• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.771-774
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• 2002

에러 발생율이 높은 이동 통신 채널 환경에서는 부호화된 비디오 스트림 전송시 발생된 채널 에러는 비디오 화질에 큰 영향을 줄 수 있다. 본 논문에서 현재 널리 사용되고 있는 H.263 부/복호화기에서 전송도중 에러가 발생했을 경우 추가적인 데이터 삽입 없이 효율적으로 에러를 은닉할 수 있는 기법에 관하여 제안하였다. 특히, 영상신호는 대개 인트라 픽쳐와 인터 픽쳐로 크게 구분되는데, 이들 중 부호화된 스트림에서 발생빈도가 놀은 인터 픽쳐에 대한 오류은닉을 우선적으로 목표로 하였다. 인터 프레임 픽쳐에서 DFD나 움직임벡터 손실시, 정확히 복원된 손실된 매크로블럭에 인접한 주변 픽셀 4*4을 이용해서 이전픽쳐에서 움직임벡터을 추정하고, 추정된 움직임 벡터을 가지고 손실된 매크로블록을 복원한다. 이때 주변블럭의 움직임벡터 추정시 소요되는 계산량은 충분히 디코더측에서 수용한다는 전제하에서 실험하였다.

• Review of KIISC
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• v.4 no.2
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• pp.74-99
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• 1994

ISO와 IEC가JTC1 을 만들기 이전인 1984년 'Digital Signature'를 만들기위한 과제가 시작되었다, 그후 3개의 과제로 세분되고 그중 첫번째의 과제로 본 문서가 가장 먼저 국제표준이 되었다. 1989년에 제목이 지금과 같이 바뀌었고, 1990년 DIS를 거쳐 1991년에 IS가 되었다. 1996년에 재검토될 예정이다.

• Journal of Conservation Science
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• v.27 no.1
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• pp.49-59
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• 2011

The damaged ceramics were repaired and restored thru various methods with various materials. The history of Ceramic repair and restoration has developed widening its areas from traditional stage utilizing applicable living material to the specified field that introduces new materials, new process methods and material analysis. Through investigations over the documents, artifacts and analysis, the period could be divided into natural material period in which uses the bonds extracted from the animals, plants and lime (prehistoric to Japanese domination period), Semi-artificial period in which mix natural material and synthetic resins such as "Jusabi"(Japanese domination period to 1970s.) and complete synthetic resin period in which introduces new materials and process methods in accordance with preservation standard (after 1980s).

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.4
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• pp.1-19
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• 2022

This study aims to discover the implications through the analysis of the characteristics and design strategies of the regeneration of the post-industrial sites in the metropolitan the Beijing-Tianjin-Tangshan region. This study provides a basis for future research and theoretical strengths for post-industrial site regeneration practices. The results of the study are as follows. First, post-industrial site regeneration projects pursue diverse goals such as industrial heritage preservation, cultural creativity, and neighborhood revitalization in the Beijing-Tianjin-Tangshan region. Second, in the design process, the characteristics and spatial levels of the space are enhanced by utilizing the original industrial space, incorporating transitional space, and using industrial facilities of varying heights. Third, old and new landscape elements are harmoniously integrated through the rational use of industrial relics and the appropriate addition of new elements. Fourth, the design emphasizes ecological soil restoration and the use of native and adaptable plants that have the capacity to remediate polluted soil. Fifth, the design combines modern artistic elements, such as sculpture and graffiti art to enrich the site and promote the revival of the post-industrial site. Sixth, urban events and public activities are actively programmed to vitalize the regenerated site.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.3
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• pp.15-24
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• 2022

In 2000, a total of 23,794ha of forest was lost due to the East Coast forest fire, and about 70% of the damaged area was concentrated in Samcheok. In 2001, artificial restoration and natural restoration were implemented in the damaged area. This study was conducted to understand the current vegetation structure 21 years after the restoration of forest fire damage in the Samcheok, Gumbong Mountain area. As a result of classifying the vegetation community, it was divided into three communities: Quercus variabilis-Pinus densiflora community, Pinus densiflora-Quercus mongolica community, and Pinus thunbergii community. Quercus variabilis, Pinus densiflora, and Pinus thunbergii planted in the artificial restoration site were found to continue to grow as dominant species in the local vegetation after restoration. As for the species diversity index of the community, the Quercus variabilis-Pinus densiflora community dominated by deciduous broad-leaf trees showed the highest, and the coniferous forest Pinus thunbergii community showed the lowest. Vegetation in areas affected by forest fires is greatly affected by reforestation tree species, and 21 years later, it has shown a tendency to recover to the forest type before forest fire. In order to establish DataBase for effective restoration and to prepare monitoring data, it is necessary to construct data through continuous vegetation survey on the areas affected by forest fires.

