• 대한전기학회논문지:전력기술부문A
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• 제55권5호
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• pp.191-194
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• 2006

Power system restoration following a wide area or complete blackout starts with energizing primary restorative transmission systems. During this primary restoration process, unexpected over-voltage may happen due to nonlinear interaction between the unloaded transformer and the transmission system. This is known as the harmonic resonance phenomenon that may cause burning out of transformer or other devices. Since the harmonic resonance originates from the nonlinear characteristics, it is very difficult to predict the occurrence of this phenomenon. This paper reports the analyses of the harmonic resonance occurred in domestic power system. Various analyses and results of the harmonic over-voltage is presented based on the PSCAD/EMTDC simulations.

• The Korean Journal of Ecology
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• 제25권1호
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• pp.1-7
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• 2002

The ecological background of a restoration project is complex and difficult to betermine without experimentation. A useful context for experiments is the well-studied process of natural succession, because the factors that drive or inhibit succession are also at work during reclamation (a form of primary succession) and restoration (which often resembles secondary succession). Using experimental studies on urban wasteland reclamation, we have tested for factors that stimulate or inhibit succession during early phases of woodland development in the Northeastern United states. The emphasis has been on mutualisms (seed dispersal, pollination, and mycorrhizae) and microsite limitations in the recruitment, growth, and reproduction of woody plants. Using plantings of seeds, seedlings, and clusters of reproductively mature plants on abandoned landfills, we have observed that (1) soil microsite deficiencies lead to very poor germination (<0.1$\%$) and seedling survival (<0.01$\%$) of most native species; (2) seed dispersal by birds is a significant and reliable source of woody plant recruitment; however (3) proximity effects are strong, with most (up to 95$\%$) of seed rain falling in the vicinity of planted clusters that are closest to putative seed sources; and (4) remnant natural woodlands are critical components of the recruitment process. To emphasize the last point, in one case, we found that the destruction of approximately 50$\%$ of nearby natural woodland vegetation led to a commensurate decline in seed rain. In another case, we found that the species richness of recruits was strictly limited by the species composition of nearby source plant communities, with no evidence of community enrichment by long distance dispersal over 5 years. We conclude from these results that the size and proximity of remnant natural populations are critical considerations when planning reclamation and restoration programs that rely on natural successional processes.

• Archives of Plastic Surgery
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• 제32권3호
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• pp.347-356
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• 2005

The wound healing process in fetus is quite different form that of adult. Regeneration plays an important role and scarless wound healing is possible in early gestational fetal period. Recently, the various effects of the hypoxia and reoxygenation in the wound healing process have been investigated by many researchers. The hypoxic state is known to alter protein synthesis and gene expression of TGF-${\beta}$, VEGF. The authors hypothesize there may be differences between fetal and adult fibroblast and this difference may play a possible role in the mechanism of scarless fetal wound healing. In this study, we investigated the growth of fibroblast, the amount of collagen deposition, the amount of protein synthesis and gene expression in TGF-${\beta}$(transforming growth factor-${\beta}$), VEGF(vascular endothelial growth factor) under the various hypoxic and reoxygenation conditions. Through these processes, we tried to determine the relationships between scarless fetal wound healing and hypoxic condition. In control group, fetal and adult fibroblasts were cultured under normoxic condition. The experimental groups were allocated into four different groups. The differences in TGF-beta, VEGF under 24, 48, 72 hours were statistically investigated. Compared to adult fibroblast group, there was a statistically significant increase (p<0.01) in the rates of protein synthesis in TGF-beta and VEGF of fetal fibroblast. In this study, these results may reflect the possibility that fetal fibroblast are more susceptible to change in oxygen and has a superior rate of angiogenesis through increased VEGF expression. The possible superiority of angiogenesis in fetal fibroblast may play an important role in scarless wound healing.

• 한국언론정보학보
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• 제38권
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• pp.73-118
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• 2007

이 연구의 목적은 위기 상황에서 조직이 내세우는 이미지 회복 전략이 대부분 언론을 통해 전달된다는 점에 착안하여, 언론보도 프레임이 공중의 이미지 회복 전략에 대한 판단에 영향을 주는가를 살펴보는 것이다. 이러한 연구 목적을 달성하기 위해서 신문을 중심으로 한 내용분석과 일반인을 대상으로 한 실험연구를 진행했다. 특히, 이 연구에서는 구체적인 위기 상황을 중심으로 조직의 이미지 회복 전략과 언론보도 프레임의 영향력을 알아보고자 하였으며, 위기 사건 중에서도 산업 전반 및 공중의 삶에 큰 영향을 주는 대표적인 사회 '위기'인 식품관련 사건을 선정하였다. 신문 내용분석 결과, 조직의 이미지 회복 전략은 대부분 일화중심 기사를 통해 공중에게 전달되는 경향을 보이고 있었다. 또한, 조직들이 구사하는 대부분의 이미지 회복 전략은 방어적인 것으로 이는 위기의 유형에 따른 이미지 회복 전략의 차별성을 보여주지 못하는 결과이다. 실험 결과, 조직들의 이미지 회복 전략은 공중이 선호하는 전략과 큰 차이를 보였으며 이러한 공중들의 인식은 프레임 유형에 따라 변화하는 양상을 보였다.

