• Title/Summary/Keyword: Variance Ratios

Search Result 119, Processing Time 0.022 seconds

Development of Prediction Model for the Na Content of Leaves of Spring Potatoes Using Hyperspectral Imagery (초분광 영상을 이용한 봄감자의 잎 Na 함량 예측 모델 개발)

  • Park, Jun-Woo;Kang, Ye-Seong;Ryu, Chan-Seok;Jang, Si-Hyeong;Kang, Kyung-Suk;Kim, Tae-Yang;Park, Min-Jun;Baek, Hyeon-Chan;Song, Hye-Young;Jun, Sae-Rom;Lee, Su-Hwan
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.23 no.4
    • /
    • pp.316-328
    • /
    • 2021
  • In this study, the leaf Na content prediction model for spring potato was established using 400-1000 nm hyperspectral sensor to develop the multispectral sensor for the salinity monitoring in reclaimed land. The irrigation conditions were standard, drought, and salinity (2, 4, 8 dS/m), and the irrigation amount was calculated based on the amount of evaporation. The leaves' Na contents were measured 1st and 2nd weeks after starting irrigation in the vegetative, tuber formative, and tuber growing periods, respectively. The reflectance of the leaves was converted from 5 nm to 10 nm, 25 nm, and 50 nm of FWHM (full width at half maximum) based on the 10 nm wavelength intervals. Using the variance importance in projections of partial least square regression(PLSR-VIP), ten band ratios were selected as the variables to predict salinity damage levels with Na content of spring potato leaves. The MLR(Multiple linear regression) models were estimated by removing the band ratios one by one in the order of the lowest weight among the ten band ratios. The performance of models was compared by not only R2, MAPE but also the number of band ratios, optimal FWHM to develop the compact multispectral sensor. It was an advantage to use 25 nm of FWHM to predict the amount of Na in leaves for spring potatoes during the 1st and 2nd weeks vegetative and tuber formative periods and 2 weeks tuber growing periods. The selected bandpass filters were 15 bands and mainly in red and red-edge regions such as 430/440, 490/500, 500/510, 550/560, 570/580, 590/600, 640/650, 650/660, 670/680, 680/690, 690/700, 700/710, 710/720, 720/730, 730/740 nm.

The Design Harmony in the Necktie with Dot Pattern

  • Jung, Su-Jin;Choi, Su-Koung
    • Journal of Fashion Business
    • /
    • v.13 no.6
    • /
    • pp.31-44
    • /
    • 2009
  • This study aims at clarifying the influence that color, tone, dot size, the combination of area ratios exercise on the harmony in dot necktie, and revealing the harmony differentiation according to the cues of various factors for pattern design. The conclusion is drawn as below, in the result that the cues which can exercise influence on the harmony of dot necktie, was analyzed by 54 stimuli. In the result of analysis of variance in order to clarify the influence which color, tone, dot size, and color area ratio exercise on dot necktie harmony, color and dot size operate appeared to be independent cues which exercise significant influence with main effect. In the result of the harmony difference analysis on color, tone, dot size, and color area ratio combination by multiple comparison, the cyan color in vivid tone was estimated to be most inharmonious in the analysis by color and tone. Viewing the harmony difference according to color and dot size, the dot size of 0.5cm in cyan was perceived to be most harmonious. Viewing the harmony difference according to color and color area ratio combination, both magenta and cyan were estimated to be positive, regardless of area ratio combination, and particularly, the case that the background was in cyan and the dots were in grey was perceived more harmonious compared to the contrary case. Viewing the harmony difference according to tone and dot sizes, the case when the dot sizes were 0.5cm, was perceived to be most positive, regardless of tone. Viewing the harmony difference according to color area ratio combination and tone, the case that the chromatic colors, cyan, magenta, and yellow was used as background, was estimated to be more harmonious, compared to the case that the achromatic color, grey was used as background. Viewing the harmony difference according to dot size and color area ratio combination, in case that the dots were in chromatic color and the background was in grey, the harmony showed difference by dot size, and the case of the dot size of 0.5cm was estimated to be most harmonious.

