• Title/Summary/Keyword: Response Surface Regression Analysis

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Application of Statistical Analysis for Optimization of Organic Wastes Acidogenesis (유기성 폐기물의 산발효 최적화를 위한 통계학적 분석 방안의 적용)

  • Jeong, Emma;Kim, Hyun-Woo;Nam, Joo-Youn;Oh, Sae-Eun;Hong, Seung-Mo;Shin, Hang-Sik
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.8
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    • pp.781-788
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    • 2008
  • This study shows how to find out optimum co-substrate conditions and continuous operating parameters for maximum acidification of three different organic wastes - livestock wastewater, sewage sludge and food waste. Design of experiments and statistical analysis were revealed as appropriate optimization schemes in this study. Analyses of data obtained from batch tests demonstrated the optimum substrate mixing ratio, which was determined by maximum total volatile fatty acids(TVFA) increase and soluble chemical oxygen demand(SCOD) increase simultaneously. Suggested optimum mixing ratio of livestock wastewater, sewage sludge and food waste was 0.4 : 1.0 : 1.1 based on COD, respectively. Response surface methodology(RSM) contributed to find out optimum operating parameter - hydraulic retention time(HRT) and substrate concentration - for the semi-continuous acidogenic fermentation of mixed organic wastes. The optimum condition for maximum TVFA increase was 2 days of HRT and 29,237 mg COD/L. Empirical equations obtained through regression analysis could predict that TVFA increase would be 73%. To confirm the validity of the statistical experimental strategies, a confirmation experiment was conducted under the obtained optimum conditions, and relative error between theoretical and experimental results was within 4%. This result reflects that using statistical and RSM technique can be effectively used for the optimization of real waste treatment processes.

Optimization for the Physical Properties of Steamed Foam Cakes Prepared with Single-stage Method by Response Surface Methodology (반응표면 분석법에 의한 단단계법 거품형 찜 케이크의 물리적 특성의 최적화)

  • Kwhak, Sung-Ho;Jang, Myung-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.4
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    • pp.557-566
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    • 2005
  • In preparation of steamed foam-cakes, effects of whipping time, amount of wheat flour, and amounts of emulsifier on physical properties of the steamed foam cakes were investigated using RSM (response surface methodology). The three independent variables selected for the RSM experiment were whipping time $(X_1)$, amount of wheat flour $(X_2)$, and amounts of wheat flour $(X_2)$, and concentration of emulsifier $(X_3)$ were set for single-stage mixing, respectively. A rotatable central composite design was used for treatment arrangement. The responses from the product for loaf volume, color values and textural properties were analysed. In the analysis of variance for the foam cakes prepared by single-stage method, significant interactions were observed between independent variables (experimental factors) and physical property like loaf volume (p<0.05); textural properties like hardness, gumminess, and chewiness (p<0.05). Among independent variables, concentration of emulsifier had the most effects on physical properties while whipping time. The ordinary points in surface response showed maximal points with physical property like colorimetric b value while other properties revealed saddle points. The 3-dimensional response surface graphs of the predicted regression models displayed decreasing loaf volumes with increasing whipping times and emulsifier concentrations beyond optimum levels. The optimum conditions for best loaf volume and textural property (hardness, gummimess and chewiness) of the products selected by extracting intersectional areas of the contour maps that commonly overlapped all characteristics were; $11\~13$ min whipping time, $470\~486\;g$ amount of wheat flour, and $19\~20\;g$ emulsifier concentration, in case of single-stage method. The median values extracted from the RSM experimental results for optimum manufacturing conditions for single-stage method, i.e., 12 min whipping time, 478 g amount of wheat flour, and 20 g emulsifier concentration were empirically proven to fit the predicted levels of physical properties from the final foam cakes.