• 조명전기설비학회논문지
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• 제17권3호
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• pp.64-72
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• 2003

배전망은 그 구조가 매우 복잡하고, 수용가와 인접되어 있으므로 송전망에 비하여 사고의 발생도 매우 빈번하다. 또한 배전망에서의 사고는 수용가에게 직접적인 피해를 발생시킬 수 있다. 따라서 수용가의 피해를 줄이고 전력공급의 안정성 확보를 위한 배전망에서의 고장진단과 정전복구는 필수적으로 요구되는 기능이다. 배전망의 정전복구는 시간적인 제약성에 종속되며, 정전복구 과정에서 발생하는 스위칭 수를 최소화하는 것이 가장 중요한 요소이다. 폭, 모든 정전구역을 한번의 스위칭으로 복구하는 것이 가장 이상적이며, 그렇지 못한 경우 여러 번의 스위칭으로 복구하여야 한다. 본 논문에서는 조작되는 스위치의 수를 최소화시키기 위한 배전망의 정전 복구 시스템을 제안하였다. 제안된 시스템에서는 휴리스틱 탐색방법과 메타-알고리즘의 동적분할 기법의 계층구조를 사용하고 있다. 제안된 정전복구 시스템의 성능을 검증하기 위하여 모의 배전망을 대상으로 성능평가를 수행하였다.

• 한국인쇄학회지
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• 제30권1호
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• pp.59-69
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• 2012

This study is Long term preservation measures which is closely related to preserving paper records, record condition evaluation, preservation measure and is conducted as follows. As for Means to Evaluate the Deterioration and Damaged Conditions of Records, research and analysis has been made on the contamination and deterioration examples such as damage, dry, stapler, metal, contamination, acidification which are the characteristics of paper record damage types. The of Paper record is one of the key procedures to evaluate the record material and its physi-chemical status in many criteria and to suggest the best preservation method. Between 1970 and 2000, the main record materials was fine paper and OMR paper along with partly newspaper and coarse paper, whereas the main recording material was ball point pen. Overall damage and deterioration status is, for record materials between 1940 and 1960, high deterioration was found and in urgent need for preservation measure and more damages are caused by tapes, staplers and metals. As for records after 1970, there is light deterioration but needs preservation process. There are approximately 3 million records produces before 2000, and assuming that there are 30 pages per record and that 30% has been damaged or deteriorated, 27 million pages are subject to preservation process. Among damaged or deteriorated records, there are large number of records impossible to go through deacidification process so manual preservation and restoration process is necessary as well. Securing manpower having preservation and restoration skills as well as preservation equipment(deacidification process, preservation and restoration) is in urgent need.

• 한국실내디자인학회논문집
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• 제14권1호
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• pp.142-150
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• 2005

This study is arranged the principles of the preservation and restoration in pre-modern architecture, presented guideline of the Intoner restoration in there, and attempted relative-analysis by cases of Japan in curtain of Saporo Houheikan. The method of Original- restorations and Repairs must be preserved In materials and technologies in order to hand over the future generations. The process and method of restorations are the important Cultural Properties as Architecture's itself. And Restorations of industrial manufactures hold the the important position in restoration of pre-modern Architectures. Because industrial technologies are developed and forgotten in rapid. Specially, because industrial materials as curtains were apt to recognize as consumption goods, historicity in that are contained the history of fabric, industrial technologies, and relations of traditional technologies. Conclusionaly, restorations of interior materials in our country are required of \circled1the construction of workframe in search and restoration for original preservation, \circled2the conception of refaires and establishment of investigation, \circled3the stocking of restoration-technologies of pre-modern cultural properties of architectures, \circled4the recognitions of record-preservation, \circled5the improvement of organization, upbring of technicians, establishment of theorical systems.

