• 한국물환경학회지
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• 제26권5호
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• pp.822-833
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• 2010

Temperature increase due to climate changes causes change of water temperature in rivers which results in change of water quality etc. and the change of river ecosystem has a great impact on human life. Analyzing the impact of current climate changes on air and water temperature is an important thing in adapting to the climate changes. This study examined the effect of climate changes through analyzing air temperature trend for Nakdong river basin and analyzed the elasticity of air-water temperature to understand the effect of climate changes on water temperature. For analysis air temperature trend, collecting air temperature data from the National Weather Service on main points in Nakdong river basin, and resampling them at the units of year, season and month, used as data for air temperature trend analysis. Analyzing for elasticity of air-water temperature, the data were collected by the Water Environment Information system for water temperature, while air temperature data were collected at the National Weather Service point nearest in the water temperature point. And using the results of trend analysis and elasticity analysis, the effect of climate changes on water temperature was examined estimating future water temperature in 20 years and 50 years after. It is judged that analysis on mutual impact between factors such as heat budget, precipitation and evapotranspiration on river water temperature affected by climate changes and river water temperature is necessary.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6561-6568
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• 2015

Background: Smokeless tobacco (SLT) has long been realized as an important component of the fight for global tobacco control. It still remains a major problem in countries like India, Bangladesh and Nepal. The objective of this study was to estimate the trends of SLT use in three countries of the SEARO WHO office. Materials and Methods: We used data from national surveys in three countries (Bangladesh, India and Nepal) to estimate trends in prevalence of current SLT use. All available nationally representative data sources were used. Estimates were weighted, age standardized and given along with 95% confidence intervals. Significance of linear trend in prevalence over time was tested using the Cochrane-Armitage test for trend. A p value of less than 0.05 was considered statistically significant. Results: We identified three surveys for Bangladesh, three for India and four for Nepal that met the selection criteria (such as Demographic and Health Surveys, WHO-STEPwise approach to Surveillance and Global Adult Tobacco Surveys). A significantly increasing trend was noticed in the prevalence of current SLT use among Bangladeshi men (20.2% to 23%, p=0.03). In India, a similar significantly increasing trend was seen among men (27.1% to 33.4%, p<0.001) and women (10.1% to 15.7%, p<0.001). In Nepal, there was a no significant trend among both men (39.1% to 31.6%, p=0.11) and women (5.6% to 4.7%, p=0.49). Conclusions: In the study countries SLT use has remained at alarmingly high levels. Usage trends do not show any signs of decline in spite of control efforts. Tobacco control measures should focus more on controlling SLT use.

• 한국콘텐츠학회논문지
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• 제20권2호
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• pp.96-104
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• 2020

온라인 쇼핑몰의 활성화로 소비자들의 소비 활동이 활발해짐에 따라 기업들은 매출 증대를 위해 소비자의 상품 트렌드 분석을 수행하고 있다. 기존의 상품 트렌드 분석 기법들은 온라인 쇼핑몰 사용자의 활동만을 고려하여 분석하기 때문에 구매 이력이 없거나 새로운 상품에 대한 트렌드를 파악하기 어렵다. 본 논문에서는 쇼핑몰에서 사용자의 트렌드와 잠재적 고객의 트렌드를 분석하기 위해 온라인 쇼핑몰 데이터와 소셜 네트워크 데이터를 결합한 트렌드 분석 기법을 제안한다. 제안하는 기법은 서비스 내 데이터 분석을 위해 사용자의 활동로그를 분석하고 활동 로그가 없는 잠재적인 사용자들의 관심도를 반영하기 위해 소셜 네트워크 데이터에서 단어 집합 추출을 통해 생성한 핫 토픽을 결합하였다. 최종적으로 상품 지수와 소셜 네트워크에서의 언급수를 활용하여 시간에 따른 상품 트렌드 변화를 탐지한다. 소셜 네트워크 데이터를 활용한 성능 평가를 통해 제안하는 기법의 우수성을 입증한다.

• 한국방재학회 논문집
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• 제9권6호
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• pp.17-30
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• 2009

본 연구에서는 강수량, 월 최대강수량, 강수일수, 일강수량 20 mm, 30 mm 및 80 mm 이상인 일수의 장기추세의 통계적 유의성을 비모수 검정법인 Mann-Kendall 검정기법과 62개 지점의 1905년부터 2004년 기간 사이의 자료를 이용하여 분석하였다. 한반도 강수특성은 연강수량과 월 최대강수량의 증가, 강수일수 감소 그리고 20 mm, 30 mm, 80 mm 이상의 일강수를 가진 강수일수 증가로 요약될 수 있다. 또한 자료의 월별 추세분석 결과는 1, 5, 6, 7, 8, 9월 강수량과 월 최대강수량은 증가추세를 보이고 3, 4, 10, 11, 12월에는 감소추세를 보인다. 또한 6, 7, 8, 9월의 일강수량 20 mm와 30 mm 이상인 강수일수는 증가추세를 보였다. 그러나 Mann-Kendall 검정결과 90%와 95% 유의수준에 대하여 유의한 증감추세를 가지는 지점의 비율은 매우 낮았다. 이러한 결과는 각 변수의 선형 증감에 따른 장기 변동보다 자료들이 가지고 있는 분산형태의 불확실성이 매우 우세함을 의미하므로 수자원 계획 등에 반영하여야 할 것이다.

