966 resultados para Observational techniques and algorithms


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The phytochemical investigation of Herissantia crispa led to the isolation of seven compounds, identified as: sitosterol 3-O-β-D-glucopyranoside, stigmasterol 3-O-β-D-glucopyranoside, 3,5,7,4'-tetrahydroxyflavone (kaempferol), 3,5,7,3',4'-pentahydroxyflavone (quercetin), unpublished in the genus Herissantia, besides β-sitosterol, kaempferol 3-O-β-D-(6''-E-p-coumaroil) (tiliroside) glucopyranoside and kaempferol 3,7-di-O-α-L-ramnopyranoside (lespedin), described for the first time in the species. The structural determination of the compounds was made by means of spectroscopy methods such as Infrared Spectroscopy, ¹H and 13C Nuclear Magnetic Resonance, with the aid of two dimensional techniques, and by comparison with literature data. The toxicity activity of the MeOH extract and lespedin on Artemia salina Leach. was also carried out.

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Zeolite-encapsulated complexes have been widely applied in hydrocarbon oxidation catalysis. The "ship-in-a-bottle" encapsulation of iron(III) complexes containing piperazine and piperazine-derivative ligands in zeolite-Y is described. The flexible ligand methodology was employed and the efficiency and reproducibility of the procedure was investigated. The catalysts were characterized employing several techniques and the results indicate the presence of coordinated and uncoordinated iron(III) ions inside and outside the zeolitic cage.

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Because of their practical applications, porous materials attract the attention of undergraduate students in a way that can be used to teach techniques and concepts in various chemistry disciplines. Porous materials are studied in various chemistry disciplines, including inorganic, organic, and physical chemistry. In this work, the syntheses of a microporous material and a mesoporous material are presented. The porosity of the synthesized materials is characterized by X-ray diffraction analysis. We show that this technique can be used to determine the pore dimensions of the synthesized materials.

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In general, the traditional Physics courses needs examples of the aplications of the Physics concepts in other areas such as Chemistry and Biology. This lacks tend to demotivate Chemistry and Biology students regarding to deal with Physical concepts developed in classroom. In this work, the analogy among mechanic and electric oscillators is investigated to be applied in Chemistry and Biology areas, showing to be valuable due to its aplication in techniques that aims to measure mass variation with high precision. This measure could be made in a direct or indirect way. These techniques are known as electrogravimetric techniques and they are important in biosensor aplications. Thus, this paper explores the electromechanic analogy in an interdisciplinary way involving areas like Physics, Chemistry and Biology. Based on this analogy, it is proposed an experiment that can be applied in different ways, i.e. by an basic approach or more deeper, depending on the students specific formation, in other words, Physics, Chemistry or Biology.

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The goal of this work was to develop a simple and rapid preparation method for patulin analysis in apple juice without previous clean-up. This method combined sonication and liquid extraction techniques and was used for determination of patulin in 37 commercial apple juices available on the market in the South of Brazil. The method performance characteristics were determined using a sample obtained in a local market fortified at five concentration levels of patulin and done in triplicates. The coefficient of variation for repeatability at the fortification level of 20.70µg.L-1 was 3.53 % and the recovery 94.63 %, respectively. The correlation coefficient was 0.9996 and agrees with the requirements for a linear analytical method value. The detection limit was 0.21µg.L-1 and the quantification limit 0.70 µg.L-1. Only three of the analyzed samples were upper the allowed level of 50.00 µg.L-1 recommended for the World Health Organization.

