• 제목/요약/키워드: geometric mean

검색결과 747건 처리시간 0.028초

고정식 메디아법을 이용한 선박의 오폐수 처리 (Ship Sewage Treatment Using Fixed Media Method)

  • 한상화;이대호;강부녕;배상범;윤종문
    • 한국해양환경ㆍ에너지학회지
    • /
    • 제13권2호
    • /
    • pp.99-104
    • /
    • 2010
  • 본 연구는 선박에서 발생되는 오폐수를 시중에서 많이 사용되고 있는 Poly Propylene를 이용한 고정식 메디아법의 처리효과를 검증하고, MLTM 및 IMO의 MEPC에서 규정하는 2010년 1월 1일 이후 선박에 설치되는 선박분뇨처리 장치의 처리수의 처리 기준에 적합하고 현장에 적용 가능한 선박분뇨처리장치를 Pilot Scale을 통해 개발 가능성을 고찰하였다. 배출수의 pH 기하평균은 7.68이고, $BOD_5$ 기하평균은 7.28 mg/l, $COD_{cr}$ 기하평균은 48.39 mg/l, TSS 기하평균은 18.00 mg/l, 잔류염소 기하평균은 0.19 mg/l, 분원성 대장균 기하평균은 1 cells/100 ml로 측정되었다. 각 항목별 처리효율은 $BOD_5$ 97.4%, $COD_{cr}$ 96.4%, TSS 97.6%로 높은 처리효율을 나타났으며, 개발한 선박분뇨처리 장치는 국토해양부 및 MEPC의 해양오염방지설비 성능시험 규정에 적합한 제품으로 판정되었다.

기하학적 평균 필터에 의한 자연스러운 움직임 편집 (On Natural Motion Editing by a Geometric Mean Filter)

  • 김진옥
    • 인터넷정보학회논문지
    • /
    • 제5권2호
    • /
    • pp.41-47
    • /
    • 2004
  • 최근 움직임 포착 시스템은 애니메이션 연구 분야에 가장 활발하게 적용되고 있다. 움직임 데이터의 포착은 움직임 포착 시스템을 실제 배우의 움직임과 연결하여 이루어진다. 본 연구는 기하학적 평균 필터를 이용하여 움직임 데이터를 편집하는 방법에 대해 다룬다. 포착한 움직임 데이터에 잡음이 끼면 부자연스러운 동작을 생성하기 때문에 동작을 자연스럽게 만들어 내는 중간 과정이 필요한데 기하학적 평균 필터를 이용하여 자연스러운 동작을 생성할 수 있도록 한 것이다. 실험 결과는 기하학적 평균필터가 다양한 공간필터 중에서 움직임 데이터의 잡음을 제거하는데 가장 우수함을 보여준다. 본 연구의 제안 방법은 실시간 애니메이션, 가상현실, 3D 응용분야등에 다양하게 응용 가능하다.

  • PDF

A NEW FIFTH-ORDER WEIGHTED RUNGE-KUTTA ALGORITHM BASED ON HERONIAN MEAN FOR INITIAL VALUE PROBLEMS IN ORDINARY DIFFERENTIAL EQUATIONS

  • CHANDRU, M.;PONALAGUSAMY, R.;ALPHONSE, P.J.A.
    • Journal of applied mathematics & informatics
    • /
    • 제35권1_2호
    • /
    • pp.191-204
    • /
    • 2017
  • A new fifth-order weighted Runge-Kutta algorithm based on heronian mean for solving initial value problem in ordinary differential equations is considered in this paper. Comparisons in terms of numerical accuracy and size of the stability region between new proposed Runge-Kutta(5,5) algorithm, Runge-Kutta (5,5) based on Harmonic Mean, Runge-Kutta(5,5) based on Contra Harmonic Mean and Runge-Kutta(5,5) based on Geometric Mean are carried out as well. The problems, methods and comparison criteria are specified very carefully. Numerical experiments show that the new algorithm performs better than other three methods in solving variety of initial value problems. The error analysis is discussed and stability polynomials and regions have also been presented.

