• Title/Summary/Keyword: Mean Analysis

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The Evaluation of the Annual Time Series Data for the Mean Sea Level of the West Coast by Regression Model (회귀모형에 의한 서해안 평균해면의 연시계열자료의 평가)

  • 조기태;박영기;이장춘
    • Journal of Environmental Science International
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    • v.9 no.1
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    • pp.19-25
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    • 2000
  • As the tideland reclamation is done on a large scale these days, construction work is active in the coastal areas. Facilities in the coastal areas must be built with the tide characteristics taken into consideration. Thus the tide characteristics affect the overall reclamation plan. The analysis of the tide data boils down to a harmonic analysis of the hourly changes of long-term tide data and extraction of unharmonic coefficients from the results. Since considerable amount of tide data of the West Coast are available, the existing data can be collected and can be used to obtain the temporal changes of the tide by being fitted into the tide prediction model. The goal of this thesis lies in assessing whether the mean sea level used in the field agrees with the analysis results from the long-term observation data obtained with their homogeneity guaranteed. To achieve this goal, the research was conducted as follows. First the present conditions of the observation stations, the land level standard, and the sea level standard were analyzed to set up a time series model formula for representing them. To secure the homogeneity of the time series, each component was separated. Lastly the mean sea level used in the field was assessed based on the results obtained form the analysis of the time series.

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Analysis of the Ozone Transport and Seasonal Variability in the Tropical Tropopause Layer using MERRA-2 Reanalysis Data (MERRA-2 재분석자료를 활용한 적도 대류권계면층의 오존 수송 및 계절변동성 분석)

  • Ryu, Hosun;Kim, Joowan
    • Atmosphere
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    • v.30 no.1
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    • pp.91-102
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    • 2020
  • MERRA-2 ozone and atmospheric data are utilized to test the usefulness of reanalysis-based tracer transport analysis for ozone in the tropical tropopause layer (TTL). Transport and mixing processes related to the seasonal variation of TTL ozone are examined using the tracer transport equation based on the transformed Eulerian mean, and the results are compared to previously proposed values from model analyses. The analysis shows that the seasonal variability of TTL ozone is mainly determined by two processes: vertical mean transport and horizontal eddy mixing of ozone, with different contributions in the Northern and Southern Hemispheres. The horizontal eddy mixing process explains the major portion of the seasonal cycle in the northern TTL, while the vertical mean transport dominates in the southern TTL. The Asian summer monsoon likely contributes to this observed difference. The ozone variability and related processes in MERRA-2 reanalysis show qualitatively similar features with satellite- and model-based analyses, and it provides advantages of fine-scale analyses. However, it still shows significant quantitative biases in ozone budget analysis.

A response spectrum method for seismic response analysis of structures under multi-support excitations

  • Li, Jian-Hua;Li, Jie
    • Structural Engineering and Mechanics
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    • v.21 no.3
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    • pp.255-273
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    • 2005
  • Based on the random vibration theory, a response spectrum method is developed for seismic response analysis of linear, multi-degree-of-freedom structures under multi-support excitations is developed. Various response quantities, including the mean and variance of the peak response, the response mean frequency, are obtained from proposed combination rules in terms of the mean response spectrum. This method makes it possible to apply the response spectrum to the seismic reliability analysis of structures subjected to multi-support excitations. Considering that the tedious numerical integration is required to compute the spectral parameters and correlation coefficients in above combination rules, this paper further offers simplified procedures for their computation, which enhance dramatically the computational efficiency of the suggested method. The proposed procedure is demonstrated for tow numerical examples: (1) two-span continuous beam; (2) two-tower cabled-stayed bridge by using Monte Carlo simulation (MC). For this purpose, this paper also presents an approach to simulation of ground motions, which can take into account both mean and variation properties of response spectrum. Computed results based on the response spectrum method are in good agreement with Monte Carlo simulation results. And compared with the MSRS method, a well-developed multi-support response spectrum method, the proposed method has an incomparable computational efficiency.

Genetic Studies of Oenothera odorata Populations in Korea Based on Isozyme Analysis

  • Huh, Hong-Wook
    • Journal of Plant Biology
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    • v.39 no.3
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    • pp.223-229
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    • 1996
  • The genetic variation in Korean evening primorse (Oeothera odorata L.) populations was examiend to estimate the level of allozyme variation within populatons using starch gel electrophoresis. 7 of 13 loci (Adh, Est-1, Est-2, Mdh-2, Pgd-2, Pgm-1, and Idh) revealed (Ps=43.2%) were polymorphic. The mean number of alleles per locus (A) and polymorphic locus (Ap) for populations were 1.64 and 2.46, respectively. The effective number of alleles (Aep) within populations relatively was low ranging from 1.08 to 1.22 with a mean of 1.14. Within populations, the mean number of allele per polymorphic loci (Ap) was 2.46, the mean number of alleles per locus (A) was 1.64, and the mean genetic diversity was 0.093. About 2.7% of the total allozyme diversity resided among populations (Mean GST=0.0274). FIS, a measure of the deviation from random mating within 13 populations, was relative low (mean FIS=0.03636). The indirect estimate of gene flow, based on the mean GST, was high (Nm=8.88). Estimates of gene flow were consistent with low levels of genetic differentiation among populations.

