• 한국측량학회지
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• 제39권2호
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• pp.113-122
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• 2021

Urban expansion, particularly converting sub-urban areas to residential and commercial land use in metropolitan areas, has been considered as a significant signal of regional economic development. However, this results in urban climate change. One of the key impacts of rapid urbanization on the environment is the effect of UHI (Urban Heat Island). Understanding the effects of urban land cover change on UHI is crucial for improving the ecology and sustainability of cities. This research reports an application of remote sensing data, GIS (Geographic Information Systems) for assessing effects of urban land cover change on the LST (Land Surface Temperature) and heat budget components in Ho Chi Minh City, where is one of the fastest urbanizing region of Vietnam. The change of urban land cover component and LST in the city was derived by using multi-temporal Landsat data for the period of 1998 - 2020. The analysis showed that, from 1998 to 2020 the city had been drastically urbanized into multiple directions, with the urban areas increasing from approximately 125.281 km² in 1998 to 162.6 km² in 2007, and 267.2 km² in 2020, respectively. The results of retrieved LST revealed the radiant temperature for 1998 ranging from 20.2℃ to 31.2℃, while that for 2020 remarkably higher ranging from 22.1℃ to 42.3℃. The results also revealed that given the same percentage of urban land cover components, vegetation area is more effective to reduce the value of LST, meanwhile the impervious surface is the most effective factor to increase the value of the LST.

• 한국IT서비스학회지
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• 제21권2호
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• pp.27-41
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• 2022

In a fiercely competitive environment, quality is a key factor that enables dashboard camera makers to maintain their competitive advantage. Quality affects consumer satisfaction, brand loyalty, and firm performance. Therefore, to remain competitive, it is important that manufacturers maintain product quality that meets consumer expectations. To this end, it is necessary to investigate customer preferences and product performance in terms of product quality and to properly allocate resources to improve the quality level such that the firm can maintain a competitive advantage. In this paper, we proposed the various ways in which manufacturing firms can determine which quality dimensions need improvement in order to secure competitiveness. To this end, we analyzed a case study of Urive to develop a quality improvement strategy through importance performance competitor analysis (IPCA). Urive's IPCA results showed that 14 quality dimensions, namely performance, size, price, ease of use, country of origin, manufacturer, brand, product certificate, warranty, distribution channel, market share, reliability, durability, and conformance, were not absolutely competitive compared with those of Mando, Inavi, and Finevu. In terms of color, Urive had an absolute competitive advantage over Mando, but not Inavi and Finevu. Urive's appearance was more competitive than Mando's, but not Inavi's and Finevu's. In terms of advertisement and serviceability, Urive was absolutely less competitive than Mando and Inavi, but had a competitive advantage over Finevu. Therefore, it is necessary to put resources and time as the first priority for performance, reliability, and durability, which have a large performance difference in common among the three brands. The quality dimensions in which resources and time need to be put in second place are price and ease of use, which have a large performance difference in common among the two brands.

• 한국방사선학회논문지
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• 제16권3호
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• pp.343-349
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• 2022

토픽 모델링을 활용하여 1989년부터 2022년까지 출판된 방사선을 주제로 한 논문을 파악하고 주제들 간의 관련성과 비중을 분석하고자 한다. 본 연구는 방사선 분야의 연구 활성화에 기여하기 위하여 2022년 최근까지 출판된 논문 717편을 대상으로 국문제목에서 도출된 토픽들을 분석하였다. 텍스트마이닝을 통해 연구의 주제 분포에 대한 전반적 연구 동향을 분석하였으며, 토픽모델링을 통해 5가지 주제를 도출해냈다. 첫째, 분석 대상 논문 중 키워드 중심으로 총 논문 717편의 연구에서 핵심어를 전처리 과정을 거쳐 최종적으로 선정된 단어는 총 1675개의 단어를 빈도 분석하였다. 둘째, 5개 토픽에 대하여 구성단어의 연관성을 중심으로 토픽을 분석한 결과 방사선, 영상, CT 임상분야에서 영상의 화질을 떨어뜨리지 않는 범위에서 선량을 최소화 하는데 연구가 주를 이루고 있음을 알 수 있었다. 또한, MRI 분야는 다양한 연구가 주를 이루었고 초음파는 다양한 부위의 질환 분석이 연구가 활발하게 시도되고 있음을 알 수 있었다.

