• Title/Summary/Keyword: concealment

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Generalized Self Spread-Spectrum Communications with Turbo Soft Despreading and Decoding

  • Tomasin Stefano;Veronesi Daniele
    • Journal of Communications and Networks
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    • v.8 no.3
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    • pp.267-274
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    • 2006
  • Self-spreading (SSP) is a spread spectrum technique where the spreading sequence is generated from data bits. Although SSP allows communications with low probability of interception by unintended receivers, despreading by the intended receiver is prone to error propagation. In this paper, we propose both a new transmitter and a new receiver based on SSP with the aim to a) reduce error propagation and b) increase the concealment of the transmission. We first describe a new technique for the generation of SSP spreading sequence, which generalizes SSPs of existing literature. We include also coding at the transmitter, in order to further reduce the effects of error propagation at the receiver. For the receiver, we propose a turbo architecture based on the exchange of information between a soft despreader and a soft-input soft-output decoder. We design the despreader in order to fully exploit the information provided by the decoder. Lastly, we propose a chip decoder that extracts the information on data bits contained in the spreading sequence from the received signal. The performance of the proposed scheme is evaluated and compared with existing spread-spectrum systems.

Recovering Corrupted Motion Vectors Using Edge Direction (경계 방향성을 이용한 손상된 움직임 벡터의 복원 기법)

  • 박정윤;이창우
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.11A
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    • pp.1880-1888
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    • 2001
  • In wireless communication systems, transmission errors degrade the reconstructed image quality severely. Among various techniques which reduce the degradation, the error concealment technique yields good performance without overheads and the modification of the encoder. In this paper, we have proposed the technique for recovering the corrupted motion vector using the edge direction of blocks which surround the corrupted block, when the video information is compressed by H.263 standard. We uses the property that each object in video sequences shows the same motion. For the estimation of edge directions, the first AC coefficients of blocks are used. Extensive simulation results show that the proposed technique yields good performance with a reduced computational complexity.

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A Study on the Characteristics and Transformation of Location of Seowon in Chosen Dynasty (조선시대 서원의 지특성 및 변화과정에 관한 연구)

  • 이상윤;김용기
    • Journal of the Korean Institute of Landscape Architecture
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    • v.23 no.1
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    • pp.157-173
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    • 1995
  • Seowons were first established during the Koryo Dynasty and contain primate shrines for the service of ancestors and ancient sages. Seowons were located in a scenic or rural place some distance from a residential area. The direct motive for building the Seowon came from the need for transcendental concealment and evasive retirement which developed as a result of oppression of scholars The indirect motivations were the development of loaming in an idyllic natural settings and the creation of a beautiful natural environment. he purpose of tai study is to investigate the characteristics and transformation process of the location of Seowon in the Chosen dynasty. The results of this research are summarized as fellows : 1. Seowons were in hilly areas with good geographical features including a nice view of the mountains and waters. Beowons were also built on the relation place of an ancient sage and of destroyed Buddist temples. 2. The location patterns of seowon in the Choson dynasty underwent three stages with the change of time Political and social phenomena influenced the transformation of the location patterns Research in this area is at an early stage. The present study was confined to an examination of 7he characteristics and transformation process of the location of seowons. However, it is hoped that this study will offer meaningful guide for further research.

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Error Concealment Technique for Image Quality Improvement of Digital TV (디지털 TV 화질 개선을 위한 전송 오류 은폐 기법)

