• Journal of Advanced Navigation Technology
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• v.14 no.2
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• pp.161-169
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• 2010

According to the recent increase in air traffic more efficient air traffic control is required. This paper proposes the algorithm for efficient air traffic flow management. Aeronautical traffic environment is different from the common traffic environment since it needs vertical and horizontal separation deviation. In this paper used vincenty's fomula, we calculated distance of route for produced weight that was applied air traffic volume in distance of route using dijkstra algorithm. Then we let aircraft selects a course that minimize to wasting of fuel and time. As a simulation result, so unlilke simply shortest course calculation of existing course calculation algorithm, we confirmed that proposed algorithm in this paper can do air traffic control more efficiently by selecting optimized route.

• Journal of Advanced Navigation Technology
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• v.21 no.5
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• pp.443-449
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• 2017

Swarm of low-cost UAVs for search mission has benefit in the sense of rapid search compared to use of single high-end UAV. As the number of UAVs forming swarm increases, not only the time for the mission planning increases, but also the system to operate UAVs has excessive burden. This paper addresses a decentralized area search algorithm adequate for multiple UAVs which takes advantages of flexibility, robustness, and simplicity. To down the cost, it is assumed that each UAV has limited ability: close-communication, basic calculation, and limited memory. In close-communication, heath conditions and search information are shared. And collision avoidance and consensus of next search direction are then done. To increase weight on un-searched area and to provide overlapped search, the score function is introduced. Performance and operational characteristics of the proposed search algorithm and mission planning logic are verified via numerical simulations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.8
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• pp.1581-1586
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• 2016

In this paper, we propose a central disaster monitoring system of the forest fire. This system provides the safe-zone and detection to reduce the suppression efforts. In existing system, it has a few providing the predicting of wildfire spread model and speed through topography, weather, fuel factor. This paper focus on the forest fire diffusion model and predictions of the path identified to ensure the safe zone. Also we have considering the forest fire of moving direction and speed for fire suppression and monitering. The proposed algorithm could provide the technique to analyze the attribute information that temperature, wind, smoke measured over time. This proposed central observing monitoring system could provide the moving direction of spred out forecast wildfire. This observing and monitering system analyze and simulation for the moving speed and direction forest fire, it could be able to predict and training the forest fire fighters in a given environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.561-564
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• 2007

In driving a car, u-turn or left turn makes the speed of car decrease considerably or require more waiting time at the cross for the traffic signal to turn green. A more straight path, therefore, is probably faster to arrive at the destination than zig-zaged path with same distance. Previous works related to the path navigation do not consider the straightness of the path. In this paper, we have proposed the path navigation algorithm with turn heuristic for enhancing the straightness of a path. We have implement the proposed algorithm and compared it with a traditional $A^*$ algorithm. The experimental result shows that the degree of the straightness of a path is enhanced by 30% and the navigation distance of a path is deceased by 3.3%.

• Journal of Broadcast Engineering
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• v.18 no.2
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• pp.167-177
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• 2013

In this paper, a motion adaptive deinterlacing algorithm is proposed. It consists of three parts: (1) modified edge-based line average, (2) pixel-based consequent five-field motion detection, and (3) block-based local characteristic for detecting true motion and calculating the motion intensity by using an improved method which is able to detect the inner part of moving objects precisely as well as to reduce the risk of false detection caused by intrinsic noises in the image. Depending on the detected motion activity level, it combines spatial and temporal methods with weighting factor. Simulations conducted on several video sequences indicate that the performance of the proposed method is superior to the conventional methods in terms of both subjective and objective video quality.

• The KIPS Transactions:PartB
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• v.10B no.6
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• pp.665-672
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• 2003

This paper describes a speech synthesis technique by concatenating unit phoneme. At that time, a major problem is that discontinuity is happened from connection part between unit phonemes, especially from connection part between unit phonemes recorded by different persons. To solve the problem, this paper uses clustered diphone, and proposes a spectral smoothing technique, not only using formant trajectory and distribution characteristic of spectrum but also reflecting human's acoustic characteristic. That is, the proposed technique performs unit phoneme clustering using distribution characteristic of spectrum at connection part between unit phonemes and decides a quantity and a scope for the smoothing by considering human's acoustic characteristic at the connection part of unit phonemes, and then performs the spectral smoothing using weights calculated along a time axes at the border of two diphones. The proposed technique removes the discontinuity and minimizes the distortion which can be occurred by spectrum smoothing. For the purpose of the performance evaluation, we test on five hundred diphones which are extracted from twenty sentences recorded by five persons, and show the experimental results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1599-1605
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• 2014

This study aimed to identify the relationship between depression of the elderly and low back pain. Data were obtained from cross-sectional surveys conducted as a part of the Community Health Survey 2008. The final analysis included data from 3,647 of the 3,649 elderly participants (aged over 65 years), as 2 responses were excluded since they were inaccurate. Data were analyzed with SPSS for Windows (ver. 19.0), using a Rao-Scott ${\chi}^2$-test and Logistic regression by applying a proper weighting. The significance threshold was set as p<0.05. Factors related to the depression of the elderly were low back pain, subjective health status, average sleep duration. Further, depression score was 1.38 times higher in elderly adults with low back pain than elderly adults without low back pain. In order to decrease depression of the elderly with low back pain the development of a program to decrease activities of daily living discomfort and management of low back pain will need to be determined. It is considered necessary to conduct further study to follow through the analysis of the various variables by applying them to the elderly with low back pain and depression.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.6
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• pp.231-236
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• 2014

The transit time of contrast agents and the parameters of time-intensity curves in ultrasonography are important factors to diagnose various diseases of a digestive organ. We have implemented an automatic parametric imaging method to overcome the difficulty of the diagnosis by naked eyes. However, the micro-bubble noise and the respiratory motions may degrade the reliability of the parameter images. In this paper, we introduce an optimization technique based on MRF(Markov Random Field) model to enhance the quality of the parameter images, and present an image tracking algorithm to compensate the image distortion by respiratory motions. A method to extract the respiration periods from the ultrasound image sequence has been developed. We have implemented the ROI(Region of Interest) tracking algorithm using the dynamic weights and a momentum factor based on these periods. An energy function is defined for the Gibbs sampler of the image enhancement method. Through the experiments using the data to diagnose liver lesions, we have shown that the proposed method improves the quality of the parametric images.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4A
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• pp.302-308
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• 2009

In this paper, two receive diversity combining techniques are proposed for single-carrier Sequency division multiple access (SC-FDMA)-based cooperative relay systems when DFT spreading sizes for mobile station (MS) and relay station (RS) are different. A simplified-MRC (5-MRC) technique performs diversity combining in the time domain using the estimated channel weight and initial values obtained by SC-FDMA signal detection. An interference rejection-MRC (IR-MRC) technique performs diversity combining in the frequency domain by adjusting DFT spreading size in the receiver. It is shown by computer simulation that the proposed receive diversity combining techniques achieve a significant performance gain over the conventional MRC technique with zero forcing (ZF) detector.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.11
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• pp.1021-1032
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• 2011

This paper presents the results of a parametric study for the design of optimal Earth-Moon transfer trajectory using mixed impulsive and continuous thrust. Various types of the optimal Earth-Moon transfer trajectories were designed by adjusting the relative weight between the impulsive and the continuous thrust, and flight time. Two very different transfer trajectories can be obtained by different combination of design parameters. Furthermore, it was found that all thus designed trajectories permit the ballistic capture by the Moon gravity. Finally, the required thrust profiles are presented and analyzed in detail.