Graphical Optimization Method Research Articles

Optimization of Alkali Treatment Conditions of Ramie Fabrics Using Box–Behnken Method

Ramie is a widely used plant fiber for making textiles and reinforcement in biodegradable composites. Pretreating cellulosic fibers with alkali before producing composites is increasingly used to enhance adhesion with polymeric resin. In this work, response surface methodology (RSM) based on the Box-Behnken technique was utilized to investigate the impact of independent variables on ramie fabric characteristics and determine the optimal treatment condition. The impact of alkali concentration, treatment time, and temperature on the breaking load and elongation at break of woven ramie fabrics were evaluated using Design-Expert software, which established the design matrix and analyzed the experimental data employing numerical and graphical optimization methods. Moreover, the impact of alkali treatment conditions on the surface morphology, structural change of ramie fabrics, and thermal properties was investigated. Based on the analysis of variance (ANOVA) results, the suggested quadratic models can adequately predict the breaking load and elongation at break of the ramie woven fabrics within the range of conditions applied in this investigation. The RSM revealed that an alkali concentration of 6.12%, a treatment time of 30 min, and a temperature of 39.13°C resulted in an optimum treatment condition with a breaking load of 518.28 N and elongation at break of 23.36%.

Optimal Design of Tilted Building Envelope Considering Air Conditioning Energy Demand, Daylight Utilization and Glare Protection—Case Study

An important energy-saving method to optimize building envelope design is the integration of local climate characteristics. This study attempts to find sloped facade configurations to balance air conditioning energy demand and daylight utilization for four directions in an area with a hot climate. Tilt angle dependence of the air conditioning energy demand, useful daylight illuminance (UDI) and daylight glare index (DGI) are selected to investigate the acceptance thresholds of the tilt angle. The final facade’s configuration is achieved by employing the graphical optimization method. An acceptable solution that balances better daylight performance and less energy consumption by air conditioning is developed. Due to the considered city being located in a low-latitude area with great daylight availability as well as a fully dimmable light control strategy, unbearable glare reduction can be achieved by benefiting from the sloped facades, without necessarily sacrificing much usable daylight. Meanwhile, there is no obvious increase in the demand for lighting energy consumption, and a good outward view is preserved. The sloped rather than vertical facade provides natural solar shading to the east-, south- and west-oriented windows while allowing low-angle winter solar heat to warm the building space. Tilt angles between 35°and 40° are preferred for the east facade, and smaller tilt angles of between 30°and 35° are recommended for the south facade. Larger tilt angles of between 40°and 45° are preferred for the west facade. However, the north-facing facade’s outward tilt would cause an undesirable increase in air conditioning energy demand. The annual air conditioning energy demand of the east-, south- and west-facing space is found to separately decrease by 7.1%, 7.3% and 9.9%, respectively, benefiting from the sloped facades.

Efficiency improvement of dual active bridge converter using simple graphical optimization method

SummaryAiming to the problems of high circulating current and low efficiency caused by the traditional strategy of dual active bridge (DAB) converter under light load, in this paper, simple graphical optimization method (GSO) is proposed to improve the efficiency of dual active bridge converter. Through the contour plot of transmission power and current stress, optimal efficiency point can be obtained by tangent of contour map under condition of constant power, and heavily calculation or complex iterations of existing conventional control strategies are avoided. Moreover, analysis of proposed graphical current stress optimization is addressed, and controller design of proposed method is given and described. Efficiency comparison between traditional modulation strategy and GSO is given to show the advantage of proposed mothed. An experimental prototype is built to verify the analysis.

