• ALGAE
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• 제18권3호
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• pp.225-232
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• 2003

Species composition, community structure and biodiversity of marine benthic community were studied in the rocky shore of Dongbaekseom, Busan. A total of 82 species of marine algae including 4 Cyanophyta, 11 Chlorophyta, 20 Phaeophyta and 47 Rhodophyta are listed. The dominant algal species were Ulva pertusa, Chondria crassicaulis, Corallina spp. and Melobesioidean algae. Sargassum thunbergii, Chondracanthus intermedia, Gelidium divaricatum and Ralfsia verrucosa were subdominant in cases of different seasons and vertical layers. Chthamalus challengeri, Littorina brevicula and Mytilus edulis were dominant zoobenthic species upper-middle layer of the intertidal zone. The community structure of this area seemed to be controlled by spatial competition with benthic marine algae. The species diversity indices estimated from different sources were quite different. Indices from coverage were 1.87, 3.98 from frequency, 2.26 from the average of total frequency and coverage and 2.15 from importance value. The similarity indices on the present study showed decreasing trends comparing to the previous benthic algal composition researches.

• 한국초지조사료학회지
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• 제17권4호
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• pp.387-398
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• 1997

This experiment was to investigate the surface coverage, sward height and dry matter yield of 63 perennial ryegrass cultivars with control cultivar, orchardgrass(Potomac) at different cutting dates(May 25, July 5, August 20 and October 5), in order to select the adaptable cultivars of perennial ryegrass in the middle region of Korea. Four perennial ryegrass cultivars, E.V. Meadea, Aberystwyth S101, Raidor and Real, didn't survive afler sowing. Surface coverage of perennial ryegrass cultivars cut in August 20 was lower than others. Sward height of perennial ryegrass cultivars at each cutting dates was lower than that of orchardgrass. There were no significant differences in sward heights of each cutting date. Dry matter yield of perennial ryegrass cultivars cut in August 20 was lower than others. Total dry matter yield of Oakpark 6% Viktoria, Petra, G. Manawa, and Kangaroo Valley was fell in the range of 11.76 and 10.37t/ha while that of orchardgrass was 12.09t/ha. On the basis of total annual dry matter yield, the adaptability of perennial ryegrass cultivars was classfied as following.

• Journal of Plant Biology
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• 제23권1호
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• pp.3-10
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• 1980

Effects of thermal effluents on the marine algal communities were investigated with the quadrat method during June, 1977-December, 1978, at the intertidal zone of Kori Nuclear Power Plant, Southeast Coast of Korea. As a result, both the number of algal species occurred in quadrat (50$\times$50cm) and the total coverage were observed to be decreased in June, 1978, at three sites near the discharge point compared with those of previous year but being recovered afterwards. The representative dominant species at the coast of Kori Nuclear Power Plant were, on the whole, Corallina pilulifera, Pachymeniopsis elliptica, and Chondrus ocellatus. Among the species, the coverage of Corallina pilulifera appeared to be rather increased, while the vegetation of Chondria crassicaulis was found to be decreased particularly in 1978. Total 102 species (3 blue-green, 16 green, 30 brown, and 53 red algae) of marine algae were identified in this study. Among them 71 species were common to 133 species reported by previous investigators during 1969-1970.

• Journal of Periodontal and Implant Science
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• 제32권3호
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• pp.555-584
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• 2002

