• KIISE Transactions on Computing Practices
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• v.24 no.1
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• pp.1-9
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• 2018

Low-power long-range networks (LoRa) has a comprehensive coverage of up to 30 km, so that long-range positioning is possible. However, the position error in the current LoRa environment is over 500 m. This makes it difficult to use practical location services in the LoRa environment. In this paper, we propose a method to improve the position accuracy by correcting an inaccurate visual error when sending a signal from a mobile node to a gateway through the reference node of each zone in the LoRa environment. Experiments were carried out using MATLAB, and a radio propagation algorithm, the Hata model, was used to cancel out the stationary noise and to evaluate the environmental noise. Experimental results showed that the error range decreased as the number of reference nodes increased and a mobile node approach the reference node.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.4
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• pp.86-93
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• 2011

The ship movement implies current position, wave, wind, and its other factors. We need to know exactly the location and the shape of the ship and control its motion because of these effects. In order to control the small ship according to the movement of the large ship, the position and shape of the ship should be given first. In this paper we propose the method with which we know the current status of the ship without dynamic equations of the ship. There are several methods to track the system such as optical, radio frequency, radar, camera, and infrared light. We propose the movement of the ship using the GPS absolute axis. But, the genuine error by the GPS itself and the movement of the ship cause the result of the GPS of not being accurate. This paper reduces the error of the location and the shape of the ship and gives the exact values of the ship movements even if the GPS implies some error itself.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.9
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• pp.782-791
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• 2013

This paper proposes the location estimation techniques of distributed targets with the multi-sensor data perceived through IR sensors of the military robots. In order to match up targets with measured azimuths, we apply the maximum likelihood (ML), depth-first, and breadth-first tree search algorithms, in which we use the measured azimuths and the number of pixels on IR screen for pruning branches and selecting candidates. After matching up targets with azimuths, we estimate the coordinate of each target by obtaining the intersection point of the azimuths with the least square error (LSE) algorithm. The experimental results show the probability of missing target, mean of the number of calculating nodes, and mean error of the estimated coordinates of the proposed algorithms.

• Journal of the Society of Disaster Information
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• v.19 no.1
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• pp.10-17
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• 2023

Purpose: In this paper, a distance estimation technique for indoor location estimation using IR-UWB is proposed and researched. We propose an algorithm that can increase the SNR lowered due to clutter or noise in an indoor environment. Method: In order to clutter suppression and detect weak signals, we analyze the existing studies of background remover, correlation, and singular vector decomposition techniques and propose an algorithm. Result: The proposed algorithm, the average error was 0.57m up to 11.5m, and the error were 0.49m from 6m to 11.5m. the average error rate was reduced by about 1m compared to the previous study. Conclusion: It can be used as a technique for detecting weak signals in clutter and noise environments for distance or location estimation, and can also be used as a human life detection technique to reduce damage to people in a disaster situation by using UWB radar which has highly transparent.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.3
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• pp.495-508
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• 2023

This paper proposes a method to find out the type and location information of Pauli X, Y, Z errors generated in quantum channels using only the quantum information processing part of the multiple-rate quantum turbo short-block code without external help from the classical information processing part. In order to obtain the location information of the Pauli X,Y error, n-auxiliary qubits and n-CNOT gates were inserted into the C[n,k,2] QSBC-QURC encoder. As a result, the maximum coding rate is limited to about 1/2 as the trade-off characteristics. The location information of the Pauli Z error for C[n,k,2] QSBC-QURC was obtained through the Clifford-based stabilizer measurement. The proposed method inherits all other characteristics of C[n,k,2] QSBC-QURC except for the coding rate.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.419-422
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• 1995

In this paper, we propose two methods for AE source location on the material with unknown AE wave velocity. By this method, we can apply this method to arbitrary material of which properties are not known exactly. Also, in this paper, the mechanism of error generation in both methods are discussed and performances are compared by using computer simulation and experiments which uses a lead break as the AE source on the aluminum plate.

• Journal of the Korean Data and Information Science Society
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• v.8 no.1
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• pp.59-70
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• 1997

We introduce several estimators of the location and the scale parameters of the two-parameter exponential distribution, and then compare these estimators by the mean square error (MSE). Using the parametric bootstrap estimators and the delete-d jackknife, we obtain the bootstrap and the delete-d jackknife confidence intervals for the location and the scale parameters and compare the bootstrap confidence intervals with the delete-d jackknife confidence intervals by length and coverage probability through Monte Carlo method.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.275-277
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• 2004

when a fault occurs, we need the fault locator to find out the location of the fault quickly. The fault locator can find out the exact location of the fault through the line constants of the catenary system. If the configuration of the catenary system is modified, the line constants is also changed. Therefore, this paper analyzes the error of the operation of the fault locator by the simulation.

• Journal of Korean Society for Quality Management
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• v.19 no.1
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• pp.51-64
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• 1991

This paper deals with a robust subset selection procedure based on Hodges-Lehmann estimators of location parameters. An improved formula for the estimated standard error of Hodges-Lehmann estimators is considered. Also, the degrees of freedom of the studentized Hodges-Lehmann estimators are investigated and it is suggested to use 0.8n instead of n-1. The proposed procedure is compared with the other subset selection procedures and it is shown to have good effciency for heavy-tailed distributions.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.875-877
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• 2003

This paper use fault location algorithm for single-phase-to-ground faults on the teed circuit of a parallel transmission line that use only local end voltage and current information. When Newton-Raphson iteration method is used, the Initial value may cause error or cause not suitable result. Suggested new calculation model uses NVP methodology, which is one of the fault tolerance technology to solve this problem. EMTP simulation result has shown effectiveness of the algorithm under various conditions.