Graphical optimization method for bidirectional corridor progression under the signal design mode of split phasing

Graphical optimization method for bidirectional corridor progression under the signal design mode of split phasing

MULTI-CRITERIA NUMERICAL OPTIMIZATION OF MECHANICAL PROPERTIES IN ULTRASONIC WELDING PROCESS PARAMETERS OF PVC-COATED HYBRID TEXTILES FOR WEATHER PROTECTION

A series of research was carried out to determine the correlation between ultrasonic welding process parameters and weld seam mechanical properties. However, multi-objective numerical optimization of coated hybrid textiles for weather protection has not been addressed. To ensure a comprehensive evaluation of ultrasonic weld seams, the research investigates the optimal solution of the multi-objective function of ultrasonic welding process parameters and formulates a single criteria objective function. Lapped and superimposed types of seams were applied based on 33 factorial designs of experiments for 6 and 12 mm welding widths. Single-criteria objective functions instead of three independent problems were developed as a generalized utility function. A single-criteria optimization method was introduced through predetermined weight and normalization within the range of acceptable/unacceptable values. Numerical and graphical optimization methods were also applied to determine possible optimal solutions through generalized utility functions. The best optimal value of the generalized utility function (0.670425 and 0.944374) was attained at welding speed (2 and 2.01564 m/min), power (93.756 and 117.973 W), and pressure force (198.803 and 239.756 N) of 6 and 12 mm welding widths, respectively. The acceptable range of satisfactory values was determined for the roof and wall of awnings and camping tents through standard, in which seam performance level indicated. Nonlinear quadratic numerical models were formulated to estimate the generalized utility function, and their results were close to the regressed diagonal line against the actual points. The statistical analysis was shown a statistically significant effect of welding process parameters on the generalized utility function.

Dosimetric Evaluation of Different Optimization Algorithms Used in Interstitial Brachytherapy of Cervical Carcinoma.

Background: Conventional optimization techniques are based on the planning approach in which positions and weights are varied to generate the desired dose distribution. Inverse planning simulated annealing (IPSA) is an advanced optimization method developed to automatically determine a suitable combination of positions to design an acceptable plan.Objective: In this study, three optimization techniques namely IPSA, graphical optimization (GROPT), and geometrical optimization (GOPT) methods are compared in high-dose-rate interstitial brachytherapy of cervical carcinoma.Material and Methods: In this retrospective study, twenty computed tomography (CT) data sets of 10 cervical cancer patients treated with Martinez Universal Perineal Interstitial Template-based interstitial brachytherapy were studied. The treatment plans generated were optimized using the IPSA, and GOPT methods. The prescribed dose was 24 Gy in 4 fractions. Plans produced using IPSA, GrOPT, and GOPT techniques were analyzed for comparison of dosimetric parameters, including target coverage, homogeneity, conformity, and organs at risk (OAR) doses.Results: V100 values for IPSA, GrOPT and GOPT plans were 95.81±2.33%, 93.12±2.76% and 88.90±4.95%, respectively. The mean D90 values for the IPSA, GrOPT, and GOPT plans were 6.45±0.15 Gy, 6.12±0.21 Gy, and 5.85±0.57 Gy, respectively. Significantly lower doses of OAR were in the IPSA plans that were more homogeneous (HI=0.66). Conformity was comparatively higher in IPSA-based plans (CI=0.75).Conclusion: IPSA plans were superior and resulted in better target coverage, homogeneity, conformity, and minimal OAR doses.

Integrated energy, daylighting, comfort and environmental performance analysis of window systems in patient rooms

This study investigates the influence of window system configurations on the energy use/cost, access to daylight and view, visual comfort and environmental performance in a one-bed hospital patient room located in a temperate climate. The methodology combines dynamic energy simulations, visual comfort and daylight analysis in a life cycle assessment study of window systems, covering a wide range of environmental indicators. In this study, multi-criteria evaluation approach is used to analyse the different design alternatives. A graphical optimization method was elaborated to filter the solutions and select the most appropriate window design based on project objectives and architectural preferences. The results show that glazing with ‘0.30 < g-values≤0.50’ and ‘0.50 < Tvis < 0.75’ have lower energy use and/or cost, lower environmental impacts while maintaining sufficient daylight levels (sDA > 55%) and showing higher quality for visual comfort. These type of glazing allows for using bigger windows which leads to a higher percentage of the outside view.

