A self-parametrization framework for meta-heuristics

Even while the scientific community has shown great interest in the analysis of meta-heuristics, the analysis of their parameterization has received little attention. It is the parameterization that will adapt a meta-heuristic to a problem, but it is still performed, mostly, empirically. There are multiple parameterization techniques; however, they are time-consuming, requiring considerable computational effort and they do not take advantage of the meta-heuristics that they parameterize. In order to approach the parameterization of meta-heuristics, in this paper, a self-parameterization framework is proposed. It will automatize the parameterization as an optimization problem, precluding the user from spending too much time on parameterization. The model will automate the parameterization through two meta-heuristics: A meta-heuristic of the solution space and one of the parameter space. To analyze the performance of the framework, a self-parameterization prototype was implemented. The prototype was compared and analyzed in a SP (scheduling problem) and in the TSP (traveling salesman problem). In the SP, the prototype found better solutions than those of the manually parameterized meta-heuristics, although the differences were not statistically significant. In the TSP, the self-parameterization prototype was more effective than the manually parameterized meta-heuristics, this time with statistically significant differences.This work was supported by national funds through the FCT - Fundação para a Ciência e Tecnologia through the R&D Units Project Scopes: UIDB/00319/2020, and EXPL/EME-SIS/1224/2021

Efektifitas Fraksinasi Kering pada Pengolahan Empulur Sagu dan Pemanfaatan Produk untuk Produksi Etanol

Starch is more easily converted to sugars and fermented into ethanol. To increase ethanol productivity, a high-gravity fermentation method was developed. Sago trees are starch-producing that do not compete with food crops, but conventional processing has a negative impact on the environment. An alternative technology to minimize environmental impact is dry fractionation, product characteristics are suitable for ethanol production. Analysis of the effectiveness the processing of sago pith and the use of products for ethanol has never been published, so the analysis is carried out based on vertical differences in stem parts and determination of the optimum conditions of the ethanol production using sago starch-rich flour. Yield, starch recovery, starch ennrichment and shift starch are observational variables for the analysis of dry fractionation effectiveness. Starch-rich flour from the results of dry fractionation of each group of stem parts is mixed with a uniform composition and used as a fermentation medium. The one factor at a time (OFAT) experiment design was used to determine the effect of variables on optimal response, and verification is carried out. The distribution of starch granule size, starch content and parenchyma fiber characteristics can affect the effectiveness . Ethanol productivity showed optimum results at liquifaction 80oC for 60 minutes, using simultaneous saccharification and fermentation (SSF), high gravity fermentation and self-flocating yeast. The application of dry fractionation technology to obtain ethanol raw materials from sago trees has the potential to increase the added value of sago cultivation and the economic value of ethanol to be more competitive.Pati lebih mudah dikonversi menjadi gula sederhana dan difermentasi menjadi etanol. Untuk meningkatkan produktifitas etanol dikembangkan metode fermentasi gravitasi tinggi. Pohon sagu merupakan tanaman penghasil pati yang tidak berkompetisi dengan tanaman pangan, namun pengolahan secara konvensional berdampak negatif pada lingkungan. Alternatif teknologi pengolahan sagu untuk meminimalkan dampak  lingkungan adalah fraksinasi kering, dan karakteristik produknya cocok digunakan sebagai bahan baku etanol. Analisa efektifitas fraksinasi kering untuk pengolahan empulur sagu dan pemanfaatan produk untuk etanol belum pernah dipublikasikan, maka  analisa efektifitas fraksinasi kering dilakukan berdasarkan perbedaan bagian batang secara vertikal dan penentuan kondisi optimum proses produksi etanol menggunakan tepung kaya pati sagu.  Rendeman, efisiensi pemisahan pati, peningkatan kadar pati dan perpindahan pati merupakan variabel pengamatan yang digunakan pada analisa efektifitas fraksinasi kering. Tepung kaya pati dari hasil fraksinasi kering dari masing-masing kelompok bagian batang dicampur dengan komposisi yang seragam dan digunakan sebagai media fermentasi. Rancangan percobaan one factor at a time (OFAT) digunakan untuk mengetahui pengaruh variabel pengujian pada response yang optimal, dan dilakukan verifikasi pengujian. Distribusi ukuran granula pati, kandungan pati dan karakteristik serat parenkima dapat mempengaruhi efektifitas fraksinasi kering empulur sagu. Produktifitas etanol menunjukkan hasil yang optimum pada suhu liquifikasi 80oC selama 60 menit, menggunakan metoda sakarifikasi dan fermentasi simultan (SSF), pada kondisi gravitasi tinggi dengan menggunakan yeast berflokukasi mandiri. Penerapan teknologi fraksinasi kering untuk mendapatkan bahan baku etanol dari pohon sagu berpotensi meningkatkan nilai tambah budi daya tanaman sagu dan nilai ekonomi etanol agar lebih kompetitif

