• 제목/요약/키워드: Cross coefficients

검색결과 807건 처리시간 0.034초

확정론적 모의기법에 의한 도시유출 해석에 관한 연구 (A Study on urban runoff by deter ministic simulation techniques.)

  • 이은영;강관원
    • 물과 미래
    • /
    • 제15권3호
    • /
    • pp.37-47
    • /
    • 1982
  • 본 연구는 확정론적 모의기법 중 영국도로시험연구소에서 개발한 R.R.L법을 포장 지역이 넓은 인천에 위치한 간석동 아파트에 적용하여 그 실용성을 검토하였다. 인천지방의 전체적이고 합리적인 결과를 얻기 위하여 과거 28년간 누가우량 곡선에서 얻은 10mm 이상 되는 강우 450개를 5분 간격으로 읽어 확률빈도통계인 HUFF의 사분위법을 이용 확률빈도백분율곡선을 얻어 R.R.L법에 적용하였다. 인천지방의 확률빈도백분률 곡선은 제2 구간이 전체의 43.2%를 나타내므로 설계우량의 우량주상도는 제을구간에서 추출함이 바람직하다.

  • PDF

RAPID PREDICTION OF ENERGY CONTENT IN CEREAL FOOD PRODUCTS WITH NIRS.

  • Kays, Sandra E.;Barton, Franklin E.
    • 한국근적외분광분석학회:학술대회논문집
    • /
    • 한국근적외분광분석학회 2001년도 NIR-2001
    • /
    • pp.1511-1511
    • /
    • 2001
  • Energy content, expressed as calories per gram, is an important part of the evaluation and marketing of foods in developed countries. Currently accepted methods of measurement of energy by U.S. food labeling legislation include measurement of gross calories by bomb calorimetry with an adjustment for undigested protein and by calculation using specific factors for the energy values of protein, carbohydrate less the amount of insoluble dietary fiber, and total fat. The ability of NIRS to predict the energy value of diverse, processed and unprocessed cereal food products was investigated. NIR spectra of cereal products were obtained with an NIR Systems monochromator and the wavelength range used for analysis was 1104-2494 nm. Gross energy of the foods was measured by oxygen bomb calorimetry (Parr Manual No. 120) and expressed as calories per gram (CPGI, range 4.05-5.49 cal/g). Energy value was adjusted for undigested protein (CPG2, range 3.99-5.38 cal/g) and undigested protein and insoluble dietary fiber (CPG3, range 2.42-5.35 cal/g). Using a multivariate analysis software package (ISI International, Inc.) partial least squares models were developed for the prediction of energy content. The standard error of cross validation and multiple coefficient of determination for CPGI using modified partial least squares regression (n=127) was 0.060 cal/g and 0.95, respectively, and the standard error of performance, coefficient of determination, bias and slope using an independent validation set (n=59) were 0.057 cal/g, 0.98, -0.027 cal/g and 1.05 respectively. The PLS loading for factor 1 (Pearson correlation coefficient 0.92) had significant absorption peaks correlated to C-H stretch groups in lipid at 1722/1764 nm and 2304/2346 nm and O-H groups in carbohydrate at 1434 and 2076 nm. Thus the model appeared to be predominantly influenced by lipid and carbohydrate. Models for CPG2 and CPG3 showed similar trends with standard errors of performance, using the independent validation set, of 0.058 and 0.088 cal/g, respectively, and coefficients of determination of 0.96. Thus NIRS provides a rapid and efficient method of predicting energy content of diverse cereal foods.

