• The Journal of the Korea Contents Association
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• v.7 no.4
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• pp.206-212
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• 2007

To evaluate the HU value of the IV catheter fragment of CT on the accuracy and size in the peripheral vein. Pilot study of profile and table functions on PC by software was calculated of HU value of IV catheter fragment. This study demonstrates the utility of volume rendering technique to localize a small, subtle IV catheter, which can easily be reformatted of MDCT reformations. IV catheter fragment optimal image described as threshold range. Volume rendering of HU using a MDCT is an excellent method for evaluation the IV catheter fragment in three dimension.

• The Journal of the Korea Contents Association
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• v.5 no.5
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• pp.305-305
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• 2005

In modern society, diseases are variously found. Also, disease can be fatal once starting attack or one misses the proper medical examination time. According to the development of society, our liver settled on exhausted status which causes high disease development ratio because of excess business, smoking and drinking. Especially liver related disease cannot be recovered, therefore it depends on internal organ transplant surgery. In this paper, calculate volume from rendered liver shape using 3-dimensional image processing method and we develop an image processing method for the image acquired by MDCT, that can simulate incision line decision according to blood vessel segmentation that can be used on liver transplant operation. Simulation results which adopt automatic liver segment abstraction algorithm show that it can help surgical operation.

• The Journal of the Korea Contents Association
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• v.9 no.3
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• pp.225-231
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• 2009

The purpose of the current study was to compare radiation dose of 64MDCT performed with automatic exposure control (AEC) with manual selection fixed tube current. We evaluated the CT scans of phantom of the chest and abdomen using the fixed tube current and AEC technique. Objective image noise shown as the standard deviation of CT value in Hounsfield units was measured on the obtained images. Compared with fixed tube current, AEC resulted in reduction of the chest and abdomen in the CTDIvol (35.2%, 5.9%) and DLP (49.3%, 3.2%). Compared with manually selected fixed tube current, AEC resulted in reduced radiation dose at MDCT study of chest and abdomen.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.538-541
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• 1999

MPEG-2 AAC(Advanced Audio Coding) is the most advanced coding scheme available for high quality audio coding. This MPEG-2 AAC audio Standard allows for ITU-R ‘indistinguishable’ quality according to at data rates of 320 kb/s for five full-bandwidth channel audio signals. The compression ratio is around a factor of 1.4 better compared to MPEG Layer 3, you get the same quality at 70% of the bitrate. This paper suggest optimization method for MDCT/IMDCT (Modified Discrete Cosine Transform/Inverse Modified Discrete Cosine Transform) in Encoder and Decoder for AAC.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.329-332
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• 1999

Currently, the most important technology is compression methods in the multimedia society. In audio compression, the method using human auditory nervous property is used. This method using psychoacoustical model is applied to perceptual audio coding, because human's audibility is limited. MPEG-II AAC(Advanced Audio Coding) is the most advanced coding scheme that is of benefit to high quality audio coding. The compression ratio is 1.4 times compared with MPEG-I layer-III. In this paper, the vector processor for MDCT/IMDCT(Modified Discrete Cosine Transform /Inverse Modified Discrete Cosine Transform) of MPEG-II AAC is designed.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.05b
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• pp.69-73
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• 2003

음향압축에 있어서 인간의 청각신경의 특성을 이용하는 방식이 사용되고 있다. 이러한 방법은 심리음향모델(psychoacustical model)에서 도입되었다. 음향압축에서는 이러한 심리음향모델을 사용하여 인간이 지각할 수 없는 한도 내에서 부호화하지 않는 지각음향부호화(perceptual audio coding)사용한다. 지각음향부호화는 분석필터와 합성필터로 각각 부호화 복호화하는데 이것은 필터뱅크(filter bank)로 구현된 서브밴드코더(subband coder) 이다. 본 논문에서는 분석필터와 합성필터에 사용되는 MDCT(Modified Discrete Cosine Transform)와 IMDCT(Inverse Modified Discrete Cosine Transform)를 FPGA에 구현하였다.

• The Journal of the Acoustical Society of Korea
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• v.25 no.2E
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• pp.74-78
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• 2006

This paper proposes an effective method for classifying emotions of the music from its acoustical signals. Two feature sets, timbre and tempo, are directly extracted from the modified discrete cosine transform coefficients (MDCT), which are the output of partial MP3 (MPEG 1 Layer 3) decoder. Our tempo feature extraction method is based on the long-term modulation spectrum analysis. In order to effectively combine these two feature sets with different time resolution in an integrated system, a classifier with two layers based on AdaBoost algorithm is used. In the first layer the MDCT-driven timbre features are employed. By adding the MDCT-driven tempo feature in the second layer, the classification precision is improved dramatically.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.708-711
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• 1999

MDCT( Modified Discrete Cosine Transform ) is one of the most compute-intensive operations in the MPEG audio coding standard. In this paper a fast algorithm to perform MDCT operation is presented. The algorithm presented in the MPEG audio coding standard requires (N/2) $\times$ N multiplications and (N/2) $\times$ (N-1) additions to generate the result, but the algorithm presented in this paper requires (N/2) $\times$ (N/2) multiplications and (N/2) $\times$ (N/2) additions to perform the same task. In this algorithm N should be multiple of 4. The algorithm was implemented using ARM processor and the processing time comparison between the original algorithm and the fast algorithm is presented.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.802-804
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• 2005

제안된 연구에서는 기존의 일반 CT(Computerized tomography) 영상이 아닌 MDCT(Multi Detector CT) 영상을 이용하여 장기 추출에 관한 연구를 진행하였다. 조영제를 이용한 복부 MDCT 영상으로부터 모폴로지(morphology) 기법을 통해 간에 근접한 노이즈를 제거하고, 기존의 Otsu threshold를 개선하여 간의 명암값 분포를 구분할 수 있는 임계치를 구하였다. 찾아진 임계치를 이용하여 영상을 이진화하고, 최종적으로 위치정보를 이용하여 간에 해당하는 부분들을 추출하였다. 이러한 방식은 명암값과 위치정보를 이용하여 간을 추출한 후 다시 노이즈 문제를 해결하는 기존의 알고리즘과 비교했을 때, 처리 방식이 단순해지고 속도가 향상되었다. 추출된 간은 간 이식술이나 절제술에 필요한 간 내부의 혈관 인식과 간의 부분체적 계산 연구에 중요한 정보로 사용될 수 있을 것이다.

• Journal of The Korean Radiological Technologist Association
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• v.29 no.1
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• pp.180-181
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• 2003