• 한국대기환경학회지
• /
• 제21권2호
• /
• pp.169-178
• /
• 2005

A critical component of air pollution modeling is the representation of atmospheric flow fields within a model domain, since an accurate air quality simulation requires an accurate portrayal of the three-dimensional wind fields. The present study investigated data assimilation using surface observational data in the complex coastal regions to simulate a realistic atmospheric flow fields. Surface observational data were categorized into three groups (Near coastal region, Far coastal region 1, Far costal region 2) by the locations where the sites are. Experiments were designed according to the location of observational stations and MM5/CALPUFF was used. The results of numerical simulation of atmospheric flow fields are used as input data for CALPUFF which predicts dispersion fields of air pollutants. The result of this study indicated that data assimilation using data in the far coastal region 2 provided an attractive method for generating realistic meteorological fields and dispersion fields of air pollutants in Gwangyang area because data in the near coastal region are variable and narrow representation.

• Progress in Superconductivity
• /
• 제4권2호
• /
• pp.114-120
• /
• 2003

We employed a method eliminating a temporally partial principal component (PC) of multichannel-recorded neuromagnetic fields for excluding spatially correlated noises from event-evoked signals. The noises in magnetoencephalography (MEG) are considered to be mainly spontaneous neuromagnetic fields which are spatially correlated. In conventional MEG experiments, the amplitude of the spontaneous neuromagnetic field is much lager than that of the evoked signal and the synchronized characteristics of the correlated rhythmic noise makes it possible for us to extract the correlation noises from the evoked signal by means of the general PC analysis. However, the whole-time PC of the fields still contains a little projection component of the evoked signal and the elimination of the PC results in the distortion of the evoked signal. Especially, the distortion will not be negligible when the amplitude of the evoked signal is relatively large or when the evoked signals have a spatially-asymmetrical distribution which does not cancel out the corresponding elements of the covariance matrix. In the period of prestimulus, there are only the spontaneous fields and we can find the pure noise PC that is not including the evoked signal. Besides that, we propose a method, called the extended temporal decorrelation method (ETDM), to suppress the distortion of the noise PC from remanent evoked signal components. In this study, we applied the Partial Principal component elimination method (PPCE) and ETDM to simulated signals and the auditory evoked signals that had been obtained with our homemade 37-channel magnetometer-based SQUID system. We demonstrate here that PPCE and ETDM reduce the number of epochs required in averaging to about half of that required in conventional averaging.

• 한국토양비료학회지
• /
• 제49권4호
• /
• pp.368-374
• /
• 2016

The perennial edible wild plants such as Aster glehnii, Solidago virgaurea subsp. gigantean, Allium ochotense, Athyrium acutipinnulum, Aruncus dioicus var. kamtschaticus and Codonopsis lanceolata have cultivated as the main income crops introduced into the fields about 30 years ago in Ulleung island. Soil samples were collected from 190 fields and assessed the effects of management practices on soil chemical properties at wild edible plant fields under no-till system. The strong acidic soils of pH 5.4 or less were detected in 45% of the soil samples. The level of soil organic matter was being held at mean $63{\pm}28g\;kg^{-1}$, 2.7 times higher than upland soils in Korea. Available phosphate and exchangeable potassium showed more than recommended levels of upland crops as $680{\pm}489mg\;kg^{-1}$ and $1.94{\pm}1.7cmol_c\;kg^{-1}$, respectively. The fields of Solidago and Aster showing strong soil acidity and high level of available phosphate and water soluble $NO_3{^-}$ were distinguished from other crops in analysis of variance and principal component analysis of soil chemicals. These results suggested that high frequency of acidic soil and high levels of available $P_2O_5$, exchangeable $K_2O$ and water soluble $NO_3{^-}$ were accompanied with the use of urea and NPK-fertilizer based on nitrogen in the field. However, further research is needed to understand the appropriate management of fertilization and the prevention of soil acidification for wild edible plants.

• Journal of Information Science Theory and Practice
• /
• 제4권1호
• /
• pp.21-29
• /
• 2016

Given the difference in research performance in various scientific fields, this study aims to weight and valuate current indicators used for evaluation of scientific productions (publications), in order to adjust these indicators in comparison to each other and make possible a more precise evaluation of scientific productions. This is a scientometrics study using documentary, evaluative, and survey techniques. The statistical population consisted of 106 top Iranian researchers, scientists, and scientific and research managers. Then their research résumé information was gathered and analyzed based on research questions. In order to compare values, the data gathered from research production performance of the population was weighted using Shannon entropy method. Also, the weights of each scientific production importance according to expert opinions (extracted from other works) was analyzed and after adjustment the final weight of each scientific production was determined. A pairwise matrix was used in order to determine the ratios. According to the results, in the area of engineering sciences, patents (0.142) in the area of science, international articles (0.074) in the area of humanities and social sciences, books (0.174), and in the area of medical sciences, international articles (0.111) had the highest weight compared to other information formats. By dividing the weights for each type of publication, the value of each scientific production compared to other scientific productions in the same field and productions of other fields was calculated. Validation of the results in the studied population resulted in very high credibility for all investigated indicators in all four fields. By using these values and normalized ratios of publication indicators it is possible to achieve precise and adjusted results, making it possible to feasibly use these results in realistic policy making.

