• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.33-34
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• 2007

LBS has many issues of wireless sensor networks and mobile communication parts. Location tracking or location sensing will be the opening of ubiquitous society's a big challenge and the beginning of infinite ubiquitous society's a chance. The purpose of this paper is study of sensing rate per reader antenna's placement and tag location and placement using RFID as location reference point with many advantages for location detection.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.41-42
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• 2006

In this paper, we propose a rapid asynchronous UWB (Ultra Wide Band) position location scheme based on double RTTs (Round-Trip Transmissions). In the proposed scheme, to avoid performance degradation of the position location in harsh multipath channel environments where LoS (Line-of-Sight) components are not always guaranteed, the remaining RTT information is solved from realistic double RTTs. Simulation results in IEEE 802.15.4a UWB channel models reveal that the proposed scheme can achieve closely comparable position location accuracy of the conventional ToA (Time of Arrival) method based on triple RTTs, while reducing the processing delay required for the calculation of the position locations.

• Journal of Advanced Navigation Technology
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• v.12 no.1
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• pp.15-21
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• 2008

In this paper, person monitoring and personal identification information management by using the location positioning device and the location management system based on GPS is analysed and developed. Mobile HTE(Mobile HTE : Mobile Home Terminal Equipment) of the developed system uses the module for transmitting PID(Personal Identification Device) information and the module based on GPS's location information. HTE transmits the received information from Mobile HTE to the Location Management System through the internet system. The Location Management System is developed for person location management and information management.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.1
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• pp.14-23
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• 2015

Although research and technology developments have recently increased to save lighting energy within buildings, such research and technology development are judged to be unsuitable for energy savings since they are limited in the sense that the application of the technology is fragmented. This study proposes a user and location awareness technology applied to dimming lighting control system and verified the effectiveness of energy savings by building a test bed. The results were as follows : 1) This study suggested a user and location awareness technology applied to dimming lighting control system. 2) The system shows 96.6% and 82.8% energy saving rates, respectively, on the basis of one user, compared to an on/off lighting control and the user and location awareness technology applied to on/off lighting control system. 3) The energy consumption of the user and location awareness technology applied to on/off lighting control system and the user and location awareness technology applied to dimming lighting control system increased to 96.6%, 88.3%, and 59.6% and 82.8%, 85.0%, 51.5%, respectively, on the basis of one, two, and three users, compared to the on/off lighting control system. This study confirmed the energy saving performance of the user and location awareness technology applied to the dimming lighting control system through performance evaluation. In this regard, further study needs to be undertaken to evaluate the performance at night time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.1
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• pp.108-118
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• 2009

In this paper we develop an indoor location tracking system and its 3D tracking monitoring viewer, viz., 3D Navigation Viewer (3DNV). We focus on the integration of an indoor location tracking system with the Virtual Reality Modeling Language (VRML), to facilitate a representation of the user's spatial information in virtual indoor environments that is synchronized with the physical location environment. The developed indoor location tracking system employs beacons as active transmitters, and a listener as a passive receiver. The distance information calculated from the difference speeds of RF and Ultrasonic signals is exploited, to determine the user's physical location. This is essential in supporting third parties like doctors and caregivers in identifying the activities and status of a particular individual via 3DNV. 3DNV serves as a unified user interface for an indoor location tracking system, showing the viewpoint and position of the target in virtual indoor environments. It was implemented using VRML, to provide an actual real time visualization of the target's spatial information.

• Journal of Computing Science and Engineering
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• v.2 no.4
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• pp.412-427
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• 2008