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Natural Convection from a Horisontal Conducting Tube with One Vertical Axial Fin. (단일수직(單一垂直)한 축방향(軸方向)의 핀을 가진 수평전도관(水平傳導管)으로 부터의 자연대류(自然對流))

  • Chung, H.S.;Kwon, S.S.
    • Solar Energy
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    • v.6 no.1
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    • pp.60-69
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    • 1986
  • Two-dimensional finite difference numerical analysis is used to study conjugate natural convection heat transfer from a horizontal conducting tube with one vertical axial fin. By increasing dimensionless fin length ($L_F$), the mean total Nusselt number of the upward fin is slightly less than that of the downward fin at $L_F\;{\le}\;0.18$ and is higher than that of the downward fin at $L_F\;>\;0.18$. However comparing the upward fin and the downward fin with the no fin, the mean total Nusselt numbers of downward fin and upward fin at $L_F=0.30$ are increased approximately 4.01% and 5.51%, respectively. As Rayleigh number, Prandtl number and Biot number increase, the mean total and the mean tube Nusselt numbers are increased, but as wall thickness increases, the mean total and the mean tube Nusselt numbers are decreased. As the fin conduction parameter increases, the mean total Nusselt number is slightly increased because of increasing the mean fin Nusselt number.

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Inhomogeneities in Korean Climate Data (II): Due to the Change of the Computing Procedure of Daily Mean (기상청 기후자료의 균질성 문제 (II): 통계지침의 변경)

  • Ryoo, Sang-Boom;Kim, Yeon-Hee
    • Atmosphere
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    • v.17 no.1
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    • pp.17-26
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    • 2007
  • The station relocations, the replacement of instruments, and the change of a procedure for calculating derived climatic quantities from observations are well-known nonclimatic factors that seriously contaminate the worthwhile results in climate study. Prior to embarking on the climatological analysis, therefore, the quality and homogeneity of the utilized data sets should be properly evaluated with metadata. According to the metadata of the Korea Meteorological Administration (KMA), there have been plenty of changes in the procedure computing the daily mean values of temperature, humidity, etc, since 1904. For routine climatological work, it is customary to compute approximate daily mean values for individual days from values observed at fixed hours. In the KMA, fixed hours were totally 5 times changed: at four-hourly, four-hourly interval with additional 12 hour, eight-hourly, six-hourly, three-hourly intervals. In this paper, the homogeneity in the daily mean temperature dataset of the KMA was assessed with the consistency and efficiency of point estimators. We used the daily mean calculated from the 24 hourly readings as a potential true value. Approximate daily means computed from temperatures observed at different fixed hours have statistically different properties. So this inhomogeneity in KMA climate data should be kept in mind if you want to analysis secular aspects of Korea climate using this data set.

A Comparative Study of Software Reliability Model Considering Log Type Mean Value Function (로그형 평균값함수를 고려한 소프트웨어 신뢰성모형에 대한 비교연구)

  • Shin, Hyun Cheul;Kim, Hee Cheul
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.10 no.4
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    • pp.19-27
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    • 2014
  • Software reliability in the software development process is an important issue. Software process improvement helps in finishing with reliable software product. Infinite failure NHPP software reliability models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, proposes the reliability model with log type mean value function (Musa-Okumoto and log power model), which made out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on mean square error (MSE) and coefficient of determination($R^2$), for the sake of efficient model, was employed. Analysis of failure using real data set for the sake of proposing log type mean value function was employed. This analysis of failure data compared with log type mean value function. In order to insurance for the reliability of data, Laplace trend test was employed. In this study, the log type model is also efficient in terms of reliability because it (the coefficient of determination is 70% or more) in the field of the conventional model can be used as an alternative could be confirmed. From this paper, software developers have to consider the growth model by prior knowledge of the software to identify failure modes which can be able to help.

