• 제목/요약/키워드: Knowledge Distributions

검색결과 101건 처리시간 0.027초

Measurements of 50 Non-polar Organic Compounds Including Polycyclic Aromatic Hydrocarbons, n-Alkanes and Phthalate Esters in Fine Particulate Matter (PM2.5) in an Industrial Area of Chiba Prefecture, Japan

  • Ichikawa, Yujiro;Watanabe, Takehisa;Horimoto, Yasuhide;Ishii, Katsumi;Naito, Suekazu
    • Asian Journal of Atmospheric Environment
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    • 제12권3호
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    • pp.274-288
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    • 2018
  • Quantitative data of 50 non-polar organic compounds constituting $PM_{2.5}$ were continuously collected and analyzed from June 2016 to October 2017 (approximately 17 months) at Ichihara, one of the largest industrial areas in Japan. Target non-polar organic compounds including 21 species of polycyclic aromatic hydrocarbons (PAHs), 24 species of n-alkanes and 5 species of phthalate esters(PAEs) were simultaneously measured by gas chromatography/mass spectrometry. Basically, the average concentrations of the total PAHs, n-alkanes and PAEs in each season remained nearly level, and seasonal variations were little throughout the study period. These results suggest that the emission sources, which are not influenced by the seasons, are the dominant inputs for the target organic compounds. Diagnostic ratios of PAHs, assessment of n-alkane homologue distributions, carbon preference index, and the contribution of wax n-alkanes from plants were used to estimate source apportionments. These results indicate that anthropogenic sources were the main contributor for most PAHs and n-alkanes throughout the study period. The concentrations of PAEs selected in this study were low because emission amounts of these chemicals were little within the source areas of the sampling site. To our knowledge, this study is the first attempt to simultaneously measure a high number of non-polar organic compounds in $PM_{2.5}$ collected from the ambient air of Japan, and the resultant data will provide valuable data and information for environmental researchers.

Estimating USLE Soil Erosion through GIS-based Decision Support System

  • Her, Y.G.;Kang, M.S.;Park, S.W.
    • 한국농공학회논문집
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    • 제48권7호
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    • pp.3-14
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    • 2006
  • The objective of this study was to develop a GIS-based decision support system (GIS-USLE system) to estimate soil erosion and evaluate its effect on concentrated upland plots in Godang district, Korea. This system was developed for the ArcView environment using A VENUE script. Three modules were used in the GIS-USLE system, namely pre-processing, the USLE factors calculator module, and post-processing. This system benefits from a user friendly environment that allows users with limited computer knowledge to use it. This system was applied to 1,285 individual upland plots ranging from 0.005 to 1.347 ha in size with an average slope steepness of 14 %. The rainfall distributions were estimated using the three methods, namely Mononobe and Yen-Chow with Triangle and with Trapezoid type, and then used to calculate the rainfall erosivity factor. The soil erosion amounts from the 1,285 individual plots in the study area by 2 year return period with a 24h maximum rainfall amount of 154.6 mm were estimated at 5 tons/ha on average. Slope appeared to be the most important factor affecting soil erosion estimation, as expected. The prototype model was applied to the project area, and the results appeared to support the practical applications. By examining many fields simultaneously, this system can easily provide fast estimation of soil erosion and thus reveal the spatial pattern of erosion from fields in a region. This study will help estimate and evaluate soil erosion in concentrated upland districts and identify the best management practices.

낙법(烙法)에 관한 중의(中醫) 논문 고찰 (A Review of the TCM Articles about Cauterization Treatment)

  • 장호정;이현주;서형식
    • 한방안이비인후피부과학회지
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    • 제31권3호
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    • pp.60-66
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    • 2018
  • Objectives : The purpose of this study is to review the chinese published papers on cauterization of traditional chinese medicine. Methods : We searched chinese published papers from 1958 until May 2017 via CNKI(China National Knowledge Infrastructure) with the keyword "cauterization". We analyzed the studies covered cauterization medical treatment, and classified them by 5 categories including periods, type of study, treatment site, experiment target site, and cauterizing method. Results : We reviewed 112 chinese papers which include 10 Original articles, 43 Review articles, and 59 Case reports. Examining yearly distributions, we can see that research on cauterization is becoming more active than in the past. In classification of 93 clinical studies by treatment site, the number of research on Tonsillitis accounts for almost half(43 studies), followed by Sore throat(14 studies). Among 10 experimental studies, Eye is the most frequently targeted organ which was used to study high intra-ocular pressure(5 studies), and retinal ganglion cell(2 studies). Lastly, there are various methods of cauterization used in papers: Branding iron(54 studies), and Red-hot needle(24 studies) are two major heating methods. Conclusions : This analysis shows that studies on the application of cauterization have been actively conducted in China these days. Furthermore, up-to-date cauterizing methods have been developed such as electric type and microwave type beyond traditional ways. We expect this article will encourage further research on cauterization in order to apply it to a variety of diseases. Then, it could become one of new effective medical treatments in Korean medicine.

