• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2003년도 추계학술대회 논문집(III)
• /
• pp.535-540
• /
• 2003

Urban transit, which takes an important role of traffic volume, is operated in four different urban communities and constructed in two urban communities. However, the urban transit of each communities has different system in operation and construction. It is not efficient to construct and operate. Furthermore, is difficult to maintain urban transit system. In this paper, the standardization of power supply system for urban transit has been performed to solve above problems.

• 한국환경생태학회지
• /
• 제12권1호
• /
• pp.91-101
• /
• 1998

본 연구팀은 변산반도국립공원내의 외변산 해변가 일대에서 처음으로 대규모 순비기나무군락지를 발견하여, 본 군락지의 보호 ㄷ책 수립과 합리적인 이용을 위한 기초자료를 제공할 목적으로 그 생육환경 및 형태적 특성 등을 조사 분석하였던 바 그 결과를 요약하면 다음과 같다. 순비기나무군락지는 서해로 돌출한 변산반도국립공원내의 부안군 변산면 격포리 작은당과 운산리 고사포해수욕장 해변가 일대에 위치하고 있었다. 군락지의 총 면적은 총 2,755m$^{2}$ 인데 , 그 중 523m$^{2}$의 훼손지가 발생하였으며, 군락지 내부와 주변에는 새로 발견된 모감주나무, 해당화, 순비기나무 등을 포함하여 28과 43속 49종 2변종의 목본식물이 자라고 있었다. 본 군락지 내에서 가장 큰 순비기나무 개체는 근원직경이 3.5cm, 지상부 포복경의 길이가 6m에 이르렀으며, 군락지내에 서식하는 순비기나무의 평균 엽장은 4.5cm, 평균 엽폭 3.3cm, 평균 엽면적 11.8cm$^{2}$, 평균 꽃의 길이 10.0cm로서 양호한 생육상태를 나타내고 있었다. 순비기나무는 지금까지 대부분 상록성이라고 기재하고 있으나, 본 조사결과 낙엽성인 것으로 확인되었다.

• 한국환경생태학회지
• /
• 제34권4호
• /
• pp.304-317
• /
• 2020

금남호남·호남정맥 마루금 일대 식생구조를 알기 위해 입지환경과 인위적 영향을 고려해 금남호남정맥 2곳, 호남정맥 4곳을 중점조사지로 골라 식생조사를 실시했다. TWINSPAN을 써서 두 정맥은 각각 7개씩의 식물군락으로 유형화됐다. TWINSPAN기법의 식별종은 식물군락의 환경요인을 간접적으로 대변하는데 두 정맥의 군락 유형은 해발고, 토양수분, 교란 등의 환경요인에 의해 분할됐다. 이 결과는 DCA 1축의 환경요인과 조화를 이루었다. 두 정맥은 모두 저지대에선 리기다소나무, 곰솔 등의 조림수종과 자생종이 서로 경쟁 관계에 있었다. 이처럼 정맥의 저지대는 조림, 개발사업 등으로 인위적 식생교란이 심한 편이었다. 상대적으로 고지대의 능선부·상부사면·정상부는 신갈나무·굴참나무·소나무가 우점하는 식생유형이 양호하게 보전됐다. 차이점으론 금남호남정맥은 호남정맥보다 해발고와 위도가 높아 신갈나무우점군락이 가장 넓게 분포했다. 반면, 호남정맥은 신갈나무와 함께 소나무우점군락이었고, 남해안에 인접해 있어 곰솔우점군락이 출현했다는 점이다. TWINSPAN과 DCA 등의 정량적 식생분석에선 종조성 변화와 그 변화를 일으키는 환경요인 추출이 중요하다. 이를 위해선 우연 출현종 제거와 환경요인을 상정한 조사계획 수립, 조사데이터의 특성에 부합한 최적의 분석기법 선택 등이 필요하다.