• 한국안전학회지
• /
• 제36권4호
• /
• pp.20-28
• /
• 2021

With an increase in the commercialization of electricity, and the development of advanced and large electric devices and various wireless radio wave services, concerns over the effects of electromagnetic fields on human health have increased. Accordingly, the World Health Organization encouraged the development of international standards by establishing the 'International Electromagnetic Fields Project' in 1996 based on studies on the harmful effects of electromagnetic fields on the human body. Moreover, the National Institute of Environmental Health Sciences (NIEHS) classified electromagnetic fields as possible carcinogens under Group 2B category, even though they have been found to have a weak correlation with those effects on human health. Mid-to-large-sized electric facilities used at industrial sites mostly adopt a commercial frequency of 60 Hz, and workers handling these facilities are exposed to such extremely low frequency (ELF) fields for a long time. A previous study suggested that exposure to ELF electromagnetic fields with frequency ranges from 0 to 300 Hz, even for a short time, at densities higher than 100 μT may have harmful effects on human body as it affects the activation of nerve cells in the central nervous system by inducing an electric field and current and stimulating muscles and the nervous system in the body. Such studies, however, focused on home appliances used by ordinary people, and research on facilities utilizing high-capacity current and operated by workers at industrial sites is lacking. Therefore, in this study, a 3000 kilowatt generator, which is a high-capacity electric facility employed at industrial sites, was investigated, and the size of the magnetic fields generated during its no-load and high-load operations per distance to produce a map was measured to reveal spots deemed hazardous according to domestic and international exposure standards. The findings of this study is expected to alleviate workers' anxiety about the harmful effects of magnetic fields on their body and to minimize the level of exposure during operations.

• 천문학회보
• /
• 제40권2호
• /
• pp.54.2-54.2
• /
• 2015

Within 100 pc of the Galactic Centre the tidal field is extremely strong. We investigate the survival of star clusters of different masses in strong tidal fields. We show that dense low-mass clusters are destroyed by strong tidal fields as the tidal fields add energy to the cluster. Only massive clusters (like the Arches) can survive for more than 1-2 Myr in strong tidal fields. Therefore, in Galactic Centre environments only massive young clusters should ever be observed.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
• /
• pp.138-147
• /
• 2002

This paper describes the present research status and plan of transmission & substation technology fields in KEPCO. The details are below: the overview of research environment in KEPCOC(KEPRI), the research results in 2001, the research items in 2002, and the long-term and short-term research plans in the field of transmission & substation technology, etc.

• 한국융합학회논문지
• /
• 제11권4호
• /
• pp.95-108
• /
• 2020

신종 코로나 바이러스(COVID-19)가 세계적으로 대유행하고 있다. 정부는 세계적인 전염병 확산에 대응할 수 있는 국가적 기술 역량 확보에 필요한 연구개발(R&D) 투자를 통해 향후 성장 동력을 확보하고 단기 경기 부양을 추진하고 있다. 따라서 코로나 바이러스에 대한 R&D 투자 및 연구현황을 종합적으로 파악하여 향후 R&D 기획의 방향성을 정립하기 위한 지식정보가 필요한 시점이다. 주요 해외 국가(미국, EU 등) R&D 과제를 기반으로 4개(세부 5개) R&D 영역을 도출하고, 국내 R&D 과제와의 비교분석을 통해 차별화된 2개 R&D 영역을 추가하였다. 제시된 6(세부 7개)개의 R&D 연구영역별 국내외 연구기관-연구과제명-과제규모-과제기간을 제시하였다. 동시에 학제 간 융합적 특징을 나타내는 R&D 과제를 제시하였다. 본 연구는 코로나 바이러스 관련 국내 경쟁 우위 영역과 차별화된 연구영역을 도출하여 현재 세계적으로 조명받고 있는 코로나 바이러스 검출 및 현장진단 역량의 우수성을 입증하고, 향후 집중 투자 영역을 제시하였다.

• 한국기술혁신학회:학술대회논문집
• /
• 한국기술혁신학회 2000년도 추계 학술대회(The 2000 Autumn Conference of korea Technology Inovation Society)(한국기술혁신학회)
• /
• pp.109-121
• /
• 2000

In the knowledge based economy, it's important to know the place where the proper knowledge locates as well as to produce the creative knowledge. This paper intends to clear up the linkage structure between research fields and its application areas. 2,135 proposals submitted to Korea Science and Engineering Foundation were analyzed to investigate the relationship between research fields and application areas. The results are as follows; first, 51.8% of the basic research is devoted to the advancement of knowledge, second, 40.8% of that is applicable to the industry, third, 49.9% of engineering and 20.2% of natural science research is applicable to the industry.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 하계학술대회 논문집 E
• /
• pp.2368-2370
• /
• 1999

A nationwide survey for electric and magnetic fields(EMFs) near overhead transmission lines has been conducted. The median values of the electric and magnetic fields of 208 transmission lines were 0.50 kV/m and 12.6 mG, respectively. The maximum values were 3.16 kV/m and 125 mG. The measured EMFs were compared with the calculated ones. The causes of the discrepancy between measured and calculated EMFs are also discussed.