Optimizing Micro-Turning Parameters during Step Turning Process on &lt;br /&gt; Titanium Alloy with RSM

An attempt was made to evaluate and improve the machining parameters of micro-turning titanium alloy with cermet insert on the titanium alloy’s surface roughness. The experiments were done using a strong statistical tool to construct a matrix by utilizing Response Surface Methodology (RSM) and Box-Behnken design for performing the micro turning. Quadratic model was generated to predict the response and also used to appraise the effect of outcomes. The results of the investigation suggest that the cutting feed as well as speed rate are the input elements that have the greatest impact on surface roughness. Numerical with graphical optimization methods are figured out to seek out the optimum method parameters. The subsequent machining conditions lead to minimum surface roughness on speed 2944 rpm, 7.23 µm/rev feed along with 15 µm depth of cut that helps to attain the great surface quality with minimum machining value and at the same time improves the productivity with 86% of optimum desirability rate.

Graphical Optimization Method for Symmetrical Bidirectional Corridor Progression

The graphical progression method can obtain grand coordinated schemes with minimal computational complexity. However, there is no standardized solution for this method, and only a few related studies have been found thus far. Therefore, based on the in-depth discussion of the graphical optimization theory mechanism, a process-oriented and high-efficiency graphical method for symmetrical bidirectional corridor progression is proposed in this study. A two-round rotation transformation optimization process of the progression trajectory characteristic lines (PTC lines) is innovatively proposed. By establishing the updated judgment criteria for coordinated mode, the first round of PTC line rotation transformation realizes the optimization of coordinated modes and initial offsets. Giving the conditions for stopping rotation transformation and determining rotation points, rotation directions, and rotation angles, the second round of PTC line rotation transformation achieves the final optimization of the common signal cycle and offsets. The case study shows that the proposed graphical method can obtain the optimal progression effect through regular graphing and solving, although it can also be solved by highly efficient programming.

Mathematical Multiobjective Optimization for Metal Hip Arthroplasty with Medical Physics Applications

Total hip metal arthroplasty (THA) model-parameters for a group of commonly used ones is optimized and numerically studied. Based on previous ceramic THA optimization software contributions, an improved multiobjective programming method/algorithm is implemented in wear modeling for THA. This computational nonlinear multifunctional optimization is performed with a number of THA metals with different hardnesses and erosion in vitro experimental rates. The new software was created/designed with two types of Sytems, Matlab and GNU Octave. Numerical results show be improved/acceptable for in vitro simulations. These findings are verified with 2D Graphical Optimization and 3D Interior Optimization methods, giving low residual-norms. The solutions for the model match mostly the literature in vitro standards for experimental simulations. Numerical figures for multifunctional optimization give acceptable model-parameter values with low residual-norms. Useful mathematical consequences/calculations are obtained for wear predictions, model advancements and simulation methodology. The wear magnitude for in vitro determinations with these model parameter data constitutes the advance of the method. In consequence, the erosion prediction for laboratory experimental testing in THA add up to the literature an efficacious usage-improvement. Results, additionally, are extrapolated to efficient Medical Physics applications and metal-THA Bioengineering designs.

MULTI-CRITERIA OPTIMIZATION OF THE FIBER CONCRETES COMPOSITIONS OF RIGID PAVEMENT

The experiment was carried out according to the optimal plan, which four factors of the composition of modified fiber concrete for rigid pavement were varied: amount of Portland cement, polypropylene fiber, metakaolin and polycarboxylate type additive. All concrete mixtures had equal mobility P2. Complex of experimental-statistical models describe the influence of factors on the properties of concrete is obtained. Selection of optimal compositions of fiber concrete of a rigid pavement was carried out using the obtained experimental-statistical models. Graphical optimization method for "squares and squares" diagrams was used. The square in the coordinates "amount of metakaolin" - "amount of complex action additive Coral ExpertSuid-5" was used as a carrier in the construction of diagrams. These values of the mechanical characteristics of concrete were used as limitation criteria: compressive strength at the age of 3 and 28 days, flexural tensile strength, frost-resistance, abrasion. Frost-resistance and abrasion are the main indicators that ensure the durability of concrete for rigid pavement in typical operating conditions. The concrete prime cost indicator was used as an optimization criterion. 2 variants of concretes compositions of classes C30/35 and C32/40 with increased durability and high strength was chosen. The selected compositions of C30/35 class concretes have frost-resistance F350, flexural tensile strength 8.0-8.2 MPa, abrasion 0.38-0.39 g/cm2, compressive strength at 3 days age 35 MPa and strength at 28 days age 54 MPa. The selected compositions of C32/40 class concretes have frost-resistance F400, flexural tensile strength 8.5-8.6 MPa, abrasion 0.34 g/cm2, compressive strength at 3 days age 38-39 MPa and strength at 28 days age 57-58 MPa. All four selected compositions have the amount of metakaolin 15-20 kg/m3, polypropylene fiber 0.9-1.5 kg/m3, polycarboxylate type additive Coral ExpertSuid-5 0.8-0.9% of the cement mass.

