• Korean Journal of Materials Research
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• v.31 no.6
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• pp.345-352
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• 2021

In this study, Ni nanoparticle supported by graphene oxide (GO) (Ni-GO) is successfully synthesized through hydrothermal synthesis and calcination, and Cr(VI) is extracted from aqueous solution. The morphology and structure of Ni-GO composites are characterized by scanning electron microscopy (SEM), trans mission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). High-resolution transmission electron microscopy (HRTEM) and XRD confirms the high dispersion of Ni nanoparticle after support by GO. Loading Ni on GO can obviously enhance the stability of Ni-GO composites. It can be calculated from TGA that the mass percentage of Ni is about 60.67 %. The effects of initial pH and reaction time on Cr(VI) removal ability of Ni-GO are investigated. The results indicate that the removal efficiency of Cr(VI) is greater than that of bared GO. Ni-GO shows fast removal capacity for Cr(VI) (<25 min) with high removal efficiency. Dynamic experiments show that the removal process conforms to the quasi-second order model of adsorption, which indicates that the rate control step of the removal process is chemical adsorption. The removal capacity increases with the increase of temperature, indicating that the reaction of Cr(VI) on Ni-GO composites is endothermic and spontaneous. Combined with tests and characterization, the mechanism of Cr(VI) removal by rapidly adsorption on the surface of Ni-GO and reduction by Ni nanoparticle is investigated. The above results show that Ni-GO can be used as a potential remediation agent for Cr(VI)-contaminated groundwater.

• Science of Emotion and Sensibility
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• v.10 no.2
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• pp.155-168
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• 2007

Social and psychological experiences in human-agent interactions are becoming more important than the task-oriented efficiency, as the influence of computer agents increases and human-agent interaction develops similarly with interpersonal interaction. Many previous studies aimed to increase social presence in human-agent interaction, in order to derive users' positive psychological experiences, by applying the factors of interpersonal communication to verbal and non-verbal communication of the agents. This study examined the effects of the exchanges of mutual self-disclosure, one of the most important communication acts in interpersonal communication, between users and interface agents. Users' attachment styles towards the perception of social presence, the evaluations toward the agents, user experiences, and the intentions for future interaction were also studied. The mediating role of social presence in dependent variables was, also, examined in this research. The results showed that exchanging self-disclosures with an agent increased the perceptions of social experience, friendly evaluations toward the agent, positive user experience, and the intentions for future interaction. Participants' attachment styles, also, affected the perceptions of the dependent variables. The effects of the exchanges of self-disclosure and participants' attachment styles were mediated by perceived social presence toward the agent. The findings of this study imply that the social and communicational aspects need to be considered in design of the agents seriously. The results also suggest that there may be differences in the psychological effects of agents on users according to the users' personality.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.4
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• pp.1-10
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• 2010

This present paper's goal is to show a virtual human agent's movement-data loci based on realistically limited perception data is human-like. To determine human-likeness of the movement-data loci, we consider interactions between two parameters: Realistically Limited Perception (RLP) data and Incremental Movement-Path data Generation (IMPG). That is to consider how the former (i.e., RLP), one of the simulated parameters of human thought or its elements dictates the latter (i.e., IMPG), one of the simulated parameters of human movement behavior. Mapping DB is a prerequisite for navigation in an agent system because it functions as an interface between perception and movement behavior. Although Hill et al. studied mapping DB methodology based on RLP, their research dealt only with a rendering camera's view point data. The agent system in this present paper was integrated with the Hill's mapping DB module and then the two parameters' interaction was considered on a military reconnaissance mission with unexpected enemy emergence. Movement loci that were generated by the agent and subjects were compared with each other. The agent system in this present research verifies that it can be a functional test bed for producing human-like movement-data loci although the human-likeness of agent is the result of a pilot test, determined by two parameters (RLP and IMPG) and only 30 subjects.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.3
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• pp.227-232
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• 2013

BCI (Brain Computer Interface) is technology to control external devices by measuring the brain activity, such as electroencephalogram (EEG), so that handicapped people communicate with environment physically using the technology. Among them, EEG is widely used in various fields, especially robot agent control by using several signal response characteristics, such as P300, SSVEP (Steady-State Visually Evoked Potential) and motor imagery. However, in order to control the robot agent without any constraint and precisely, it should take advantage of not only a signal response characteristic, but also combination. In this paper, we try to use the fusion of motor imagery and P300 from EEG for practical use of robot control in BCI environment. The results of experiments are confirmed that the recognition rate decreases compared with the case of using one kind of features, whereas it is able to classify each both characteristics and the practical use technology based on mobile robot and wireless BCI measurement system is implemented.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.645-648
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• 2007

This paper describes database server management system by mobile device. Our system can control database server immediately in any where by mobile device. We have developed the dataset server CE which interface with mobile device, database management system which rons in mobile device and web services which connect the mobile database with desktop database. External mobile device communicate with web service agent via wireless equipment. Our system includes dataset server CE client engine, web service server agent and mobile device management system. Through the test by an application program, we have confirmed that our system operates very well each others.