Evaluation of translucency of monolithic zirconia and framework zirconia materials

  • Tuncel, Ilkin;Turp, Isil;Usumez, Aslihan
    • The Journal of Advanced Prosthodontics
    • /
    • v.8 no.3
    • /
    • pp.181-186
    • /
    • 2016
  • PURPOSE. The opacity of zirconia is an esthetic disadvantage that hinders achieving natural and shade-matched restorations. The aim of this study was to evaluate the translucency of non-colored and colored framework zirconia and monolithic zirconia. MATERIALS AND METHODS. The three groups tested were: non-colored framework zirconia, colored framework zirconia with the A3 shade according to Vita Classic Scale, and monolithic zirconia (n=5). The specimens were fabricated in the dimensions of $15{\times}12{\times}0.5mm$. A spectrophotometer was used to measure the contrast ratio, which is indicative of translucency. Three measurements were made to obtain the contrast ratios of the materials over a white background ($L^*w$) and a black background ($L^*b$). The data were analyzed using the one-way analysis of variance and Tukey HSD tests. One specimen from each group was chosen for scanning electron microscope analysis. The determined areas of the SEM images were divided by the number of grains in order to calculate the mean grain size. RESULTS. Statistically significant differences were observed among all groups (P<.05). Non-colored zirconia had the highest translucency with a contrast ratio of 0.75, while monolithic zirconia had the lowest translucency with a contrast ratio of 0.8. The mean grain sizes of the non-colored, colored, and monolithic zirconia were 233, 256, and 361 nm, respectively. CONCLUSION. The translucency of the zirconia was affected by the coloring procedure and the grain size. Although monolithic zirconia may not be the best esthetic material for the anterior region, it may serve as an alternative in the posterior region for the bilayered zirconia restorations.

A Study on the Consumer Perception and Factor Analysis of Food Tourism (음식관광에 대한 소비자의 인식 및 요인분석)

  • Kim, Eun-Hae;Lee, Min-A
    • Korean Journal of Community Nutrition
    • /
    • v.15 no.1
    • /
    • pp.83-93
    • /
    • 2010
  • The purpose of this study is to investigate consumer perception and importance of food tourism properties and performance of the properties in Sangju province of Gyeongsangbuk-do. The study has found that persons who have food tourism experiences (75 persons, 50.7%) had slightly more than not experience persons (72 persons, 48.6%). Additionally, most of the respondents were usually satisfied with the local foods. Also, it was found that food tourism had been taken 1-2 times per 6 months (48 persons, 64.0%) on average, and 135 persons (91.2%) had intention of experiencing food tourism. According to the result of Importance-Performance Analysis (IPA) on consumers' food tourism properties, high importance was on 'There are attractive landscapes.' ($4.52\;{\pm}\;0.56$), 'Accommodations with reasonable price.' ($4.18\;{\pm}\;0.80$), and 'The food of the area is famous.' ($4.15\;{\pm}\;0.73$); and the properties such as 'There are local specialty shops or markets selling local produce.' ($3.03\;{\pm}\;0.83$), 'The climate is temperate.' ($3.03\;{\pm}\;0.87$), and 'There are attractive landscapes.' ($3.02\;{\pm}\;0.98$) showed average performance. A factor analysis about consumers' importances to the food tourism properties shows that the factors were divided into four kinds and each of the factors were named as 'convenience-stable propensity', 'valued-oriented propensity', 'adventurous-aggressive propensity' and 'traditional-active propensity'. Variance ratios of each factor were 22.319%, 10.286%, 8.723% and 6.239%, respectively. According to the result of a reliability analysis, Cronbach's alpha value was 0.8621, implying that reliability of each item was very high. Therefore, it is considered that development of food tourism products and promotion strategies therefore should be designed based on the importance of food tourism properties hereafter.

Investment Performance of Markowitz's Portfolio Selection Model over the Accuracy of the Input Parameters in the Korean Stock Market (한국 주식시장에서 마코위츠 포트폴리오 선정 모형의 입력 변수의 정확도에 따른 투자 성과 연구)

  • Kim, Hongseon;Jung, Jongbin;Kim, Seongmoon
    • Journal of the Korean Operations Research and Management Science Society
    • /
    • v.38 no.4
    • /
    • pp.35-52
    • /
    • 2013
  • Markowitz's portfolio selection model is used to construct an optimal portfolio which has minimum variance, while satisfying a minimum required expected return. The model uses estimators based on analysis of historical data to estimate the returns, standard deviations, and correlation coefficients of individual stocks being considered for investment. However, due to the inaccuracies involved in estimations, the true optimality of a portfolio constructed using the model is questionable. To investigate the effect of estimation inaccuracy on actual portfolio performance, we study the changes in a portfolio's realized return and standard deviation as the accuracy of the estimations for each stock's return, standard deviation, and correlation coefficient is increased. Furthermore, we empirically analyze the portfolio's performance by comparing it with the performance of active mutual funds that are being traded in the Korean stock market and the KOSPI benchmark index, in terms of portfolio returns, standard deviations of returns, and Sharpe ratios. Our results suggest that, among the three input parameters, the accuracy of the estimated returns of individual stocks has the largest effect on performance, while the accuracy of the estimates of the standard deviation of each stock's returns and the correlation coefficient between different stocks have smaller effects. In addition, it is shown that even a small increase in the accuracy of the estimated return of individual stocks improves the portfolio's performance substantially, suggesting that Markowitz's model can be more effectively applied in real-life investments with just an incremental effort to increase estimation accuracy.