We propose ID-exchange protocol for Connectionless Location-Awareness Service (CLAS) to locate mobile nodes in indoor sensor network. When adapting location-awareness service to sensor network, the target system must be designed in accordance with various metrics which reflect the system requirement. We especially consider sustainability of the existing service which has been provided for its original purpose, such as environmental monitoring. The detailed meaning of sustainability here is that, even if location-awareness service is newly added to the existing service, the system must be assured to retain a stable network condition, and to deal with newly caused traffic properly. The CLAS ID-exchange protocol is especially designed for fixture and mobile nodes communication to achieve these properties. The protocol operates on 802.15.4 MAC layer to make mobile node work independently of the procedure to build routing table of fixture node, so a stable routing condition can be achieved even if there are many mobile nodes. Moreover, the dedicated frequency channel is assigned only for this protocol, so that traffic caused by location-awareness service can be distributed to another channel. A real system adapting the protocol was implemented to monitor fire and authorities' positions. We verified the overhead and elapsed time for location-awareness. The result shows the proposed protocol has a high performance in detecting speed, traffic distribution, and stability of overall network.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.63-66
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• 2006

This paper proposes an ultrasonic location system based on the spread spectrum principle. Compared with the existing ultrasonic location systems, the proposed system combines the spread spectrum and amplitude modulation principles. As a result, the proposed ultrasonic location system is advantageous in that it can improve positioning accuracy and detection sensitivity by the spread spectrum principle, it simplifies transmitter and receiver circuits by the amplitude modulation, and it is easy to upgrade its performance by the software functionalities. The advantages and performance of the proposed location system are demonstrated by experiments.

• IEIE Transactions on Smart Processing and Computing
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• v.1 no.2
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• pp.117-124
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• 2012

A client collaboration (CC) system is proposed for a user relay system. The proposed scheme focuses on the management of transmit power and leakage interference. In the proposed CC system, edge users transmit signals to the masters considered as user relays. The masters relay the signals of the edge users to the base station using the resource blocks (RBs) that are assigned to the edge users. The leakage interference and power consumption were analyzed in the CC system. In addition, an optimal master location problem was formulated based on the signal-to-leakage-plus-noise ratio (SLNR). Because the optimal master location problem is quite complex, a sub-optimal master location problem was proposed and a closed-form sub-optimal master location was obtained. The edge users generate smaller leakage interference and power consumption in the proposed CC system compared to the system without the CC. The numerical results showed that the edge users generate smaller leakage interference and power consumption in the proposed CC system compared to the system without the CC, and the average throughput increases.

• Journal of Sensor Science and Technology
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• v.28 no.6
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• pp.395-401
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• 2019

This paper proposes a method for estimating the location of a magnetized tip that is inside a non-transparent space or body by using arrayed giant magnetoresistance (GMR) sensors. In general, an object located in such an opaque space can be detected using X-rays, magnetic fields, ultra-sonic sensors, etc., depending on its characteristics. X-ray is mostly used for medical purposes but frequent exposure to it could cause harm to patients as well as doctors. In this study, how well a GMR sensor is applicable instead of an X-ray is investigated. The sensor's voltage output is experimentally fitted to distance with a relationship of 3rd degree polynomial. To detect a small magnetized tip with 900 Oe inside a human body, a 2×2 arrayed GMR sensor and a location estimation algorithm based on information acquired from four sensors is developed. Evaluation tests show that the suggested method is applicable to limited cases with a distance less than 33-55 mm, and the location of a magnet tip is estimated relatively well with an error less than 1.5 mm.

• The Journal of Sustainable Design and Educational Environment Research
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• v.22 no.4
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• pp.9-17
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• 2023

This study explores school location, school environment, educational conditions, and appropriate scale of schools in the context of Sejong City's development area and identifies effective school establishment plans based on the analysis of the needs of the educational community. The research questions for this study include, first, what is the change trend in the number of students as a result of the opening of schools in the development area of Sejong City to the present, and what differences are there between Sejong and other new cities? Second, what challenges arise in school location due to the occurrence of oversized schools and undergraduate institutions? Third, what challenges arise in school location that would limit the ability to create a safe school environment? Fourth, what aspects need to be improved in school location decisions to promote proper placement? A survey was conducted among parents and faculty members to collect data. The findings revealed that first, when establishing a school, identifying an appropriate location for the school was the top priority of the respondents. The second was the proximity of the school to dense housing, with a parent drop zone next to the school site. Third, to address the issue of lack of playgrounds and special class and care classes, respondents called for various measures such as securing school sites within a certain area. Finally, integrated operation schools and school facilities are required in preparation for decreasing school-age populations due to low birth rates.