• 제목/요약/키워드: Concentration Estimation

검색결과 943건 처리시간 0.028초

해양레저용 요트의 마스트 러그 형상에 따른 응력집중계수 추정 (An Estimation of the Stress Concentration Factor for Mast Lug of Yacht with Different Shapes)

  • 노지선;오동진;김명현
    • Journal of Welding and Joining
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    • 제30권1호
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    • pp.72-77
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    • 2012
  • Recently, according to the increase of income and development of quality of life, the leisure industry has been developed. In particular, the interest of design and manufacture technology of leisure yacht has significantly increased. However, domestic market of leisure ships is currently in its initiating stage. So research and development for structural strength of leisure yacht need to be investigated. In this study, lug of yacht's mast which is known for a critical damage region is explicitly considered. This paper deals with the estimation of stress concentration factors (SCFs) for lug of yacht's mast depending on dimensions of lug using hot spot stress. Also, SCF formulae is suggested using parametric study.

Multiple change-point estimation in spectral representation

  • Kim, Jaehee
    • Communications for Statistical Applications and Methods
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    • 제29권1호
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    • pp.127-150
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    • 2022
  • We discuss multiple change-point estimation as edge detection in piecewise smooth functions with finitely many jump discontinuities. In this paper we propose change-point estimators using concentration kernels with Fourier coefficients. The change-points can be located via the signal based on Fourier transformation system. This method yields location and amplitude of the change-points with refinement via concentration kernels. We prove that, in an appropriate asymptotic framework, this method provides consistent estimators of change-points with an almost optimal rate. In a simulation study the proposed change-point estimators are compared and discussed. Applications of the proposed methods are provided with Nile flow data and daily won-dollar exchange rate data.

Software Sensing for Glucose Concentration in Industrial Antibiotic Fed-batch Culture Using Fuzzy Neural Network

  • Imanishi, Toshiaki;Hanai, Taizo;Aoyagi, Ichiro;Uemura, Jun;Araki, Katsuhiro;Yoshimoto, Hiroshi;Harima, Takeshi;Honda , Hiroyuki;Kobayashi, Takeshi
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제7권5호
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    • pp.275-280
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    • 2002
  • In order to control glucose concentration during fed-batch culture for antibiotic production, we applied so called “software sensor” which estimates unmeasured variable of interest from measured process variables using software. All data for analysis were collected from industrial scale cultures in a pharmaceutical company. First, we constructed an estimation model for glucose feed rate to keep glucose concentration at target value. In actual fed-batch culture, glucose concentration was kept at relatively high and measured once a day, and the glucose feed rate until the next measurement time was determined by an expert worker based on the actual consumption rate. Fuzzy neural network (FNN) was applied to construct the estimation model. From the simulation results using this model, the average error for glucose concentration was 0.88 g/L. The FNN model was also applied for a special culture to keep glucose concentration at low level. Selecting the optimal input variables, it was possible to simulate the culture with a low glucose concentration from the data sets of relatively high glucose concentration. Next, a simulation model to estimate time course of glucose concentration during one day was constructed using the on-line measurable process variables, since glucose concentration was only measured off-line once a day. Here, the recursive fuzzy neural network (RFNN) was applied for the simulation model. As the result of the simulation, average error of RFNN model was 0.91 g/L and this model was found to be useful to supervise the fed-batch culture.

3D-ESPI 시스템을 이용하여 결정된 응력집중계수가 피로수명에 미치는 영향에 관한 연구

  • 김성찬
    • 선박안전
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    • 제12권
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    • pp.36-43
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    • 2003
  • Fatigue life estimation by the theoretical stress concentration factors are, in general, considerably different from test results. And in calculating stress concentration factor, it is very difficult to consider actual geometry and material property which are the notch shapes, imperfections or defects of materials such as porosities inclusions and casting defects, etc. Therefore, the paper deals with the experimental method to find out the more exact stress concentration factors by measuring the strain distributions on each specimen by 3D-ESPI(Electronic Speckle Pattern Interferometry) System. Then the fatigue lives are compared between theoretical calculations using stress concentration factors determined by 3D-ESPI system and fatigue test results

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등유의 소화성능 평가를 위한 불활성 가스의 소화농도에 관한 연구 (A Study on the Extinction Concentration of Inert Gas for Extinction Performance Estimation of Kerosene)

  • 최재욱
    • 한국안전학회지
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    • 제22권3호
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    • pp.34-38
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    • 2007
  • The experiment was done to investigate extinguishing concentrations of different inert gases of verying concentrations made in contact with Kerosene. The experimental results obtained are as follows; at a standard amount of air flow was 40L/min, the extinguishing concentration of Argon, Nitrogen, Carbon dioxide and Helium for Kerosene were 36.5%, 27.3%, 17.4%, 12.3%, respectively. And, according to these results, Helium of 12.3% showed the lowest extinguishing concentration.