일부 제련 및 리사지 사업장에서 공기중 납 노출농도의 변화 (The change of air lead concentrations in litharge making and smelting industries)

  • 최재욱;김남수;조광성;함정오;이병국
    • 한국산업보건학회지
    • /
    • 제20권1호
    • /
    • pp.10-18
    • /
    • 2010
  • To provide necessary information for future environmental monitoring of smelting and litharge making industries in Korea, environmental monitoring dataset of air lead concentration of 4 lead industries(1 primary smelting, 2 secondary smelting and 1 litharge making industry) were analyzed from 1994 to 2007. Data were compared using geometric mean and standard deviation with minimum and maximum values according to year of measurement, type of lead industries and type of operation of lead industries. The geometric mean and standard deviation of air concentration for a total of 1140 samples in all lead industries for overall 14 years were 70.7${\mu}g/m^3$ and 5.51 with minimum of 1${\mu}g/m^3$ and maximum of 9,185 ${\mu}g/m^3$. The overall geometric means of air concentration were above the permissible exposure levels(PEL) until year of 2001 and thereafter they were remained at the level of half of PEL. The geometric means of primary smelting, secondary smelting and litharge making industry for overall 14 years were 21.7${\mu}g/m^3$(number of samples: 353), 82.5${\mu}g/m^3$(number of samples: 357) and 164.2 ${\mu}g/m^3$(number of samples: 430) respectively. In primary smelting industry, the highest geometric mean air concentration was 35.4 ${\mu}g/m^3$ in the secondary smelting operation; followed by casting operation (24.9 ${\mu}g/m^3$) and melting operation (14.9 ${\mu}g/m^3$), respectively. On the other hand, in secondary smelting industries, the highest geometric mean air concentration was 125.4${\mu}g/m^3$ in melting operation; followed by casting operation (90.5${\mu}g/m^3$) and pre-treatment operation (43.4${\mu}g/m^3$), respectively. However, in litharge making industries, there were no significant differences of geometric mean air concentrations between litharge operation and stabilizer operation. The proportion of over PEL (50${\mu}g/m^3$) was highest in litharge industry and followed by secondary smelting industries. However The proportions of over PEL(${\mu}g./m^3.$) were decreased by the years of environmental monitoring. The significant reduction of mean air lead concentration since year of 2000 was observed due to more active environmental engineering control and new introduction of new operation in manufacturing process, but may be also influenced by non-engineering method such as reduction of operation hours or reduction of exposure time during actual environmental measurement by industrial hygienist according to more strict enforcement of occupational and safety law by the government.

Some Optimal Convex Combination Bounds for Arithmetic Mean

  • Hongya, Gao;Ruihong, Xue
    • Kyungpook Mathematical Journal
    • /
    • 제54권4호
    • /
    • pp.521-529
    • /
    • 2014
  • In this paper we derive some optimal convex combination bounds related to arithmetic mean. We find the greatest values ${\alpha}_1$ and ${\alpha}_2$ and the least values ${\beta}_1$ and ${\beta}_2$ such that the double inequalities $${\alpha}_1T(a,b)+(1-{\alpha}_1)H(a,b)<A(a,b)<{\beta}_1T(a,b)+(1-{\beta}_1)H(a,b)$$ and $${\alpha}_2T(a,b)+(1-{\alpha}_2)G(a,b)<A(a,b)<{\beta}_2T(a,b)+(1-{\beta}_2)G(a,b)$$ holds for all a,b > 0 with $a{\neq}b$. Here T(a,b), H(a,b), A(a,b) and G(a,b) denote the second Seiffert, harmonic, arithmetic and geometric means of two positive numbers a and b, respectively.

흡입독성 연구에 이용될 0.25% 염화카드뮴 네뷸라이징 용액 에어로졸의 입경 (Particle Size of Aerosol from 0.25% Cadmium Chloride Nebulizing Solution for Inhalation Toxicology Study)

  • 정재열;이기남
    • 동의생리병리학회지
    • /
    • 제17권5호
    • /
    • pp.1257-1263
    • /
    • 2003
  • The modified engineering methodology and the modified electronic circuit in classical ultrasonic principles were applied to ultrasonic aerosol nebulizer for inhalation toxicology study of cadmium aerosol. 1532.96ppm Cd nebulizing solution was used to generate cadmium aerosol for particle size analysis with the modifying source and inlet temperatures. The results of particle size analysis for cadmium aerosol were as following. The highest particle counting for source temperature 20℃ was 399.75 × 10² in inlet temperature 100℃ and particle diameter 0.75㎛. The highest particle counting for source temperature 50℃ was 399.70 × 10² in inlet temperature 50℃ and particle diameter 0.75㎛. The highest particle counting for source temperature 70℃ was 411.14 × 10² in inlet temperature 100℃ and particle diameter 0.75㎛. The ranges of geometric mean diameter were 0.74-0.79㎛ in source temperature 20℃, 0.65-0.72㎛ in source temperature 50℃, and 0.65-0.80㎛ in source temperature 70℃. The smallest geometric mean diameter was 0.65㎛ in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the largest geometric mean diameter was 0.80㎛ in source temperature 70℃ and inlet temperature 100℃. The ranges of geometric standard deviation were 1.71-1.80 in source temperature 20℃, 1.27-1.61 in source temperature 50℃, and 1.27-2.29 in source temperature 70℃. The lowest geometric standard deviation was 1.27 in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the highest geometric standard deviation was 2.29 in source temperature 70℃ and inlet temperature 100℃. Generated aerosol for cadmium inhalation toxicology study was polydisperse aerosol with the above geometric standard deviation 1.2. The ranges of mass median diameter(MMD) were 1.75-2.25㎛ in source temperature 20℃, 1.27-1.61㎛ in source temperature 50℃, and 1.27-2.29㎛ in source temperature 70℃. The smallest MMD was 1.27㎛ in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the largest MMD was 2.29㎛ in source temperature 70℃ and inlet temperature 100℃. Cadmium chloride concentration in nebulizing solution affected the particle size and distribution of cadium aerosol in air. MMO for inhalation toxicology testing in OECD and EU is less than 3㎛ and EPA guidance is less than 4㎛. In our results, in source temperatures of 20, 50, 70℃, and inlet temperatures of 20, 50, 100, 150, 200, 250℃ were conformed to the those guidance.