Effects of Red Peppers on the Its Pungency and Color during Kimchi Fermentation (고춧가루가 발효중 김치의 매운맛과 색도에 미치는 영향)

  • 구경형;박재복;박완수
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.6
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    • pp.1034-1042
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    • 2004
  • This study was carried out to investigate preparation of reconstructed red peppers, effects of pungency and redness of red peppers on the Kimchi quality using central composite design and response surfaces methodology. Capsaicinoids and ASTA (American Spice Trading Association) value put in X$_1$, X$_2$ of independent variable. The result of response surface regression analysis of reconstructed red peppers, correlation coefficient ($R^2$) of overall pungency intensity, persistence and degree of redness was 0.935, 0.935 and 0.821, respectively. After it was made Kimchi samples with reconstructed red peppers, it was examined pH, titratable acidity and lactic acid bacteria of its during fermentation. In the initial fermentation period of Kimchi, it showed pH of 5.46∼5.78, titratable acidity of 0.27∼0.31%, salt content of 2.26∼2.48% and lactic acid bacteria of 4.05${\times}$10$^{5}$ ∼6.23${\times}$10$^{5}$ , respectively. And it showed traditional fermentation pattern in the pH, titratable acidity and microbes of the middle (appropriate fermentation) and last (excessive) fermentation period. While capsaicinoids content in the Kimchi decreased a little according to extend fermentation period, ASTA value showed low correlation reconstructed red pepper and fermentation period. Also, it was analyzed correlation coefficient ($R^2$) of independent variables (capsaicinoids, X$_1$; ASTA value, X$_2$) between sensory attribute in the Kimchi during fermentation. The result of regression analysis, $R^2$ in the overall pungency intensity, persistence and degree of redness showed 0.515, 0.675, 0.784, respectively.

Analysis of Extraction Characteristics of Phytoestrogen Components from Punica granatum L. (석류 phytoestrogen 성분의 추출특성 분석)

  • Kim, Seong-Ho;Kim, In-Ho;Kang, Bok-Hee;Cha, Tae-Yang;Lee, Jin-Hyung;Kim, Jong-Myeong;Rim, Soon-Ok;Song, Kyung-Sik;Song, Bang-Ho;Kim, Jong-Guk;Lee, Jin-Man
    • Applied Biological Chemistry
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    • v.48 no.4
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    • pp.352-357
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    • 2005
  • The optimization of extraction conditions of phytoestrogen from pomegranate by hot water was conducted by analyzing the extraction characteristics. The purpose of this study was effective utilization of bioactive components of pomegranate, and the analyzing was performed with response surface methodology (RSM). This study established 10 sections based on the central composite design with the independent variables of extraction temperature (60, 70, 80, 90, $100^{\circ}C$) and extraction time (1, 2, 3, 4, 5 hr) to predict the optimal conditions for extraction of the effective components. The dependent variables were measured for extracted materials, those were, the major components such as chlorogenic acid, kaempferol, $17-{\alpha}-estradiol\;and\;17-{\beta}-estradiol$ content, and regression analysis was performed by SAS program, and optimal conditions for each characteristics were predicted, and the characteristics of extraction were analyzed by response surface methodology. It was found that chlorogenic acid, kaempferol, and $17-{\alpha}-estradiol$ content were greatly affected by extraction temperature. However, $17-{\beta}-estradiol$ content was affected significantly by extraction time. Regression formulas for each variable were elicited from this study, and the chlorogenic acid, kaempferol, $17-{\alpha}-estradiol\;and\;17-{\beta}-estradiol$ content depending on response surface methodology factor were superimposed. It was shown that optimal temperature and extraction time were $98{\sim}100^{\circ}C\;and\;3{\sim}5$ hrs, respectively.

Analysis of Impact Acoustic Property of Apple Using Piezo-Polymer Film Sensor (고분자 압전 박막 센서를 이용한 사과의 충격 음파 특성 분석)

  • Kim, Man-Soo;Lee, Sang-Dae;Park, Jeong-Hak;Kim, Ki-Bok
    • Journal of the Korean Society for Nondestructive Testing
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    • v.28 no.2
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    • pp.144-150
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    • 2008
  • In this study, the PVDF (polyvinylidene fluoride) piero-film sensor was applied to measure the internal quality of apple. The developed sensor detected the response signal through apple after mechanical impact on the surface of apple. The acoustical parameters at time domain such as rise time (RT), ring down count (RC), energy (EN), event duration (ED) and peak amplitude (PA) and acoustical parameter at frequency domain such as spectral density (SE) were analyzed. The size of waveform decreased as storage time of apple increased. The frequency at maximum magnitude was shifted to lower frequency band according to the storage time. The acoustical parameters showed strong relationship with storage time. The multiple linear regression equation was developed to estimate storage time of apple using the acoustical parameters at time domain and its coefficient of determination was 0.97. The internal quality of apple according to storage time is predictable using developed PVDF sensor and acoustical parameters defined in this study.