Solution of periodic notch problems in an infinite plate using BIE in conjunction with remainder estimation technique

  • Chen, Y.Z.
    • Structural Engineering and Mechanics
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    • 제38권5호
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    • pp.619-631
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    • 2011
  • This paper provides a complex variable BIE for solving the periodic notch problems in plane plasticity. There is no limitation for the configuration of notches. For the periodic notch problem, the remainder estimation technique is suggested. In the technique, the influences on the central notch from many neighboring notches are evaluated exactly. The influences on the central notch from many remote notches are approximated by one term with a multiplying factor. This technique provides an effective way to solve the problems of periodic structures. Several numerical examples are presented, and most of them have not been reported previously.

농작물중(農作物中) 중금속오염도(重金屬汚染度)와 1일섭취량(日攝取量) 및 허용기준설정(許容基準設定)에 관(關)한 연구(硏究) (A Study on the Crops Pollution with Heavy Metal)

  • 염용태;배은상;윤배중
    • Journal of Preventive Medicine and Public Health
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    • 제13권1호
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    • pp.3-12
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    • 1980
  • Certain heavy metals which may lead peoples to poisonous status are widely used in industry and their uses have been increasing along with rapid industrialization of this country. Such an increasement of metal uses aggravates the status of environmental pollution affecting foodstuffs which are the most important life supporting factor of animal and humanbeing. Concerning the safety measures to minimize food-borne transmission of such hazardous metals, surveillance is the backbone of them and probably more so with a potential problem such as intoxication. Theoretically, this surveillance should include the determination of levels of heavy metal toxicants in foods, the determination of food consumption patterns and typical total diet, and the estimation of total load of the metal contaminant from all sources of exposure including air, water, and occupational sources. In recent year, actually, such estimates on the total daily intake of some heavy metals from foods have been made in several developed countries and a wide variation of date by season, locality, and research method was recognized. Also in this country, this kind of research data is vitally needed to make up for the serious shortage or lack of references to estimate the total amount of heavy metal intake of the people. In this study, a modification model for estimation of the total daily intake of cadmium copper, nickel, zinc, and lead through foods was applied and concentrations of the above metals in crops cultivated in this country were measured with atomic absorption spectro photometer to get the following results. 1. Level of heavy metal concentration in crops Generally, the levels of such metals in essential crops such as rice, cucumber, radish. chinese cabbage, apple, pear, grape, and orange are similar or lower than those in Japan and other developed countries. By the way, a striking result on cadmium concentration was increasement of its concentration in rice from $0{\sim}0.035ppm$ in 1970 to 0.11ppm in this study. However, the value is still far below the. Japanese Permissible Lebel of 1.0ppm. 2. Estimation of total daily intake per capita from foods A new model for estimation was devised utilizing levels of metal concentration in foods, amount of food consumed, and other food factors. Based on the above method, the daily intake of cadmium was estimated to be $70.53{\mu}g/man/day$ in average which was as high as the Limit Value of ILO/WHO(up to $71.4{\mu}g/man/day$). Also, 3.89mg of Zinc, 1.65mg of cuppor, 0.32mg of lead were given as the total daily intake per capita by this research. 3. Efficacy of washing or skinning to decrease the amount of metals in crops After washing the crops sufficiently with commercial linear alkylate sulfonate, the concentration of heavy metals could be reduced to $50{\sim}80%$ showing decreasement rate of $20{\sim}50%$. Also, after skinning the fruits, decreasement rate of the heavy metal concentration shelved $0{\sim}50%$.