• 한국해양학회지:바다
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• 제23권2호
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• pp.63-75
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• 2018

본 연구에서는 분위회귀를 이용하여 1993~2016년 동안의 한반도 조위 자료의 장주기 선형 추세를 분석하였다. 일반 선형회귀(OLS: Ordinary Least Square)와 50% 중간 분위 회귀 결과를 비교했을 때 특히 황해에서 약 2~3 mm/year의 회귀 결과의 차이를 발견하였으며, 이는 극한 값 변화에 기인함을 확인할 수 있었다. 또한 해역별로 하위(1%) 분위와 중간(50%) 분위, 상위(99%) 분위의 값이 모두 다르게 나타났다. 황해의 대부분 지역에서는 상위 분위와 하위 분위가 모두 증가하는 경향을 나타냈으나, 유의미한 "상향 발산형" 회귀 결과를 보였다. 이는 상위 분위가 중간 분위에 비해 유의미하게 크게 나타나는 경향을 의미한다. 대한민국 남해안에서는 상위 분위가 하위 분위보다 더 작은 증가 값을 가지는 "상향 수렴형" 회귀 결과가 특징적으로 나타났다. 이러한 경향은 조화 분석을 통해 알려진 조석 분조들을 제거한 결과에서는 없어지는 것을 확인하였다. 그러므로 분위 회귀의 지역적 특성은 조석 세기의 장주기 변동과 연관이 있다고 추측된다.

• Journal of Animal Science and Technology
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• 제65권4호
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• pp.792-803
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• 2023

This study aimed to assess the impact of weather events on the sorghum-sudangrass hybrid (Sorghum bicolor L.) cultivar production trend in the central inland region of Korea during the monsoon season, using time series analysis. The sorghum-sudangrass production data collected between 1988 and 2013 were compiled along with the production year's weather data. The growing degree days (GDD), accumulated rainfall, and sunshine duration were used to assess their impacts on forage production (kg/ha) trend. Conversely, GDD and accumulated rainfall had positive and negative effects on the trend of forage production, respectively. Meanwhile, weather events such as heavy rainfall and typhoon were also collected based on weather warnings as weather events in the Korean monsoon season. The impact of weather events did not affect forage production, even with the increasing frequency and intensity of heavy rainfall. Therefore, the trend of forage production for the sorghum-sudangrass hybrid was forecasted to slightly increase until 2045. The predicted forage production in 2045 will be 14,926 ± 6,657 kg/ha. It is likely that the damage by heavy rainfall and typhoons can be reduced through more frequent harvest against short-term single damage and a deeper extension of the root system against soil erosion and lodging. Therefore, in an environment that is rapidly changing due to climate change and extreme/abnormal weather, the cultivation of the sorghum-sudangrass hybrid would be advantageous in securing stable and robust forage production. Through this study, we propose the cultivation of sorghum-sudangrass hybrid as one of the alternative summer forage options to achieve stable forage production during the dynamically changing monsoon, in spite of rather lower nutrient value than that of maize (Zea mays L.).

• 정보과학회지
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• 제31권2호
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• pp.54-62
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• 2013

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.779-783
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• 1992

In recent years, it is strongly required to supply high quality electrical power without insulation failure in distribution power cables. Therefore the exact measurement and judgment ar out deterioration degree of cables are essential to increase that supplying reliability. This paper will introduce various diagnostic methods of off-line and live-line cables also propose the judgement criteria and newly trend of diagnostic technique at present.

• Environmental Analysis Health and Toxicology
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• 제16권2호
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• pp.103-114
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• 2001

Worldwide trend of waste treatment technology is rapidly transferring from "incineration system" to "gasification & melting system" which can derive the resources from waste and charge no more environmental burden to nature. And therefore it is necessary for our country to adopt gasification & melting system urgently to present the land pollution and lack of landfill area. Among several gasification and melting processes Daewoo-Thermoselect gasification and melting system is the representative process which can transfer waste to resources such as sin-gas, molten slag, metal hydroxide, mixed salt and sulfur through the process of compaction, degasification, gasification and melting.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.15-22
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• 2002

The modern welding technology hue more then 100 years history, and during that period, the welding has been playing an important role in the development of the manufacturing processes/systems as a key technology. In the time we enter the 21st century, it is question how to develop the innovative and attractive welding technology, in particular by the younger generation. The present report discussed the future trend of welding engineering mainly in Japan after reviewing the previous growth of welding engineering.