• 한국환경복원기술학회지
• /
• 제19권6호
• /
• pp.1-17
• /
• 2016

The study was aimed to understand the ecological status of the Maebongsan urban forest in Cheongju-si through investigating the vegetation, soil characteristics, and soil microarthropods. Phytosociological analysis for twenty plots revealed that the plant communities were classified into Pinus rigida community, Robinia pseudoacacia community, Castanea crenata community, Quercus acutissima community, Pinus strobus community, Pinus koraiensis community, and Larix kaempferi community. The importance value showed that afforestation tree species like Castanea crenata, Robinia pseudoacacia, and Pinus rigida dominate the urban forest. DBH analysis indicated that although the plant communities seem to be under the succession to Quercus forest, the dominance of Castanea crenata and Robinia pseudoacacia might still persist for several more decades. The properties of soils from the plant communities showed that loamy sand and sandy loam in soil texture, low organic matters, and severe acidification. The abundance of soil microarthropods were not different among the plant communities except Castanea crenata community and Pinus koraiensis community. The two communities showed especially low abundance of collembola and acarina. Thus, we can say that Castanea crenata community and Pinus koraiensis community seem to have been influenced strongly by anthropogenic activities.

• Journal of the korean society of oceanography
• /
• 제36권3호
• /
• pp.83-92
• /
• 2001

An investigation on the zonal communities in Chokchon macrotidal flat, Incheon, Korea, was carried out on July 1994, eight years after the initial survey done by Frey et al. (1987a and b). A survey transect (4 km long) was established with 41 stations having an equi-interval of 100 m. Macrofaunas were sampled in July 1994. R-mode cluster analysis and ordination analysis (detrended correspondence analysis or DCA) were performed. The aims of the investigation were to: (1) observe the distribution and abundance patterns, including zonation of benthic macrofaunal communities in the area; and (2) gain information about faunal changes between two different periods. The primary feature of distribution was corresponded with Frey's zonation, and this was shaped by three level-specific species groups. Significant changes in dominant species were detected when compared with the faunal assemblages of 1986. The bivalve mollusk, Meretrix petechialis, seemed to have disappeared. Two newly arrived organic pollution indicator species, Theora fragilis and Capitella capitata, were regarded as impregnable proof of response to eutrophication, although the concrete evidence on the eutrophication source was not found.

• Asia pacific journal of information systems
• /
• 제25권4호
• /
• pp.642-661
• /
• 2015

Interpersonal trust has become essential for online communities because people have managed to be in a situation without face-to-face encounters. To identify the structural relationships between interpersonal trust and learning performance, we analyzed the relationship between two types of trust, namely, cognitive and affective, as well as two dimensions of learning performance, namely, learning satisfaction and knowledge application. We also identified the moderating role of social norms in the relationship between trust and learning performance. Results of analysis are as follows. First, cognitive trust significantly affected the two dimensions of performance. Second, affective trust exhibited a significant effect on learning satisfaction, but did not affect knowledge application. Third, the relationships between the two performance factors were significant and direct. Lastly, social norms appeared to moderate the effects of cognitive trust on knowledge application and affective trust on satisfaction. These findings suggest that organizations, which would like to optimize task-oriented performance of their learning communities, should consider linking strategies between community satisfaction and practical knowledge application.

• 한국주거학회논문집
• /
• 제26권1호
• /
• pp.119-128
• /
• 2015

This study aimed to develop Korean types of the university-based continuing care retirement community. CCRCs (Continuing care retirement communities), where senior residents are guaranteed to get continuous cares without moving out even under their deteriorating health condition, has been identified as the appropriate residences that can accommodate aging-in-place needs. Aging-in-place may be ideal for the increasing senior population and older households. Recently in the United States, as many retirees looked for intellectually and physically active environments that also offer intergenerational programs, university-based retirement communities (UBRCs) became popular and their number reached 60 campuses nationwide. This numbers is expected to grow significantly over the next two decades. We conducted case studies that targeted two representative UBRCs and identified four categories of main features. They were general characteristics, architectural features, services or programs, and management system. This study result highlighted key features of the UBRCs that can be the foundation for the future UBRCs development in Korea.