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The objective of this dissertation is to improve the dynamic simulation of fluid power circuits. A fluid power circuit is a typical way to implement power transmission in mobile working machines, e.g. cranes, excavators etc. Dynamic simulation is an essential tool in developing controllability and energy-efficient solutions for mobile machines. Efficient dynamic simulation is the basic requirement for the real-time simulation. In the real-time simulation of fluid power circuits there exist numerical problems due to the software and methods used for modelling and integration. A simulation model of a fluid power circuit is typically created using differential and algebraic equations. Efficient numerical methods are required since differential equations must be solved in real time. Unfortunately, simulation software packages offer only a limited selection of numerical solvers. Numerical problems cause noise to the results, which in many cases leads the simulation run to fail. Mathematically the fluid power circuit models are stiff systems of ordinary differential equations. Numerical solution of the stiff systems can be improved by two alternative approaches. The first is to develop numerical solvers suitable for solving stiff systems. The second is to decrease the model stiffness itself by introducing models and algorithms that either decrease the highest eigenvalues or neglect them by introducing steady-state solutions of the stiff parts of the models. The thesis proposes novel methods using the latter approach. The study aims to develop practical methods usable in dynamic simulation of fluid power circuits using explicit fixed-step integration algorithms. In this thesis, twomechanisms whichmake the systemstiff are studied. These are the pressure drop approaching zero in the turbulent orifice model and the volume approaching zero in the equation of pressure build-up. These are the critical areas to which alternative methods for modelling and numerical simulation are proposed. Generally, in hydraulic power transmission systems the orifice flow is clearly in the turbulent area. The flow becomes laminar as the pressure drop over the orifice approaches zero only in rare situations. These are e.g. when a valve is closed, or an actuator is driven against an end stopper, or external force makes actuator to switch its direction during operation. This means that in terms of accuracy, the description of laminar flow is not necessary. But, unfortunately, when a purely turbulent description of the orifice is used, numerical problems occur when the pressure drop comes close to zero since the first derivative of flow with respect to the pressure drop approaches infinity when the pressure drop approaches zero. Furthermore, the second derivative becomes discontinuous, which causes numerical noise and an infinitely small integration step when a variable step integrator is used. A numerically efficient model for the orifice flow is proposed using a cubic spline function to describe the flow in the laminar and transition areas. Parameters for the cubic spline function are selected such that its first derivative is equal to the first derivative of the pure turbulent orifice flow model in the boundary condition. In the dynamic simulation of fluid power circuits, a tradeoff exists between accuracy and calculation speed. This investigation is made for the two-regime flow orifice model. Especially inside of many types of valves, as well as between them, there exist very small volumes. The integration of pressures in small fluid volumes causes numerical problems in fluid power circuit simulation. Particularly in realtime simulation, these numerical problems are a great weakness. The system stiffness approaches infinity as the fluid volume approaches zero. If fixed step explicit algorithms for solving ordinary differential equations (ODE) are used, the system stability would easily be lost when integrating pressures in small volumes. To solve the problem caused by small fluid volumes, a pseudo-dynamic solver is proposed. Instead of integration of the pressure in a small volume, the pressure is solved as a steady-state pressure created in a separate cascade loop by numerical integration. The hydraulic capacitance V/Be of the parts of the circuit whose pressures are solved by the pseudo-dynamic method should be orders of magnitude smaller than that of those partswhose pressures are integrated. The key advantage of this novel method is that the numerical problems caused by the small volumes are completely avoided. Also, the method is freely applicable regardless of the integration routine applied. The superiority of both above-mentioned methods is that they are suited for use together with the semi-empirical modelling method which necessarily does not require any geometrical data of the valves and actuators to be modelled. In this modelling method, most of the needed component information can be taken from the manufacturer’s nominal graphs. This thesis introduces the methods and shows several numerical examples to demonstrate how the proposed methods improve the dynamic simulation of various hydraulic circuits.