Exposed root surfaces can cause esthetic problems, hypersensitivity, and root caries. Numerous efforts have been tried to cover the recessed root surfaces, and various techniques have been developed and introduced. Among these, subepithelial connective tissue graft which shows high coverage rate in various researches, has the advantage of good color match, less discomfort to the donor site, rich vascularity, and high predictability. Following results were obtained after investigating 6 and 18 months post operatively, 98 cases of subepithelial connective tissue graft from 48 patients who underwent subepithelial connective tissue graft procedure in the department of periodontology, college of dentistry, Yonsei university. 1. The total average root coverage of Miller class I, II & III were 76.2?24% at 6 months follow-up and 75?25.2% at 18 months follow-up with no statistically significant difference between the follow-up periods.(p<0.05) 2. The percentage of teeth showing complete coverage were 41.9% at 6 months follow-up and 39.2% at 18 months follow-up. 3. At 6 months follow-up, Miller classification I showed 84.9?20.7%, class II showed 82.5?17.7%, and class III showed 62.3?24.5% of coverage. In class III recession, statistically significantly less root coverage was observed compared to class I & II. (p(0.05) 4. At 18 months follow-up, Miller classification I showed 92.2?13.5%, class II showed 84.3?17.4%, and class III showed 59.5?24.5% of coverage. In class III recession, statistically significantly less root coverage was observed compared to class I & II. (p<0.05) In conclusion, subepithelial connective tissue graft for class I and II recession can be used as a clinically predictable treatment modality for root coverage.

• 한국콘텐츠학회논문지
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• 제20권2호
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• pp.172-181
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• 2020

본 연구는 SNU팩트체크 센터(factcheck.snu.ac.kr)에 공개돼 있는 언론사의 팩트체크 기사를 분석했다. 팩트체크 기사 중 복수 언론사를 통해 검증이 이뤄진 교차검증 기사 50건을 연구 대상으로 정하고, 팩트체크 대상 주제, 유형, 성격, 언론사 간 판단 결과 일치도, 활용 근거가 무엇인지 검토했다. 연구결과, 언론사들은 대체로 대선·총선 후보자나 정치인 발언 등 정치 관련 주제를 팩트체킹하고 있었다. 팩트체크 대상의 유형은 주로 객관적인 사실이나 의견 혹은 해석이 개입될 수 있는 정보였으며, 발언 자체의 사실을 확인하는 기사나 인과관계, 비교 기준 시기나 대상에 따라 달리 해석될 수 있는 성격을 가진 정보에 대해 팩트체킹을 하고 있는 것으로 나타났다. 언론은 평균적으로 '대체로 사실 아님' 에 가까운 판단을 했으며, 주로 관계자 취재 및 관련 기관 자료, 정부 자료, 전문가 발언 등을 판단 근거로 활용하는 경향을 보였다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권8호
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• pp.3617-3619
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• 2012

Background: The completeness of cancer registration is a major validity index of any reported cancer incidence. The present study aimed to evaluate the esophageal cancer incidence registered in the Tehran Metropolitan Area Cancer Registry. Materials and methods: The data on esophageal cancer abstracted from three sources of 1) pathology departments, 2) medical records, and 3) death certificates during 2003 till 2007 were utilized. The completeness of the data sources were evaluated using coverage (defined as the proportion of a community population with esophageal cancer identified by the source) and density (defined as the proportion of non-empty fields of the data by source). Results: A total 1,404 cases of esophageal cancer were reported for the duration of the study. Pathology provided 771, medical records 432, and death certificates 609. The coverage was 0.55 for pathology, 0.31 for medical records, and 0.43 for death certificates. The respective density values were 0.82, 0.96 and 0.98, respectively. Pathology (0.45) was the most complete source followed by medical records (0.42), and death certificates (0.29). Discussion: A low degree of completeness dictates putting more effort into case finding plus abstracting data more thoroughly.

• 한국통신학회논문지
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• 제34권1A호
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• pp.18-26
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• 2009

기존의 무선 통신 시스템에서 신호의 수신 범위를 늘리고 수율을 증가시키기 위해 릴레이를 이용하는 방식이 다양하게 고려되고 있다. 하지만, 릴레이를 이용하는 방식은 변조 방식에 따라 제한된 수신 범위를 갖고 릴레이가 추가됨에 따라 추가적인 시간슬롯이 요구되는 단점이 있다. 본 논문에서는 계층적 변조방식과 두 개의 분산된 릴레이를 결합하여 2 홉 시스템을 구현하며, 수율과 최대 전송가능 영역을 모두 증대시킬 수 있는 방식을 제안한다. 제안된 방식에서는 단말의 위치에 따라 다른 레벨을 가지는 데이터의 수신이 가능함에 따라 최대수신가능 영역이 증대되고 수율이 약 2배 증가되는 이득을 얻을 수 있었다.

