• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.3
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• pp.320-331
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• 2019

In this paper, we propose a method of TMA(Target Motion Analysis) performance improvement using target elevation tracking and fusion in conformal array sonar. One of the most important characteristics of conformal array sonar is to detect a target elevation by a vertical beam. It is possible to get a target range to maximize advantages of the proposed TMA technology using this characteristic. And the proposed techniques include target tracking, target fusion, calculation of target range by multipath as well as TMA. A simulation study demonstrates the outstanding performance of proposed techniques.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.134.5-134
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• 2001

The capability of environment recognition is very important for mobile robot. Especially, a function of target tracking is necessary in monitoring and watching an object using mobile robot. In general, vision sensors such as CCD camera and laser range finder were used for tracking of a moving target. However, they are not only affected by intensity of illumination in environment but also require high performance processors to process large amount of data. Therefore, in this paper, we propose the construction of target tracking system for mobile robot using only ultrasonic sensors to cope with these problems.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.117-117
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• 2018

• Journal of Ocean Engineering and Technology
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• v.19 no.1 s.62
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• pp.64-70
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• 2005

Target Strength(TS) is an important factor for the detection of the target in an active sonar system: thus the numerical model for the prediction of TS is widely being developed. For the frequency range of several kHz, the most important scattering mechanism is known to be specular reflection, which is largely affected by the geometrical shape of the target. In this paper, a numerical algorithm to predict TS is developed based on the Kirchhoff approximation which is computationally efficient. The developed algorithm is applied to the canonical targets of simple shapes, for which the analytical solutions exist. The numerical results show good agreement with the analytical solutions. Also, the algorithm is applied to more complex scatterers, and is compared with the experimental data obtained in the water tank experiment for the purpose of verifying the developed numerical model. Discussions on the effect of spatial sampling and other aspects of numerical m odeling are presented.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.4
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• pp.350-357
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• 2015

Many countries have been developing and operating an underwater surveillance system in order to protect their oceanic environment from infiltrating hostile marine forces which intend to lay mines, conduct reconnaissance and destroy friendly ships anchored at the harbor. One of the most efficient methods to detect unidentified submarine approaching harbor is sensing variation of magnetism of target by magnetic sensors. This measurement system has an advantage of high possibility of detection and low probability of false alarm, compared to acoustic sensors, although it has relatively decreased detection range. The contents of this paper mainly cover the analysis of possible effectiveness of magnetic sensors. First of all, environmental characteristics of surveillance area and magnetic information of simulated targets has been analyzed. Subsequently, a signal processing method of separating target from geomagnetic field and methods of estimating target location has been proposed.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.4
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• pp.521-530
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• 2014

In this paper, the glint effect of maritime target to a radar system was analyzed by simulation and field test with a barge and corner reflectors. From the experiment, we proposed a glint measurement method of a real maritime target and it was indicated that the glint effect between the simulation results and real measurement is similar. Also it was founded that the glint effect is related to the relative amount of RCS(Radar Cross Section) difference among major scattering point and minor scattering points. Finally, the experiment showed the glint effects of the rotating barge with some different combinations of scattering points.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.2
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• pp.133-138
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• 2016

This paper describes the track initiation and target-tracking filter for ship tracking in a marine environment by using Light Detection And Ranging (LiDAR). LiDAR with three-dimensional scanning capability is more useful for target tracking in the short to medium range compared to RADAR. LiDAR has rotating multi-beams that return point clouds reflected from targets. Through preprocessing the cluster of the point cloud, the center point can be obtained from the cloud. Target tracking is carried out by using the center points of targets. The track of the target is initiated by investigating the normalized distance between the center points and connecting the points. The regular track obtained from the track initiation can be maintained by the target-tracking filter, which is commonly used in radar target tracking. The target-tracking filter is constructed to track a maneuvering target in a cluttered environment. The target-tracking algorithm including track initiation is experimentally evaluated in a sea-trial test with several boats.

• Ocean and Polar Research
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• v.42 no.2
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• pp.157-169
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• 2020

This study aimed to analyze the effect of total allowable catches (TACs) on the target species. First to effects analyse of TACs, the 8 TAC target species and 75 non-target species were selected for which catch data were available before and after the introduction of the TACs. The 8 target species were simply compared to catch changes before and after TACs. Through the comparison, it was confirmed how the catches of target fishes have changed after the implementation of the TACs. Secondly, the Difference In Differences(DID) analysis was conducted to confirm the effects of the TACs on the catches of the target fishes using the catch data of 8 TAC target species and 75 non-TAC species. Finally, to overcome the limitations of the DID analysis, the random effects model was estimated to confirm the effects of the TACs on the catch of the TAC target species. Overall, this study confirmed that the TACs affects catches of target species, not only through simple comparisons of catches before and after the introduction of the TACs but also through econometric analysis.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.355-358
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• 2006

An underwater mooing target position tracking system using image tracking system of CPMC is developed to use in a test basin. Generally the performance tests of Autonomous Underwater Vehicles(AUVs) are conducted in the sea. Some efforts to perform the test in a test basin are exist, because the real sea tests need much time and manpower. And also the real sea tests are high cost. There is a restriction to acquire the position of AUVs using sonar sensor system in the test tank, because many sound reflecters are exist in a test basin. In this paper a position tracking system for underwater mooing target developed to break though this restriction. A Tank-test is conducted to examine the performance of the position tracking system.

• Journal of the Society of Naval Architects of Korea
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• v.44 no.6
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• pp.572-578
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• 2007

A Rigid Inflatable Boat (RIB) is now widely used for commercial and military purpose. In this paper, it is supposed that seven-meter-class RIB be used as an unmanned target ship for naval training. In order to develop many tactical maneuvering patterns of a target ship, a simple horizontal maneuvering model of a RIB is needed. Therefore, models of speed and yaw rate are constructed as the first-order differential equations based on Lewandowski#s empirical formula for steady turning circle diameter of a conventional planning hull. Some parameters in the models are determined using the results of sea trial tests. Finally, proposed models are validated through the comparison of the simulation result with the sea trial result for a specific scenario. Even though a simple model does not represent the horizontal motion of a RIB precisely, however, it can be used enough to develop tactical trajectory patterns.