• Journal of Institute of Control, Robotics and Systems
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• v.18 no.4
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• pp.375-383
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• 2012

Together with the GPS-based approach, geolocation through mobile communication networks is a key technology for location-based service. Since the Mobile WiMAX system is considered as a candidate for fourth-generation mobile systems, it is important to investigate its location capability. The geolocation of Mobile WiMAX can be realized when the preamble symbols in the down-link channel are appropriately used for a TDOA (Time-Difference-of-Arrival) approach. However, the cellular structure of Mobile WiMAX inevitably generates co-channel interference, and it is difficult for the mobile terminal to acquire distance measurements from multiple base stations. Therefore, for geolocation via multilateration using the Mobile WiMAX network, it is very important to increase hearability. This paper proposes a geolocation method for Mobile WiMAX which employs interference cancellation and preamble signal overlapping for the enhancement of hearability. A novel interference cancellation strategy for complex-valued Mobile WiMAX signals is presented which has an iterative structure. Simulation results show that the proposed geolocation method provides the user's position with an accuracy of less than 20 m through the Mobile WiMAX cellular network if there is no multi-path or NLOS (None-Line-of-Sight).

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2089-2091
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• 2008

Most of specifications are composed by letters and the contents of specifications are very bulky. There exists correlation between the detailed contents. Therefore, to be achieved suitable quality of electricity function; it requires effectively organized and well expressed structured system. Therefore, it should be considered that assuring user's safety and guarantee capability of electricity installation through development of making such systematic specifications and supply of a technology that heighten consummative technology. Because the scope of electricity construction that requires making specification is very wide, in order to save resources and improve the level of technology, it is required that the standard of technology that is composed in the electricity construction that is from unit of electricity construction to whole electricity construction should be united and controlled nationally.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.361-364
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• 2007

A small sized device with computing, communicating, sensing capability is changing our life. It will be deployed in the world and acquire a lot of data from the world. It is used for various applications such as military surveillance, environmental monitoring, structure health monitoring, building management, asset tracking, etc. In this paper we focus on USN middleware for asset tracking. A mobile asset is moving here and there within a specific area. The USN middleware tracks the mobile assets in real-time by using sensor nodes and notify their current positions to a user. To achieve the goal, the USN middleware provides some features related to the positions of mobile assets.. They are storing location data by using 3D indexing method, retrieving them by using spatio-temporal query, making trace of an asset, and retrieving the history data of an asset. In the paper, we developed USN middleware to adapt the requirements of asset tracking. It can help users increase the efficiency of their business related to mobile assets and make a valuable decision.

• Korean Journal of Construction Engineering and Management
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• v.17 no.3
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• pp.98-107
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• 2016

An information system in a construction project has been typically used for drawing, document management, and administration process. And it has limitations to support real-time communication and collaboration among project stakeholders. The objective of this research is to improve communication, information share, and task management by developing a collaboration platform among project stakeholders supporting various communication methods and contents. The platform developed in this research, named as CCP, aims to support communication and collaboration related activities beyond the scope of legacy systems at construction sites. CCP was validated through pilot test and user survey, and it was found to be very helpful for sharing and distributing information, tracking and recording, and improving a user's work capability.

• Korean Journal of Remote Sensing
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• v.29 no.2
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• pp.253-261
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• 2013

Current surveying and spatial information technology incorporates information and communication technology and is user friendly. However, it is not convenient to use in the field because a connection to a computer, such as a laptop, tablet PC, or desktop PC, is needed to obtain the survey results and the coordinates of the surveyed points. To solve this problem, we developed an app that can display surveyed data on a map and the current survey results through a connection between a total station and smartphone using a Bluetooth wireless communication device. The app allows users to perform field work simultaneously with office work in the field, because it consists of Bluetooth, closed traverse survey, current status survey, and coordinate conversion modules. The proposed app should increase user convenience and the operational capability of the total station in the field.

• Korean Institute of Interior Design Journal
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• v.14 no.5 s.52
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• pp.98-105
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• 2005

Through advanced computer technology, our physical environment became a flexible and liquid space that is a multi-functional space structure, hetero-alliance, formless, interactivity. We attempt to interpretate Deleuze's Other geometry as a space designer. Hence first, the aim of this study is to define the meaning of the Other and Other geometry. Second, to extract keywords out of the Other geometry to analyze the work. Third, to analyze the work using the space formative languages(blob, blurring, distortion, folding, layering, lightness, nesting, repetition, shear, transparency, twisting, unfolding, warping, waving, and weaving). The 13 works were selected which have been issued after year 2000 with the focus on liquid space studies. The methods of this study are literature research and contents analysis. The results of the analysis were as follows. First, the source is the Other who is a hidden potentials in the surrounding environment, and this source has the capability of making it part of reality anytime. Other geometry means it is a theory that is comprised of various lines that with the kind of experiences that one has in life. Second, the key words that were extracted from the theory of Deleuze's Other geometry were of (1)hetero-alliance(reflected in a sculptured shape or a fluid abstract form), (2)dis-form(by speculating the user's movements, and combining space elements with external forces), (3)interactivity (information was exchanged real time between the user and his environment where the space took on a sensory institution). Finally, after studying the works using the space formative languages, we found that blob, warping, waving were used externally, and repetition, warping and waving for mostly used internally.

