# 4.6 Model Building For Monthly Temperature Series Case Study

1164 Words 5 Pages
4.6 Model building for monthly temperature series
According to Takele (2012), the process of model fitting involves data plotting, data transformation if necessary, identification of dependence order, estimation of parameter, diagnostic analysis and choosing appropriate model. In this section, a univariate SARIMA methodology is used to model maximum and minimum monthly temperatures of Nairobi.

4.7 Model Identification
ACF and PACF plots are used in the identification of the values p, q, P and Q. For the non-seasonal part, spikes of the ACF at low lags are used to identify the value of q while the value of p is identified by observing the spikes at low lags of the PACF. For the seasonal part the value of Q is observed from the ACF at lags that are multiples of S
Its AIC was -930.17. The Box – Ljung test yielded a chi square of 1.6412 with a p value equal to 0.9496. From Box – Ljung test, the p value of 0.9496 > 0.05 and this confirms that SARIMA (0, 0, 2) (0, 1, 1) is adequate for forecasting.
Minimum temperature time series-SARIMA (1, 0, 0) (0, 1, 1)12
Parameter Estimate Standard error ar1 0.4153 0.0534 sma1 -1.0000 0.0309
Table 11: Parameter estimates for SARIMA (1, 0, 0) (0, 1, 1)12
SARIMA (1, 0, 0) × (0, 1, 1)12 has an estimated variance of 0.004611 with a log likelihood of 346.57. Its AIC was -687.14. The Box – Ljung test yielded a chi square of 3.3259 with a p value of 0.767. From the Box – Ljung test, the p value of 0.767 > 0.05 and this confirms that SARIMA (1, 0, 0) (0, 1, 1) is adequate for forecasting.

4.1.0 Diagnostic Analysis
For a well fitted model, the standardized residuals estimated from the model should behave as an independent and identically distributed sequence with zero mean and constant variance.

4.1.1 Diagnostic analysis for Maximum temperature

• ## Analysis Of Dafoliflozin And Saxagliptin

Abstract: A simple, novel, and sensitive method developed for estimation of Dappagliflozin and Saxagliptin. The method was carried out on reverse- phase C18 inertsil column, with mixture of Methanol: Water ( 80:20) ratio as a mobile phase, 1 ml / min flow rate. Different analytical parameters such as linearity, precision, accuracy, Limit of detection (LOD), Limit of Quantification (LOQ), robustness were determined according to the International conference on Harmonization ICH guidelines. The regression analysis for the linearity data analysis for the linear data analysis shows a good correlation coefficient of Dapagliflozin and Saxagliptin with r = 0.999 in the concentration range of 20-70 g /ml. Retention times of Dapagliflozin and Saxagliptin…

Words: 781 - Pages: 4
• ## Quetiapine Fumarate Case Study

A good linearity relation (r2=0.999) was obtained between drug concentration and average peak areas. The limit of detection and limit of quantification of the instrument were calculated 0.02 and 0.06 μg/ml, respectively. The accuracy of the method validation…

Words: 1867 - Pages: 8
• ## Differences Of The Fepo4 Crystal

The following relation expresses the temperature dependence of the tilt angle: δ2 = 2/3 δ02 [1 + (1 – ¾ (T – Tc/T0 – Tc))^1/2] Where δ0 is the decrease in tilt angle at the transition temperature (980K) and Tc is the temperature for the second-order transition. 2 Paragraph 2 We have already observed that the phase transition temperature is 980K, which implies that FePO4 will possess an α structure below this temperature and a β structure above this temperature. α- FePO4 Possesses trigonal symmetry while that of ofβ-FePO4 is…

Words: 923 - Pages: 4
• ## Challenges Of Vertical Heat Exchange Network Development In Chemical Engineering

