• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.6
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• pp.768-775
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• 2009

In this paper, the sound source localization system in real time which uses the time delay of arrival signal is proposed. This system uses minimum microphones and surveillance camera for estimation of the sound source localization and sound direction. To apply this system to the military field, four models(model1~model4) are derived. Model 1 can be used to evaluate the sound source localization at the long distance. Model2 and model3 can be applied to estimate the sound direction. Model4 is useful for the special purpose and potable device. It is possible for this system to be used for the military guard and surveillance. As a result of experiments, It is shown that this system can estimate the sound source localization and the sound direction using minimum microphones.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.290-293
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• 2009

In this paper, we propose a method to estimate pointing region in real-world from images of cameras. In general, arm-pointing gesture encodes a direction which extends from user's fingertip to target point. In the proposed work, we assume that the pointing ray can be approximated to a straight line which passes through user's face and fingertip. Therefore, the proposed method extracts two end points for the estimation of pointing direction; one from the user's face and another from the user's fingertip region. Then, the pointing direction and its target region are estimated based on the 2D-3D projective mapping between camera images and real-world scene. In order to demonstrate an application of the proposed method, we constructed an ICGS (interactive cinema guiding system) which employs two CCD cameras and a monitor. The accuracy and robustness of the proposed method are also verified on the experimental results of several real video sequences.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.8
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• pp.615-618
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• 2016

This paper proposes a method to estimate vertical interaction force to the end of the surgical instrument by measuring reaction force at the part supporting the trocar. Relation between the force to the trocar and the interaction force is derived using the beam theory. The vertical interaction force is modeled as a function of the reaction force to the trocar and the distance between the drape plate and the trocar. Experimental results show that error is induced by the asymmetric shape of the trocar tip because contact position between the instrument and the trocar tip is changed depending on the direction of the interaction force. The theoretical relation, therefore, is compensated and reduced. Average $L_2$ relative error of the estimated force in the x-direction and the y-direction is 5.81 % and 5.99 %, respectively.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.999-1002
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• 2002

In this paper, we proposes an adaptive method for reducing the computational overhead of fine-to-coarse MRME at the finest resolution level by considering for the spatial and spectral characteristics between wavelet decomposition levels simultaneously. As we know, there is high correlation between the adjacent blocks and it can give the very important clue to estimate motion at finest level. So, in this paper, using the initial motion vector and the adjacent motion vector in the coarsest level, we determine the optimal direction that will be minimized the estimation error in the finest level. In that direction, we define the potential searching region within the full searching region that is caused to increase much computational overhead in the FtC method. Last, in that region, we process the efficient 2-step motion estimation. and estimate the motion vector at finest resolution level. And then, this determined motion vector is scaled to coarser resolutions. As simulation result, this method is similar to computational complexity of the CtF MRME method and very significantly reduces that of the FtC MRME method. In addition, they provide higher quality than CtF MRME, both visually and quantitatively

• Journal of Advanced Navigation Technology
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• v.16 no.2
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• pp.204-210
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• 2012

In this paper, we study the method of estimating direction of departure(DOD) and direction of arrival(DOA) using estimation of signal parameters via rotational invariant techniques (ESPRIT) in uniform linear array MIMO radar system. While it is possible to improve the resolution by increasing the numbers of physical antennas and snapshots after matched filtering, such methods generally give rise to increase in complexity. In this paper, we propose to improve the resolution by optimally allocating the number of transmit and receive antennas. In particular, we show that the performance is optimized when the number of the receive antennas is approximately twice that of transmit antennas.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.7A
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• pp.766-774
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• 2004

The future mobile communication system can support not only voice but also multimedia applications such as data, image and video. It requires greater resources than the voice-oriented mobile system. Efficient resource reservation and hand-over schemes are necessary to maintain the same QoS of transmitted multimedia traffic because the QoS may be defected by some delay and information loss during hand-over. This paper proposes a resource reservation scheme to accommodate multimedia traffics in mobile multimedia networks. In our scheme the position of mobile is estimated in two steps, that is, sector estimation and zone estimation. With this position information, the moving direction is determined. According to simulation results, our scheme provides a better performance than conventional methods.

