• International Journal of Control, Automation, and Systems
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• v.6 no.5
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• pp.731-739
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• 2008

The docking and recharging system for a mobile robot must guarantee the ability to perform its tasks continuously without human intervention. This paper proposes two docking mechanisms with localization error-compensation capability for an auto recharging system. The mechanisms use friction forces or magnetic forces between the docking parts of the robot and those of the docking station. It is a structure to improve the allowance ranges of lateral and directional docking offsets, in which the robot is able to dock into the docking station. In this paper, auto-recharging system and the features of the proposed mechanisms are verified with experimental results using simple homing method.

• Journal of Astronomy and Space Sciences
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• v.37 no.3
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• pp.187-197
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• 2020

In order to avoid the high cost and high risk of demonstration mission of rendezvous-docking technology, missions using nanosatellites have recently been increasing. However, there are few successful mission cases due to many limitations of nanosatellites like small size, power limitation, and limited performances of sensor, thruster, and controller. To improve the probability of rendezvous-docking mission success using nanosatellite, a rendezvous-docking phase analysis tool for nanosatellites is developed. The tool serves to analyze the relative position and attitude control of the chaser satellite at the docking phase. In this tool, the Model Predictive Controller (MPC) is implemented as a controller, and Extended Kalman Filter (EKF) is adopted as a filter for noise filtering. To verify the performance and effectiveness of the developed tool for nanosatellites, simulation study was conducted. Consequently, we confirmed that this tool can be used for the analysis of relative position and attitude control for nanosatellites in the rendezvous-docking phase.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.352-360
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• 2019

This paper proposes a docking assessment algorithm for an autonomous underwater vehicles (AUVs) with sensor uncertainties. The proposed algorithm consists of two assessments, state assessment and probability assessment. The state assessment verifies the reachability by comparing forward distance to the docking station with expected distance to reach same depth as the docking station and necessity for correcting its route by comparing calculated inaccessible areas based on turning radius of the AUV to position of the docking station. When the AUV and the docking station is close enough and the state assessment is satisfied, the probability assessment is conducted by computing success probability of docking based on the direction angle, relative position to the docking station, and sensor uncertainties of the AUV. The final output of the algorithm is decided by comparing the success probability to threshold whether to try docking or to correct its route. To verify the validation of the suggested algorithm, the scenario that the AUV approaches to the docking station is implemented through Matlab simulation.

• Journal of Ocean Engineering and Technology
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• v.36 no.3
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• pp.181-193
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• 2022

This study presents a mission management technique that is a key component of underwater docking system used to expand the operating range of autonomous underwater vehicle (AUV). We analyzed the docking scenario and AUV operating environment, defining the feasible initial area (FIA) level, event level, and global path (GP) command to improve the rate of docking success and AUV safety. Non-holonomic constraints, mounted sensor characteristic, AUV and mission state, and AUV behavior were considered. Using AUV and docking station, we conducted experiments on land and at sea. The first test was conducted on land to prevent loss and damage of the AUV and verify stability and interconnection with other algorithms; it performed well in normal and abnormal situations. Subsequently, we attempted to dock under the sea and verified its performance; it also worked well in a sea environment. In this study, we presented the mission management technique and showed its performance. We demonstrated AUV docking with this algorithm and verified that the rate of docking success was higher compared to those obtained in other studies.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.67-72
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• 2006

Questionnaire survey on performance requirement of ship’s speed such as not only accuracy but also response and robustness were carried out, and the experiments to survey the GPS performances of static and dynamic characteristics were carried out simultaneously. In this paper, the questionnaire survey focusing on docking maneuvering, some analytic results of the survey, the results of GPS performance, and the possibility of adaptation for docking maneuvering on SDME and GPS are discussed. Consequently, from the results of questionnaire survey the performance requirement of ship’s speed in docking/anchoring maneuvering have need under 1cm/sec on the standard deviation, and speed information from GPS was adopted to use maneuvering information in docking/anchoring.

• Bulletin of the Korean Chemical Society
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• v.28 no.2
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• pp.211-219
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• 2007

The subtle but significant differences and thereby the lack of consensus in active site structures among the crystal structures of cyclin-dependent kinase 2 (CDK2) has hampered structure-based drug design. In this study, we devised a simple but effective ‘mutation, pharmacophore-guided docking, followed by mutation' strategy to generate an “average” CDK2 structure, which was used for ligand docking study to successfully reproduce 30 out of 32 X-ray ligand positions within 2.0 A of heavy atom RMSD. This novel docking method was applied for structure-based 3D QSAR with CoMSIA study of a series of structurally related ligands, which showed a good discrimination between CDK2 binders and nonbinders.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.3
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• pp.585-594
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• 2017

Wireless Docking system can provide enhanced convenience to user experience of handheld device such as smart phone by using previously deployed peripheral devises such as monitor and keyboard. In this environment, user can easily use the handheld device with variable peripheral devices at any docking system place. This system would be composed of peripherals except host computing device contrarily to previous desktop and laptop environment. For this system, Wi-Fi Alliance has been developing standard technology based on Wi-Fi Direct(Wi-Fi Peer-to-Peer Technical Specifications v1.2, 2010) technology. However, this system can make a problem which may lead to complex connectivity on handheld device due to non-compatible communication interface. To address given problem, we designed a new method of Bluetooth tunneling technology via previous Wi-Fi Direct communication, and evaluated it with experiment results.

• Journal of Advanced Navigation Technology
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• v.25 no.3
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• pp.177-184
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• 2021

This paper proposes an assessment method using probability-based index for safe and successful underwater docking of autonomous underwater vehicles(AUVs) to the docking stations(DSs). The proposed method assesses the probability of docking according to the degree to which the state of the AUV is consistent with the state criteria for docking. The assessment is performed within a specific area considering the kinematic constraints and docking plans of the AUV. The assessment process is defining probability density function, calculating probabilities for reaching the docking station according to the difference to position and heading criteria, and computing the probability-based index in real-time. We verify the validity of the proposed method through analyzing the data acquired on operation test.

• Journal of Space Technology and Applications
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• v.1 no.1
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• pp.7-22
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• 2021

In this paper, we describe the results of the docking phase test in the ground environment of the rendezvous/docking technology verification satellite under development for the first time in Korea. rendezvous/docking technology is a high-level technology in space technology, which is also very important for accessing and performing tasks on relative objects in space orbit. In this paper, we describe the ground test results that the chaser finally docks the fixed target using an air bearing device. Based on the thrust control algorithm in the docking phase and the relative object recognition and relative distance estimation algorithm using visual-based sensors validated in this paper, we intend to use them for later expansion to rendezvous/docking algorithms in three-dimensional space for testing in space.

• Journal of Ocean Engineering and Technology
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• v.30 no.3
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• pp.177-185
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• 2016

In this study, the model developed by Hong (2012) was modified to describe the consecutive docking/undocking situation and was also applied to investigate the effect on seawater circulation in Busan port by consecutive docking/undocking at the connecting bridge of Busan port. Numerical experiments for various docking/undocking cases were performed by dumping the initial concentration within Busan Port and indicated that the concentration in Busan port becomes steady state without numerical wiggles after sufficient time (at least 20 or 30 days). In addition, it was found that the seawater circulation under ship docking was slightly reduced in comparison with that under ship undocking, and the approach time to the target concentration under all the docking cases increased in comparison with the undocking case.