• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.4
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• pp.52-61
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• 2007

Temporal and spatial variations of sea water largely affect on the pattern of underwater sound propagation. Acoustic environmental changes and their effects on underwater sound propagation in the northern part of the East Sea, which have been poorly studied mainly due to lack of observations, are investigated by analyzing the hydrographic data acquired since 1993. Severe changes in acoustic environments are associated with various physical processes such as deep convection, thermal fronts, and eddies in the northern part of the East Sea. Spatio-temporal variations of sound speed field and the layer of the maximum sound speed are categorized into six typical cases. Using a sound source of 5 kHz, acoustic transmission losses are calculated range-independently for the six typical cases. Significant differences among the patterns of transmission loss in the six cases suggest that a different tactics are required when we operate in the northern part of the East Sea.

• MALSORI
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• no.67
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• pp.1-16
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• 2008

Stress effects upon Korean vowels were investigated with reference to rhythm. We measured three acoustic correlates (Duration: VOT, Vowel Duration; F0; Intensity) of stress from the seven pairs of stressed vs. unstressed Korean vowels /i, ${\varepsilon}(e)$, a, o, u, i, e/. The results of the experiment revealed that stress gave only inconsistent and weak effects on duration, which supports that Korean is not a stress-timed language as far as strong stress effects on duration are still considered crucial in stress-timing. On the other hand, Korean stressed vowels were most characterized with higher F0 and next with stronger intensity. But speakers generally showed tactics to reversely use F0 and intensity in stressing an utterance rather than proportionately strengthening both of the two acoustic correlates of stress. There was found great inter-speaker variability especially in the variations of duration.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.2
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• pp.140-148
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• 2021

In this paper, we intend to improve the availability by integrating Sonobuoy, the most essential detection system used in anti-submarine operations, with LTE communication of smart devices. Anti-submarine capability to respond to the threat of North Korean submarine forces is becoming increasingly important, and continuous research and development is required. This paper aims to enhance the ability of acoustic tactics by using a military-only LTE communication system installed on a ship, smart devices that can be linked to it, and a multi-static sonobuoy controlled by them. The proposed system can increase the visual effect by not only displaying coordinate values by receiving accurate coordinate information of each sonobuoy to a smart device, but also displaying a marker on a map.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.1
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• pp.5-26
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• 2013

Since the optimized use of sonar systems for target tracking is a practical problem for naval operations, the measure of mission achievability is needed for preparing efficient sonar-maneuver tactic. In order to quantify the mission achievability or Measure Of Effectiveness(MOE) for given sonar-maneuver tactics, we developed and tested a simulation algorithm. The proposed algorithm for tracking is based on Measure Of Performance(MOP) for localization and tracking system of sonar against target. Probability of Detection(PD) using steering beam patterns referenced to the aspect angle of sonar is presented to consider the tracking-performance of sonar. Also, the integrated software package, named as Optimal Acoustic Search Path Planning(OASPP) is used for generating sonar-maneuver patterns and vulnerability analysis for a given scenario. Through simulation of a simple case for which the intuitive solution is known, the proposed algorithm is verified.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.5
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• pp.1253-1258
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• 2013

This Paper deals with detection and defense methods for underwater weapons because there are so many dangers of underwater weapons not only in the war period but also in the peace time. Underwater mines are the representative strategic arms. The sensors and target detection methods, threat elimination method of mines included in this paper. Among the various sensors of mine, we use the magnetometor for target detection method in the simulation and execute the analysis of magnetic field of detected target ships. It will be also provided that effectiveness of target detection, sweeping method of mine, tactics of mine planning and mine sweeping and so on.