• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1155-1163
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• 2010

An algorithm of the conventional wavelet shift keying is carried out that the scaling function and wavelet are encoded to 1(mark) and 0(space) for the input binary data, respectively. Two bit modulation technique which uses four carrier frequencies is existed. Four carrier frequencies are defined as scaling function, inversed scaling function, wavelet, and inversed wavelet, which are encoded to 10, 11, 00 and 01, respectively. In this paper, we defined 4-ary SWSK (4-ary scaling wavelet shift keying) which is two bit modulation, and it is derived to the probability of bit error and symbol error of the defined system from QPSK. In order to analyze to the performance of 4-ary SWSK, we are obtained in terms of the probability of bit error and symbol error for QPSK (quadrature phase shift keying), MFSK(M-ary frequency shift keying) and proposed method. As a results of simulation, we confirmed that the proposed method was superior to the performance in terms of the probability of bit error and symbol error.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.478-485
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• 2019

As environmentally sound agriculture emphasize gradually as well as the importance of environment, many studies on weed and soil nematode control of new concept which does not affect adversely environment are in progress. For this purpose, plant seeds which are representative weed species in field were selected and treated with microwave having generating capacity of $17.73kw/m^3$, and investigated germination rates of weed seeds and the number of soil nematode according to soil moisture contents, soil depth and irradiation times. The microwave effect on the germination rates was extremely high in soil moisture content of 40% and irradiation time over 40 seconds for irradiation time, while soil depth did not affect germination rate. In view of the results so far achieved, it seems that universal dispersed microwave system is effective for the control of weed seeds.

• Journal of the Mineralogical Society of Korea
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• v.32 no.3
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• pp.185-200
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• 2019

This study aimed to liberate gold from invisible gold concentrate (Au = 1,840.00 g/t) through microwave nitric acid leaching experiments. For the purpose, this study conducted microwave-nitric acid leaching experiments and examined nitric acid concentration effect, microwave leaching time effect and sample addition effect. The results of the experiments were as follows: Au (gold) contents were not detected in all of the microwave leaching conditions. In the insoluble-residue, weight loss rate tended to decrease as the nitric acid concentration, microwave leaching time and sample addition increased. In an XRD analysis with solid-residue, it was suggested that gypsum and anglesite were formed due to dissolution of calcite and galena by nitric acid solution. When a fire assay was carried out with insoluble-residue, it was discovered that gold contents of the solid-residue were 1.3 (Au = 2,464.70 g/t) and 28.8 (52,952.80 g/t) times more than those of concentrate. But in the gold contents recovered, a severe gold nugget effect appeared. It is expected that the gold nugget effect will decrease if a sampling method of concentrate is improved in the microwave-nitric acid leaching experiments and filtering paper with smaller pore size is used for leaching solution and burned filter paper is used for sampling in lead-fire assay.

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.1
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• pp.19-27
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• 2001

The conventional fractal image compression based on wavelet transform has the disadvantage that the encoding takes many time, since it finds the optimum domain for all the range blocks. In this paper, we propose the fractal image compression based on wavelet transform using the SAS(Self Affine System) techniques. It consists of the range and domain blocks in the wavelet transform, and the range blocks select the domain which is located the relatively same position. In the encoding process, the proposed methods introduce SAS techniques that the searching process of the domains blocks is not required. Therefore, it can perform a fast encoding by reducing the computational complexity. And, the image quality is improved using the different scale factors for each level and the sub-tree in the decoding. As a result, the image quality and the compression ratio are adjustable by the scale factors.

• Journal of Korea Multimedia Society
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• v.5 no.4
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• pp.415-425
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• 2002

In this paper, we present a content-based image retrieval method which is based on the feature extraction in the wavelet transform domain. In order to overcome the drawbacks of the feature vector making up methods which use the global wavelet coefficients in subbands, we utilize the energy value of wavelet coefficients, and the shape-based retrieval of objects is processed by moment which is invariant in translation, scaling, rotation of the objects The proposed methods reduce feature vector size, and make progress performance of classification retrieval which provides fast retrievals times. To offer the abilities of region-based image retrieval, we discussed the image segmentation method which can reduce the effect of an irregular light sources. The image segmentation method uses a region-merging, and candidate regions which are merged were selected by the energy values of high frequency bands in discrete wavelet transform. The region-based image retrieval is executed by using the segmented region information, and the images are retrieved by a color, texture, shape feature vector.