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Visual data mining (VDM) tools employ information visualization techniques in order to represent large amounts of high-dimensional data graphically and to involve the user in exploring data at different levels of detail. The users are looking for outliers, patterns and models – in the form of clusters, classes, trends, and relationships – in different categories of data, i.e., financial, business information, etc. The focus of this thesis is the evaluation of multidimensional visualization techniques, especially from the business user’s perspective. We address three research problems. The first problem is the evaluation of projection-based visualizations with respect to their effectiveness in preserving the original distances between data points and the clustering structure of the data. In this respect, we propose the use of existing clustering validity measures. We illustrate their usefulness in evaluating five visualization techniques: Principal Components Analysis (PCA), Sammon’s Mapping, Self-Organizing Map (SOM), Radial Coordinate Visualization and Star Coordinates. The second problem is concerned with evaluating different visualization techniques as to their effectiveness in visual data mining of business data. For this purpose, we propose an inquiry evaluation technique and conduct the evaluation of nine visualization techniques. The visualizations under evaluation are Multiple Line Graphs, Permutation Matrix, Survey Plot, Scatter Plot Matrix, Parallel Coordinates, Treemap, PCA, Sammon’s Mapping and the SOM. The third problem is the evaluation of quality of use of VDM tools. We provide a conceptual framework for evaluating the quality of use of VDM tools and apply it to the evaluation of the SOM. In the evaluation, we use an inquiry technique for which we developed a questionnaire based on the proposed framework. The contributions of the thesis consist of three new evaluation techniques and the results obtained by applying these evaluation techniques. The thesis provides a systematic approach to evaluation of various visualization techniques. In this respect, first, we performed and described the evaluations in a systematic way, highlighting the evaluation activities, and their inputs and outputs. Secondly, we integrated the evaluation studies in the broad framework of usability evaluation. The results of the evaluations are intended to help developers and researchers of visualization systems to select appropriate visualization techniques in specific situations. The results of the evaluations also contribute to the understanding of the strengths and limitations of the visualization techniques evaluated and further to the improvement of these techniques.

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The objective of this work was to correlate data on light microscopy observations through histochemical analysis and polarized light techniques and investigations in transmission electron microscopy (TEM) to characterize the reserve materials in C. peltophoroides Benth. (Leguminosae-Caesalpinoideae) cotyledons, popularly known as "sibipiruna", a tropical tree species with wide distribution in Brazil. The cotyledon mesophyll, especially in the abaxial face, is rich in unsaturated neutral lipids contained in numerous lipid bodies dispersed in the cytoplasm. Proteins, more concentrated in the adaxial face of the cotyledons, occur in all the mesophyll and are stored in protein bodies containing globoids, with variable number and size, responsible for accumulation of mineral reserves. Calcium oxalate druses have distribution restricted to the cotyledons adaxial face and are associated with protein bodies. Starch, also distributed all over the cotyledon mesophyll, occurs in small amounts in plastids with developed lamellar system. Secretory cavities rich in phenolic compounds occur among procambial strands.

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Delays in the justice system have been undermining the functioning and performance of the court system all over the world for decades. Despite the widespread concern about delays, the solutions have not kept up with the growth of the problem. The delay problem existing in the justice courts processes is a good example of the growing need and pressure in professional public organizations to start improving their business process performance.This study analyses the possibilities and challenges of process improvement in professional public organizations. The study is based on experiences gained in two longitudinal action research improvement projects conducted in two separate Finnish law instances; in the Helsinki Court of Appeal and in the Insurance Court. The thesis has two objectives. First objective is to study what kinds of factors in court system operations cause delays and unmanageable backlogs and how to reduce and prevent delays. Based on the lessons learned from the case projects the objective is to give new insights on the critical factors of process improvement conducted in professional public organizations. Four main areas and factors behind the delay problem is identified: 1) goal setting and performance measurement practices, 2) the process control system, 3) production and capacity planning procedures, and 4) process roles and responsibilities. The appropriate improvement solutions include tools to enhance project planning and scheduling and monitoring the agreed time-frames for different phases of the handling process and pending inventory. The study introduces the identified critical factors in different phases of process improvement work carried out in professional public organizations, the ways the critical factors can be incorporated to the different stages of the projects, and discusses the role of external facilitator in assisting process improvement work and in enhancing ownership towards the solutions and improvement. The study highlights the need to concentrate on the critical factors aiming to get the employees to challenge their existing ways of conducting work, analyze their own processes, and create procedures for diffusing the process improvement culture instead of merely concentrating of finding tools, techniques, and solutions appropriate for applications from the manufacturing sector

