• Title, Summary, Keyword: 양자화 모델

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Illumination estimation based on valid pixel selection from CCD camera response (CCD카메라 응답으로부터 유효 화소 선택에 기반한 광원 추정)

  • 권오설;조양호;김윤태;송근호;하영호
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.5
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    • pp.251-258
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    • 2004
  • This paper proposes a method for estimating the illuminant chromaticity using the distributions of the camera responses obtained by a CCD camera in a real-world scene. Illuminant estimation using a highlight method is based on the geometric relation between a body and its surface reflection. In general, the pixels in a highlight region are affected by an illuminant geometric difference, camera quantization errors, and the non-uniformity of the CCD sensor. As such, this leads to inaccurate results if an illuminant is estimated using the pixels of a CCD camera without any preprocessing. Accordingly, to solve this problem the proposed method analyzes the distribution of the CCD camera responses and selects pixels using the Mahalanobis distance in highlight regions. The use of the Mahalanobis distance based on the camera responses enables the adaptive selection of valid pixels among the pixels distributed in the highlight regions. Lines are then determined based on the selected pixels with r-g chromaticity coordinates using a principal component analysis(PCA). Thereafter, the illuminant chromaticity is estimated based on the intersection points of the lines. Experimental results using the proposed method demonstrated a reduced estimation error compared with the conventional method.

Video Watermarking Scheme with Adaptive Embedding in 3D-DCT domain (3D-DCT 계수를 적응적으로 이용한 비디오 워터마킹)

  • Park Hyun;Han Ji-Seok;Moon Young-Shik
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.15 no.3
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    • pp.3-12
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    • 2005
  • This paper introduces a 3D perceptual model based on JND(Just Noticeable Difference) and proposes a video watermarking scheme which is perceptual approach of adaptive embedding in 3D-DCT domain. Videos are composed of consecutive frames with many similar adjacent frames. If a watermark is embedded in the period of similar frames with little motion, it can be easily noticed by human eyes. Therefore, for the transparency the watermark should be embedded into some places where motions exist and for the robustness its magnitude needs to be adjusted properly. For the transparency and the robustness, watermark based on 3D perceptual model is utilized. That is. the sensitivities from the 3D-DCT quantization are derived based on 3D perceptual model, and the sensitivities of the regions having more local motion than global motion are adjusted. Then the watermark is embedded into visually significant coefficients in proportion to the strength of motion in 3D-DCT domain. Experimental results show that the proposed scheme improves the robustness to MPEG compression and temporal attacks by about $3{\sim}9\%$, compared to the existing 3D-DCT based method. In terms of PSNR, the proposed method is similar to the existing method, but JND guarantees the transparency of watermark.

Dual Codec Based Joint Bit Rate Control Scheme for Terrestrial Stereoscopic 3DTV Broadcast (지상파 스테레오스코픽 3DTV 방송을 위한 이종 부호화기 기반 합동 비트율 제어 연구)

  • Chang, Yong-Jun;Kim, Mun-Churl
    • Journal of Broadcast Engineering
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    • v.16 no.2
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    • pp.216-225
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    • 2011
  • Following the proliferation of three-dimensional video contents and displays, many terrestrial broadcasting companies have been preparing for stereoscopic 3DTV service. In terrestrial stereoscopic broadcast, it is a difficult task to code and transmit two video sequences while sustaining as high quality as 2DTV broadcast due to the limited bandwidth defined by the existing digital TV standards such as ATSC. Thus, a terrestrial 3DTV broadcasting with a heterogeneous video codec system, where the left image and right images are based on MPEG-2 and H.264/AVC, respectively, is considered in order to achieve both high quality broadcasting service and compatibility for the existing 2DTV viewers. Without significant change in the current terrestrial broadcasting systems, we propose a joint rate control scheme for stereoscopic 3DTV service based on the heterogeneous dual codec systems. The proposed joint rate control scheme applies to the MPEG-2 encoder a quadratic rate-quantization model which is adopted in the H.264/AVC. Then the controller is designed for the sum of the left and right bitstreams to meet the bandwidth requirement of broadcasting standards while the sum of image distortions is minimized by adjusting quantization parameter obtained from the proposed optimization scheme. Besides, we consider a condition on maintaining quality difference between the left and right images around a desired level in the optimization in order to mitigate negative effects on human visual system. Experimental results demonstrate that the proposed bit rate control scheme outperforms the rate control method where each video coding standard uses its own bit rate control algorithm independently in terms of the increase in PSNR by 2.02%, the decrease in the average absolute quality difference by 77.6% and the reduction in the variance of the quality difference by 74.38%.

Classification of Consonants by SOM and LVQ (SOM과 LVQ에 의한 자음의 분류)

  • Lee, Chai-Bong;Lee, Chang-Young
    • The Journal of the Korea institute of electronic communication sciences
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    • v.6 no.1
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    • pp.34-42
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    • 2011
  • In an effort to the practical realization of phonetic typewriter, we concentrate on the classification of consonants in this paper. Since many of consonants do not show periodic behavior in time domain and thus the validity for Fourier analysis of them are not convincing, vector quantization (VQ) via LBG clustering is first performed to check if the feature vectors of MFCC and LPCC are ever meaningful for consonants. Experimental results of VQ showed that it's not easy to draw a clear-cut conclusion as to the validity of Fourier analysis for consonants. For classification purpose, two kinds of neural networks are employed in our study: self organizing map (SOM) and learning vector quantization (LVQ). Results from SOM revealed that some pairs of phonemes are not resolved. Though LVQ is free from this difficulty inherently, the classification accuracy was found to be low. This suggests that, as long as consonant classification by LVQ is concerned, other types of feature vectors than MFCC should be deployed in parallel. However, the combination of MFCC/LVQ was not found to be inferior to the classification of phonemes by language-moded based approach. In all of our work, LPCC worked worse than MFCC.