  • PDF

CHALLENGING APPLICATIONS FOR FT-NIR SPECTROSCOPY

  • Goode, Jon G.;Londhe, Sameer;Dejesus, Steve;Wang, Qian
    • 한국근적외분광분석학회:학술대회논문집
    • /
    • 한국근적외분광분석학회 2001년도 NIR-2001
    • /
    • pp.4112-4112
    • /
    • 2001
  • The feasibility of NIR spectroscopy as a quick and nondestructive method for quality control of uniformity of coating thickness of pharmaceutical tablets was investigated. Near infrared spectra of a set of pharmaceutical tablets with varying coating thickness were measured with a diffuse reflectance fiber optic probe connected to a Broker IFS 28/N FT-NIR spectrometer. The challenging issues encountered in this study included: 1. The similarity of the formulation of the core and coating materials, 2. The lack of sufficient calibration samples and 3. The non-linear relationship between the NIR spectral intensity and coating: thickness. A peak at 7184 $cm^{-1}$ was identified that differed for the coating material and the core material when M spectra were collected at 2 $cm^{-1}$ resolution (0.4 nm at 7184 $cm^{-1}$). The study showed that the coating thickness can be analyzed by polynomial fitting of the peak area of the selected peak, while least squares calibration of the same data failed due to the lack of availability of sufficient calibration samples. Samples of coal powder and solid pieces of coal were analyzed by FT-NIR diffuse reflectance spectroscopy with the goal of predicting their ash content, percentage of volatile components, and energy content. The measurements were performed on a Broker Vector 22N spectrometer with a fiber optic probe. A partial least squares model was constructed for each of the parameters of interest for solid and powdered sample forms separately. Calibration models varied in size from 4 to 10 PLS ranks. Correlation coefficients for these models ranged from 86.6 to 95.0%, with root-mean-square errors of cross validation comparable to the corresponding reference measurement methods. The use of FT-NIR diffuse reflectance measurement techniques was found to be a significant improvement over existing measurement methodologies in terms of speed and ease of use, while maintaining the desired accuracy for all parameters and sample forms.(Figure Omitted).

  • PDF

비명시적 평가지표를 활용한 농촌정책 평가 (A Quantitative Evaluation of Composite Indicators : Empirical Analysis of Comprehensive Rural Village Development Project)

  • 황재희;이성우
    • 농촌계획
    • /
    • 제22권4호
    • /
    • pp.25-36
    • /
    • 2016
  • The purpose of this study is to construct a quantitative evaluation method that can analyze the policy effectiveness with the construction of a implicit composite index incorporating spatial econometrics models. In order to propose a methodological framework for the program evaluation, this study conducts an empirical analysis with the application of the Comprehensive Rural Village Development Project (CRVDP) which explicitly claims to achieve comprehensive goal of community development. The present study pays particular attention to quantifying the composite evaluation index and drawing net effect through the application of a series of spatial econometrics models. The spatial unit of the analysis is drawn at Eup-Myeon level in rural areas in Korea, and the time horizon is in between 2005 and 2010. We utilize the Korean Agricultural Census data in 2005 and 2010. Three steps of methodological processes are needed to satisfy the objective of the present study. First, we apply factor analysis to construct the composite index that represents comprehensive settlement environment in rural area. The index should be matched with the main objective of the CRVDP. Second, we apply the derived index to a series of spatial econometrics model as dependent variable. Lastly, utilizing the estimated coefficients of the econometrics models, we apply decomposition technique to estimate CRVDP's net effect from both cross-sectional and longitudinal perspectives. We find that the results of the decomposition analysis by the execution of the CRVDP are positively associated with the explicit object of the project.

Surface Modification by Atmospheric Pressure DBDs Plasma: Application to Electroless Ni Plating on ABS Plates