  • 서재원;호요성
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 1999.06b
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    • pp.35-40
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    • 1999
  • 이 논문은 디지털 TV의 압축 비트열을 전송할 때, 채널 오류로 인해 디지털 TV 디코더에서 화면을 재생할 때 발생할 수 있는 화질의 저하를 최소화시키는 방법을 기술한다. 텔레비전과 같은 단방향 방송 시스템에서 전송 도중에 오류가 발생하여 수신측에서 전송 오류를 제대로 정정하기 곤란할 때, 재생된 화면이 심각하게 훼손될 수 있다. 이때 오류로 인한 화면의 손상을 주변의 공간적 또는 시간적 상관 정보를 이용하여 화면을 복원하는 동작을 오류 은폐라고 한다. 최근 디지털 TV나 고선명 TV의 기본 부호화 방식으로 많이 사용하고 있는 MPEG 비디오 표준 방식은 공간적인 중복 정보를 압축하기 위해 DCT 변환을 수행하며, 시간적인 중복 정보를 압축하기 위해 움직임 예측과 움직임 보상 방법을 이용한다. 또한 MPEG 비디오 압축 방식은 일종의 차분 부호화 방법을 사용하기 때문에 현재 화면에서 오류가 발생하면 현재 화면뿐만 아니라, 시간적으로 나중에 부호화된 화면에도 오류가 전파된다. 본 논문에서는 MPEG 비트열의 채널 오류의 영향을 분석하여 화면간에 존재하는 시간적인 중복성을 이용하여 움직임 벡터를 추정하여 손상된 부분을 은폐시키는 방법을 제안한다. 기본적으로 손상된 매크로블록의 위와 아래로 인접한 화소값들을 움직임 벡터의 추정에 사용한다. 제안된 방법들 중에서 주변 움직임 벡터들의 가중치를 이용한 평균값 방법과 초기 움직임 벡터를 이용한 확장 영역 움직임 추정 방법이 우수한 결과를 보였다.

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A Study on the Renaissance/Baroque Characteristics Appearing in Contemporary Architecture - Focused on the Analysis of National Museum of Modern and Contemporary Art Seoul Branch and Dongdaemun Design Plaza from the Concept Frame of Wölffrin - (현대건축에 나타난 르네상스적/바로크적 특성에 관한 연구 - 뵐플린의 개념틀에 의한 국립현대미술관 서울관과 동대문디자인플라자의 비교분석을 중심으로 -)

  • Kim, In-sung
    • Korean Institute of Interior Design Journal
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    • v.26 no.1
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    • pp.142-152
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    • 2017
  • This study investigated Renaissance and Baroque architectural characteristics found in contemporary public buildings in Seoul, which are National Museum of Modern and Contemporary Art Seoul Branch(MMCA) and Dongdaemun Design Plaza(DDP). Among H. $W{\ddot{o}}lfflin^{\prime}s$ five categories for Renaissance-Baroque art study, four categories (Clearness/Unclearness, Plane/Recession, Closed form/Open form, Multiplicity/Unity) are applied for the analysis as the architectural issues of Transparency/Concealment, Exhibited/Experienced Depth, Formal/Figural, and Composed harmony/Generated Unity. As a result, MMCA showed the characteristics of the extreme of Modern classic such as transparency, homogenization of space, formalism, and composition of multiple elements. Meanwhile, the study could find various Baroque characteristics from DDP such as separation of indoor and outdoor, phenomenological depth, rule breaking, and generation of figure. The study finally argued that DDP would not be an anti-modern, but try to inherit and overcome the modern architecture to explore different possibilities, and that the similar relationship between Renaissance and Baroque art could be found in these two cases.

Motion Vector Recovery Based on Homogeneous Motion Area for H.263 Video Communications (H.263 비디오 통신을 위한 동일 움직임영역 기반 움직임벡터 복원)

  • Kim, Jeong-Hyeon;Son, Nam-Rye;Park, Seong-Chan;Hwang, Seong-Un;Yun, Gi-Song;Son, Deok-Ju;Lee, Gwi-Sang
    • The KIPS Transactions:PartB
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    • v.8B no.1
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    • pp.43-49
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    • 2001
  • 이동통신 채널과 같이 에러 발생율이 높은 환경에서 부호화된 비디오를 전송할 때 채널에어에 손상된 비트스트림은 복호되기 어려울 뿐만 아니라, 비트스트림의 다른 부분으로까지 에러를 전파시킨다. 한 프레임에 손실블록이 있을 때 기존방법에서는 주변블록들의 움직임벡터 평균을 구하거나 비슷한 예측을 통해 손실블록의 움직임벡터를 복원한다. 그러나 손실블록이 움직이는 객체의 경계부근에서 발생할 때 기존방법은 효율적이지 못한다. 따라서 제안 알고리즘은 기존방법보다 정확한 움직임벡터를 예측하기 위해 손실블록의 주변블록들 중세서 동일한 움직임을 갖는 블록들로 구성된 영역을 찾은 후, 동일움직임영역에 포함된 블록들의 움직임벡터를 이용하여 손실된 블록을 복원한다. 실험결과 제안방법이 기존방법에 비해 PSNR과 시각적인 화질면에서 우수한 성능을 보임을 알 수 있다.