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감천 유역의 TOC 농도 추정을 위한 회귀 모형 개발 및 평가 (Development and Evaluation of Regression Model for TOC Contentation Estimation in Gam Stream Watershed)

  • 정강영;안정민;이경락;김신;유재정;천세억;이인정
    • 한국환경과학회지
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    • 제24권6호
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    • pp.743-753
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    • 2015
  • In this study, it is an object to develop a regression model for the estimation of TOC (total organic carbon) concentration using investigated data for three years from 2010 to 2012 in the Gam Stream unit watershed, and applied in 2009 to verify the applicability of the regression model. TOC and $COD_{Mn}$ (chemical oxygen demand) were appeared to be derived the highest correlation. TOC was significantly correlated with 5 variables including BOD (biological oxygen demand), discharge, SS (suspended solids), Chl-a (chlorophyll a) and TP (total phosphorus) of p<0.01. As a result of PCA (principal component analysis) and FA (factor analysis), COD, TOC, SS, discharge, BOD and TP have been classified as a first factor. TOCe concentration was estimated using the model developed as an independent variable $BOD_5$ and $COD_{Mn}$. R squared value between TOC and measurement TOC is 0.745 and 0.822, respectively. The independent variable were added step by step while removing lower importance variable. Based on the developed optimal model, R squared value between measurement value and estimation value for TOC was 0.852. It was found that multiple independent variables might be a better the estimation of TOC concentration using the regression model equation(in a given sites).

강우강도를 고려한 도달시간 산정식 (The Time of Concentration Considering the Rainfall Intensity)

  • 유동훈;김종희;이민호;이상호
    • 한국수자원학회논문집
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    • 제44권7호
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    • pp.591-599
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    • 2011
  • 도달시간 산정식에서 강우강도는 고려되어야 할 매우 중요한 요소이지만 일반적으로 강우강도식의 복잡함 때문에 도달시간 산정에서 강우강도를 충분히 고려하지 못하고 있는 실정이다. 본 연구에서는 도달시간 계산의 정확성을 높이기 위하여 강우강도와 재현기간을 도달시간 산정식의 유도에 포함시켰다. 강우강도식으로는 Sherman형 식을 사용하였고, 건설교통부에서 발행한 확률강우량도에서 독취한 강우강도 값으로 수식의 지역상수를 추정하였다. 그리고 확률강우량을 간결하게 계산하기 위하여 Sherman형 식의 지역상수를 등치선도로 나타냈다. 기존의 연구에서는 일반형 강우강도식을 대입하여 반복계산으로 도달시간을 산정하였지만, 본 연구에서는 Sherman형 강우강도식을 도달시간 수식에 대입함으로써 반복계산이 필요 없는 간단한 도달시간 식이 유도되었다. 연구 결과로부터, 도달시간 계산에 강우강도의 영향을 반영하기 위하여 Sherman형 식의 사용을 추천한다. 그리고 재현기간과 우리나라에서 위치가 정해지면, 강우강도식의 지역상수를 간편하게 추정할 수 있고, 강우강도가 고려된 도달시간을 계산할 수 있다.

호흡률법에 의한 하수의 질산화성 질소화합물 추정 (Estimation of Nitrifiable Nitrogen Compounds in Municipal Wastewater by Respirometry)

  • 김동한
    • 상하수도학회지
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    • 제21권3호
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    • pp.295-303
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    • 2007
  • Nitrogen compounds in municipal wastewater can be divided into biodegradable and nonbiodegradable fractions with biodegradability. Biodegradable nitrogen compounds can be removed through biological nitrification and denitrification processes, and nonbiodegradable nitrogen compounds affect the effluent quality of biological nutrient removal processes. The amount of nitrifiable nitrogen compounds, which are the sum of ammonia and biodegradable organic nitrogen, has been estimated by respirometry. Respirometry shows good estimation of the concentration of nitrifiable nitrogen when a synthetic sample of ammonium chloride is dosed. The estimated concentration of nitrifiable nitrogen compounds in municipal wastewater is close to ammonia concentration in municipal wastewater, but it is lower than that for the synthetic sample. If nitrogen assimilated into cell synthesis of nitrifiers and heterotrophs is considered, the total amounts of nitrifiable nitrogen compounds, which are nitrified and assimilated, could be more accurately estimated. The concentration of nitrifiable nitrogen compounds, which are biodegradable, is about 31 mg N/l, and this is 119% of ammonia and 94% of total nitrogen. Ammonia, nitrate, biodegradable organic nitrogen, and nonbiodegradable nitrogen are about 79%, 1%, 15%, and 5% of the total nitrogen in municipal wastewater, respectively.