World Logistics Evolution & Marketing Strategy for Korea's Enhanced Port Competition (세계물류발전과 한국의 항만경쟁력 강화를 위한 마케팅 전략)

  • Gim, Jin-Goo
    • Journal of Korea Port Economic Association
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    • v.24 no.4
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    • pp.363-384
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    • 2008
  • This study aims at improving Korea's competitiveness in port logistics through marketing strategy with integrating the conceptual approach into the empirical one and combining both the oldest military treatise and the newest evaluating model in social science that was applied by the HFP(hierarchical fuzzy process) model enhanced by the KJ method. The empirical results of this study show Busan in the middle among subject ports. At present, Korea plays a reciprocal role in the port market in East Asia, but in the medium- and long-term, Korea's ports will vie together with most major ports in the East Asian region. A descriptive investigation shows that Korea's developing tasks in port logistics must be considered in the context of the direction for developing port policies, the necessity of expanding port facilities in the capital region, securing the sufficient traffic volume through the establishment of the hinterland linking system and its positive utilization, and reforming the direction for developing the global logistics through increased port competitiveness. In the short- and medium-term, Korea must use the opportunity factor of 'Growth and open door policy of China' as a geoeconomic advantage and to utilize Korea's ports as a gate to Chinese foreign trade. With the rise of China's economy, China also plays a significant role in both port and airport markets. Hence, the linking system between the two must be established to meet the expanding traffic volume, especially in the capital area. Moreover, it is necessary for Korea to secure port logistics through the establishment of the hinterland linking system and its positive utilization. The great accomplishment of this paper is to present strategies to increase Korea's port competitiveness in the rapidly changing environments of world logistics with the focus on both the oldest military strategic treatise and the newest empirical method in social science. In order to reinforce this study, it needs further compensative research because the evaluation structure could be subdivided with more extensive and precise criteria.

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A Study on Family Caregivers' Preferences for Utilization of Community-based Welfare and Health-care Services (요보호 노인 부양가족의 재가복지 및 재가보건 서비스 유형별 이용의향에 관한 연구 - 2002년도 서울시 노인복지 기초수요조사 자료 분석 -)

  • Kim, Hye-Kyung
    • Korean Journal of Social Welfare
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    • v.56 no.4
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    • pp.123-147
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    • 2004
  • The purposes of this study are, 1) to explore the factors related to the family caregivers' preferences for service utilization both of the community-based welfare and health-care services, and 2) to examine the reasons why not want to use services analyzing a survey data obtained from family caregivers(n=1,000). Anderson and Newman's Behavior model was employed to examine the factors related to the preferences for service utilization. The main results are as follows. 1) Logistic regression analyses demonstrated that predisposing factor(such as age and relations with frail elderly) and enabling factor(such as economic status, secondary caregiver, informal informational support provider, etc) were significant predictor for caregivers' preference for service utilization. Contrary to an expectation, needs factor was negatively related to the preference for service. More specifically, the more they have service needs, the less they show their willingness to use community-based service both in welfare and health-care services except for care education program. 2) Caregiver identified 'family caregiving consciousness'(family should take care of frail elderly, elderly dislike be taken care of) as an important reason not want to use community services next to financial factor. These findings have several implications for policy making especially for 'public long-term care insurance' which was planned to start in 2007.

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Connection of Dongmu Lee Je-ma's Sa-Sang Theory & Ken Wilber's all-quadrant approach (동무 이제마의 사상설(四象說)과 캔 윌버의 사상한(四象限) 일고(一考))

  • Heo, Hoon
    • Journal of Korean Philosophical Society
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    • v.116
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    • pp.411-435
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    • 2010
  • Ken Wilber(1949~) tries to approach integration of philosophy, emphasising the advent of the perennial philosophy in the exchange of scholarships at the present day. He suggests All Quadrant(四象限) for the first step to reach his integrated approach. In addition, his approach concretizes for AQAL(All Quadrant, All Level). His AQAL approach which can be divide into inside/outside, singular/plural, or interobjectivity/intersubjectivity is applied to a lot of fileds such as ecology, management, criminology, medical treatment and its boundary is getting bigger. The merits of Quadrant is that it can solve the problem of the plain(平原), which resolves the strength of subjective interior(cultural contexts) into the external existence(social system). From view of Dongmu Lee Je-ma(1837~1900), a former philosopher, Sa-Sang theory['Affairs-Mind-body-Objects(事心身物)', 'Heaven-Human-nature-Order(天人性命)] is in accord with Wilber in content. In Dongmu's writing, Quadrant(Affairs-Mind-body-Objects') called Sa-Sang theory(四象學) or Sasang Constitional Medicine(四象醫學) is basic component in order to explain the structure of all nature. 'Heaven-Human-nature-Order'; That is, 'Affairs-Mind-body-Objects' results in 'Heaven-Human-nature-Order' focused on human being(human body) in the universe. In other words, Sa-Sang theory is the same as the Wilver's inclusive perspectives from the universe and human being. Dongmu's Sa-Sang theory is compared with C. G. Jung(1875~1961)'s psychology and it helps both fields confirm the foundation and extend the province of application. Comparision of Dongmu's Quadrant with Wilber's is not just analogical reasoning. In comparison, Dongmu's Sa-Sang theory is more delicated and crystallized than Wilber's in medical prospective. Dongmu regards Quadrant not as diseases, but as origin of Physiology and Pathology. And he explains all of their courses as Quadrant.