The Optimum Performance of Building Integrated Photovoltaic (BIPV) Windows Under a Semi-Arid Climate in Algerian Office Buildings

Recently, Building Integrated Photovoltaic (BIPV) windows have become an alternative energy solution to achieve a zero-energy building (ZEB) and provide visual comfort. In Algeria, some problems arise due to the high energy consumption levels of the building sector. Large amounts of this energy are lost through the external envelope façade, because of the poorness of the window’s design. Therefore, this research aimed to investigate the optimum BIPV window performance for overall energy consumption (OEC) in terms of energy output, heating and cooling load, and artificial lighting to ensure visual comfort and energy savings in typical office buildings under a semi-arid climate. Field measurements of the tested office were carried out during a critical period. The data have been validated and used to develop a model for an OEC simulation. Extensive simulations using graphical optimization methods are applied to the base-model, as well as nine commercially-available BIPV modules with different Window Wall Ratios (WWRs), cardinal orientations, and tilt angles. The results of the investigation from the site measurements show a significant amount of energy output compared to the energy demand. This study revealed that the optimum BIPV window design includes double-glazing PV modules (A) with medium WWR and 20% VLT in the southern façade and 30% VLT toward the east–west axis. The maximum energy savings that can be achieved are 60% toward the south orientation by double-glazing PV module (D). On the other hand, the PV modules significantly minimize the glare index compared to the base-model. The data extracted from the simulation established that the energy output percentages in a 3D model can be used by architects and designers in early stages. In the end, the adoption of optimum BIPV windows shows a significant enough improvement in their overall energy savings and visual comfort to consider them essential under a semi-arid climate.

Nonlinear Comparative Optimization for Biomaterials Wear in Artificial Implant Technology

Today, artificial implants (AI) industry depends strongly on tribological constitution of the material (s) of the implant. Erosion, corrosion, tribocorrosion and biocorrosion are essential factors to determine both functionality and lifetime of the AIs. Histo-Biocompatibility is also an additional constraint, indispensable for implant manufacturing process. The prediction of durability, based on the computational and experimental study of constituents of AI material (s) are key factors to obtain objective data of any AI characteristics. This contribution deals with a computational comparative analysis of materials for hip implants using Archard’s model mainly. Selected hip implant material hardness are Co-Cr alloy and Titanium types. Method is carried out with specific material data, e.g., hardness or wear constants, nonlinear optimization and graphical subroutines. Results presented are both numerical and graphical. Particular interest is focused on application of the 3D Graphical Optimization method.

Inverse methods and integral-differential model demonstration for optimal mechanical operation of power plants – numerical graphical optimization for second generation of tribology models