RSNT-cFastICA for Complex-Valued Noncircular Signals in Wireless Sensor Networks

  • Deng, Changliang;Wei, Yimin;Shen, Yuehong;Zhao, Wei;Li, Hongjun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권10호
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    • pp.4814-4834
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    • 2018
  • This paper presents an architecture for wireless sensor networks (WSNs) with blind source separation (BSS) applied to retrieve the received mixing signals of the sink nodes first. The little-to-no need of prior knowledge about the source signals of the sink nodes in the BSS method is obviously advantageous for WSNs. The optimization problem of the BSS of multiple independent source signals with complex and noncircular distributions from observed sensor nodes is considered and addressed. This paper applies Castella's reference-based scheme to Novey's negentropy-based algorithms, and then proposes a novel fast fixed-point (FastICA) algorithm, defined as the reference-signal negentropy complex FastICA (RSNT-cFastICA) for complex-valued noncircular-distribution source signals. The proposed method for the sink nodes is substantially more efficient than Novey's quasi-Newton algorithm in terms of computational speed under large numbers of samples, can effectively improve the power consumption effeciency of the sink nodes, and is significantly beneficial for WSNs and wireless communication networks (WCNs). The effectiveness and performance of the proposed method are validated and compared with three related BSS algorithms through theoretical analysis and simulations.

격자구조모델을 이용한 선체 PE블록의 반목 반력 해석 시스템 개발 (Three-Dimensional Grillage Analysis of Reaction Forces on Supports of Pre-Erection Block)

  • 류철호;김성찬;김동근
    • 한국해양공학회지
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    • 제27권4호
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    • pp.1-8
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    • 2013
  • Many PE (pre-erection) blocks are supported by wooden, concrete, or steel supports when they are stocked in the outdoor areas of a shipyard. Their positions and numbers are planned on the basis of the workers' experience. Recently, many shipyards have been making PE blocks with various shapes and weight distributions because of the variety of ships and building technologies. Therefore, it is now necessary to deal with blocks that they have no experience with. We propose a method to conveniently and quickly evaluate the structural safety of PE block supports, without the need for special knowledge and technology related to structural analysis. This method can reduce the large number of man hours (MH) normally needed for the analysis. The three-dimensional grillage analysis is performed for a simplified grillage model of a PE block. For efficiency, the grillage model of the PE block is automatically built from its three-dimensional CAD model, and its weight is also automatically distributed on the grillage model. The integrated system has been comprehensively implemented to perform the grillage analysis for the reaction forces on block supports. This paper describes how to make a grillage model of a PE block and estimate the weight distribution of the block on this grillage model. These steps are verified by comparing the supports reaction forces to those of the 3D finite element analysis for the PE blocks that are provided by a shipyard.

콘크리트재료의 열특성 및 수화열 해석 (Characterization of Thermal Properties of Concrte and Temperature Prediction Model)

  • 양성철
    • 콘크리트학회지
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    • 제9권2호
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    • pp.121-132
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    • 1997
  • 콘크리트의 열해석은 콘크리트 초기온도, 환경조건 및 시멘트의 수화 등에 의해 특징지워진다. 이러한 상호관계를 모두 고려한 프로그램을 만들어서, 콘크리트재료의 열특성과 환경조건을 감안한 콘크리트 구조물의 온도해석을 하였다. 시멘트 수화의 특성으로는 활성화에너지, 단위열량, 수화열이 있으며 이러한 인자들에 의해 콘크리트의 내부열 발생이 영향을 받는다. 본 연구에서는 활성화에너지와 수화열을 상대강도-등가재령모델에 의해 구했으며, 단위열량은 등온열량측정법에 의해 실험적으로 구하였다. 또한 콘크리트 구조물의 온도분포를 실험적으로 구하여 수치해석모델과 비교하였다. 먼저 위에서 제시된 모든 조건들에 대한 parametric 해석을 실시하여 프로그램의 신뢰성을 확보하였다. 그리고 원주형시편을 만들어서 온도분포 및 변화를 측정하여 수치해석에 의해 예측된 온도분포와 비교하였다.