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Parameters such as tolerance, scale and agility utilized in data sampling for using in Precision Agriculture required an expressive number of researches and development of techniques and instruments for automation. It is highlighted the employment of methodologies in remote sensing used in coupled to a Geographic Information System (GIS), adapted or developed for agricultural use. Aiming this, the application of Agricultural Mobile Robots is a strong tendency, mainly in the European Union, the USA and Japan. In Brazil, researches are necessary for the development of robotics platforms, serving as a basis for semi-autonomous and autonomous navigation systems. The aim of this work is to describe the project of an experimental platform for data acquisition in field for the study of the spatial variability and development of agricultural robotics technologies to operate in agricultural environments. The proposal is based on a systematization of scientific work to choose the design parameters utilized for the construction of the model. The kinematic study of the mechanical structure was made by the virtual prototyping process, based on modeling and simulating of the tension applied in frame, using the.

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The erosion is the degradation of soil with effects on crop productivity and pollution of the environment. To understand the spatial variability of this phenomenon, geostatistical techniques and concepts of soil-landscape can be used to identify landscape compartments with different potential of erosion. The aim of this study was to understand the factors of erosion in landscape compartments and the relations with the magnetic susceptibility (MS) of the soils in a slope in Gilbués, state of Piauí (PI), Brazil. Sampling meshes were set in compartments I and II with 121 points and in compartment III with 99 points spaced every 10 meters. There was significant difference to erodibility (K) and risk of erosion (RE); the spatial variability of MS was lower than the factors of soil erosion. The soil losses (A), the natural erosion potential (NEP), the RE and the MS had spatial relation with the topographic factor, indicating dependence of the erosion with the relief. We concluded that losses of soil, natural erosion potential and risk of erosion have spatial relation with the topographic factor, showing the dependence of the erosion factors with the relief. The soil magnetic susceptibility can be used as an auxiliary variable in the indirect quantification of the erodibility factor and the risk of soil erosion.

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The bioavailability of metals and their potential for environmental pollution depends not simply on total concentrations, but is to a great extent determined by their chemical form. Consequently, knowledge of aqueous metal species is essential in investigating potential metal toxicity and mobility. The overall aim of this thesis is, thus, to determine the species of major and trace elements and the size distribution among the different forms (e.g. ions, molecules and mineral particles) in selected metal-enriched Boreal river and estuarine systems by utilising filtration techniques and geochemical modelling. On the basis of the spatial physicochemical patterns found, the fractionation and complexation processes of elements (mainly related to input of humic matter and pH-change) were examined. Dissolved (<1 kDa), colloidal (1 kDa-0.45 μm) and particulate (>0.45 μm) size fractions of sulfate, organic carbon (OC) and 44 metals/metalloids were investigated in the extremely acidic Vörå River system and its estuary in W Finland, and in four river systems in SW Finland (Sirppujoki, Laajoki, Mynäjoki and Paimionjoki), largely affected by soil erosion and acid sulfate (AS) soils. In addition, geochemical modelling was used to predict the formation of free ions and complexes in these investigated waters. One of the most important findings of this study is that the very large amounts of metals known to be released from AS soils (including Al, Ca, Cd, Co, Cu, Mg, Mn, Na, Ni, Si, U and the lanthanoids) occur and can prevail mainly in toxic forms throughout acidic river systems; as free ions and/or sulfate-complexes. This has serious effects on the biota and especially dissolved Al is expected to have acute effects on fish and other organisms, but also other potentially toxic dissolved elements (e.g. Cd, Cu, Mn and Ni) can have fatal effects on the biota in these environments. In upstream areas that are generally relatively forested (higher pH and contents of OC) fewer bioavailable elements (including Al, Cu, Ni and U) may be found due to complexation with the more abundantly occurring colloidal OC. In the rivers in SW Finland total metal concentrations were relatively high, but most of the elements occurred largely in a colloidal or particulate form and even elements expected to be very soluble (Ca, K, Mg, Na and Sr) occurred to a large extent in colloidal form. According to geochemical modelling, these patterns may only to a limited extent be explained by in-stream metal complexation/adsorption. Instead there were strong indications that the high metal concentrations and dominant solid fractions were largely caused by erosion of metal bearing phyllosilicates. A strong influence of AS soils, known to exist in the catchment, could be clearly distinguished in the Sirppujoki River as it had very high concentrations of a metal sequence typical of AS soils in a dissolved form (Ba, Br, Ca, Cd, Co, K, Mg, Mn, Na, Ni, Rb and Sr). In the Paimionjoki River, metal concentrations (including Ba, Cs, Fe, Hf, Pb, Rb, Si, Th, Ti, Tl and V; not typical of AS soils in the area) were high, but it was found that the main cause of this was erosion of metal bearing phyllosilicates and thus these metals occurred dominantly in less toxic colloidal and particulate fractions. In the two nearby rivers (Laajoki and Mynäjoki) there was influence of AS soils, but it was largely masked by eroded phyllosilicates. Consequently, rivers draining clay plains sensitive to erosion, like those in SW Finland, have generally high background metal concentrations due to erosion. Thus, relying on only semi-dissolved (<0.45 μm) concentrations obtained in routine monitoring, or geochemical modelling based on such data, can lead to a great overestimation of the water toxicity in this environment. The potentially toxic elements that are of concern in AS soil areas will ultimately be precipitated in the recipient estuary or sea, where the acidic metalrich river water will gradually be diluted/neutralised with brackish seawater. Along such a rising pH gradient Al, Cu and U will precipitate first together with organic matter closest to the river mouth. Manganese is relatively persistent in solution and, thus, precipitates further down the estuary as Mn oxides together with elements such as Ba, Cd, Co, Cu and Ni. Iron oxides, on the contrary, are not important scavengers of metals in the estuary, they are predicted to be associated only with As and PO4.

