• The KIPS Transactions:PartC
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• v.17C no.2
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• pp.181-189
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• 2010

HAP(High Altitude Platform) is a stationary aerial platform positioned in the stratosphere between 17Km and 22Km height and it could act as an MBS (Mobile Base Station). HAP based Network has advantages of both satellite system and terrestrial communication system. In this paper we study the deploy of multiple HAP MBS that can provides efficient communication for users. For this study, EM(Expectation Maximization) clustering algorithm is used to cluster terrestrial mobile nodes. The object of this paper is improving EM algorithm into the clustering algorithm for efficiency in variety aspects considering distance between mobile terminal units and speed of mobile terminal units, and estimating performance of HAP MBS deploy technique with use of improved EM algorithm using RWP (Random Waypoint) node mobility.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.8
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• pp.930-935
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• 2019

Our proposed system, MobiAutoBot, is a conceptual model of robotics process automation software at a cognitive automation level that can support mobile devices. MobiAutoBot consists of two parts: MobiAutoBot controller and MobiAutoBot runner. The MobiAutoBot controller directs, monitors, and interacts the Job on the mobile device, and the MobiAutoBot runner installed on the mobile device performs the commanded operation. If we provide automation for mobile devices to small businesses through our proposed MobiAutoBot, we can build low-cost robotic process automation functions that can be linked to existing information systems with mobile devices such as simple smartphones, even without an expensive information-based infrastructure. Our proposal is expected to serve as an opportunity to spread automation of robotics processes even to small and medium-sized companies and individual users who are difficult to equip with all information system infrastructure.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.2
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• pp.182-194
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• 2023

Traffic impact assessment plays a crucial role in resolving traffic issues that may arise during the implementation of urban and transportation projects. However, reported results diverge, presumably because the items reviewed differ. In this study, we analyze traffic improvement measures approved for traffic impact assessment, identify key items, and present items that should be included in assessments. Specifically, TF-IDF and N-gram analysis and text mining were performed with focus on urban development projects approved in Gyeonggi Province. The results obtained show that keywords associated with newly established transportation infrastructure, such as roads and intersections, were essential assessment items, followed by the locations of entrances and exits and pedestrian connectivity. We recommend that considerations of the items presented in this study be incorporated into future traffic impact assessment guidelines and standards to improve the consistency and objectivity of the assessment process.

• Journal of Aerospace System Engineering
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• v.17 no.2
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• pp.26-37
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• 2023

Urban air mobility (UAM) is being developed as part of the next-generation aircraft, which could be a viable solution to entrenched problems of urban traffic congestion and environmental pollution. A new airport platform called vertiport as a space where UAM can take off and land vertically is also being introduced. Noise regulations for UAM will be strict due to its operation in a highly populated urban area. Ground effects caused by vertiport can directly affect aerodynamic forces and noise characteristics of UAM. In this study, ground effects of vertiport on aerodynamic loads, vorticity field, and far-field noise were analyzed using Lattice-Boltzmann Method (LBM) simulation and Ffowcs Williams and Hawkings (FW-H) acoustic analogy with a permeable surface method.

• Journal of Cadastre & Land InformatiX
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• v.52 no.1
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• pp.105-118
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• 2022

The demand for information related to 3D spatial objects model in metaverse, smart cities, digital twins, autonomous vehicles, urban air mobility will be increased. 3D model construction for spatial objects is possible with various equipments such as satellite-, aerial-, ground platforms and technologies such as modeling, artificial intelligence, image matching. However, it is not easy to quickly detect and convert spatial objects that need updating. In this study, based on spatial information (features) and attributes, using matching elements such as address code, number of floors, building name, and area, the converged building DB and the detected building DB are constructed. Both to support above and to verify the suitability of object selection that needs to be updated, one system prototype was developed. When constructing the converged building DB, the convergence of spatial information and attributes was impossible or failed in some buildings, and the matching rate was low at about 80%. It is believed that this is due to omitting of attributes about many building objects, especially in the pilot test area. This system prototype will support the establishment of an efficient drone shooting plan for the rapid update of 3D spatial objects, thereby preventing duplication and unnecessary construction of spatial objects, thereby greatly contributing to object improvement and cost reduction.