A Study on Development of the Prediction Model Related to the Sound Pressure in Terms of Frequencies, Using the Pass-by and NCPX Method (Pass-by계측과 NCPX계측에 의한 주파수 별 음압 예측 모델 개발에 관한 연구)

  • Kim, Do Wan;Mun, Sungho;An, Deok Soon;Son, Hyeon Jang
    • International Journal of Highway Engineering
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    • v.15 no.6
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    • pp.79-91
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    • 2013
  • PURPOSES : The methods of measuring the sound from the noise source are Pass-by method and NCPX (Noble Close Proximity) method. These measuring methods were used to determine the linkage of TAPL (Total Acoustic Pressure Level) and SPL (Sound Pressure Level) in terms of frequencies. METHODS : The frequency analysis methods are DFT (Discrete Fourier Transform) and FFT (Fast Fourier Transform), CPB (Constant Percentage Bandwidth). The CPB analysis was used in this study, based on the 1/3 octave band option configured for the frequency analysis. Furthermore, the regression analysis was used at the condition related to the sound attenuation effect. The MPE (Mean Percentage Error) and RMSE (Root Mean Squared Error) were utilized for calculating the error. RESULTS : From the results of the CPB frequency analysis, the predicted SPL along the frequency has 99.1% maximum precision with the measured SPL, resulting in roughly 1 dB(A) error. The TAPL results have precision by 99.37% with the measured TAPL. The predicted TAPL results at this study by using the SPL prediction model along the frequency have the maximum precision of 98.37% with the vehicle velocity. CONCLUSIONS : The Predicted SPL model along the frequency and the TAPL result by using the predicted SPL model have a high level of accuracy through this study. But the vehicle velocity-TAPL prediction model from the previous study by using the log regression analysis cannot be consistent with the TAPL result by using the predicted SPL model.

Cluster Analysis for Foot Type(I) - The subject of the college women between the age of 19~23 years - (발의 형태 분석을 위한 군집분석(I) - 19~23세 여자 대학생을 중심으로 -)

  • 문명옥
    • Journal of the Korean Society of Clothing and Textiles
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    • v.18 no.2
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    • pp.211-220
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    • 1994
  • The purpose of this study was to analyze the foot type by cluster analysis for footwear. The sample size for the study was 200 college womens between age 19 and 23 in Pusan urban area. There were measured 17 items of the foot for factor analysis and cluster analysis. The result was as follows : 1. 1'here were 9 items selected by factor analysis. 2.'rho cluster analysis of the foot must be analyzed by direct and indirect measurement indivisually. 3. The cluster analysis of the direct measurement ; Cluster 1 : 1'he foot length is all much the same to mean value of this age group and the items of width and circumference are relatively small to other clusters. Cluster 2 ; The foot length is relatively small to other clusters and the items of width and circumference are all much the same to mean value of this age group. Cluster 3 ; The foot sine Is relatively large to other clusters. 4. The cluster analysis of indirect measurement ; Cluster 1 ; The (cot print angle is high find Metatarso-Phalanx angle is transformed Cluster 2 ; The foot print angle is low and Melatarso-Phalanx angle is normal. Cluster 3 : Tho foot print angle Is middle and Metatarso-Phalanx angle is all the mush same to mean value of this age group. Cluster 4 . The foot print angle Is the most value and Metatarso-Phalanx angle is normal.

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Hematological and biochemical analysis of Korean indigenous cattle according to the ages (한우의 연령에 따른 혈액 및 혈청 화학치 분석)

  • Cho, Hyun-Ung;Ko, Won-Seuk;Son, Hyong-Won;Lee, Mi-Jin;Song, Hee-Jong;Park, Jin-Ho
    • Korean Journal of Veterinary Service
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    • v.31 no.1
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    • pp.137-147
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    • 2008
  • Investigations for hematologic and biochemical values and the differential count of WBC for Korean indigenous cattle (KIC)is rarely performed. Therefore, when the index of complete blood counts (CBC) and biochemical analysis of KIC was requested, it had many difficulties to make the results for blood condition since the standard hematologic and biochemical values of KIC are lacking. In the present study, we have investigated the hematologic and biochemical values and the differential count of WBC for blood of total 252 KIC and 17 striped cattle (SC) as a control. As a result, the mean values of RBC and platelet of KIC were significantly decreased by age (P<0.05). The mean values of RBC, HCT, MCV and MCHC between KIC and SC of the same age (2 - 3 years) showed the statistical significance (P<0.05). Also, in the WBC of KIC, the mean values were decreased according to the age from $12.8{\times}10^3/{\mu}l$ under 1 year to $8.5{\times}10^3/{\mu}l$ over 5 years. In the differential count of WBC of KIC, it showed generally the rates of 45% lymphocyte and 35% segmented neutrophil. In the biochemical analysis, the mean values of BUN and globulin were significantly increased according to the age (P<0.05). Additionally, in comparative analysis between pregnant and non-pregnant group of KIC, the mean values of Hg and HCT in pregnant group were significantly decreased (P<0.05). In conclusion, data obtained from this study may be valuable as a standard for interpretation of the results in hematologic and biochemical analysis of KIC.