• Journal of Korean Library and Information Science Society
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• v.25
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• pp.83-107
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• 1996

The purpose of this study is to experiment online public access catalog enhancements to improve its subject access capability. Three catalog databases, enhanced with title keywords, controlled vocabulary, and content words with controlled vocabulary respectively, were implemented. 18 searchers performed 2 subject searshes against 3 different catalog databases. And the transaction logs are analyzed. The results of the study can be summarized as follows : Controlled vocabulary catalog database achieved 41.8% recall ratio in average ; the addition of table of contents words to the controlled vocabulary is an effective technique with increasing recall ration upto 55% without decreasing precision ; and the database enhanced with title keywords shows 31.7% recall ratio in average. Of the three kinds of catalog databases, only the catalog with contents words produced 2 unique relevant documents. The results indicate that both user training and system development is required to have better search performance in online public access catalog.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.68-69
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• 2014

In the battery based applications such as electric vehicle and energy storage system, the performance of the system highly depends on the reliability of the battery. However, it is difficult to obtain the accurate information about the state-of-health (SOH) of battery during its operation. In this paper a 3kw battery charger with battery diagnosis function which can estimate the SOH of the battery by using online impedance spectroscopy technique is introduced. For the charger phase shift full bridge converter with synchronous rectification has been adopted to implement the charge and diagnosis functions. The impedance spectroscopy is performed after the charge to obtain the information about the internal impedance of the battery module, hence the SOH can be estimated online by observing the impedance variation of the battery over time. All the design procedure of the proposed charger is detailed and the feasibility of the system is verified by the experimental results.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.4
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• pp.286-295
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• 2007

This paper presents an intelligent PID control for stochastic systems with nonstationary nature. We optimally determine parameters of a PID controller through learning algorithm and propose an online PID control to compensate system errors possibly occurred in realtime implementations. A dynamic Bayesian network (DBN) model for system errors is additionally explored for making decision about whether an online control is carried out or not in practice. We apply our control approach to traffic control of Transmission Control Protocol (TCP) networks and demonstrate its superior performance comparing to a fixed PID from computer simulations.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.2
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• pp.127-133
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• 2002

Most structures are constantly influenced by repeated weathering phenomena and load action during a period of its utilization, and their component materials become superannuated and their design performance becomes slowly lost. Therefore, it is thought that it is necessary to develop the online monitoring system that can make a great contribution to the maintenance management and disaster prevention of the building structure by sensing any slight change of the entire structure regardless of its inside and outside. Especially, this study was intended to explain the entire system of the online structure by interpreting welded built-up H-beams, of structural steel members having many advantages in terms of the qualities of structural materials, through limit state design, and presenting the basic plan to apply it to the structure.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.447-448
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• 2013

This paper investigates a new approach based on the fuzzy-logic controlled methodology that is suitable for analyzing and evaluating large format $LiMn_2O_4$ cell performance via online state-of-health (SOH) estimation for energy storage system (ESS) applications. First of all, the values of the cell resistance R and maximum cell capacity $Q_{max}$ are calculated from three factors such as voltage, current, and time that were measured by discharging/charging sequence. Then, using two values R and $Q_{max}$ previously calculated, present SOH of an arbitrary $LiMn_2O_4$ cell can be estimated using the defined fuzzy-logic inference system. The main advantage of this approach is wide parameters tuning possibility for good correspondence of SOH decay with other accurate estimation method and the possibility to perform suitable online SOH estimation.

• Asia pacific journal of information systems
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• v.17 no.1
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• pp.59-76
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• 2007

Information and Communication Technologies (ICT) changed our everyday business drastically. Business routines have been transformed to online activities. New theories and models were developed for the brand new online environment. For online negotiations, however, the research on new mechanisms is not enough, especially for bilateral distributive negotiations. A reserve price reporting mechanism (RPR) together with its extended version (ERPR) is proposed in this paper. The key improvement of reserve price reporting mechanisms is to let the negotiators report their reserve price to a third-party system before they actually start the negotiation. A prototype of this RPR system is developed and a lab experiment is conducted to test the performance of the two mechanisms compared with traditional direct bargaining (TDB) mechanism. The results of the experiment support that the reserve price report mechanisms proposed are more efficient than the traditional one in several dimensions including social welfare.

• Electronics and Telecommunications Trends
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• v.36 no.2
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• pp.75-82
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• 2021

Online action detection (OAD) in a streaming video is an attractive research area that has aroused interest lately. Although most studies for action understanding have considered action recognition in well-trimmed videos and offline temporal action detection in untrimmed videos, online action detection methods are required to monitor action occurrences in streaming videos. OAD predicts action probabilities for a current frame or frame sequence using a fixed-sized video segment, including past and current frames. In this article, we discuss deep learning-based OAD models. In addition, we investigated OAD evaluation methodologies, including benchmark datasets and performance measures, and compared the performances of the presented OAD models.

• The Journal of Korea Robotics Society
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• v.16 no.4
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• pp.313-318
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• 2021

This paper proposes a new method to generate inverse reachability maps that are more efficient for mobile manipulators than the previous algorithms. The base positioning is important to perform the given tasks. Using the inverse reachability method, we can know where to place the robot's base for given tasks. For example, the robot successfully performed the task with relocation, even when the target is initially in a low manipulability area or outside the workspace. However, there are some inefficiencies in the online process of the classical inverse reachability method. We describe what inefficiencies appear in the online phase and how to change the offline process to make the online efficient. Moreover, we demonstrate that the proposed approach achieves better performance than usual inverse reachability approaches for mobile manipulation. Finally, we discuss the limitations and advantages of the proposed method.

• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.381-382
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• 2020

In the battery energy storage system, battery cells are connected in series to increase the operating voltage. Due to the difference in characteristics, the performance degradation of cells is dissimilar. This paper proposes an online DC internal impedance estimation for battery cells in the series string using a matrix-switched capacitor converter, which is already verified as useful for the series balancing of the cells. The simulation in the hardware in the loop test rig shows good accuracy and the feasibility of the proposed method.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.1014-1023
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• 2013

Rapid developments of Information and Communication Technologies(ICT) have made people learn with online contents allowing learning at onilne universities. The environments of offering educational contents at online universities differ from those at offline-based ones, so that alternative variables need to be considered in order to enhance learning effectiveness in online settings. In this study, the effects of Self-Regulated Learning(SRL) and motivation on learner-instructor interactions and academic performance in an online university were addressed. As a result, SRL and motivation not only directly affected both interactions and achievements, but also indirectly affected achievements via interactions. Also, learner-instructor interactions were directly effective on learning achievements. The implications of the research included comprehensive understandings of the structural relationships of teaching- and learning-related variables on learning. Suggestions were made based on the results.