Bioequivalence Assessment of Nabumetone Tablets in Healthy Korean Volunteers

  • Park, Moon-Hee;Shin, In-Chul
    • Biomolecules & Therapeutics
    • /
    • v.15 no.2
    • /
    • pp.118-122
    • /
    • 2007
  • This study was performed to evaluate the bioequivalency between the Osmetone$^{TM}$ Tablet (Myeongmoon Pharm. Co., Ltd.) as a test formulation and the Relafen$^{TM}$ Tablet (Handok Pharm. Co., Ltd.) as a reference formulation. Twenty-four healthy male volunteers were administered the formulations by the randomized Latin square crossover design, and the plasma samples were determined by a high performance liquid chromatography (HPLC) with Ultra-Violet (UV) detector. AUC$_t$, C$_{max}$ and T$_{max}$ were obtained from the time-plasma concentration curves, and log-transformed AUC$_t$ and C$_{max}$ and log-untransformed T$_{max}$ values for two formulations were compared by statistical tests and analysis of variation. AUC$_t$ was determined to be 897.8${\pm}$431.1 ug.hr/ml for the reference formulation and 902.3${\pm}$408.4 ug.hr/ml for the test formulation. The mean values of C$_{max}$ for the reference and test formulations were 24.2${\pm}$8.9 and 24.0${\pm}$9.5 ug/ml, respectively. The AUC$_t$ and C$_{max}$ ratios of the reference Relafen$^{TM}$ Tablet to the test Osmetone$^{TM}$ Tablet were +5.01% and -0.83%, respectively, showing that the mean differences were satisfied the acceptance criteria within 20%. The results from analysis of variance for logtransformed AUC$_t$ and C$_{max}$ indicated that sequence effects between groups were not exerted and 90% confidence limits of the mean differences for AUC$_t$ and C$_{max}$ were located in ranges from log 0.80 to log 1.25, satisfying the acceptance criteria of the KFDA bioequivalence. The Osmetone$^{TM}$ Tablet as the test formulation was considered to be bioequivalant to the Relafen$^{TM}$ Tablet used as its reference formulation, based on AUC$_t$ and C$_{max}$ values.

A Study on Estimation of the Delivery Ratio by Flow Duration in a Small-Scale Test Bed for Managing TMDL in Nakdong River (낙동강수계 수질오염총량관리를 위한 시범소유역 유황별 유달율 산정방법 연구)

  • Shon, Tae-Seok;Park, Jae-Bum;Shin, Hyun-Suk
    • Journal of Korean Society on Water Environment
    • /
    • v.25 no.5
    • /
    • pp.792-802
    • /
    • 2009
  • The objective of this study is to construct the watershed management system with link of the non-point sources model and to estimate delivery ratio duration curves for various pollutants. For the total water pollution load management system, non-point source model should be performed with the study of the characteristic about non-point sources and loadings of non-point source and the allotment of pollutant in each area. In this study, daily flow rates and delivered pollutant loads of Nakdong river basin are simulated with modified TANK model and minimum variance unbiased estimator and SWAT model. Based on the simulation results, flow duration curves, load duration curves, and delivery ratio duration curves have been established. Then GIS analysis is performed to obtain several hydrological geomorphic characteristics such as watershed area, stream length, watershed slope and runoff curve number. As a result, the SWAT simulation results show good agreements in terms of discharge, BOD, TN, TP but for more exact simulation should be kept studying about variables and parameters which are needed for simulation. And as a result of the characteristic discharges, pollutants loading with the runoff and delivery ratios, non-point sources effects were higher than point sources effects in the small-scale test bed of Nakdong river basin.