Reducción y control de costos en empresa de manufactura con Seis Sigma (Reduction and control of costs in manufacturing company with Six Sigma)

Abstract: This case study indicates how the statistics and engineering analysis Six Sigma lead us to find the root-cause operational solutions, resulting on improvement in quality and control of our processes. After defining the real root-cause problem and proving them statistically, it shows us how we can control and improve operations by eliminating waste and generating annual savings in this empirical research, reducing 40% of the use of coatings generating savings greater than $1,000,000.00 MN. Resumen: Este caso de estudio indica como la estadística y el análisis ingenieril Seis Sigma nos llevan a encontrar las soluciones operativas de causa raíz, llevando a que mejoremos la calidad y control de nuestros procesos. Después de definir el verdadero problema de causa raíz y comprobarlo estadísticamente, nos muestra cómo podemos controlar y mejorar el control de las operaciones eliminando los desperdicios y generando ahorros anuales en esta investigación empírica, reduciendo el 40$1, 000,000.00 M.N. anual

Reducción y control de costos en empresa de manufactura con Seis Sigma

Abstract: This case study indicates how the statistics and engineering analysis Six Sigma lead us to find the root-cause operational solutions, resulting on improvement in quality and control of our processes. After defining the real root-cause problem and proving them statistically, it shows us how we can control and improve operations by eliminating waste and generating annual savings in this empirical research, reducing 40% of the use of coatings generating savings greater than $1,000,000.00 MN.Keywords: process entitlement, quality control, scrap, six sigma, wasteJEL: L00, M11Resumen: Este caso de estudio indica como la estadística y el análisis ingenieril Seis Sigma nos llevan a encontrar las soluciones operativas de causa raíz, llevando a que mejoremos la calidad y control de nuestros procesos. Después de definir el verdadero problema de causa raíz y comprobarlo estadísticamente, nos muestra cómo podemos controlar y mejorar el control de las operaciones eliminando los desperdicios y generando ahorros anuales en esta investigación empírica, reduciendo el 40$1, 000,000.00 M.N. anual.Palabras clave: control de calidad, desperdicios, muda, seis sigma, línea bas

Optimisation and kinetic modelling for the production of 5- aminolevulinic acid by Rhodopseudomonas palustris in the solid state fermentation