• Journal of Korean Society for Quality Management
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• v.51 no.3
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• pp.461-479
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• 2023

Purpose: It emphasizes the importance of cost analysis for weapons systems that require enormous develop- ment costs, analyzes the problems of cost analysis steps from a practical point of view, and presents the direction of business development in terms of cost analysis reliability, timeliness, and efficiency. Methods: It analyzes the R&D cost of Micro satellites with a complex cost structure and large scale according to engineering estimation procedures, derives major analysis step-by-step problems, and presents business development directions. Results: Problems with standards and assumptions, data collection, cost division structure, and cost estimation methods were derived through the micro satellite cost analysis process, and business development directions such as expanding common standards, standardizing basic data, standardizing cost division structures and cost items, and data asset were presented. Conclusion: In order to develop work in terms of cost analysis reliability, timeliness, and efficiency, it is important to prepare and standardize standards and rules for detailed tasks at each analysis stage, and through this, it is expected that high utilization value and systematic cost data will be assetized in the future.

• Journal of electromagnetic engineering and science
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• v.7 no.4
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• pp.161-168
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• 2007

A fast correlative vector direction finding(CVDF) system using active dipole antenna array for mobile direction finding(DF) applications is presented. To develop the CVDF system, the main elements such as active dipole antenna, multi-channel direction finder, and search receiver are designed and analyzed. The active antenna is designed as composite structure to improve the filed strength sensitivity over the wide frequency range, and the multi-channel direction finder and search receiver are designed using DDS-based PLL with settling time of below 35 us to achieve short signal processing time. This system provides the capabilities of the high DF sensitivity over the wide frequency range and allows for high probability of intercept and accurate angle of arrival(AOA) estimation for agile signals. The design and performance analysis according to the external noise and modulation schemes of the CVDF system with five-element circular array are presented in detail.

• Journal of the Society of Disaster Information
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• v.13 no.1
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• pp.51-58
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• 2017

This paper proposes a direction estimation scheme with directional speaker and smart device for evacuation guidance. When there is worst disaster environment filled with smoke and noisy sound, evacuee can not get any information about evacuation routes. The proposed scheme can be used for detecting evacuation routes with audible and inaudible signal from directional speaker. At this point, evacuee can get evacuee guidance by using smartphone application that the proposed scheme is applied. The performance of the proposed scheme is evaluated by experiment with three different types of smart devices in large indoor environment. The purpose of experiment is to detect the direction of transmitted signal from directional speaker. Therefore, The experiment is conducted by analyzing the strength of transmitted signal by distance. The experimental results show that even if the smart device is located up to 20m away from the speaker, it is possible to detect the sending direction of the signal. We confirmed the possibility of the proposed technology in 8kHz and 20kHz signal detection by smart device.

• The Transactions of the Korea Information Processing Society
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• v.7 no.2S
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• pp.638-648
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• 2000

This paper introduces a new technique for block is matching motion estimation. Since the temporal correlation of the image sequence, the motion vector of a block is highly related to the motion vector of the same coordinate block in the previous image frame. If we can obtain useful and enough information from the motion vector of the same coordinate block of the previous frame, the total number of search points used to find the motion vector of the current block may be reduced significantly. Using that idea, an efficient predicted direction search algorithm (PDSA) for block matching algorithm is proposed. Based on the direction of the blocks of the two successive previous frames, if the direction of the to successive blocks is same, the first search point of the proposed PDSA is moved two pixels to the direction of the block. The searching process after moving the first search point is processed according to the fixed search patterns. Otherwise, full search is performed with search area $\pm$2. Simulation results show that PSNR values are improved up to the 3.4dB as depend on the image sequences and improved about 1.5dB on an average. Search times are reduced about 20% than the other fast search algorithms. Simulation results also show that the performance of the PDSA scheme gives better subjective picture quality than the other fast search algorithms and is closer to that of the FS(Full Search) algorithm.