• 한국정보통신학회논문지
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• 제19권3호
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• pp.645-650
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• 2015

영상 획득 시 렌즈의 부정확한 초점이나 영상 획득 시스템의 흔들림 등으로 인해 영상 복원이 요구된다. 이런 영상 복원 문제는 하나의 열화 영상에서 원 영상을 추출해야 하는 부적절하게 정립된 역 문제 (ill-posed reverse problem)이다. 본 논문은 기준 영상을 도입하여 기존의 영상 복원 방법과 비교할 때 복원 영상의 신호잡음비를 유사하게 유지하면서 계산 속도를 향상시키는 방법을 제안하였다. 제안된 방법은 새로운 비용 함수를 통해 영상과 커널을 몇 단계의 갱신을 통해 영상 열화에 사용되었다고 추정되는 커널을 얻는다. 위너 필터는 전 단계에서 구한 커널과 기준 영상을 이용하여 원 영상의 추정치를 구하였다.

• 한국습지학회지
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• 제25권4호
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• pp.394-407
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• 2023

생태복원은 문제가 있는 생태적 공간을 진단하고, 온전한 자연을 분석하여 얻은 정보를 바탕으로 훼손된 생태계를 치유하여 본래의 모습과 유사한 건강한 모습으로 되돌려놓는 생태기술이다. 성공적인 복원을 이루기 위해서는 일련의 절차를 존중하여 사업이 추진되어야 한다. 그러나 국내에서 진행되는 복원사업은 진단평가에 관계없이 적극적인 복원 위주로 추진하여 비용과 에너지를 낭비하고 효과는 크지 않다. 대조생태정보가 활용되지 않아 훼손된 자연을 되돌리기 위한 생태복원이 자연의 모습과 크게 다른 모습을 연출하며 또 다른 훼손을 유발하고 있다. 복원효과가 평가되지 않아 성공여부를 판단할 수 없어 사업이 계속되어도 발전이 없고 효과도 없다. 그러나 선진사회는 이러한 절차를 존중하여 학문적 진전을 이루어낸 것은 물론 생태복원이 하나의 산업으로 자리 잡아 환경을 개선하는 것은 물론 경제적 측면에서도 큰 효과를 거두고 있다. 따라서 국제사회는 생태복원을 기후변화를 비롯해 지구적 차원의 환경문제를 해결할 수 있는 중요한 수단으로 인식하여 국제기구가 중심이 되어 상처입은 지구를 치료하기 위한 사업을 활발하게 추진해 나가고 있다. 그러나 국내에서 추진된 복원사업은 효과 평가 결과 대부분 수준 이하로 평가되었다. 그럼에도 불구하고 이러한 수준을 향상시키는데 중요한 기여를 할 수 있는 생태복원을 하나의 새로운 산업으로 정립하기 위한 계획을 수준 낮은 사업을 주도해 온 당사자들이 가로막고 있어 문제를 더욱 악화시키고 있다. 이러한 문제를 해결하기 위해 사전과 사후로 구분하여 엄정하고 바른 사업 평가 제도를 도입하여 불량사업을 걸러낼 필요가 있다. 나아가 생태복원을 하나의 산업으로 신설하여 그 과정을 시장의 원리에 맡길 필요가 있다.

• 한국환경복원기술학회지
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• 제27권3호
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• pp.1-18
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• 2024

The study aims to establish a direction for forest ecological restoration by classifying forest types and understanding the ecological characteristics of the Uljin forest area damaged by a large fire in 2022. Hierarchical cluster analysis and indicator species analysis were conducted on 78 survey plots located in the forest fire-affected area, and four forest cover types were derived: P. densiflora pure forests, P. densiflora dominant forests, mixed broad-leaved forests, and Q. variabilis dominant forests. As a result of visually comparing changes in forest types before and after forest fire damage, by classifying data according to whether or not upper dead trees are included, it was confirmed that pine forests, which have a high proportion of pine trees, spread widely due to forest fire damage. However, broad-leaved mixed forests and oyster oak dominant forests showed characteristics of maintaining concentration, indicating that pine forests were severely damaged. As a result of the important value analysis, during the process of natural recovery after a forest fire, the species that appear early in the lower layer are the sprouts of existing species such as Quercus mongolica Fisch. ex Ledeb., Quercus variabilis Blume, Fraxinus sieboldiana Blume, Rhododendron mucronulatum Turcz. The distribution of diameter at breast height by forest cover type showed that among areas with extreme forest fire damage, the proportion of dead trees was relatively high and structural changes were large in P. densiflora pure forests and P. densiflora dominant forests where pine trees had a high distribution ratio. However, if continuous monitoring is carried out in the future with reference to the results of this study and plant data is collected and analyzed from a mid- to long-term perspective, it is believed that it will be used as useful data to promote forest ecological restoration projects in forest fire-affected areas.