Abstract Stepping forward from a previous conference contribution, the article focuses on extension of inverse problem algorithms to integral-differential modelling and formal/strict demonstration of graphical-optimization method. It shows evident-mathematical and 3D-imaging proofs of the graphical optimization method with L1 Norm simulations and algorithms. At present, Linear/Nonlinear Optimization mathematical methods constitute the choice of preference in getting improvements for erosion and corrosion simulations- determinations in general tribology, biotribology and tribocorrosion. The method(s) developed are classical numerical optimization settings for objective functions, programming optimization and simulations, and special software for imaging in 3D. Results are diverse and the range of their applications is wide. First, the article provides a definite formal demonstration of the nonlinear graphical optimization both in numerical results and in imaging. Then, the authors propose the development of programming optimization and mathematical proofs-algorithms of the integral-differential model for various models. Subsequently, an overview of stochastic erosion methods based on Markov Chain is presented in the article. Finally, the second generation of tribology models is defined and conceptually explained. To summarise, the article comprises new findings towards modernization of tribology, biotribology and tribocorrosion models, gathering innovative research branches for future extension of the mathematical modelling progress. The results can be applied to both general techniques and mechanical engineering. The analytical and numerical demonstration of the integral-differential model constitutes a key point and essential result of the research. Extension to electromagnetic and electronic models of these methods is also considered feasible and practical

Graphical optimization method for coupled heat exchanger network and reactor

In chemical process industry, the reactor’s operating parameters (conversion and selectivity) affect their temperatures, as well as the integration of the Heat Exchanger Network (HEN). It is necessary to consider the integration of the HEN and the optimization of the reactor parameters simultaneously. A Pinch-based method is developed to integrate HEN and optimize the inlet and outlet temperature and energy consumption of reactors with multiple reactions. Based on the reaction kinetics, mass balance and energy balance, equations are deduced to show relations among temperatures, selectivity and conversion of reactor, energy consumption and the energy consumption of unit production. According to the Composite Curves, the effect of temperature variation on HEN is analyzed for exothermic and endothermic reactions, respectively, and relations among temperatures, selectivity, utilities, energy consumption of unit product and conversion are deduced and plotted in the same diagram. The optimal utilities, inlet/outlet temperature, selectivity and conversion of the reactor can be identified from this diagram. A benzene to cyclohexene process is studied to illustrate the application of the proposed method, and the result shows that the energy consumption of unit product can be reduced by 16.3% when the conversion of benzene is increased from 0.4 to 0.58.

Stabilizing O/W Emulsions by Soy Protein Concentrate + Maltodextrin and Optimizing the Process by Using Response Surface Methodology

Stability is one of the key quality parameters of emulsion systems, which goes a long way in predicting the shelf life of emulsion products. In this study, the effect of emulsifier (soy protein concentrate (SPC) + maltodextrin (MDX)), dispersed phase (lycopene in oil solution) and homogenizer speed on emulsion stability were investigated and optimized using response surface methodology (RSM). Independent variables were lycopene content (10-20%, w/w), SPC+ MDX as emulsifier and surfactant (30-40%, w/w) and the homogenizer speed (14000-18000 rpm). Responses were droplet size, viscosity and creaming index as stability indicators of the emulsions. According to RSM analysis and models, optimized variables showed a good fit to quadratic equations for droplet size and viscosity with correlation coefficients (R2) of 0.9571 and 0.9826, respectively. After model simplification with backward stepwise solution, the R2 values for droplet size and viscosity decreased slightly to 0.9504 and 0.9826, respectively. Creaming values were fitted properly with linear model, and R2 was 0.8030. Graphical optimization methods were adapted for preparing the best lycopene emulsifying conditions and were predicted to be: homogenizer speed of 18000 rpm; lycopene content of 20% w/w, and SPC+MDX concentration of 36.95% w/w.

Implementation of experimental design methodology in preparation and characterization of zolmitriptan loaded chitosan nanoparticles

The present study investigated the implementation of 32 factorial design of experiment and statistical analysis for the optimization of chitosan nanoparticles containing zolmitriptan an antimigraine drug. The influence of chitosan concentration (X1) and sodium tripoly phosphate (X2) on responses namely nanoparticle size (Y1), and entrapment efficiency (Y2), was studied. As per design, nine runs of nanoparticles were prepared by modified ionic gelation method using high speed vortex mixing. The particle size was found in the range of 151-880 nm and entrapment efficiency was 72.3-81.2%. A statistical analysis was performed using licensed design expert software V.8.0 with respect to ANOVA, regression analysis. The contour plots and response surface plots showed visual representation of relationship between the experimental responses and the set of independent variables. Regression model equations were validated by a numerical and graphical optimization method. Further, optimized drug loaded nanoparticles showed +23.7mV zeta potential indicating storage stability, electron micrograph reflects spherical shape and mixed type of drug release followed by Fickian diffusion (n=0.266) was observed. Thus, using systematic factorial design approach, desirable goals can be achieved in shortest possible time with lesser number of experiments which was proven to be an effective tool in quality by design.Mandlik and Ranpise, International Current Pharmaceutical Journal, February 2017, 6(3): 16-22http://www.icpjonline.com/documents/Vol6Issue3/01.pdf