• Journal of Intelligence and Information Systems
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• v.11 no.3
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• pp.129-139
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• 2005

The rapid growth of IT technologies enables the quality of human's daily life to be improved dramatically, Contrasting to the services in previous computing environment directed by user's request, the services in ubiquitous computing era of new IT technology are provided through recognizing users intention and utilizing context-aware information suited to the user. According to the contextual information, agents need to set a dynamic goal to achieve and work collaboratively with other agents. Agents that take control over their behaviors with capability of communicating with other agents become a thrust in this up-coming computing environment. This work focuses on building ontologies, shared knowledge bases among agents, to improve semantical interoperability among agents. More attention is given to the construction and effective management of ontology repository along with its requirement and organization. Ontology agent suggested takes an initiative role to manage the repository in a distributed manner and to facilitate the use of ontology in a multi-agent environment.

• Nuclear Engineering and Technology
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• v.41 no.6
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• pp.785-796
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• 2009

A KALIMER-600 concept which is a type of sodium-cooled fast reactor, has been developed at KAERI. It uses sodium as a primary coolant and is a pool-type reactor to enhance safety. Also, a supercritical carbon dioxide ($CO_2$) Brayton cycle is considered as an alternative to an energy conversion system to eliminate the sodium water reaction and to improve efficiency. In this study, a simplified model for analyzing the thermodynamic performance of the KALIMER-600 coupled with a supercritical $CO_2$ Brayton cycle was developed. To develop the analysis model, a commercial modular modeling system (MMS) was adopted as a base engine, which was developed by nHance Technology in USA. It has a convenient graphical user interface and many component modules to model the plant. A new user library for thermodynamic properties of sodium and supercritical $CO_2$ was developed and attached to the MMS. In addition, some component modules in the MMS were modified to be appropriate for analysis of the KALIMER-600 coupled with the supercritical $CO_2$ cycle. Then, a simplified performance analysis code was developed by modeling the KALIMER-600 plant with the modified MMS. After evaluating the developed code with each component data and a steady state of the plant, a simple power reduction and recovery event was evaluated. The results showed an achievable capability for a performance analysis code. The developed code will be used to develop the operational strategy and some control logics for the operation of the KALIMER-600 with a supercritical $CO_2$ Brayton cycle after further studies of analyzing various operational events.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.179-193
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• 2022

Amid the explosive growth of various metaverse platforms, there is no unified indicator to measure, analyze, and evaluate based on customer experience. Therefore, the usability evaluation factors in metaverse were identified through a heuristic methodology and literature review, to evaluate the metaverse, a two-to three-dimensional virtual world platform. A measurable system was established by subdividing 20 items in 5 fields, including user control, information structure, design and content, and usage environment, derived through Delphi technique. Based on this, after experiencing the actual contents of major metaverse platforms such as Roblox and Zepeto, usability was evaluated and comparative verification was conducted. As a result, it was estimated that metaverse user experience could be improved as its utility was derived relatively high in terms of user control and content. This study constitutes a theoretical contribution by extending the usability evaluation system, which has been widely used in the field of service design, to the fields of extended reality and mixed reality. At the same time, it has practical key findings of providing basic judgment standards to stakeholders in the metaverse field, as well as policy implications for digital capability enhancement and industry revitalization.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.1
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• pp.17-31
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• 2004

The subway play an important part in serious traffic problems. However, because subway system is a closed environment, many serious air pollution problems occurred in subway stations and injured passenger's health. Therefor, it is a necessary to identify sources and to estimate pollutant sources in order to protect passenger's health and to keep clean subway environment. The purpose of this study was to analyze a air quality in the subway stations and to apply a new receptor methodology for quantitatively estimate of PM10 sources. In this study, the size distributions of particulate matters has been measured by using Aerosizer LD (U.S.A., API, Inc.). It's real time measurement capability of time-of-flight technique offers a significant advantage of user convenience and air pollution management. Also, the mass concentrations of PM 10 has been measured by using mini-vol portable sampler (U.S.A., Airmetrics Co.). The sampling performed in Seoul subway stations during the period of February 2000 and April 2000. The number distribution data used in this study consisted of 26 raw data sets in the Jongno-sam-ga station. Correlation Analysis can be used in subway stations for source separation and identification. Then, number contribution from each source is determined by the particle number balance (PNB). The mass concentration data used in this study consisted of 31 raw data in the 8 different stations. The mass contributions of PM10 sources in the concourse by using PMF/CMB model.