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Differences in the microscopic morphology of the hoof in forelimbs and hindlimbs of horses have been scarcely reported in the literature, especially concerning the distribution of primary and secondary epidermal laminae in the different regions. This study aimed to determine the density of primary and secondary epidermal laminae in the hoof of horses. For this, it was used fore and hindlimbs of 16 adult mixed breed horses. With a cross section 0.5 cm above the sole, it was quantified the primary epidermal laminae in the regions of the toe, and of lateral and medial quarters. Fragments with about 1cm ³ were taken from the proximal, middle and distal thirds of the hooves, in the different regions, subjected to conventional histological techniques and examined with an optical microscope. Data were statistically analyzed in relation to the fore and hindlimbs and between their various regions. The density of primary epidermal laminae varied around the hoof circumference, with greater values in the hoof toe, which gradually decreased towards the bulb of the hoof, without difference between thoracic and pelvic limbs. The average density of the secondary epidermal laminae per primary epidermal lamina does not change around the circumference of the hoof. Our findings indicated that the density of epidermal laminae is not different between fore and hindlimbs. The variation in the density of primary epidermal laminae around the hoof seems to be part of an adaptive response to different stresses in each region. A better understanding of the structural morphology contributes to a better understanding of the diagnosis, pathophysiology, and treatment of disorders that affect the hoof.