• Journal of Forest and Environmental Science
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• 제38권2호
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• pp.110-121
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• 2022

Leaf functional traits widely have been used to understand the environmental controls of resource utilization strategy of plants along the environmental gradients. By using key leaf functional traits, we quantified the relationships between leaf traits and local climate throughout the distributional range of Rhododendron caucasicum Pall. in eastern and western Georgian mountains (the South Caucasus). Our results revealed, that all traits showed high levels of intraspecific variability across study locations and confirmed a strong phenotypic differentiation of leaf functional variation along the east-west longitudinal gradient in response to the local climate; out of the explored climatic variables, the moisture factors related to precipitation and number of precipitation and dry days for winter and growth seasons were more strongly related to leaf trait variation than the elevation and air temperature. Among studied leaf traits, the leaf specific area (SLA) showed the highest level of variability indicating the different resource utilization strategies of eastern and western-central Rh. caucasicum individuals. High SLA leaves for western-central Caucasian individuals work in relatively resource-rich environments (more humid in terms of precipitation amount and the number of precipitation days in winter) and could be explained by preferential allocation to photosynthesis and growth, while eastern Caucasian samples work in resource-poor environments (less humid in terms of precipitation amount and the number of precipitation days in winter) and the retention of captured resources is a higher priority appearing in a low SLA leaves. However, more evidence from a broader study of the species throughout its distribution range by including additional environmental factors and molecular markers are needed for firmer conclusions of intraspecific variability of Rh. caucasicum.

• 한국콘텐츠학회논문지
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• 제22권3호
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• pp.430-441
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• 2022

ICT 기술의 발전에 힘입어 다양한 모바일 어플리케이션이 속속들이 등장하고 이들이 개인의 삶 속에 깊이 파고든 시점, 영화산업의 새로운 성장판로를 모색하기 위하여 본 연구는 영화 콘텐츠 관련 어플리케이션의 성장 방안을 논의하였다. 실증연구를 통하여 영화 콘텐츠 관련 어플리케이션이 갖춰야 할 핵심요인을 탐색하기 위하여 본 연구에서는 정보시스템 성공 모델을 활용하여 각 품질요인이 영화 소비자의 영화에 대한 태도와 관람의도에 미치는 영향을 알아보았다. 연구 결과, 영화 콘텐츠 관련 어플리케이션의 품질요인 중 가장 중요한 요인은 정보 품질요인이었으며, 이어 서비스 품질이 차선으로 중요한 요인임이 도출되었다. 본 연구에서는 이와 같은 연구 결과를 바탕으로 국내 영화 산업의 발전을 위해 영화 콘텐츠 관련 어플리케이션들이 개선되어야할 방안을 제시하여 새로운 유통 채널로서의 영화 콘텐츠 관련 어플리케이션의 방향성을 제안하였다.

• 한국자원식물학회지
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• 제35권5호
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• pp.607-613
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• 2022

Vulpia octoflora (Walter) Rydb.가 경기도 여주시 강천리 일대에서 발견되었다. 본 종은 북아메리카 원산으로 알려져 있으며, 최근 호주와 일본, 우크라이나에서 침입외래식물로 보고된 바 있다. V. octoflora는 주로 건조한 모래나 자갈 모래밭에 자라는 잡초성 식물로, 도로변을 따라 개방된 지역이나 인위적 교란 지역에서 빈번하게 발견된다. 본 종은 최근에 국내에 보고된 침입외래식물인 들묵새아재비와 유사하나, 소수당 달리는 소화의 수가 더 많고, 호영 정단부의 까락의 길이가 짧은 것으로 명확히 구분된다. 본 연구에서는 주요 형질에 대한 기재, 지리적 분포, 도해도, 화상자료와 국내에 분포하는 동속 분류군의 검색표를 제공하고자 한다.

• 인간식물환경학회지
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• 제24권2호
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• pp.219-227
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• 2021

Background and objective: Urban street trees play an important role in carbon reduction in cities where greenspace is scarce. There are ongoing studies on carbon reduction by street trees. However, information on the carbon reduction capacity of street trees based on field surveys is still limited. This study aimed to quantify carbon uptake and storage by urban street trees and suggest a method to improve planting of trees in order to increase their carbon reduction capacity. Methods: The cities selected were Sejong, Chungju, and Jeonju among cities without research on carbon reduction, considering the regional distribution in Korea. In the cities, 155 sample sites were selected using systematic sampling to conduct a field survey on street environments and planting structures. The surveyed data included tree species, diameter at breast height (DBH), diameter at root collar (DRC), height, crown width, and vertical structures. The carbon uptake and storage per tree were calculated using the quantification models developed for the urban trees of each species. Results: The average carbon uptake and storage of street trees were approximately 7.2 ± 0.6 kg/tree/yr and 87.1 ± 10.2 kg/tree, respectively. The key factors determining carbon uptake and storage were tree size, vertical structure, the composition of tree species, and growth conditions. The annual total carbon uptake and storage were approximately 1,135.8 tons and 22,737.8 tons, respectively. The total carbon uptake was about the same amount as carbon emitted by 2,272 vehicles a year. Conclusion: This study has significance in providing the basic unit to quantify carbon uptake and storage of street trees based on field surveys. To improve the carbon reduction capacity of street trees, it is necessary to consider planning strategies such as securing and extending available grounds and spaces for high-density street trees with a multi-layered structure.