Design and Optimization of Differential Ring Oscillator for IR-UWB Applications in 0.18 μm CMOS Technology

This study presents a two-stage ring voltage-controlled oscillator (VCO) for use in impulse-radio ultra-wideband (IR-UWB) applications. A systematic and efficient graphical optimization method was employed to find the optimal dimensions of the VCO which give a best performance. A good agreement was observed between the desired specifications and simulation results with regard to the optimum component size of the VCO circuit. The operation range of the VCO was extended to cover an ultra-wide tuning range of 176.6%. The phase noise was [Formula: see text]107.1[Formula: see text]dBc/Hz at 10[Formula: see text]MHz offset frequency from a carrier frequency of 4[Formula: see text]GHz. The power consumption of VCO was 7.41[Formula: see text]mW from a 1.8[Formula: see text]V supply voltage. A large tuning range, low power, and appropriate phase noise were obtained with the optimum components size obtained through the optimization method.

반응표면분석법을 이용한 단감 고추장 장아찌 품질의 최적화 연구

The purpose of this study was to determine the optimum sodium concentration (0∼8%), soaking time (4∼20 min) and storage time (0∼60 day) for preparation of persimmon jangachi with kochujang sauce using response surface methodology. Physicochemical properties (salinity, pH, Hunters color value, cutting force, and sensory evaluation) of persimmon kochujang jangachi were analyzed during storage at 20°C for 60 days. When the proximate composition of persimmon was analyzed, moisture content, crude protein content, crude lipid content, and crude ash content were 85.41%, 0.51%, 0.22%, and 0.20%, respectively. For persimmon kochujang jangachi manufactured with different sodium concentrations, soaking times, and storage times, salinity, pH, Hunters color value of L, a, and b, color, flavor, taste, texture, and overall preference were represented by a quadratic model. Cutting force was represented by a linear model pattern. In conclusion, the optimal formulation for persimmon kochujang jangachi, as assessed by numerical and graphical optimization methods, was a sodium concentration of 6.91%, soaking time of 11.36 minutes, and storage time of 25.18 days.

Preparation of Lycopene Emulsions by Whey Protein Concentrate and Maltodextrin and Optimization by Response Surface Methodology

In this investigation, response surface methodology (RSM) was used to optimize preparation of lycopene emulsions. To do this, lycopene content (10–20%, w/w), amount of whey protein concentrate (WPC) + maltodextrin (MD) (30–40%, w/w), and homogenization speed (14000–18000 rpm) were considered as independent variables and droplet size, viscosity, and creaming index of the emulsions were considered as dependent variables. Results showed that droplet size and viscosity could be adequately fitted into quadratic models with multiple regression coefficients of 0.9763 and 0.9957, respectively; however, creaming index was fitted with linear model and a regression coefficient of 0.8670. According to the RSM equations, the linear term of all three independent variables and the quadratic term of homogenization speed had significant effect on the droplet size of emulsions; while viscosity was significantly affected by the linear term of the independent variables plus the quadratic term of WPC + MD concentration, interactions between homogenization speed and WPC + MD, and interactions between lycopene content and WPC + MD concentrations. Also, all three independent variables significantly affected creaming index of emulsions. The graphical optimization method was adapted to find the best emulsifying conditions and it was predicted that the optimum conditions for preparation of lycopene emulsions would be at homogenization speed of 18000 rpm, lycopene content of 18.85% w/w, and WPC + MD concentration of 37.16% w/w.