• Journal of the Korea Computer Graphics Society
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• v.29 no.3
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• pp.21-31
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• 2023

In this paper, we introduce a case study of cinematography using digital human in virtual production. This case study deals with the system overview of virtual production using LEDs and an efficient filming pipeline using digital human. Unlike virtual production using LEDs, which mainly project the background on LEDs, in this case, we use digital human as a virtual actor to film scenes communicating with a real actor. In addition, to film the dialogue scene between the real actor and the digital human using a real-time engine, we automatically generated speech animation of the digital human in advance by applying our Korean lip-sync technology based on audio and text. We verified this filming case by using a real-time engine to produce short drama content using real actor and digital human in an LED-based virtual production environment.

• Journal of KIISE:Software and Applications
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• v.32 no.6
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• pp.532-541
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• 2005

We examined the wave pattern of the spleen by using abdominal CT images of a patient with liver cirrhosis, and found that they are different from those of a person with a normal liver. In the abdominal CT image of the patient with liver cirrhosis, there is a deep wave part on the left side of the spleen. In the case of the normal liver, there are waves on the left side, but they aren't deep. Therefore, the total area of waving parts of the spleen with liver cirrhosis is found to be greater than that of the spleen with the normal liver. Moreover, when examining circularity by abstracting the waves of the spleen from the image with liver cirrhosis, we found they are more circular than those of the spleen accompanied by a normal liver. This paper suggests an automatic method to diagnose liver cirrhosis by using the wave pattern of the spleen in abdominal CT images on the basis of the two principles. It tells us that we can judge if the liver has liver cirrhosis automatically, without the manual test of the ratio of caudate lobe to right lobe, only with the spleen.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.10B
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• pp.1375-1381
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• 2001

영상 부호화 기법에 적용하여 향상된 성능을 나타내는 균일 양자화기를 제안하였다. 또한 두 가지 형태의 서로 다른 균일 양자화기에 대하여 비트율-왜곡(rate-distortion) 특성을 분석하였다. 분석결과 입력(input source)의 평균값을 기준으로, 구간값(decision level)을 이동시키는 제안한 양자화 기법이 다른 양자화기 보다 향상된 비트율-왜곡 특성을 보였다. 아울러 제안한 양자화기를 웨이브릿 변환 부호화기에 적용한 결과, 여러 가지 영상에 대하여 기존의 양자화 기법보다 우수한 결과를 얻었다.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.1
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• pp.43-47
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• 2015

In this work, a broadband microstrip (MSL) - to - waveguide (WR12) transition has been presented for millimeter-wave module applications. For improvement of a bandwidth, the radial MSL electrical-probe is designed on the low-loss organic dielectric substrate. The designed and tested characteristics of the proposed transition are characterized in terms of an insertion and return loss. Considering the loss contribution of the cable adapter and waveguide transition for the measurement, the proposed transition loss can be analyzed as -1.88 and -2.01 dB per a transition at 70 and 80 GHz, respectively. The bandwidth of the proposed transition for reflection at -10 dB is 26 GHz at all test frequencies from 67 to 95 GHz. Compared to the state-of-the-art results, improvement of 8.3 % is achieved for the operation bandwidth.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.4
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• pp.38-38
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• 2001

본 논문에서는 웨이브릿 영역에서의 영역 분류와 대역간 예측 및 선택적 벡터 양자화를 이용한 다분광 화상테이타 압축 기법을 제안하였다. 이 방법에서는 각 대역을 웨이브릿 변환 후, 각 대역의 기저밴드의 대역별 특성을 이용하여 영역 분류를 행하였다. 그리고, 다른 대역과 해상도가 동일하고 공간적 분산이 작으며 분광적 상관성이 큰 기준대역 (reference channel)을 결정한 뒤, 이를 영역별 스칼라 및 분류별 가변 벡터 양자화를 행하여 부호화 하였다. 또한 기준대역과의 대역간 상관성이 큰 대역들에 대해서는 영역별 대역간 예측을 행한 후, 활동도가 높은 블록에 대해서만 선택적 벡터 양자화로 부호화를 행하였다. 이때, 활동도가 높은 블록들의 위치정보는 기준대역으로부터 얻어지는 임계치 지도 (threshold map; THMAP)를 이용하였다. 즉, 제안한 방법에서는 각 대역에 대해 웨이브릿 영역에서의 영역 분류 후 영역별 대역간 예측을 행함으로써 다분광 화상데이타에 존재하는 대역간 중복성을 제거하고 선택적 벡터 양자화를 행함으로써 대역내 중복성을 효과적으로 제거하여 압축효율을 향상시킨다. 실제 원격 센싱된 인공위성 화상데이타에 대한 실험을 통하여 제안한 기법의 부호화 효율이 기존의 기법에 비하여 우수함을 확인하였다.