• The KIPS Transactions:PartC
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• v.9C no.4
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• pp.459-466
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• 2002

This paper proposes a robust speaker identification algorithm based on the wavelet filter banks and multiple decision-making scheme. Since the proposed speaker identification algorithm has a structure performing the identification algorithm independently for each subband, the noise effect of an subband can be localized. Through this process, we can obtain more robust results for the environmental noises which generally have band limited frequency. In the experiments, the proposed method showed more 15∼60% improvement than the vector quantization method for the various noisy environments.

• Applied Chemistry for Engineering
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• v.1 no.2
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• pp.124-132
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• 1990

In order to improve the mechanical properties and fracture toughness of HPT 1071/DDS system, poly(aryl etherimide) (PEI) was incorporated in the resin system. In HPT 1071/DDS system, mechanical properties of cured epoxy resins were not strongly dependent on the concentration of DDS curing agent strongly. In the case of HPT 1071/DDS/PEI system, the fracture toughness and flexural properties of epoxy resins increased with increasing the concentration of PEI. SEM micrographs of cured epoxy resin indicated that the phase separation occured at the low concentration of PEI in this system. In addition, investigation of the relationship between mechanical properties and the morphology of modified epoxy resin was undertaken in HPT 1071/DDS/PEI system.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.8 no.1
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• pp.53-56
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• 1994

PID controller is being used in many servo control systems. However, when a control system has disturbance or time variable characteristic, it is very difficult to guarantee the robustness of the system. In the way of solving this problem, in this paper, a control method using the PID controller with Fuzzy Logic Regulator is presented. Fuzzy Logic Regulator is designed by error and error change, the kth sampling control input is decided by the addition of the kth sampling defuzzification value and the (k-l)th sampling defuzzification value. Control input is transmitted to input. The robust control function of Fuzzy Logic Regulator is demonstrated by the computer simulation.

• The Journal of the Acoustical Society of Korea
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• v.39 no.1
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• pp.8-15
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• 2020

In this paper, we propose a frame synchronization algorithm for robust to the combined effects of large Doppler fluctuations and extended, time-varying multipath in the underwater acoustic communication. From the algorithm, we can recover a high timing error which is occurred from an acoustic propagation delay and uncertainty of oscillator between transmitter and receiver. In order to verify the performance of the synchronization algorithm, the lake trial results are used. The lake experiments are performed in a Gyeongcheonho located in Mungyeong-si, Gyeongsangbuk-do. We can see that the start position of frame is adjusted after the frame synchronization while the receiver moving.

• Journal of Digital Convergence
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• v.11 no.6
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• pp.169-174
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• 2013

Speech recognition, the problem of performance degradation is the difference between the model training and recognition environments. Silence features normalized using the method as a way to reduce the inconsistency of such an environment. Silence features normalized way of existing in the low signal-to-noise ratio. Increase the energy level of the silence interval for voice and non-voice classification accuracy due to the falling. There is a problem in the recognition performance is degraded. This paper proposed a robust speech detection method in noisy environments using a silence feature normalization and voice energy maximize. In the high signal-to-noise ratio for the proposed method was used to maximize the characteristics receive less characterized the effects of noise by the voice energy. Cepstral feature distribution of voice / non-voice characteristics in the low signal-to-noise ratio and improves the recognition performance. Result of the recognition experiment, recognition performance improved compared to the conventional method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.8C
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• pp.810-823
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• 2005

The transmission of duplicate packets provides a great loss-resilience without undue time-delay in the video transmission over packet loss networks. But this method generally deteriorates the problem of traffic congestion because of the increased bit-rate required for duplicate transmission. In this paper, we propose an efficient packetization and duplicate transmission of video packets. The proposed method transmits only the video signal with high priority for each video macroblock that is quite small in volume but very important for the reconstruction of the video. The proposed method significantly reduces the required bit-rate for duplicate transmission. An efficient packetization method is also proposed to reduce additional packet overhead which is required for transmitting the duplicate data. The duplicated high priority data of the Previous video slice is transmitted as a Piggyback to the data Packet of the current video slice. It is shown by simulations that the proposed method remarkably improves the packet loss-resilience for video transmission only with small increase of redundant duplicated data for each slice.

• Journal of Environmental Impact Assessment
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• v.6 no.2
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• pp.189-196
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• 1997

• Proceedings of the Korea Multimedia Society Conference
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• 2002.11b
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• pp.242-245
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• 2002

최근 인터넷의 보편화로 인한 디지털 컨텐츠의 폭발적 요구 증가로 디지털 저작권 보호를 위한 여러 기술들이 연구되고 있다. 디지털 워터마킹은 디지털 컨텐츠의 저작자의 정보를 삽입하여 저작권을 보호하는 기술이다. 본 논문에서는 DCT 영역에서 대역확산을 이용하여 이미지 압축에 강인하고, 비 가시성이 뛰어난 워터마킹 기술을 제안한다.

• 대한생식의학회:학술대회논문집
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• 2004.11a
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• pp.99.1-99.1
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• 2004

• 대한생식의학회:학술대회논문집
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• 2004.11a
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• pp.100-100
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• 2004