The approach of the bioprocess system engineering (BPSE) serves as a systematic methodology to better understand the overall performance of complex biological system through optimisation process and development of a compatible macroscopic kinetic model. Based on the BPSE approach, the production of 5- aminolevulinic acids (ALA) by Rhodopseudomonas palustris (Rp) via solid state fermentation (SSF), using the palm empty fruit bunch as solid state medium was studied. Optimisation studies were carried out using a full-factorial design and the response surface methodology approach. A maximum ALA yield of 43.72 mg/kg was achieved under the following optimum conditions: moisture content of 63.13 %, incubation temperature of 30.3 °C, pH 7, inoculums density of 40 % (v/w), 3.64 mM glycine and 23.03 mM succinic acid for 48 hours via SSF. Three mathematical models including the Logistic, Gompertz and Luedeking-Piret models were proposed and compared based on their goodness of curve-fitting to the SSF experimental data. The Logistic model incorporated with Luedeking-Piret model was developed and best represented (R2 >0.95) the underlying kinetic behaviour of the growth of Rp, the formation of ALA and the consumption of substrates for the production of ALA by Rp in SSF at the optimum condition. The computed kinetic parameters including the maximum specific growth rate (μm= 0.232 h-1) with the maximum Rp biomass concentration (Xmax= 316.4 x 10-9 CFU.g-1) for the modelling of Rp growth; the growth-associated (α= 8.249 mg.kg-1.h-1) and non-growth associated (β = -1.660 mg.kg-1.h-1) coefficients for the modelling of ALA formation, and the Rp growth associated and the ALA formation associated on substrate consumption coefficient (YX/S = 0.132 and YP/S = 0.141) for the modelling of substrate consumption were evaluated. These values were then validated between the predicted data and the experimental data using the least square curve fitting analysis and the ordinary differential equation solver (ODE45) using the Matlab software

Modèle dynamique d’amélioration : un cadre théorique permettant le succès des stratégies corporatives de résolution de problèmes et d'amélioration

Pourquoi les démarches de résolution de problèmes échouent-elles et comment éviter ces échecs? Cette recherche vise à comprendre le contexte dans lequel s’exerce la résolution de problèmes, les interrelations des facteurs qui l’influencent et enfin, l’approche à privilégier. Parmi les principaux sujets couverts, on retrouve la caractérisation des problèmes, les obstacles, les facteurs humains, la maturité des organisations ainsi que le mode d’intervention prescrit. Initié en recherche-action, ce mémoire est le fruit d’une démarche exploratoire basée sur la littérature et sur les meilleures pratiques recensées en milieu industriel. Un des principaux résultats est que les éléments de contexte se regroupent en trois dimensions interdépendantes qui sont la situation problématique, le solutionneur et le processus de résolution de problèmes. Une métadimension, la gestion, prévoit l'évolution des trois premières dimensions dans le temps et selon le niveau de maturité. Le principal constat est que les approches de résolution de problèmes conventionnelles focalisent l’énergie et les ressources sur la méthode et les outils. Ceci justifie le développement d’experts qui travaillent en retrait des opérations sur des problématiques compatibles avec les outils. L’évaluation et la priorisation des situations problématiques s’en trouvent donc négligées. De plus, l’auteur a identifié le délai d’intervention et la perception du contexte comme étant les deux principaux facteurs d’échec. Nous prescrivons que, peu importe leur niveau de maturité, les organisations doivent : 1) réduire le temps de détection, de prise en charge et de résolution des problèmes; 2) aller constater, définir et mesurer les symptômes et les éléments des situations problématiques de façon exhaustive en équipes multidisciplinaires collaboratives, incluant les gens directement impliqués; 3) en toutes circonstances, aborder la résolution des situations problématiques avec une méthodologie simple visant l’analyse des causes, telle A3 ou 8D