  • Song, Hoshik;Choi, Jin Moon;Kim, Tae Wan
    • Transactions on Electrical and Electronic Materials
    • /
    • 제14권3호
    • /
    • pp.133-138
    • /
    • 2013
  • Acrylonitrile-butadiene-styrene (ABS) plastic is a polymer material extensively used in electrical and electronic applications. Nickel (Ni) thin film was deposited on ABS by electroless plating, after its surface was treated and modified with atmospheric plasma generated by means of dielectric barrier discharges (DBDs) in air. The method in this study was developed as a pre-treatment for electroless plating using DBDs, and is a dry process featuring fewer processing steps and more environmentally friendliness than the chemical method. After ABS surfaces were modified, surface morphologies were observed using a scanning electron microscope (SEM) to check for any physical changes of the surfaces. Cross-sectional SEM images were taken to observe the binding characteristics between metallic films and ABS after metal plating. According to the SEM images, the depths of ABS by plasma are shallow compared to those modified by chemically treatment. The static contact angles were measured with deionized (DI) water droplets on the modified surfaces in order to observe for any changes in chemical activities and wettability. The surfaces modified by plasma showed smaller contact angles, and their modified states lasted longer than those modified by chemical etching. Adhesion strengths were measured using 3M tape (3M 810D standard) and by 90° peel-off tests. The peel-off test revealed the stronger adhesion of the Ni films on the plasma-modified surfaces than on the chemically modified surfaces. Thermal shock test was performed by changing the temperature drastically to see if any detachment of Ni film from ABS would occur due to the differences in thermal expansion coefficients between them. Only for the plasma-treated samples showed no separation of the Ni films from the ABS surfaces in tests. The adhesion strengths of metallic films on the ABS processed by the method developed in this study are better than those of the chemically processed films.

여러 가지 형태의 립이 설치된 수평채널의 열전달 및 압력강하 특성에 관한 수치해석 (Numerical analysis on heat transfer and pressure drop characteristics in a horizontal channel with various ribs)

  • 김지훈;허주녕;안성후;이두호;손영석;신지영
    • Journal of Advanced Marine Engineering and Technology
    • /
    • 제37권1호
    • /
    • pp.40-46
    • /
    • 2013
  • 열전달 향상을 위하여 이차유동을 발생시켜 열전달을 증가시키는 방법에는 여러 가지가 있다. 본 연구에서는 수평채널에 다양한 형태의 립을 설치하여 유속을 변화시켰을 때의 열전달 및 압력강하 특성을 수치해석을 통하여 고찰하였다. 립은 수평채널의 아랫면에 설치하였고, 립의 높이는 5mm이다. 립이 $60^{\circ}$ 기울어지고 그루브도 설치된 경우 열전달 특성이 가장 우수하게 나타났는데, 이는 주유동이 립을 따라 흘러가면서도 유속이 어느 정도 유지되기 때문이다. 끊어진 립에서 주유동이 립의 저항을 적게 받으면서 압력강하가 가장 작게 나타났다. 모든 립의 형태에서 유속이 증가함에 따라 열전달이 향상되는 경향을 보였지만 성능계수는 감소하였다.

인공식생을 이용한 해빈침식방지에 관한 수리실험 (A Hydraulic Experiment Using Artificial Seaweed for Coastal Erosion Prevention)

  • 김범모;전용호;윤한삼
    • 한국해양환경ㆍ에너지학회지
    • /
    • 제19권4호
    • /
    • pp.266-273
    • /
    • 2016
  • 본 연구는 인공식생에 의한 파 에너지 저감과 해빈침식방지를 평가하기 위해서 2차원 수리모형실험을 수행하였다. 실험에서는 인공식생 유무 및 평상파/폭풍파 입사 조건의 규칙파 영향하에서 해빈단면 변화와 파고 반사율을 조사하였다. 주요 연구 결과로는 1) 인공식생이 없는 조건에서는 파 조건에 의해서 연안사주 높이가 증가하고 해안선의 후퇴가 나타났으나 2) 1B(폭=0.8 m) 또는 2B(폭=1.6 m)의 인공식생을 설치한 조건에서는 해안선의 전진 및 퇴적현상이 발생하였다. 이를 통해 인공식생이 해빈 단면에 영향을 줄 수 있으며 해빈침식방지공법으로써 적용가능함을 알 수 있었다.

