• Journal of the Institute of Convergence Signal Processing
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• 제14권2호
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• pp.95-98
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• 2013

The LMS(Least Mean Square) algorithm, one of the most famous, is generally used because of tenacity and high mating spots and simplicity of realization, But it has trade-off between nonuniform collection and EMSE(Excess mean square error). To overcome this weakness, a variable step size is used widely, but it needs a lot of calculation loads. In this paper, we suggest changed algorithm in case of environment changes of cars and reduce amount of calculation as it uses original signal and noise signal of IGC(Instantaneous Gain Control) algorithm. In this paper, logarithmic function is removed because of real-time processing IGC. The performance of proposed algorithm is tested to adaptive noise canceller in automobile.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제33권4호
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• pp.348-355
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• 2000

This paper described the relationship between the behavior of the Israeli carp, Cyprinus carpio and the environmental noise level due to the dynamite explosion work. The experiment was conducted in the cage ($L10{\times}W4{\times}D4 m$) of aquaculture located at Chungjoo Lake, Chechon, in 1997. The fish trajectory was obtained by the telemetry system in which a pulsed ultrasonic pinger ($50 kHz, {\phi}16{\times}L70 mm$) attached to the fish was tracked three dimensionally, and the underwater noise levels were measured. The results of the study were as follows: 1. The underwater noise levels in the normal blasting measured at a distance of 400 m from the source of noise increased by $40 dB (re 1 {\mu}Pa)$ compared to the levels before explosion. The dominant frequency and the increased power spectrum level of the underwater noise by the explosion work were $75 to 100 Hz and 22.9 to 35.3 dB$, respectively. 2. The underwater noise levels in the test blasting measured at a distance of 350 m from the source of noise increased by average $49.5 dB (re 1 {\mu}Pa)$compared to the levels before explosion. 3. The swimming area of the fish was reduced with the time after explosion, and after more than one hour the fish represented the similar swimming area and behavior to the status of right before explosion. 4, The swimming depth layer of the fish was most of the case at the sea surface less than 1,0 m except during explosion or right after of it. But the fish swam downward when an external stimulus like the explosion noise was given to the fish. 5. The average swimming speeds of the fish before, during and after the works were about 1.2 times, 1.9 times and 1.0 times of the body length, respectively, and the speed of the fish with explosion was faster 1.6 times than the speed without of that. Consequently, the explosion noise levels measured by this study were sufficiently high to affect the fish, and the heavy shock by the explosion works could produce a considerable unfavorable effects to the fish.

• The Journal of the Acoustical Society of Korea
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• 제19권8호
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• pp.78-83
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• 2000

Passive sonar system is designed to classify the underwater targets by analyzing and comparing the various acoustic characteristics such as signal strength, bandwidth, number of tonals and relationship of tonals from the extracted tonals and frequency lines. First of all the precise detection and extraction of signal frequency lines is of particular importance for enhancing the reliability of target classification. But, the narrowband frequency lines which are the line formed in spectrogram by a tonal of constant frequency in each frame can be detected weakly or discontinuously because of the variation of signal strength and transmission loss in the sea. Also, it is very difficult to detect and extract precisely the signal frequency lines by the complexity of impulsive ambient noise and signal components. In this paper, the automatic detection and extraction method that can detect and extract the signal components of frequency tines precisely are proposed. The proposed method can be applied under the bad conditions with weak signal strength and high ambient noise. It is confirmed by the simulation using real underwater target data.

• The Journal of Korean Institute of Communications and Information Sciences
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• 제19권11호
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• pp.2094-2105
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• 1994

This paper contains a Hough transform based projection method derived from Radon transform for tracking dim unresolved(sub-pixel) moving targets that move along straight line parths across a time sequential image data. In contrast to several recently presented Hough transform methods using a compressed image referred to as the track map our proposed technique utilizing a set of projections taken along arbitrary orientations effectively increases the changes of target detection, and creates a robust track estimation environment by incorporating all the available knowledge obtained from the projections. Moreover, in order to quantitatively assess the estimation capability of the projection-based Hough transform algorithm, the analytical bounds on the Hough space parameter errors introduced by image space noise contamination are derived. The simulation yielded promising results of estimating the track parameters even under low signal to noise rations when our technique was tested against the time sequential sets of real infrared image data referred to as the HiCamps.

• Journal of the Institute of Electronics and Information Engineers
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• 제51권9호
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• pp.238-247
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• 2014

The milking robot system is very important to detect correctly the teats position in the moving condition of cow. Also, the robot manipulator must control tracking the teat cup to the detected teat position. The presented milking robot is designed using the one point laser sensor for teat position detection. The teats of cow are detected by the laser scanning unit and the manipulator has the function of 3 axes moving control unit. The presented teat detection method and the electrical driving manipulator have the advantages of a simple, low cost and very quiet. The designed manipulator is realized by the totally electrical motor and servo poison control algorithm with velocity PID compensation. The presented robot is realized using the teat detection unit, 4 teat cups, 3 axes robot arm, 6 servo motors and automatic milking control line. The designed robot is experimented in the cow farm and is satisfied with the designed performance specification for milking robot manipulator.

• The Journal of the Acoustical Society of Korea
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• 제43권3호
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• pp.351-360
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• 2024

With the increasing use of drone technology, the Unmanned Aerial Vehicle (UAV) is now being utilized in various fields. However, this increased use of drones has resulted in various issues. Due to its small size, the drone is difficult to detect with radar or optical equipment, so acoustical tracking methods have been recently applied. In this paper, a method of localization of multiple drones using the acoustic characteristics of the quadcopter drone is suggested. Because the acoustic characteristics induced by each rotor are differentiated depending on the type of drone and its movement state, the sound source of the drone can be reconstructed by spatially clustering the results of the estimated positions of the blade passing frequency and its harmonic sound source. The reconstructed sound sources are utilized to finally determine the location of multiple-drone sound sources by applying the source localization algorithm. An experiment is conducted to analyze the acoustic characteristics of the test quadcopter drones, and the simulations for three different types of drones are conducted to localize the multiple drones based on the measured acoustic signals. The test result shows that the location of multiple drones can be estimated by utilizing the acoustic characteristics of the drone. Also, one can see that the clarity of the separated drone sound source and the source localization algorithm affect the accuracy of the localization for multiple-drone sound sources.