• Journal of KIISE
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• v.42 no.2
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• pp.264-271
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• 2015

The general way to use a triangulation method is based on PTMP communication between an object and wireless modules in an environment, which is established by more than three wireless modules, to recognize the location of an object. Thus, this method has a problem that the PTMP-based system can only be applied in an environment where the wireless infra is already established. In order to solve this problem, the PTP communication schemes have been proposed but they are insufficient to generalize because they lack specific verification. In this paper, problems of an existed location estimation algorithm based on PTP communication are analyzed, and we propose a location estimation algorithm of a fixed object that satisfyies the condition of a single receiver being substituted to multiple receivers. A location estimation system we designed and implemented using CSS wireless communication modules to evaluate the proposed algorithm. We verify, by experimental results, that the optimum moving interval for the location estimation is 3m in indoor environment of $10m{\times}16m{\times}1m$.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.3
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• pp.60-66
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• 2012

In this paper, we propose abandoned object detection algorithm. When abandoned object was occluded other object, the existing methods cannot detect abandoned object because those methods are not able to estimate the location of abandoned object. In order to overcome this problem, the proposed algorithm extracts the corners around abandoned object. The detected corners are linked to center of abandoned object called by supporters. We can then estimate the location of abandoned object by using supporters. Therefore, the proposed algorithm can detect and estimate the location of abandoned object, when abandoned object is occluded by other object. For this reason, the proposed algorithm can be applied to intelligent surveillance system to prevent bomb terror, which disguises as luggage or box.

• Spatial Information Research
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• v.20 no.2
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• pp.165-172
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• 2012

The query of the K closest object pairs between two object sets frequently occurs at recently retrieval systems. The circular location property of objects should be considered for efficiently process queries finding such a K nearest object pair. In this paper, we propose the optimal algorithm finding the K object pairs which are closest to each other in a search space with a circular domain and show its performance by experiments. The proposed algorithm optimizes the cost of finding the K nearest object pairs by using the circular search distances which is much applied the circular location property.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.9 no.2
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• pp.48-55
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• 2010

This paper proposes a realtime tracking algorithm of mobile object in indoor or outdoor environment. For this purpose the proposed system selects location data closer to mobile objects in real time using Triangulation method and DCM (Database Correlation Method). Also, this system utilizes the adjusted location data selected by using Kalman filter to improve the location accuracy of transfer object. Be studied in existing the Kalman filter have unstable location data until its settlement because of it extracts current values by using the past the information. However, proposed location tracking system don't apply existent Kalman filter to this system and it permits precisional tracking location by using more effective methods.

• Korean Journal of Cognitive Science
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• v.21 no.4
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• pp.697-723
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• 2010

Recent studies report that in terms of object memory, survival context has mnemonic advantage over other context conditions (e.g., Nairne et al, 2007). The present experiments explored whether this effect can also affect task-irreverent object location memory, and tested whether the context can change gender difference in object location memory. Participants were asked to rate the relevance of pictures presented at random locations (experiment 1) or words (experiment 2) under survival context or moving context. After rating the pictures or words, they answered recall test and location retrieval test. The results revealed higher accuracy in memory for objects encoded under survival context. Moreover, survival processing enhanced location memory, and the survival advantage in location memory emerged among woman.

• Journal of Information Processing Systems
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• v.13 no.5
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• pp.1410-1429
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• 2017

Mobility arises naturally in the Internet of Things networks, since the location of mobile objects, e.g., mobile agents, mobile software, mobile things, or users with wireless hardware, changes as they move. Tracking their current location is essential to mobile computing. To overcome the scalability problem, hierarchical architectures of location databases have been proposed. When location updates and lookups for mobile objects are localized, these architectures become effective. However, the network signaling costs and the execution number of database operations increase particularly when the scale of the architectures and the numbers of databases becomes large to accommodate a great number of objects. This disadvantage can be alleviated by a location caching scheme which exploits the spatial and temporal locality in location lookup. In this paper, we propose a hierarchical location caching scheme, which acclimates the existing location caching scheme to a hierarchical architecture of location databases. The performance analysis indicates that the adjustment of such thresholds has an impact on cost reduction in the proposed scheme.

• Journal of the Korea Society of Computer and Information
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• v.28 no.2
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• pp.63-68
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• 2023

In this paper, we introduce a system that tracks and shares the position of objects based on tags. After receiving the location information of objects through the tag location tracking app, the location of the tag is shared as a group, and the shared users also check the location of objects in real time. Our system offer a differentiated function that allows multiple users to manage and supervise the location of objects, compared to legacy systems. The GPS module and Bluetooth are connected to the Arduino board to obtain the location information of the tag and check it through the Android app. We used Android Studio to create app, and the tag brings up the location of the object. The location of the tag is stored in the phpMyadmin DB and the latitude/longitude is received to the Android app and displayed on the map of the app. The proposed system will be useful for loss prevention and managing public goods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.5
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• pp.1083-1094
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• 2012

Commercialized location estimation System with high accuracy is widely used for various services. However, if the systems aren't completely installed in an indoor, location estimation accuracy tend to be very poor. In this paper, indoor location estimation algorithm to improve the accuracy of object location, by correcting the location information obtained from a system that does not fully install, is proposed. In this paper, UWB-based Ubisense system that provides high position accuracy in an indoor environment was utilized. In conclusion, this paper was able to improve the positioning accuracy, by correcting that information about the location of the measured object in position estimation system.

• The Journal of Information Systems
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• v.19 no.1
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• pp.1-17
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• 2010

This paper proposes an updating policy of indoor moving object databases (IMODB) for location-based services. our method applies the Ka1man filter on the recently collected measured positions to estimate the moving object's position and velocity at the moment of the most recent measurement, and extrapolate the current position with the estimated position and velocity. If the distance between the extrapolated current position and the measured current position is within the threshold, in other words if they are close then we skip updating the IMODB. When the IMODB needs to know the moving object's position at a certain moment T, it applies the Kalman filter on the series of the measurements received before T and extrapolates the position at T with the estimations obtained by the Kalman filter. In order to verify the efficiency of our updating method, we performed the experiments of applying our method on the series of measured positions obtained by applying the fingerprinting indoor positioning method while we are actually walking through the test bed. In the analysis of the test results, we estimated the communication saving rate of our method and the error increment rate caused by the communication saving.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.72-75
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• 2005

Uncertainty of objects in Moving Object Database is a coherent property. It has been discussed in a lot of researches on modelling and query processing. The previous studies assume that uncertain future time is determined through utilizing recent speed and direction of vehicles. This method is simple and useful for estimating the time of the near future location. However, it is not appropriate when we estimate the time of the far future location. Therefore, in this paper, we propose a concept of planned route. It is used to estimate uncertain future time, which has to be located at a given point. If the route of an object is planned beforehand its locations are uncertainly distributed near that route. By a simple projection operation, the probability that a location lies in the planned route is increased. Moreover, we identify the future time of an object based on the speed for passing the route, which is offered via a website.