초등학생의 성 성숙, 성 성숙 태도 및 신체 자존감 (Sexual Maturation, Attitudes towards Sexual Maturity, and Body Esteem in Elementary-School Children)

  • 박선아;최은영;이은희;변미경;이병주;정계아
    • 여성건강간호학회지
    • /
    • 제24권2호
    • /
    • pp.219-228
    • /
    • 2018
  • Purpose: The purpose of this study is to evaluate sexual maturation, attitudes toward sexual maturity, and body esteem in the sexual development of Korean elementary-school boys and girls. Methods: A descriptive cross-sectional study was conducted with 399 fifth and sixth graders (192 boys and 207 girls). The data were analysed with a $x^2$ test, t-test, and Pearson correlation coefficients. Results: Among the 207 girls, 70.5% had pubic hair growth, 68.1% had breast development, and 56.0% had a menstrual period. In boys, 59.4% of the 192 subjects experienced the development of external genitalia and 52.6% had pubic hair growth. Sexual maturation was related to grade (boys, t=7.07, p=.008; girls, t=12.76, p<.001), age (t=-2.20, p=.030; t=-4.11, p<.001), height (t=-5.16, p<.001; t=-7.52, p<.001), and weight (t=-2.89, p=.004; t=-5.19, p<.001) in both boys and girls. Girls were more likely to have sexual maturity than boys ($x^2=22.29$, p<.001). Boys showed more positive attitudes toward sexual maturity (t=2.10, p=.036) and higher body esteem (t=2.12, p=.035) than girls. Conclusion: This study shows that sexual maturation, attitude toward sexual maturity, and body esteem in sexual development differ between boys and girls. The findings indicate that it is necessary to develop a tailored sex-education program according to the sex of elementary-school children.

부패와 정부지출의 변동성 (Corruption and Government Expenditure Volatility)

  • 임응순;황진영;송인상
    • 한국산학기술학회논문지
    • /
    • 제12권1호
    • /
    • pp.188-194
    • /
    • 2011
  • 본 연구에서는 83개 국가 간 통계자료를 이용해 부패와 정부지출의 변동성 간의 관련성을 검토했다. 한 국가의 부패의 정도는 Kaufmann et al.(2008)에서 제공한 부패의 통제와 국제투명성기구에서 제공한 부패인식지수로 나타내며, 정부지출의 변동성은 1990~2005년 기간의 연도별 정부지출 변동률의 표준편차를 이용한다. 실증분석 결과한 국가의 부패의 통제와 부패인식지수(높은 수치일수록 투명함)는 정부지출의 변동성에 통계적으로 유의한 음(-)의 영향을 미치는 것으로 추정됐다. 그러나 한 국가의 부패의 정도를 부패인식지수로 나타낼 경우 그 추정계수의 통계적 유의성은 다소 감소했다. 이상의 결과는 유럽의 OECD 국가를 제외한 작은 수의 표본에 대해서도 여전히 성립했다. 그러므로 본 연구의 실증분석 결과는 부패한 국가의 정부관리 혹은 정치인은 경제운영과 관련된 규칙을 불규칙적으로 변동시켜 자신들의 영역을 강화시키려는 경향이 있기 때문에 정부지출의 변동성이 상대적으로 크게 나타날 가능성을 시사한다.

접합 영상 검출을 위한 마르코프 천이 확률 및 동시발생 확률에 대한 선택적 특징 추출 방법 (Selective Feature Extraction Method Between Markov Transition Probability and Co-occurrence Probability for Image Splicing Detection)

  • 한종구;엄일규;문용호;하석운
    • 한국정보통신학회논문지
    • /
    • 제20권4호
    • /
    • pp.833-839
    • /
    • 2016
  • 본 논문에서는 효율적인 접합 영상 검출을 위한 마르코프 천이 및 동시발생 확률에 대한 선택적 특징 추출 방법을 제안한다. 제안하는 방법에서는 이산 코사인 변환 영역에서 블록간 계수의 차이를 이용하여 특징들을 구성하고, 특징들의 각 위치에서 원 영상과 접합영상의 특징 분포의 상이성을 확인하기 위해 Kullback-Leibler 수렴값을 구한다. 이를 바탕으로, 마르코프 확률 특징과 동시발생 확률 특징 가운데 해당 위치에서 가장 큰 차이값을 갖는 특징을 선택하여 최종 특징으로 선택하고, SVM 분류기를 이용하여 학습 및 테스트한 후 그 유효성을 판별한다. 실험 결과를 바탕으로 제안하는 방법이 기존의 방법보다 제한된 특징수로 높은 영상접합 조작 결과를 보임을 확인하였다.