this article is to analyze the impact of the various LPI indicators of Korea's trading partners. The impact of LPI on trade varies according to the income level of the trading partners. The results show that an improvement in any of the components of the LPI can lead to significant growth in a country's trade flow. Exports to Korea will increase as the LPI of the trading partner country is higher. This index has a greater impact on the exports of low-income countries.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.1
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• pp.79-92
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• 2019

In this paper, we propose a method to determine whether to install the accommodation facility of the multi-utility tunnel more effectively in the basic planning phase, and to set up an evaluation system to determine the configuration and kind of accommodation facility. For the configuration of the accommodation facility, 98 alternatives were analyzed for 7 accommodation facility. For the evaluation system of the accommodation facility, index related to feasibility and economic in basic planning phase were selected. The evaluation system classified as spatial, effective, and cost evaluation was presented reflecting the selected index, and AHP analysis was performed for weight setting. The results of this study will be helpful for users including designers to shorten the time and increase the efficiency in the process of determining accommodation facility of the multi-utility tunnel in basic planning phase.