As it was mentioned in Introduction section, Qhot oil= 15 kW, Qcooling water = 534 kW (SPRINT results) for vertical heat exchange should be the same, because utilities and temperature boundaries of the blocks remain constant. Table 4. Heat loads of generated heat exchange matches Block 1 (kW) Block 2 (kW) Block 3 (kW) H1. C1 37.244 H1.C2 254.760 H1.C3 271.996 44.000 4.000 H1.QW 15.000 H2.C1 42.756 H2.C2 277.240 H2.C3 40.000 QS.C1 519.996 QS.C3 14.004 QW – cooling water, QS – hot oil b) Criss-cross heat…

Words: 1736 - Pages: 7
• ## Theoretical Analysis For Hphx's Performance

Theoretical analysis for HPHX's performance by using dimension analysis theory. Assumptions Steady operation conditions exist. The surface temperature of the condenser section is equal to the temperature of Refrigerant R-22. Properties The exit temperature of air, and thus the mean temperature, is not known. We evaluate the air properties at the assumed mean temperature of 42OC (will be checked later) and 1 atm as following: K= 0.02722 (W/m.K) =1.1204 kg⁄m^3 C_p=1.007 kJ⁄(kg.K) Pr=0.71175 =0.00001924 kg⁄(m.s) 〖Pr〗_s=0.71819 Analysis It is given that D =0.00953 (m), S_L= S_T=0.0254…

Words: 1086 - Pages: 5
• ## Freundlich And Langmuir: An Analysis Of Absorption Isotherm Models

qt CV or MB amount that adsorbed onto unit weight of adsorbent at any time t (mg/g) K1 is the rate constant for pseudo-first-order model (L/min). The value of qe and K1 were found from slope and intercept of linear relation between log (qe- qt) with t at the given concentrations. The straight line between log (qe- qt) and the time emphasize the applicability of the equation (7) , fig. (11). The pseudo second-order is given in equation: ........................................................................................................(8) Where: qe CV or MB amount that adsorbed onto unit weight of adsorbent at equilibrium (mg/gm).…

Words: 1209 - Pages: 5
• ## Essay On Effect Of Temperature On Amylase

The results of the test were found to be: α equaled 0.05 > p-range, degrees of freedom equaled 16, the t-value was equal to 8.68, and the p value range was 0.05 > p-range Table 2. Class Data for Starch Digested (mg/mL) Tube # Tube 2 Tube 3 Temperature 4 °C 24 °C Group 1 0.04…

Words: 1966 - Pages: 8
• ## The Pros And Cons Of Distillation

The desired fraction of the heavy key and light key in the bottoms and distillate respectively is at least 99%. The relative volatility of the components is calculated at the initial temperature using Equation 2. lnα_(LK-HK)= (P_LK^*)/(P_HK^* ) (2) The vapour pressure values were obtained from Aspen and can be found in Appendix A. The relative volatility is 4.06 and found is Nmin is 6.56. To calculate the minimum feed stage Equation 3 is used. N_(F,min)=(l n⁡([x_LK/x_Hk ]_dist/[z_LK/z_Hk ]))/(lnα_(LK-HK) ) (3) This yields NF,min = 2.26 Underwood equations The underwood equations estimate the minimum reflux ratio of the distillation column.…

Words: 996 - Pages: 4
• ## Dissolved Gas Analysis Essay

8.3.2 Linear calibration using a least squares regression can also be used. The “goodness of fit” of the linear regression, given as r2 by the software, must be greater than or equal to 0.995. 8.4 Verify the calibration curve with an independent standard for each gas. The second source ICV must be within 20% of its expected value for each analyte. 8.5 Also examine the calculated value of the lowest calibration standard (MRL).…

Words: 1252 - Pages: 5
• ## Ideal Gas Law

Only one gas was selected from the choices. This particular experiment used the data for ammonia. Then, the one was divided by the volume, to compute the real volume. Next, the ideal pressure of the gas was calculated by multiplying it by 1/V, the temperature, in Kelvins, and the gas constant, C. Ammonia had a temperature of 373K and the gas constant was 8.314J/(mol*K). Next, the real Z-value was calculated by the equation(real pressurePa*real volumeL)/(8.314J/(mol*K) *373K).…

Words: 1321 - Pages: 6