• Spatial Information Research
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• v.21 no.5
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• pp.73-82
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• 2013

In recent years, according to the increase of interests in indoor space, various researches are being carried out for the construction and services of indoor spatial information. BIM data is very useful to build indoor spatial information. Accordingly, many studies for the use of BIM data on GIS part are in progress. In order to take advantage of BIM data on GIS part, the conversion technology for building indoor data and visualization techniques are required. However, most of the previous researches are focused on the conversion technology to construct indoor spatial information by importing BIM data into GIS applications while there is few research on visualization. In this study, an indoor LOD(Level of Detail) model is proposed to apply to on indoor facility management system when indoor data was constructed based on BIM data for the linkage between BIM and GIS.

• Journal of Ubiquitous Convergence Technology
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• v.2 no.2
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• pp.67-77
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• 2008

Representation of various types of information in an interactive virtual reality environment on mobile devices had been an attractive and valuable research in this new era. Our main focus is presenting spatial indoor location sensing information in 3D perception in mind to replace the traditional 2D floor map using handheld PDA. Designation of 3D virtual reality by Virtual Reality Modeling Language (VRML) demonstrates its powerful ability in providing lots of useful positioning information for PDA user in real-time situation. Furthermore, by interpolating portal culling algorithm would reduce the 3D graphics rendering time on low power processing PDA significantly. By fully utilizing the CC2420 chipbased sensor nodes, wireless sensor network was established to locate user position based on Received Signal Strength Indication (RSSI) signals. Implementation of RSSI-based indoor tracking method is low-cost solution. However, due to signal diffraction, shadowing and multipath fading, high accuracy of sensing information is unable to obtain even though with sophisticated indoor estimation methods. Therefore, low complexity and flexible accuracy refinement algorithm was proposed to obtain high precision indoor sensing information. User indoor position is updated synchronously in virtual reality to real physical world. Moreover, assignment of magnetic compass could provide dynamic orientation information of user current viewpoint in real-time.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.25 no.4
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• pp.467-474
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• 2001

The mathematical model of a air-conditioning system is generally very complex and difficult to apply to controller design. In this paper, simple models applicable to the controller design are obtained by modeling the air-conditioning system by single-input single-output between compressor speed and indoor temperature, and by multi-input single-output between compressor speed, indoor fan speed and indoor temperature. Using these empirical models, model predictive control(MPC) technique was implemented for indoor temperature control of the air-conditioning system. It has been shown from various experiments that the indoor temperature control based on the MPC scheme yields reasonably good tracking performance with smooth changes in plant inputs. this multi-input multi-output MPC approach can be extended to multi air- conditioning systems where the conventional PID control scheme is very difficult to apply.

• Korean Journal of Remote Sensing
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• v.31 no.2
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• pp.171-182
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• 2015

We propose a camera system to acquire indoor stereo omni-directional images and its calibration method. These images can be utilized for indoor precise mapping and sophisticated imagebased services. The proposed system is configured with a rotating stereo line camera system, providing stereo omni-directional images appropriate to stable stereoscopy and precise derivation of object point coordinates. Based on the projection model, we derive a mathematical model for the system calibration. After performing the system calibration, we can estimate object points with an accuracy of less than ${\pm}16cm$ in indoor space. The proposed system and calibration method will be applied to indoor precise 3D modeling.

• The Journal of Information Technology
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• v.7 no.3
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• pp.1-10
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• 2004

Considerable efforts has been recently devoted to the determination of accurate channel models for the Power Line environment, both for the indoor and outdoor cases. The common denominator and limitation of the known and previously published models is the particular type of approach followed. In this paper is concerned with a power line channel modeling for the more fast and efficiently power line communication experiment. A capacitor load channel simulator is a essential equipment in the power line modem development for indoor network. We accomplished a channel modelling by the frequency response method about the total 224 capacitor load cases. On the basis of this measurement modeling it is here revealed that the PLC is a more deterministic media that commonly believed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.10B
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• pp.1240-1245
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• 2011

In this paper, channel modeling and analysis of wireless visible light communication(VLC) were studied in indoor circumstance. Photons emitted from LED straightly moved and navigated within indoor, after that a part of photons reached on PD via LOS(Line Of Sight) or NLOS(None Line Of Sight). These received signals had characteristics of delay profile and attenuation, which was multiple-path fading. In this paper, computer simulation of VLC channel was executed under the condition that two LEDs were used for transmitter and three PDs were located at different positions of the 20*8*2.3m sized indoor. BER performance simulation was excuted based on the characteristics of each VLC channel.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.20 no.6
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• pp.409-415
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• 2008

Recently, Indoor air quality (IAQ) is one of the most important problem in our daily life of modern societies. Mechanical ventilation system is being recommended as an effective method to improve IAQ in apartment houses. And then, in Korea, building industry should install ventilation system in apartment house by the building construction code. In this study, to improve IAQ caused by microbial and chemical contaminant such as bacteria and TVOC, three types of mechanical ventilation system of apartment house including HRV were simulated by multizone modeling. Simulation results suggest an appropriate and economical renovation method of apartment house ventilation system for reducing indoor air contamination.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.319-324
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• 2006

The purpose of this study Is to evaluate the efficacy of multizone simulation that enables to grasp of details about microbial contaminant problem in an multistoried apartment. We used actual indoor test data to figure up microbial contaminant level as initial value for the multizone simulation and estimated the various effects of indoor occupant infected with germs and the performance of air sterilization by using multizone simulation in substitute for infeasible experimental approach. The results show that natural ventilation make ourselves generally useful for removing indoor microbial contaminants. The results also show that the performance of air sterilization reach the maximum in the case of using mechanical ventilation and UVGI air sterilizer. The conclusion is that this multizone simulation is useful tool for actual design method for Immune building systems.

• Spatial Information Research
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• v.23 no.4
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• pp.91-101
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• 2015

Due to recent increase of indoor spatial information demands, several international standards have been published for indoor spatial information. OGC has also recently published two standards for indoor space; CityGML and IndoorGM. CityGML aims to provide a standard for 3D city modeling and the level of details (LoD) 4 covers the indoor space. IndoorGML focuses only on indoor space and provides several functions to complement the weakness of CityGML. It is therefore recommended to apply IndoorGML as a combination with CityGML. However since the weakness and strengths between these standards are not yet fully studied and understood, there is no well-defined guideline to apply them in a proper way. It means that we need to carry out a comparative study between them for their proper integration. For this reason, we discuss the pros and cons of these standards from two use-cases. The sites for the use-cases cover Lotte World Mall and Jongno-5 subway station, respectively. We studied these use-cases to compare CityGML and IndoorGML through the data construction of CityGML and IndoorGML for these sites. And based on several application scenarios, we also analyzed the weakness and strengths of each standard from different viewpoints. We expect that these comparative studies will be helpful to make a guideline on the application and integration between CityGML and CityGML.

• Korean Journal of Computational Design and Engineering
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• v.11 no.1
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• pp.11-19
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• 2006

For several years, a research about the simulation for shipyard and shipbuilding has been performed. This research is based on the concept of PLM (Product Lifecycle Management) and DM (Digital Manufacturing). Global leading companies and research center are trying to get a good position of PLM, especially M&S field. Digital shipbuilding is to computerize shipyard facilities and shipbuilding processes, and to simulate expected scenarios of shipbuilding processes using a computer model in order to resolve a potential problem such as a bottleneck processes, and over loaded resources. In this paper, simulation methodology for shipbuilding is described. In addition, a local and global strategy for the use of simulation methodology is suggested. Finally, case studies about an indoor shop and an outdoor shop are described.