Optimal Condition for Manufacturing Water Extract from Mandarin Orange Peel for Colored Rice by Coating (유색미 제조용 감귤과피 물추출 균질액의 제조조건 최적화)

  • Seo, Sung-Soo;Youn, Kwang-Sup;Shin, Seung-Ryeul;Kim, Soon-Dong
    • Korean Journal of Food Science and Technology
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    • v.35 no.5
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    • pp.884-892
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    • 2003
  • This study was conducted to optimize the water homogenization process of mandarin orange peel for colored rice. Four variables were used to determine the optimum conditions for homogenization speed, time, temperature, and water volume with a five level central composite design and response surface methodology. The process was optimized using the combination of EI and b values of rice coated with water extract of the mandarin orange peel. The effect of water volume was the most significant compared to the other variables on the quality of water homogenate. The regression polynomial model was a suitable (p>0.05) model by lack-of-fit analysis showing high significance. To optimize the process, based on surface response and contour plots, individual contour plots for the response variables were superimposed. The optimum conditions for manufacturing water extract from mandarin orange was with 8,500 rpm homogenization speed, 2.8 min time, $53^{\circ}C$ temperature, and 42 mL water volume with the maximum of restricted variables of EI above 400 and h value above 24.

Central Composite Design Matrix (CCDM) for Phthalocyanine Reactive Dyeing of Nylon Fiber: Process Analysis and Optimization

  • Ravikumar, K.;Kim, Byung-Soon;Son, Young-A
    • Textile Coloration and Finishing
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    • v.20 no.2
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    • pp.19-28
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    • 2008
  • The objective of this study was to apply the statistical technique known as design of experiments to optimize the % exhaustion variables for phthalocyanine dyeing of nylon fiber. In this study, a three-factor Central Composite Rotatable Design (CCRD) was used to establish the optimum conditions for the phthalocyanine reactive dyeing of nylon fiber. Temperature, pH and liquor ratio were considered as the variable of interest. Acidic solution with higher temperature and lower liquor ratio were found to be suitable conditions for higher % exhaustion. These three variables were used as independent variables, whose effects on % exhaustion were evaluated. Significant polynomial regression models describing the changes on % exhaustion and % fixation with respect to independent variables were established with coefficient of determination, R2, greater than 0.90. Close agreement between experimental and predicted yields was obtained. Optimum conditions were obtained using surface plots and Monte Carlo simulation techniques where maximum dyeing efficiency is achieved. The significant level of both the main effects and interaction was observed by analysis of variance (ANOVA) approach. Based on the statistical analysis, the results have provided much valuable information on the relationship between response variables and independent variables. This study demonstrates that the CCRD could be efficiently applied for the empirical modeling of % exhaustion and % fixation in dyeing. It also shows that it is an economical way of obtaining the maximum amount of information in a short period of time with least number of experiments.

The Effects of Emotional Labor on Fatigue Scale of Private Security Guards in Regular Exercise (시큐리티 요원의 규칙적인 운동참여 활동이 감정노동과 피로도에 미치는 영향)

  • Kim, Eui-Young
    • Korean Security Journal
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    • no.62
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    • pp.205-221
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    • 2020
  • The purpose of this study was to examine the effects of emotional labor on fatigue in regular private participation of sports workers, and to provide basic data to improve the welfare and working environment of private security guards, the core of private security industry. The survey response of 260 private security guards was used as the final analysis data, and the following conclusions were drawn through statistical tests of factor analysis, t-test, correlation analysis, and multiple regression analysis using the SPSS Windows 18.0 statistical program. First, the private security guards who regularly participate in sports showed lower sub-variability of fatigue, physical, exhaustion, and nervous system fatigue than private security guards who did not participate in sports. Second, it was found that fatigue was lower as the inner variables became higher, and that as the surface behavior became higher, the fatigue factor was lower. In conclusion, regular exercise participation can reduce emotional labor and improve fatigue of civil security personnel.