• 생태와환경
• /
• 제49권4호
• /
• pp.271-278
• /
• 2016

Forest clear-cutting operations influence biodiversity through habitat changes and food resource availability for inhabitant species. This study examined the effects of clear-cutting on forest arthropod communities. Arthropods were collected from two different forest treatment areas (clear-cut and control) in summer and autumn. In each treatment area, arthropods were sampled from both crown and ground surfaces using sweeping and pitfall trap methods, respectively. Then, the taxonomic order of the collected arthropod specimens was easily identified. Results indicate that arthropod abundance and number of taxa present were higher at ground surface than at crown levels in both clear-cut and control areas. At crown level, more homopteran species were present in clear-cut areas than in control areas in summer. At ground surface, populations of Isopoda and Opiliones were higher in control areas than in clear-cut areas, whereas numbers of Araneae, Orthoptera, and Hymenoptera were greater in clear-cut areas. Cluster analysis and principal component analysis showed distinct differences between clear-cut and control communities at crown level in summer and at ground surface in autumn. Thus, our results indicate that clear-cutting significantly influences arthropod communities, and higher taxa are valuable for conducting rapid biological assessments of ecosystem disturbances.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제16권8호
• /
• pp.2587-2605
• /
• 2022

In order to efficiently detect community structure in complex networks, community detection algorithms can be designed from the perspective of node similarity. However, the appropriate parameters should be chosen to achieve community division, furthermore, these existing algorithms based on the similarity of common neighbors have low discrimination between node pairs. To solve the above problems, a noval community detection algorithm using closeness similarity based on common neighbor node clustering entropy is proposed, shorted as CSCDA. Firstly, to improve detection accuracy, common neighbors and clustering coefficient are combined in the form of entropy, then a new closeness similarity measure is proposed. Through the designed similarity measure, the closeness similar node set of each node can be further accurately identified. Secondly, to reduce the randomness of the community detection result, based on the closeness similar node set, the node leadership is used to determine the most closeness similar first-order neighbor node for merging to create the initial communities. Thirdly, for the difficult problem of parameter selection in existing algorithms, the merging of two levels is used to iteratively detect the final communities with the idea of modularity optimization. Finally, experiments show that the normalized mutual information values are increased by an average of 8.06% and 5.94% on two scales of synthetic networks and real-world networks with real communities, and modularity is increased by an average of 0.80% on the real-world networks without real communities.

• The Korean Journal of Ecology
• /
• 제15권4호
• /
• pp.411-431
• /
• 1992

The present study was undertaken to classify and describe the vegetation around andong dam area, kyong-buk, korea$(36^{\circ}\;35^{\prime}\;N, \;128^{\circ}\;47^{\prime}\;E)$ by methods of the ZM school of phytosociology. The investigations were carried out in the plot. The homogeneous part of forest and grass communities was analyzed by recording the combined scale of cover-abundance and sociability of all species found in the plot. The community data obtained were classified into two associations and seven communities; festuco onvinae-pinetum densiflorae assoc. nov., quercetum variabili-serratae, quercus acutissima community, larix leptolepis, populus tomentiglandulosa, acer canadensis, prunus spp. afforestations, robinia pseudo-acacia-commelina communis community and acer palmatum cv. afforestation. The grass vegetation was divided into six associations and seventeen communities; lactuco indicae- humuletum japonicae, eragrostio ferruginei-plantaginetum asiaticae, polygonetum thunbergii, phragmitetum japonicae, eragrostio ferruginei-plantaginetum asiaticae, polygonetum thunbergii, phragmitetum japonicae, artemisio-potentilletum chinesis, eleusinetum indicae, amorpha freticosa, artemisia princeps, achyranthes fauriei and other fourteen communities. amoung the above vegetationship of the vegetation units with their environments was outlined.