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Mass-produced paper electronics (large area organic printed electronics on paper-based substrates, “throw-away electronics”) has the potential to introduce the use of flexible electronic applications in everyday life. While paper manufacturing and printing have a long history, they were not developed with electronic applications in mind. Modifications to paper substrates and printing processes are required in order to obtain working electronic devices. This should be done while maintaining the high throughput of conventional printing techniques and the low cost and recyclability of paper. An understanding of the interactions between the functional materials, the printing process and the substrate are required for successful manufacturing of advanced devices on paper. Based on the understanding, a recyclable, multilayer-coated paper-based substrate that combines adequate barrier and printability properties for printed electronics and sensor applications was developed in this work. In this multilayer structure, a thin top-coating consisting of mineral pigments is coated on top of a dispersion-coated barrier layer. The top-coating provides well-controlled sorption properties through controlled thickness and porosity, thus enabling optimizing the printability of functional materials. The penetration of ink solvents and functional materials stops at the barrier layer, which not only improves the performance of the functional material but also eliminates potential fiber swelling and de-bonding that can occur when the solvents are allowed to penetrate into the base paper. The multi-layer coated paper under consideration in the current work consists of a pre-coating and a smoothing layer on which the barrier layer is deposited. Coated fine paper may also be used directly as basepaper, ensuring a smooth base for the barrier layer. The top layer is thin and smooth consisting of mineral pigments such as kaolin, precipitated calcium carbonate, silica or blends of these. All the materials in the coating structure have been chosen in order to maintain the recyclability and sustainability of the substrate. The substrate can be coated in steps, sequentially layer by layer, which requires detailed understanding and tuning of the wetting properties and topography of the barrier layer versus the surface tension of the top-coating. A cost competitive method for industrial scale production is the curtain coating technique allowing extremely thin top-coatings to be applied simultaneously with a closed and sealed barrier layer. The understanding of the interactions between functional materials formulated and applied on paper as inks, makes it possible to create a paper-based substrate that can be used to manufacture printed electronics-based devices and sensors on paper. The multitude of functional materials and their complex interactions make it challenging to draw general conclusions in this topic area. Inevitably, the results become partially specific to the device chosen and the materials needed in its manufacturing. Based on the results, it is clear that for inks based on dissolved or small size functional materials, a barrier layer is beneficial and ensures the functionality of the printed material in a device. The required active barrier life time depends on the solvents or analytes used and their volatility. High aspect ratio mineral pigments, which create tortuous pathways and physical barriers within the barrier layer limit the penetration of solvents used in functional inks. The surface pore volume and pore size can be optimized for a given printing process and ink through a choice of pigment type and coating layer thickness. However, when manufacturing multilayer functional devices, such as transistors, which consist of several printed layers, compromises have to be made. E.g., while a thick and porous top-coating is preferable for printing of source and drain electrodes with a silver particle ink, a thinner and less absorbing surface is required to form a functional semiconducting layer. With the multilayer coating structure concept developed in this work, it was possible to make the paper substrate suitable for printed functionality. The possibility of printing functional devices, such as transistors, sensors and pixels in a roll-to-roll process on paper is demonstrated which may enable introducing paper for use in disposable “onetime use” or “throwaway” electronics and sensors, such as lab-on-strip devices for various analyses, consumer packages equipped with product quality sensors or remote tracking devices.

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The main strengths of professional knowledge-intensive business services (P-KIBS) are knowledge and creativity which needs to be fostered, maintained and supported. The process of managing P-KIBS companies deals with financial, operational and strategic risks. That is why it is reasonable to apply risk management techniques and frameworks in this context. A significant challenge hides in choosing reasonable ways of implementing risk management, which will not limit creative ability in organization, and furthermore will contribute to the process. This choice is related to a risk intelligent approach which becomes a justified way of finding the required balance. On a theoretical level the field of managing both creativity and risk intelligence as a balanced process remains understudied in particular within KIBS industry. For instance, there appears to be a wide range of separate models for innovation and risk management, but very little discussion in terms of trying to find the right balance between them. This study aims to shed light on the importance of well-managed combination of these concepts. The research purpose of the present study is to find out how the balance between creativity and risk intelligence can be managed in P-KIBS. The methodological approach utilized in the study is strictly conceptual without empirical aspects. The research purpose can be achieved through answering the following research supporting questions: 1. What are the characteristics and role of creativity as a component of innovation process in a P-KIBS company? 2. What are the characteristics and role of risk intelligence as an approach towards risk management process implementation in a P-KIBS company? 3. How can risk intelligence and creativity be balanced in P-KIBS? The main theoretical contribution of the study conceals in a proposed creativity and risk intelligence stage process framework. It is designed as an algorithm that can be applied on organizational canvas. It consists of several distinct stages specified by actors involved, their roles and implications. Additional stage-wise description provides detailed tasks for each of the enterprise levels, while combining strategies into one. The insights driven from the framework can be utilized by a vast range of specialists from strategists to risk managers, and from innovation managers to entrepreneurs. Any business that is designing and delivering knowledge service can potentially gain valuable thoughts and expand conceptual understanding from the present report. Risk intelligence in the current study is a unique way of emphasizing the role of creativity in professional knowledge-intensive industry and a worthy technique for making profound decisions towards risks.