• Journal of Convergence for Information Technology
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• v.10 no.3
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• pp.1-6
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• 2020

Information System is influenced by the innovation of new IT. Therefore, IS should response to external environment's changes quickly. Particularly, resilience should be considered in barriers of IS. This study suggests a new information system evaluation model in which resilience is added to the existing factors of Delone and Mclean. Then the effect of resilience is evaluated through the DEA(Data Envelopment Analysis) based on a survey targeting 115 users of a mid-sized manufacturing company. The results show that the effect of resilience is stronger than any other factors in the previous researches. We, thus, suggest that the resilience should be included as an evaluation factor of the ISO27001 information security standard in order to enhance the absorptive capacity of the information system.

• Journal of Broadcast Engineering
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• v.24 no.2
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• pp.264-272
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• 2019

In this paper, we propose a 3D human body reconstruction and refinement method from the frames extracted from a video to obtain natural and smooth motion in temporal domain. Individual frames extracted from the video are fed into convolutional neural network to estimate the location of the joint and the silhouette of the human body. This is done by projecting the parameter-based 3D deformable model to 2D image and by estimating the value of the optimal parameters. If the reconstruction process for each frame is performed independently, temporal consistency of human pose and shape cannot be guaranteed, yielding an inaccurate result. To alleviate this problem, the proposed method analyzes and interpolates the principal component parameters of the 3D morphable model reconstructed from each individual frame. Experimental result shows that the erroneous frames are corrected and refined by utilizing the relation between the previous and the next frames to obtain the improved 3D human reconstruction result.

• Journal of Korean Society of Forest Science
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• v.101 no.1
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• pp.20-27
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• 2012

The flowed soil volume is able to be estimated simply from topographic data of before and after the debris flow. However, it is often difficult to obtain high resolution topographic data before debris flow because debris flow was occurred in mountainous area and airborne Lidar data was mainly surveyed in urban area. For this reason, Woo(2011) developed the topographic restoration method that can reconstruct the topography before the debris flow using airborne Lidar data. In this study, we applied the topographic restoration method on Inje county, Bongwha county and Jecheon city, produced topography data before debris flow that RMSE is from 0.16 to 0.34 m. Also, a soil variation was analyzed by topography data before and after debris flow, and it was used to estimate a real soil volume flowed to downstream and a spatial distribution showing collapses, flows, sedimentations appeared to debris flow.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.4
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• pp.247-256
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• 2021

In this paper, we propose a packet loss concealment (PLC) algorithm using pitch harmonic motion prediction and adaptive signal amplitude prediction and. The spectral motion prediction method divides the spectral motion of the previous usable frame into predetermined sub-bands to predict and restore the motion of the lost signal. In the proposed algorithm, the speech signal is classified into voiced and unvoiced sounds. In the case of voiced sounds, it is further divided into pitch harmonics using the pitch frequency to predict and restore the pitch harmonic motion of the lost frame, and for the unvoiced sound, the lost frame is restored using the spectral motion prediction method. When the continuous loss of speech frames occurs, a method of adjusting the gain using the least mean square (LMS) predictor is proposed. The performance of the proposed algorithm was evaluated through the objective evaluation method, PESQ (Perceptual Evaluation of Speech Quality) and was showed MOS 0.1 improvement over the conventional method.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.327-333
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• 2015

In order to identify the post-fire changes of ant assemblages after a forest fire, ants were surveyed at three survey sites (artificial reforestation site, natural reforestation site, and unburned forest site) in a burned forest area for eight years from 2005 using pitfall traps. 24 species were collected, and Nylanderia flavipes was the most abundant. Ant species preferring forest habitats (e.g. Aphaenogaster japonica. Lasius spathepus, and Plagiolepis flavescens) more occurred at the unburned forest site and the natural reforestation site, whereas ant species preferring open habitat (e.g., Formica japonica, Camponotus japonicus, and Tetramorium caespitum) more occurred at the artificial reforestation site. Ordination analysis indicated that ant communities of the artificial reforestation site were more changed compared with those of the natural reforestation site after the fire. The communities of the natural reforestation site were restored to the pre-fire state in five to six years after fire, whereas those of the artificial forest site seemed to take about 25 years to restore.