퍼지메쉬를 이용한 3차원 균열에 대한 응력확대계수 해석 시스템 (Stress Intensity Factor Analysis System for 3D Cracks Using Fuzzy Mesh)

  • 이준성;이은철;최윤종;이양창
    • 한국지능시스템학회논문지
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    • 제18권1호
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    • pp.122-126
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    • 2008
  • 상용화된 FEM 코드와 3차원 솔리드 모델러를 통합하여 3차원 균열에 대한 자동 응력확대계수 해석 시스템을 개발하였다. 하나 또는 몇 개의 3차원 균열을 포함하는 기하학적 모델을 정의한다. 시스템에 저장된 몇 개의 절점패턴을 선택하면 자동적으로 퍼지지식 처리기법을 이용한 기하학적 모델 전 영역에 절점들이 중첩되어진다. 절점들은 생성되어지고 데로우니삼각화 법에 의한 사면체 솔리드요소가 생성되어진다. 최종적으로 완전한 유한요소 모델이 생성되어져 응력해석을 수행하게 된다. 본 논문은 몇몇 함수들을 실현시키기 위한 방법론에 대해 묘사하고 있으며 시스템의 타당성을 제시하였다.

비강내 주기유동장의 실험적 해석에 관한 연구 (The experimental research on periodic airflow in human nasal cavity)

  • 김성균;손영락;신석재
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.1687-1692
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    • 2004
  • CT 사진을 이용하여 살아있는 사람의 비강 형상을 얻고 RP 를 이용하여 모형을 만들고 이 모형 으로 정교한 비강 유로 모형을 제작하였고, 호흡을 정확하게 모사하는 펌프를 만들었다. 사람의 호흡 데이터를 이용하여 캠을 제작하고 대형 피스 톤 펌프를 만들어 사람의 호흡을 정확 하게 모사 하였다. 이를 이용하여 생리적 주기를 갖는 비강 내 유동에 대한 결과를 획득하고 기존의 일정유량 하의 실험결과와 비교 분석하였다.

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키워드 분포를 고려한 효과적 특허검색기법 (Searching Patents Effectively in terms of Keyword Distributions)

  • 이우기;송종수;강민구
    • 정보화연구
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    • 제9권3호
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    • pp.323-331
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    • 2012
  • 지식정보화 시대의 본격화와 함께 지식재산권, 그 중에서도 특허의 중요성이 더욱 커져가고 있다. 이에 따라 효율적인 특허정보 검색방법의 필요성이 높아지고 있지만, 기존의 특허검색 엔진은 불리언 모델을 기반으로 단어의 존재 여부만을 파악하는 방식으로 검색결과에 노이즈 데이터가 너무 많이 포함되어 특허 검색에 오랜 시간을 허비하게 만들므로 '전문검색가'들이 수동으로 찾아주고 있는 실정이다. 이에 본 논문에서는 기존의 일반적 문서검색과 특허검색과의 차이점을 밝히고, 기존 특허검색의 한계성을 분석한다. 나아가 특허검색에 특화된 효과적 방법론 제안하여 검색 키워드가 각 특허 문서 내에서 차지하는 중요도와 각 문서 내에서 키워드 사이의 관계성을 파악하고 이에 대한 랭킹을 정하여 키워드와 관계성이 높은 특허가 상위에 랭크하며 노이즈 데이터를 하위에 랭크 함으로써 검색 결과에서 노이즈 데이터의 비율을 대폭 줄이는 방법을 제안한다. 마지막으로 실험을 통하여 Kipris 검색 결과와 비교함으로써 제안한 방법론의 우수성을 입증하였다.

분위회귀분석을 이용한 개업 치과의사의 의료수익과 소득에 미치는 요인 (Factors Associated with Dental Revenue and Income of Self-Employed Dentist by Using a Quantile Regression Method)

  • 최형길;김명기
    • 보건행정학회지
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    • 제25권3호
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    • pp.240-251
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    • 2015
  • Background: Dentist's income is quite variable. We investigate the factors underlying the distribution of dental revenue and dentist income. Methods: Financial and structural variables of private dental practices(N=13,967) were examined with 2010 Economic Census microdata which include non-insurance revenue. We conducted quantile regression method(QRM) and ordinary least square(OLS) in treating skewness and heteroskedasticity of distributions. The effective estimation for the upper and lower range of distribution becomes possible by QRM. Results: Mid-career dentists are shown to have higher revenue and income. Male dentists achieve the higher revenue and income than female dentists in all quantiles. Group practices show lower income per owner than solo practices significantly. The revenue and income are increased with increasing size of clinics. The high cost in renting the clinic office is found to have a big positive effect on the revenue but a little positive effect on the income. Interestingly the density of dentists shows negative effect on the lowest quantile of the revenue but positive effect on the highest quantile. The lowest quantile of the revenue in the capital areas have the relatively high revenue. The lowest quantile of the income in metropolitan city show higher income than those in other areas significantly. Conclusion: The suggested QRM is shown to have more effective and efficient tool in finding out determinants of dentists' revenue and income of our concern. The results of this study are expected to be employed for dentists preparing for the opening practices in their organizational settings and locational selections. The distributional efficiency of dental human resources could be accomplished if policy makers guide dentists with this knowledge.