京都大学 / 新制・課程博士 / 博士(医学) / 甲第25159号 / 医博第5045号 / 京都大学大学院医学研究科医学専攻 / (主査)教授 中山 健夫, 教授 森田 智視, 教授 永井 洋士 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 新制・課程博士 / 博士(情報学) / 甲第25439号 / 情博第877号 / 京都大学大学院情報学研究科数理工学専攻 / (主査)教授 山下 信雄, 教授 梅野 健, 准教授 加嶋 健司 / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

[pt] Elementos de paredes finas com seções transversais abertas têm sido amplamente empregados em aplicações de engenharia. Embora as aplicações convencionais e os códigos de projeto se concentrem predominantemente em elementos de aço, observa-se um interesse crescente no uso de materiais alternativos, especialmente compósitos. Entre estes, polímeros reforçados com fibra (FRP) têm sido cada vez mais empregados devido às suas propriedades benéficas. No entanto, a natureza ortotrópica das colunas FRP, produzidas através de pultrusão, apresenta um desafio, uma vez que as prescrições convencionais de projeto para estruturas de aço não podem ser aplicadas diretamente. Assim, mais pesquisas são essenciais para fornecer normas de projeto confiáveis para membros estruturais em FRP. Entre as geometrias tradicionais de seção aberta, seções cantoneira têm sido comumente empregadas. Apesar de sua simplicidade geométrica, colunas com seção cantoneira apresentam uma flambagem estrutural e um comportamento dinâmico complexos, que decorre do fato de tais colunas apresentarem diferentes modos de deformação, função de suas propriedades geométricas e materiais, incluindo interação modal, principalmente entre os modos de flexão e torção. Este trabalho se concentra na investigação das características de flambagem e vibração de colunas pultrudadas FRP com seção cantoneira, abrangendo seções de abas iguais e desiguais, e abrangendo colunas curtas a longas. Para isso, são desenvolvidos modelos de dimensão reduzida (ROMs) baseados na teoria clássica não linear de placas (CPT) proposta por von Kármán. A seção cantoneira é modelada como duas placas, com restrições de continuidade imposta na ligação entre ambas. Utilizando o software GBTul, é conduzida uma investigação abrangente da participação modal nos modos de flambagem e vibração. Com base nesta análise, o campo de deslocamentos de cada placa para todos os ROMs é aproximado por funções de interpolação derivadas analiticamente, que são usadas para discretizar o sistema contínuo com base no método de Ritz. Pela aplicação do princípio de Hamilton, os problemas de autovalor e equações não lineares de movimento são derivados. São realizadas análises paramétricas dimensionais e adimensionais, com cargas críticas e frequências de vibração comparadas favoravelmente com os resultados do GBTul. Caminhos pós-flambagem são explorados resolvendo-se os sistemas de equações de equilíbrio não lineares para cada ROM. A influência dos parâmetros geométricos e materiais na rigidez pós-flambagem é investigada, juntamente com a sensibilidade às imperfeições geométricas iniciais. Finalmente, a estabilidade de colunas sob carregamento axial harmônico é avaliada resolvendo-se numericamente as equações não lineares de movimento usando-se o método Runge-Kutta de quarta ordem. As regiões de instabilidade paramétrica são determinadas em função da frequência e magnitude da força de excitação harmônica, considerando a influência do material, do amortecimento e da geometria da seção transversal. Os diagramas de bifurcação são obtidos empregando-se o método da força bruta e técnicas de continuação, esclarecendo as bifurcações associadas aos limites de instabilidade paramétrica. A evolução das bacias de atração de soluções coexistentes é investigada, proporcionando uma avaliação da integridade dinâmica. Os resultados demonstram que a coluna pode perder estabilidade sob níveis de carga bem abaixo da carga estática de flambagem e, portanto, os projetistas devem ter cautela ao trabalhar com essas estruturas sujeitas a cargas axiais variáveis no tempo. / [en] Thin-walled elements with open cross sections have been widely employed in engineering applications. While conventional applications and design codes predominantly focus on steel members, a growing interest has emerged in exploring alternative materials, particularly composites. Among these, fiber reinforced polymer (FRP) has witnessed increased application owing to its advantageous properties. However, the orthotropic nature of FRP columns, produced through pultrusion, presents a challenge as conventional design prescriptions for structural steel cannot be directly applied. Thus, further research is essential to derive reliable design rules for FRP members. In the realm of traditional open section geometries, angle sections have been commonly employed. Despite their geometric simplicity, angles exhibit a complex structural buckling and dynamic behaviour which arises from the fact that such columns may undergo different deformation modes, according to their geometric and material properties, with modal interaction observed, particularly between flexural and torsional modes. This work focuses on investigating the buckling and vibration characteristics of pultruded FRP angle sections, encompassing both equal and unequal-leg sections, and spanning short to long columns. For this, reduced order models (ROMs) are developed based on the classical von Kármán nonlinear plate theory (CPT). The angle section is modelled as two plates, with continuity constraints considered at the common boundary. Utilizing GBTul software, a comprehensive investigation of modal participation in linear buckling and vibration modes is conducted. Based on this analysis, the plate displacement field for each ROM is approximated by suitable analytically derived interpolating functions, which are used to discretize the continuous system on the basis of the Ritz energy method. By application of Hamilton s principle, the eigenvalue problems and nonlinear equations of motion are derived. Parametric dimensional and nondimensional analyses are carried out, with critical loads and vibration frequencies compared favorably with GBTul results. Post-buckling paths are explored by solving the systems of nonlinear equilibrium equations for each ROM. The influence of geometric and material parameters on post-buckling stiffness is investigated, along with the sensitivity to initial geometrical imperfections. Finally, the stability of the columns under harmonic axial loading is assessed by numerically solving the nonlinear equations of motion using the fourth-order Runge-Kutta method. Parametric instability regions are determined as a function of the frequency and magnitude of the harmonic excitation force, considering the influence of material, damping, and cross-sectional geometry. Bifurcation diagrams are obtained employing the brute force method and continuation techniques, clarifying the bifurcations associated to the parametric instability boundaries. The evolution of basins of attraction of coexisting solutions is investigated, providing an evaluation of dynamic integrity. The results demonstrate that the column may lose stability at load levels well below the static buckling loads and, therefore, designers must exercise caution when working with these structures subjected to time-varying axial loads.