• 한국응용곤충학회지
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• 제61권4호
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• pp.623-631
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• 2022

깨알벌레과는 전세계적으로 약 100속, 1,000여 종이 알려져 있다. 깨알벌레들은 다양한 서식처에서 채집되며, 깃털 모양의 날개와 작은 크기로 쉽게 구분된다. 이 중 Acrotrichis속은 깨알벌레과의 약 4분의 1을 차지하나, 국내에서는 Acrotrichis lewisii (Matthews, 1884b)만이 2020년에 처음으로 기록되었다. 본 연구에서는 전국 농경지 생물상 변동조사 중 제주에서 채집된 A. thoracica (Waltl, 1838)와 A. grandicollis (Mannerheim, 1844)를 국내에 처음으로 보고한다. 이 두 종의 외형과 세부 사진, 분포도 그리고 한국산 Acrotrichis속의 분류키를 함께 제공한다.

• 한국표면공학회지
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• 제56권2호
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• pp.160-168
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• 2023

Recently, investigation on metallization is a key for a stretchable display. Amorphous metal such as Ni and Zr based amorphous metal compounds are introduced for a suitable material with superelastic property under certain stress condition. However, Ni and Zr based amorphous metals have too high resistivity for a display device's interconnectors. In addition, these metals are not suitable for display process chemicals. Therefore, we choose an aluminum based amprhous metal Al-Mo as a interconnector of stretchable display. In this paper, Amorphous Forming Composition Range (AFCR) for Al-Mo alloys are calculated by Midema's model, which is between 0.1 and 0.25 molybdenum, as confirmed by X-ray diffraction (XRD). The elongation tests revealed that amorphous Al-20Mo alloy thin films exhibit superior stretchability compared to pure Al thin films, with significantly less increase in resistivity at a 10% strain. This excellent resistance to hillock formation in the Al20Mo alloy is attributed to the recessed diffusion of aluminum atoms in the amorphous phase, rather than in the crystalline phase, as well as stress distribution and relaxation in the aluminum alloy. Furthermore, according to the AES depth profile analysis, the amorphous Al-Mo alloys are completely compatible with existing etching processes. The alloys exhibit fast etch rates, with a reasonable oxide layer thickness of 10 nm, and there is no diffusion of oxides in the matrix. This compatibility with existing etching processes is an important advantage for the industrial production of stretchable displays.

• Journal of Ecology and Environment
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• 제46권1호
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• pp.76-84
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• 2022

Background: Climate and livestock grazing are key agents in determining current Mongolian steppe vegetation communities. Together with plant coverage or biomass, palatability of steppe community is regarded as a useful indicator of grassland degradation, in particular, at grazing hotspots in arid and semi-arid grasslands. This study analyzed relationships between livestock grazing pressure and steppe vegetation palatability at three summer pastures with different aridity (dry, xeric, and mesic) and livestock numbers (1,100, 1,800, and 4,100 sheep units, respectively). At each site, it was surveyed coverage, biomass, and species composition of different palatability groups (i.e., palatable [P], impalatable [IP], and trampling-tolerant [TT]) along a 1-km transect from grazing hotspots (i.e., well) in every July from 2015 to 2018. Results: In results, total vegetation coverage increased with wetness, 7 times greater at mesic site than dry one in averages (33.1% vs. 4.5%); biomass was 3 times higher (47.1 g m^-2 vs. 15.7 g m^-2). Though P was the dominant palatability group, the importance of IP in total coverage increased with aridity from mesic (0.6%) to dry (40.2%) sites. Whereas, TT increased with livestock numbers across sites. Locally, IP was observed more frequently near the wells and its spatial range of occurrence becomes farther along the transects with aridity across sites from mesic (< 100 m) to dry (< 700 m from the well). Conclusions: Our results showed that the importance of IP and its spatial distribution are different at both local and regional scales, indicating that the palatability parameters are sensitive to discern balance between selective-grazing demand and climate-driven foraging supply in Mongolian rangelands.