• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.388-390
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• 2003

Recent trend of sensor-less control of induction motor applied for commuter trains in Japan is introduced. Although many inverter-fed Induction motor driven trains have been produced so far, most of them were slip frequency based conventional V/f control system using shaft encoder. There arises a new trend to apply speed sensor-less vector control., for this inverter-fed induction motor drive system. The purpose of sensor-less control is to save, cost and improve system reliability. Several sensor-less systems now under testing on the actual railway company. This paper describes the survey of the fundamental structure and feature of representative sensor-less systems mentioned above.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.558-560
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• 1997

In recent years, it becomes a worldwide trend that the power utilities focus their attention to the automation of their power plants and distribution systems, employing recent developed communication technologies. Following this trend, KEPCO has installed optical communication links along its power distribution lines and at the same time, has exhausted much efforts to implement its own Distribution Automation Systems(DAS) in possible early date. This paper presents some of initial design efforts toward KEPCO's DAS at KEPRI.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.998-1001
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• 2003

Recent trend of sensor-less control of induction motor applied for commuter trains in Japan is introduced. Although many inverter-fed induction motor driven trains have been produced so far, most of them were slip frequency based conventional V/f control system using shaft encoder. There arises a new trend to apply speed sensor-less vector control., for this inverter-fed induction motor drive system. The purpose of sensor-less control is to save, cost and improve system reliability. Several sensor-less systems now under testing on the actual railway company. This paper describes the survey of the fundamental structure and feature of representative sensor-less systems mentioned above.

• 한국융합학회논문지
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• 제4권1호
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• pp.15-20
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• 2013

게임 엔진은 게임 개발에 필요한 소프트웨어 구성 요소를 재사용할 수 있게 해주는 것으로 대표적인 게임 엔진으로는 언리얼 엔진, 크라이 엔진, 유니티3D 엔진 등이 있다. 본 논문에서는 이 3개의 엔진들을 중심으로 최근 기술 동향을 살펴보고 차세대 게임 엔진 동향을 논한다. 그리고 게임 제작에 관한 교육 방법을 제시한다.

• 대기
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• 제27권1호
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• pp.1-16
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• 2017

In this study, trends of upper jet stream characteristics (intensity, altitude, latitude, and longitude) over the Asia-North Pacific region during the recent 30 (1979~2008) years were analyzed by using four reanalysis datasets (CFSR, ERA-Int., JRA-55, MERRA). We defined the characteristics of upper jet stream as the averages of mass weighted wind speed, mass-flux weighted altitude, latitude and longitude between 400 and 100 hPa. Due to the vertical averaging of jet stream characteristics, our results reveal a weaker spatial variabilities and trends than previous studies. In general, the four reanalysis datasets show similar jet stream properties (intensity, altitude, latitude and longitude) although the magnitude and trends are slightly different among the reanalysis datasets. The altitude of MERRA is slightly higher than that of others for all seasons. The domain averaged intensity shows a weakening trend except for winter and the altitude of jet stream shows an increasing trend for all seasons. Also, the meridional trend of jet core shows a poleward trend for all seasons but it shows a contrasting trend, poleward trend in the continental area but equatorward trend in the Western Pacific region during summer. The zonal trend of jet core is very weak but a relatively strong westward trend in jet core except for spring and winter. The trends of jet stream characteristics found in this study are thermodynamically consistent with the global warming trends observed in the Asia-Pacific region.

• Asian Pacific Journal of Cancer Prevention
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• 제16권14호
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• pp.5859-5861
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• 2015

Background: Kidney cancer has shown an increasing trend in recent decades. This study aimed to determine change in the incidence rate between 2003 and 2009 in Iran. Materials and Methods: In this study, national cancer registry data were used. Crude incidence rates were calculated per 100,000 and age-standardized incidence rates (ASRs) were computed using the direct standardization method and the world standard population. Significant trend of incidence rates was examined by the Cochran-Armitage test for linear trend. Results: A total of 6,944 cases of kidney cancer were reported. The incidence cases increased from 595 patients in 2003 to 1,387 patients in 2009. Sex ratio (male to female) was 1.67. ASR also increased from 1.18 in 2003 to 2.52 in 2009 per 100,000, but the increasing trend was not significant. Conclusions: A slow increasing trend of incidence rate was observed in the study population. This may be due to an increase of risk factors. It is suggested to perform a study on risk factors for the cancer.

• 한국실내디자인학회논문집
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• 제22권3호
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• pp.81-90
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• 2013

There has been current trend running through each generation. All the leading areas in the fashion, art, architect industries etc. are absorbing the needs of the mass users and getting popular and high attentions from the society. One of recent trends are the interior design utilizing the aged style of materials such as bricks, antique and vintage objets. It is applied not only for the cafeteria, movie theater, museum but the cultural space. It reflects the brand-new and Utopian interpretation of design longings for the nostalgia and the old ages. This goes back to the picturesque aesthetics in the 1980s. The term "picturesque" means "picture-like". And it originated from the Utopian vision taken from the landscape paintings of English aristocrat's trip to Europe. it mainly reflects people's longing for the nostalgia and their the happy days in the past. In recent days of bad economies, it has been found in various areas from people's desire for the prosperity in the last days. The objective of this study is to examine the up-current trend of picturesque aesthetics and see its characteristics and how it can be applied to the interior design. And the feasibility study for the necessity of the picturesque aesthetics, any spatioperceptual elements and capable space for human beings to be made for an eclectic space in the desolate modern day life.

• 한국식품위생안전성학회지
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• 제2권4호
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• pp.215-237
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• 1987

This study was conducted to prepare some information about food poisoning outbreaks in Korea. In this study, all reported data were reviewed, but the data during recent ten years (1977-1986) were mainly analyzed because of data shortage. We used three year moving averages in order to investigate the trend to food poisoning outbreaks, by year, foodborne pathogens, specific foods, and place food contaminated or mishandled.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1027-1029
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• 2000

Electric vehicle(EV), hybrid electric vehicle(HEV) and fuel cell electric vehicle(FEV) are seen as one way of reducing the harmful effects of traffic and of improving energy efficiency. Therefore the status and developing trend of the EV, HEV and FEV are given in this paper. A major aspect of alternative drive trains is the electric drive train. The automotive aspect in developing electric drive trains is emphasized.

• East Asian mathematical journal
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• 제35권4호
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• pp.489-508
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• 2019

In this paper we used text mining method to analyze journals of mathematics education posterior to the year of 2016. To figure out trends of mathematics education research. we analyzed the key words largely mentioned in the recent mathematics education journals by Term Frequency and Term Frequency-Inverse Document Frequency method. We also looked at how these keywords match up with the key words that appear of education to prepare for future society. This result can infer the characteristics of mathematics education research in the aspect upcoming research topics.