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An Analysis of Multi-View Fashion Design Reflected in the Perception of Time and Space (연속적 시·공간관이 반영된 다(多)시점 패션디자인 분석)

  • Kim, Minji;Kan, Hosup
    • Journal of Fashion Business
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    • v.19 no.2
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    • pp.136-148
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    • 2015
  • The purpose of this thesis is to study multi-view fashion design with an analysis of multi-view art's formation and philosophical perspective. The production of unique artwork is dependent on how we see, think and represent what is around us. Multi-view art has great potential as a concept related to the continuity of time and space, it is not limited to space and time but it extends to infinitely, according to the artist's will and imagination. The study of time and space has been used as principles for deriving the formative of multi-view art, and the principles applied for analyzing multi-view fashion design. And the formation of multi-view art is reflected in fashion design. Simultaneity, deconstructivity, continuity and virtuality in terms of multi-view art are support the formation of multi-view fashion design, such as fabrication, expandability, concealment and transparency. As such, it is important to study multi-view fashion design as a creative design method with immense potential for further development.

Robust speech quality enhancement method against background noise and packet loss at voice-over-IP receiver (배경잡음 및 패킷손실에 강인한 voice-over-IP 수신단 기반 음질향상 기법)

  • Kim, Gee Yeun;Kim, Hyoung-Gook
    • The Journal of the Acoustical Society of Korea
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    • v.37 no.6
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    • pp.512-517
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    • 2018
  • Improving voice quality is a major concern in telecommunications. In this paper, we propose a robust speech quality enhancement against background noise and packet loss at VoIP (Voice-over-IP) receiver. The proposed method combines network jitter estimation based on hybrid Markov chain, adaptive playout scheduling using the estimated jitter, and speech enhancement based on restoration of amplitude and phase to enhance the quality of the speech signal arriving at the VoIP receiver over IP network. The experimental results show that the proposed method removes the background noise added to the speech signal before encoding at the sender side and provides the enhanced speech quality in an unstable network environment.

The Road to Empire: Journeys to Europe and Far Eastern Asia by Natsume Soseki ('제국'으로 가는 길 - 나쓰메 소세키의 유럽과 아시아 여행)

  • YOON, Sang-In
    • Cross-Cultural Studies
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    • v.33
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    • pp.263-286
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    • 2013
  • Is this a right way in politics that attitude of Japanese scholars to separate Natsume Soseki from the expansionism of pre-war Japan to protect 'sanctity'? Nowadays, most Japanese scholars are regarded to share the desire that minimize the memory of the behavior of Japanese Imperialism in East Asia, such as Korea, China, etc. Furthermore, 'the desire to minimize' inescapably concluded in avoidance, concealment, at last the temptation of deliberate misleading. Until now, the controversy about the Natsume Soseki's travel to Korea and Manchuria has repeated in defence and criticism surrounding the self-awareness and recognition of others of Natsume Soseki, making the expression in a record of Natsume's travel as the subject of study, for example, the degrading expression about Chosun people and scorn for Chinese and Russian. This paper will investigate that Natsume's travel is the political practice which is combined with the desire for the empire, focusing on the political context in the action of journey of Natsume and its contents other than the expression itself.

A Study on the Realities and Preventive Countermeasures of Child Abuse Committed by Biological Parents by information analysis.

  • Ryu, Chae-Hyoung;Yoon, Hyun-Seok
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.5
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    • pp.171-177
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    • 2019
  • In this paper, we analyze the current phenomenon of child abuse crimes based on the information gathered by the National Child Protection Agency. The purpose of this paper is to diagnose the seriousness of child abuse by biological parents based on the analyzed information and propose measures against it. Comprehensive and integrated measures are needed for child abuse committed by biological parents due to abuse concealment, continuity of damage, and inactive national intervention by considering punishment on attackers through national intervention, fundamental in-depth psychological counseling, therapeutic care, promoting recovery of victims, and ultimately continuous and regular management and monitoring as a long-terms measure. To do so, developing customized and individual educational programs and make them obligations can be first presented to identify child abuse in advance and build up preventive systems based on the principle of family preservation. In addition, problems should be addressed at a fundamental level by performing various and active therapeutic treatments such as psychological treatment, mental treatment, or drug treatment gradually and through phases for biological parents who commit child abuse and contributing to recovering the relationship. Furthermore, proper protection and treatment service should be provided to children victimized by abuse by extending professional children care facilities and adopting the professional family commission system as measures by separating family.