일반화 기하분포를 이용한 ARL의 수정에 관한 연구 (A Study on the Alternative ARL Using Generalized Geometric Distribution)

  • 문명상
    • 품질경영학회지
    • /
    • 제27권4호
    • /
    • pp.143-152
    • /
    • 1999
  • In Shewhart control chart, the average run length(ARL) is calculated using the mean of a conventional geometric distribution(CGD) assuming a sequence of identical and independent Bernoulli trials. In this, the success probability of CGB is the probability that any point exceeds the control limits. When the process is in-control state, there is no problem in the above assumption since the probability that any point exceeds the control limits does not change if the in-control state continues. However, if the out-of-control state begins and continues during the process, the probability of exceeding the control limits may take two forms. First, once the out-of-control state begins with exceeding probability p, it continues with the same exceeding probability p. Second, after the out-of-control state begins, the exceeding probabilities may very according to some pattern. In the first case, ARL is the mean of CGD with success probability p as usual. But in the second case, the assumption of a sequence of identical and independent Bernoulli trials is invalid and we can not use the mean of CGD as ARL. This paper concentrate on that point. By adopting one generalized binomial distribution(GBD) model that allows correlated Bernoulli trials, generalized geometric distribution(GGD) is defined and its mean is derived to find an alternative ARL when the process is in out-of-control state and the exceeding probabilities take the second form mentioned in the above. Small-scale simulation is performed to show how an alternative ARL works.

  • PDF

석면 해체·제거시 공기 중 노출수준과 영향요인 (A Study on the Factors Affecting Asbestos Exposure Level from Asbestos Abatement in Building Demolition Sites)

  • 김지영;이송권;이정희;임무혁;강성욱;피영규
    • 한국산업보건학회지
    • /
    • 제19권1호
    • /
    • pp.8-15
    • /
    • 2009
  • This study was examined to find out asbestos exposure level the factors which affected the level at asbestos abatement sites. We visited a total of thirteen building demolition sites(3 apartments, 3 schools, 4 stores, and 3 houses) were visited to collect samples and related data from August to November, 2006. The results of this study were as follows 1. The results of an analysis of bulk samples to identify types of asbestos at the asbestos abatement sites showed that the kinds of the asbestos detected were chrysotile by 50.0%, were tremolite by 2.6%, and were the contents of chrysotile by 3 to 20%. 2. The geometric mean concentration of asbestos was 0.007 f/cc(range 0.001-0.34 f/cc) and its geometric standard deviation was 5.83. Of the samples, however, 12 exceeded the Korean Occupational Exposure Limit(0.1f/cc). 3. Of the materials, textile material had the highest concentration with geometric mean of 0.016 f/cc. When asbestos-containing materials were removed using T type tools, the geometric mean concentration of asbestos was 0.061 f/cc. The level by this method was much higher than by other removal methods. In analysis by the type of building, the geometric mean concentration of asbestos in stores was 0.042 f/cc and was higher than in other buildings. 4. The Poisson regression analysis was applied to find out the factors that affect the airborne asbestos concentration. As a result of the analysis, removal using a T type tool was the most important factor affecting the asbestos concentration(p<0.01). In conclusion, the airborne asbestos concentration(geometric mean) in asbestos abatement sites was 0.007 f/cc(0.001~0.34 f/cc), and 12(14.6%) of all samples were over the 0.1 f/cc. These results showed that asbestos abatement workers have been exposed to the high level of airborne asbestos because they have not been keeping asbestos removal rule. In accordance with increases of the number of building demolition sites, the better government regulation on asbestos abatement methods should be made and be performed well at building demolition sites.