• 대한원격탐사학회지
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• 제32권1호
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• pp.25-38
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• 2016

With the increasing need for high temporal resolution satellite imagery for monitoring land surfaces, this study evaluated the temporal resolution of the NDVI composites from Geostationary Ocean Color Imager (GOCI) data. The GOCI is the first geostationary satellite sensor designed to provide continuous images over a $2,500{\times}2,500km^2$ area of the northeast Asian region with relatively high spatial resolution of 500 m. We used total 2,944 hourly images of the GOCI level 1B radiance data obtained during the one-year period from April 2011 to March 2012. A daily NDVI composite was produced by maximum value compositing of eight hourly images captured during day-time. Further NDVI composites were created with different compositing periods ranging from two to five days. The cloud coverage of each composite was estimated by the cloud detection method developed in study and then compared with the Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua cloud product and 16-day NDVI composite. The GOCI NDVI composites showed much higher temporal resolution with less cloud coverage than the MODIS NDVI products. The average of cloud coverage for the five-day GOCI composites during the one year was only 2.5%, which is a significant improvement compared to the 8.9%~19.3% cloud coverage in the MODIS 16-day NDVI composites.

• Membrane and Water Treatment
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• 제10권1호
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• pp.57-65
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• 2019

This study assessed the contribution of emergent vegetation (Phragmites australis, Typha latifolia, and Nelumbo nucifera) to the submerged surface area, the amount of biofilms attached to the submerged portions of the plants, and the treatment performance of a free water surface (FWS) constructed wetland. Results showed that a 1% increase ($31m^2$) in the vegetative area resulted in an increase of $220m^2$ of submerged surface area, and 0.48 kg Volatile Suspended Solids (VSS) of attached biofilm. As the vegetation coverage increased, effluent organic matter and total Kjeldahl nitrogen decreased. Conversely, a higher nitrate concentration was found in the effluent as a result of increased nitrification and incomplete denitrification, which was limited by the availability of a carbon source. In addition, a larger vegetation coverage resulted in a higher phosphorus in the effluent, most likely released from senescent biofilms and sediments, which resulted from the partial suppression of algal growth. Based on the results, it was recommended that constructed wetlands should be operated with a vegetation coverage of just under 50% to maximize pollutant removal.

• Asian Pacific Journal of Cancer Prevention
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• 제14권4호
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• pp.2243-2248
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• 2013

Background: To compare the dosimetric coverage of target volumes and organs at risk in the radical treatment of nasopharyngeal carcinoma (NPC) between intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3DCRT). Materials and Methods: Data from 10 consecutive patients treated with IMRT from June-October 2011 in Penang General Hospital were collected retrospectively for analysis. For each patient, dose volume histograms were generated for both the IMRT and 3DCRT plans using a total dose of 70Gy. Comparison of the plans was accomplished by comparing the target volume coverage (5 measures) and sparing of organs at risk (17 organs) for each patient using both IMRT and 3DCRT. The means of each comparison target volume coverage measures and organs at risk measures were obtained and tested for statistical significance using the paired Student t-test. Results: All 5 measures for target volume coverage showed marked dosimetric superiority of IMRT over 3DCRT. V70 and V66.5 for PTV70 showed an absolute improvement of 39.3% and 24.1% respectively. V59.4 and V56.4 for PTV59.4 showed advantages of 18.4% and 16.4%. Moreover, the mean PTV70 dose revealed a 5.1 Gy higher dose with IMRT. Only 4 out of 17 organs at risk showed statistically significant difference in their means which were clinically meaningful between the IMRT and 3DCRT techniques. IMRT was superior in sparing the spinal cord (less 5.8Gy), V30 of right parotid (less 14.3%) and V30 of the left parotid (less 13.1%). The V55 of the left cochlea was lower with 3DCRT (less 44.3%). Conclusions: IMRT is superior to 3DCRT due to its dosimetric advantage in target volume coverage while delivering acceptable doses to organs at risk. A total dose of 70Gy with IMRT should be considered as a standard of care for radical treatment of NPC.