Development of an Onion Vinegar Beverage Containing Yuza (Citrus junos Sieb ex Tanaka) and Its Biological Activity (유자 첨가 양파발효음료의 제조 및 생리활성)

  • Jeong, Eun-Jeong;Cha, Yong-Jun
    • Journal of Life Science
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    • v.26 no.5
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    • pp.563-570
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    • 2016
  • Onion vinegar has an undesirable flavor and taste that results from alcohol and acetic acid production from fermentation. In this study, we have used onion vinegar to develop an onion vinegar beverage with better sensory quality. The objective of this study was to determine the optimum blending ratio by using response surface methods to produce an onion vinegar beverage containing Yuza (Citrus junos Sieb ex Tanaka). The optimal formula for a fermented onion beverage was determined using a central composite design by the response surface methodology. The independent variables were obtained by regression analysis of the reaction surface of brown sugar, apple extracts and Yuza extracts. The optimum mixing ratio for onion vinegar:water:brown sugar:apple extracts:Yuza extracts was 6.0:77.6:4.9:9.2:2.3 (w/w). The actual overall acceptance was 7.08 under optimum conditions, which was close to the maximum predicted value of 6.96. The concentration of phenolic compounds, total flavonoids, and quercetin present in the onion vinegar beverage was 14.8 mg/100 g, 2.6 mg/100 g and 1.4 mg/100 g, respectively. The onion vinegar beverage showed antimicrobial activity against Staphylococcus aureus, Escherichia coli, Salmonella typhimurium and Enterobacter aerogenes. It also showed antioxidant effects, with a DPPH radical inhibition rate of 18.2% and superoxide dismutase (SOD)-like activity of 11.5%. In conclusion, the onion vinegar beverage described here seems to have nutritional value and potential biological activity.

An Alternative Model for Determining the Optimal Fertilizer Level (수도(水稻) 적정시비량(適正施肥量) 결정(決定)에 대한 대체모형(代替模型))

  • Chang, Suk-Hwan
    • Korean Journal of Soil Science and Fertilizer
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    • v.13 no.1
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    • pp.21-32
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    • 1980
  • Linear models, with and without site variables, have been investigated in order to develop an alternative methodology for determining optimal fertilizer levels. The resultant models are : (1) Model I is an ordinary quadratic response function formed by combining the simple response function estimated at each site in block diagonal form, and has parameters [${\gamma}^{(1)}_{m{\ell}}$], for m=1, 2, ${\cdots}$, n sites and degrees of polynomial, ${\ell}$=0, 1, 2. (2) Mode II is a multiple regression model with a set of site variables (including an intercept) repeated for each fertilizer level and the linear and quadratic terms of the fertilizer variables arranged in block diagonal form as in Model I. The parameters are equal to [${\beta}_h\;{\gamma}^{(2)}_{m{\ell}}$] for h=0, 1, 2, ${\cdots}$, k site variable, m=1, 2, ${\cdots}$ and ${\ell}$=1, 2. (3) Model III is a classical response surface model, I. e., a common quadratic polynomial model for the fertilizer variables augmented with site variables and interactions between site variables and the linear fertilizer terms. The parameters are equal to [${\beta}_h\;{\gamma}_{\ell}\;{\theta}_h$], for h=0, 1, ${\cdots}$, k, ${\ell}$=1, 2, and h'=1, 2, ${\cdots}$, k. (4) Model IV has the same basic structure as Mode I, but estimation procedure involves two stages. In stage 1, yields for each fertilizer level are regressed on the site variables and the resulting predicted yields for each site are then regressed on the fertilizer variables in stage 2. Each model has been evaluated under the assumption that Model III is the postulated true response function. Under this assumption, Models I, II and IV give biased estimators of the linear fertilizer response parameter which depend on the interaction between site variables and applied fertilizer variables. When the interaction is significant, Model III is the most efficient for calculation of optimal fertilizer level. It has been found that Model IV is always more efficient than Models I and II, with efficiency depending on the magnitude of ${\lambda}m$, the mth diagonal element of X (X' X)' X' where X is the site variable matrix. When the site variable by linear fertilizer interaction parameters are zero or when the estimated interactions are not important, it is demonstrated that Model IV can be a reasonable alternative model for calculation of optimal fertilizer level. The efficiencies of the models are compared us ing data from 256 fertilizer trials on rice conducted in Korea. Although Model III is usually preferred, the empirical results from the data analysis support the feasibility of using Model IV in practice when the estimated interaction term between measured soil organic matter and applied nitrogen is not important.

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