Dynamic optimisation for energy efficiency of injection moulding process

Low carbon economy has emerged as an important task in China since the energy intensity and carbon intensity reduction targets were clearly prescribed in its recent Twelfth Five-Year Plan during 2011-2015. While the largest enterprises have undertaken initial initiative to reduce their energy consumption, small and medium-sized enterprises (SMEs) will need to share the responsibilities in meeting the nation’s targets. However, there is no established structure for helping SMEs to reduce their efficiency gap and hence the implementation of energy-saving measures in SMEs still remains patchy. Addressing this issue, this thesis seeks to understand the critical barriers faced by SMEs and aims to develop proprietary methodologies that can facilitate manufacturing SMEs to close their efficiency gap. Process parameters optimisation is perceived to be an effective “no-cost” strategy which can be conducted by SMEs to realise energy efficiency improvement. A unique design of experiment (DOE) introduced by Dorian Shainin offers a simplistic framework to study process optimisation, but its application is not widespread and being criticised over its working principles. In order to address the inherent limitations of the Shainin’s method, it was integrated with the multivariate statistical methods and the signal-response system in the empirical study. The nature of the research aim also requires a theoretical approach to evaluate the economic performance of the energy efficiency investment. Hence, a spreadsheet-based decision support system (file SERP.xlsm) was created via dynamic programming (DP) method. The main contributions of this thesis can be subdivided into empirical level and theoretical level. At the empirical level, a technically feasible yet economically viable approach called “multi-response dynamic Shainin DOE” was developed. An empirical study on the injection moulding process was presented to examine the validity of this novel integrated methodology. The emphasis has been on the integration of multivariate techniques and signal-response analysis. The former successfully identified the critical factors to energy consumption and moulded parts’ impact performance regardless of the great fluctuation in the impact response. The latter enables the end-user to achieve different performance output based on the particular intent. At the theoretical level, the “DP-based spreadsheet solution” provides a convenient platform to help the rationally-behaved decision makers evaluate the energy efficiency investments. A simple hypothetical case study on the injection moulding industry was illustrated how the decision-making process for equipment replacement can evolve over time. To sum up, both proprietary methodologies enhance the dynamicity in the optimisation process to support injection moulding industry in closing their efficiency gap. The study at the empirical level was limited by the absence of real industrial case study where it is important to justify the practicality of the proposed methodology. Regarding the theoretical level, the dataset for initial validation on the spreadsheet solution was not available. Finally, it is important to continue the future work on the research limitations in order to increase the cogency of the proprietary methodologies for common use in the industry

Dynamic optimisation for energy efficiency of injection moulding process

Low carbon economy has emerged as an important task in China since the energy intensity and carbon intensity reduction targets were clearly prescribed in its recent Twelfth Five-Year Plan during 2011-2015. While the largest enterprises have undertaken initial initiative to reduce their energy consumption, small and medium-sized enterprises (SMEs) will need to share the responsibilities in meeting the nation’s targets. However, there is no established structure for helping SMEs to reduce their efficiency gap and hence the implementation of energy-saving measures in SMEs still remains patchy. Addressing this issue, this thesis seeks to understand the critical barriers faced by SMEs and aims to develop proprietary methodologies that can facilitate manufacturing SMEs to close their efficiency gap. Process parameters optimisation is perceived to be an effective “no-cost” strategy which can be conducted by SMEs to realise energy efficiency improvement. A unique design of experiment (DOE) introduced by Dorian Shainin offers a simplistic framework to study process optimisation, but its application is not widespread and being criticised over its working principles. In order to address the inherent limitations of the Shainin’s method, it was integrated with the multivariate statistical methods and the signal-response system in the empirical study. The nature of the research aim also requires a theoretical approach to evaluate the economic performance of the energy efficiency investment. Hence, a spreadsheet-based decision support system (file SERP.xlsm) was created via dynamic programming (DP) method. The main contributions of this thesis can be subdivided into empirical level and theoretical level. At the empirical level, a technically feasible yet economically viable approach called “multi-response dynamic Shainin DOE” was developed. An empirical study on the injection moulding process was presented to examine the validity of this novel integrated methodology. The emphasis has been on the integration of multivariate techniques and signal-response analysis. The former successfully identified the critical factors to energy consumption and moulded parts’ impact performance regardless of the great fluctuation in the impact response. The latter enables the end-user to achieve different performance output based on the particular intent. At the theoretical level, the “DP-based spreadsheet solution” provides a convenient platform to help the rationally-behaved decision makers evaluate the energy efficiency investments. A simple hypothetical case study on the injection moulding industry was illustrated how the decision-making process for equipment replacement can evolve over time. To sum up, both proprietary methodologies enhance the dynamicity in the optimisation process to support injection moulding industry in closing their efficiency gap. The study at the empirical level was limited by the absence of real industrial case study where it is important to justify the practicality of the proposed methodology. Regarding the theoretical level, the dataset for initial validation on the spreadsheet solution was not available. Finally, it is important to continue the future work on the research limitations in order to increase the cogency of the proprietary methodologies for common use in the industry