• Journal of the Korea Society of Computer and Information
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• v.21 no.4
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• pp.31-38
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• 2016

The interface between servers and clients and system management in the cloud computing environment is different from the existing computing environment. The technology for information protection. Management and user authentication has become an important issue. For providing a more convenient service to users, SSO technology is applied to this cloud computing service. In the SSO service environment, system access using a single key facilitates access to several servers at the same time. This SSO authentication service technology is vulnerable to security of several systems, once the key is exposed. In this paper, we propose a technology to solve problems, which might be caused by single key authentication in SSO-based cloud computing access. This is a distributed agent authentication technology using a multiple SSO agent to reinforce user authentication using a single key in the SSO service environment. For user authentication reinforcement, phased access is applied and trackable log information is used when there is a security problem in system to provide a safe cloud computing service.

• Journal of the Korean Ceramic Society
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• v.52 no.1
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• pp.19-22
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• 2015

The joining behavior of YSZ ceramics to the glasses used in the $9Al_2O_3-24ZrO_2-51SiO_2-16R_2O$ and $9Al_2O_3-24ZrO_2-51SiO_2-7La_2O_3-9R_2O$ (wt%) glass systems was investigated. The glass transition and softening temperatures were determined to be $430^{\circ}C$ and $760^{\circ}C$, respectively. The behavior of the contact angle was inversely proportional to an increase in the temperature. The Zr element in YSZ acted as a nucleation agent and contributed to the bonding behavior at the interface.

• Information and Communications Magazine
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• v.34 no.2
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• pp.12-19
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• 2017

The LED technology advancement introduce cuttingedge technology on Internet of Things (IoT) to connect the physical world to the digital realm, using digital smart lighting infrastructure called Internet of light (IoL). This paper proposes an Integrated IoT agent on networked smart LED lighting controller called IoL Filed Gateway using lighting infrastructure in which a lighting system that can connect to a network and can be monitored and controlled from a centralized system or via the cloud. The IoL Field Gateway defines new world of smart connected intelligence, lighting can become an integral and responsive part of everyday human life environments. The proposed connected lighting gateway uses the concept of multi-hop ad hoc network using visible light communication (VLC) with RF wireless technologies and Wired PLC (Power Line Communication). This connectivity and intelligence integrated into LED-based luminaires form the backbone of smart buildings and cities and make the Internet of Things (IoT) vision feasible and enables the lighting administrator can control numerous lightings easily and visitors can get visual information from the lightings with their smart devices. The proposed IoL gateway design is emulated on Arduino based HW platform with VLC, RF, and PLC connectivity and evaluated with four sensor interface.

• Korean Journal of Materials Research
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• v.8 no.12
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• pp.1077-1081
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• 1998

Wood powder as reinforcing fillers and polyethylene as a matrix have been used for wood plastic composites (WPC). In preparing WPC, counting agents (such as MA and MAOMS) were also used in order to improve the bonding force between matrix and fillers. In this study, the effect of wood powder, MA, MAOMS concentration on the mechanical properties and interface phenomena on the composites was evaluated The tensile strength of 3wt% MA-treated composites reached its maximum value of 25.91MPa while 3wt% MAOMS-treated composites attained the maximum value of 22.48MPa. The maximum impact strength of MA and MAMOS-treated composites were 44.38J/m and 36.09J/m, respectively, when 3wt% of coupling agent was introduced.

• Proceedings of the KAIS Fall Conference
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• 2003.11a
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• pp.57-64
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• 2003

Achieving the beneficiary goal of recent discovery in human genome project still needs a way to retrieve and analyze the exponentially expanding bio-related information. Research on bio-related fields naturally applies knowledge discovered to the current problem and make inferences to extract new information where shared concepts and data containing information need to be defined and used in a coherent way. In such a professional domain, while the need to help users reduce their work and to improve search results has been emerged. methods for systematic retrieval and adequate exchange of relevant information are still in their infancy. The design of our system aims at improving the quality of information retrieval in a professional domain by utilizing both corpus-based and concept-based ontology. Meta-rules of helping users to make an adequate query are formed into an ontology in the domain. The integration of those knowledge permits the system to retrieve relevant information in a more semantic and systematic fashion. This work mainly describes the query models with details of GUI and a secondary query generation of the system.