Numerical Analysis for Consolidation of Compressible Soils (압축성 모의 압밀에 대한 수치해석 -다층토를 중심으로-)

  • Kim, Pal-Gyu;Song, Yong-Hui;Lee, Hwan-Gi
    • Geotechnical Engineering
    • /
    • v.1 no.1
    • /
    • pp.5-12
    • /
    • 1985
  • Ocassionally it is used for simple extensions of Terzahgi's theory to account for time-depend- tint loading but there is little evidence of application in more complicated consolidation theories that take into account such effects as nonlinear stress.strain, layered systems or large strains. The purpose of this paper provides an efficient computer algorthm based on numerical analysis using finite difference method which account for multi-layered soils to determine the degree of consolidation and excess pore pressures relative to time and positions more realistically. The explicitly scheme of solving the consolidation equations has been investigated from the point of view of the stability conditions and the convergence with variance of the operator as well as to obtain an optimal divided depth ratios of total depth. A comparison of the settlement predictions with both the classical analysis and the algorithm based on numerical analysis indicates that the new algorithm scheme is found to be superior to the classical theory in the layered soils.

  • PDF

Development and Psychometric Evaluation of the Patient Safety Violation Scale in Medical Oncology Units in Iran

  • Shali, Mahboobeh;Ghaffari, Fatemeh;Joolaee, Soodabeh;Ebadi, Abbas
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.17 no.9
    • /
    • pp.4341-4347
    • /
    • 2016
  • Background: Patient safety is one of the key components of nursing care for cancer cases. Valid and reliable context-based instruments are necessary for accurate evaluation of patient safety in oncology units. The aim of the present study was to develop and evaluate the psychometric properties of the Patient Safety Violation Scale in medical oncology units in Iran. Materials and Methods: In this methodological study, a pool of 58 items was generated through reviewing the existing literature. The validity of the 58-item scale was assessed through calculating impact score, content validity ratio, and content validity index for its items as well as conducting exploratory factor analysis. The reliability of the scale was evaluated by assessing its internal consistency and testretest stability. Study sample consisted of 300 oncology nurses who were recruited from thirteen teaching hospitals affiliated to Tehran University of Medical Sciences, Tehran, Iran. Results: Sixteen items were excluded from the scale due to having low impact scores, content validity ratios, or content validity indices. In exploratory factor analysis, the remaining 42 items were loaded on five factors including patient fall, verification of patientidentity, harm during care delivery, delay in care delivery, and medication errors. These five factors explained 62% of the total variance. The Cronbach's alpha of the scale and the test-retest interclass correlation coefficient were equal to 0.933 and 0.92, respectively. Conclusions: The 42-item Patient Safety Violation Scale is a simple and short scale which has acceptable validity and reliability. Consequently, it can be used for assessing patient safety in clinical settings such as medical oncology units and for research projects.

Effect of Selective Thoracic Extensor Strengthening Exercise Using a Foam-Roller on Thoracic and Lumbar Extensor Muscle Activity (폼-롤러를 이용한 가슴폄근의 선택적 강화 운동이 가슴폄근과 허리폄근의 근활성도에 미치는 영향)

  • Kim, Bumjun;Weon, Jonghyuck
    • Journal of The Korean Society of Integrative Medicine
    • /
    • v.4 no.4
    • /
    • pp.101-108
    • /
    • 2016
  • Purpose : The purpose of this study was to determine the effect of selective thoracic extensor strengthening exercises in the sitting position using a foam-roller by investigating the electromyographic(EMG) activities of the thoracic and lumbar extensors. Methods : Eighteen healthy subjects with no medical history of back pain were recruited. EMG activity was recorded from thoracic extensor(TE) and lumbar extensor(LE) while subjects performed three thoracic extension exercises: prone thoracic extension(PTE), prone thoracic extension with abdominal draw-in maneuver(PTE-ADIM), and sitting thoracic extension using a foam-roller(STE). TE and LE EMG activity, and TE/LE EMG activity ratio were analyzed by one-way repeated-measures analysis of variance(ANOVA). Where a significant difference was identified, a Bonferroni correction was performed(p<.017, .05/3). Results : TE and LE EMG activity, and TE/LE EMG activity ratio differed significantly among the three exercises(p<.05). Post hoc pair-wise comparison with Bonferroni correction showed that TE muscle activity in the STE exercise was significantly different from PTE and PTE-ADIM exercises(p<.017). There was no significant difference between TE muscle activity for PTE and PTE-ADIM exercises(p>.017). LE muscle activity and TE/LE ratios were significantly different among the three exercises p<.017). Conclusion : TE/LE ratio showed superior selective thoracic extensor strengthening for the STE exercise than PTE and PTE-ADIM exercises. Therefore, we recommend STE exercise for selective thoracic extensor strengthening.