Studiens syfte var att undersöka socialsekreterares upplevelser av förkortad arbetstid med bibehållen heltidslön, samt hur förkortad arbetstid påverkar socialsekreterarnas intentioner att stanna kvar inom socialtjänsten. För att besvara studiens syfte användes en kvalitativ metod i form av individuella intervjuer med åtta socialsekreterare som arbetat både 40 timmars arbetsvecka och 30 timmars arbetsvecka inom socialtjänsten. Work-life balance och Herzbergs tvåfaktorsteori var de teoretiska utgångspunkterna som genomsyrat studien. Resultatet visade att socialsekreterare upplever att förkortad arbetstid medför flera positiva faktorer såsom ökad effektivitet i arbetet, bättre återhämtning och mer arbetsglädje. Personalgruppens sammanhållning, mer begränsad tillgänglighet samt möjligheter till fortbildning var faktorer som fungerade bättre vid 40 timmars arbetsvecka. Resultatet visade därtill att socialsekreterarnas intentioner att stanna kvar inom socialtjänsten har ökat i samband med införandet av förkortad arbetstid. Att förkortad arbetstid är kompatibelt med familjeliv, pendling och ett ökat välbefinnande fick fler socialsekreterare att stanna kvar inom socialtjänsten. Slutsatsen som kunde dras var att förkortad arbetstid effektiviserar arbetet inom socialtjänsten samt förbättrar balansen mellan arbete och privatliv för socialsekreterare. Därtill kunde vi konstatera att förkortad arbetstid är en gynnsam investering i socialtjänsten som verksamhet för att öka socialsekreterares intentioner att stanna kvar, likaså attrahera nya medarbetare och på så vis få bukt på den personalflykt som råder inom svensk socialtjänst. / The purpose of the study was to investigate social workers experiences of reduced working hours, with maintained full-time salary, as well as how reduced working hours affect the social workers intention to remain in social services. To answer the purpose of the study, a qualitative method was used through individual interviews with eight social workers who worked both 40- hour work weeks and 30-hour work weeks in social services. Work-life balance and Herzberg ́s two-factor theory are the theoretical points that permeated the study. The result showed that social workers experience that reduced working hours bring several positive factors such as increased efficiency at work, better recovery and more job satisfaction. The cohesion of the staff group, more limited availability and opportunities for continuing education were factors that worked better with a 40-hour work week. The result also showed that the intentions of the social workers to remain in the social service have increased since reduced working hours. The fact that reduced working hours are compatible with family life, commuting and increased well- being caused more social workers to remain in social services. The conclusion that could be drawn was that reduced working hours make work in social services more efficient and improve the balance between work and private life for social workers. In addition, we were able to state that reduced working hours is a necessary investment to increase social workers intentions to stay, as well as attract new employees and thereby overcome the staff flight that prevails within Swedish social services.

Simulations and modeling of large-scale systems are vital to understanding real world phenomena. However, even advanced numerical models can only approximate the true physics. The discrepancy between model results and nature can be attributed to different sources of uncertainty including the parameters of the model, input data, or some missing physics that is not included in the model due to a lack of knowledge or high computational costs. Uncertainty reduction approaches seek to improve the model accuracy by decreasing the overall uncertainties in models. Aiming to contribute to this area, this study explores uncertainty quantification and reduction approaches for complex physical problems. This study proposes several novel probabilistic and statistical approaches for identifying the sources of uncertainty, modeling the errors, and reducing uncertainty to improve the model predictions for large-scale simulations. We explore different computational models. The first class of models studied herein are inherently stochastic, and numerical approximations suffer from stability and accuracy issues. The second class of models are partial differential equations, which capture the laws of mathematical physics; however, they only approximate a more complex reality, and have uncertainties due to missing dynamics which is not captured by the models. The third class are low-fidelity models, which are fast approximations of very expensive high-fidelity models. The reduced-order models have uncertainty due to loss of information in the dimension reduction process. We also consider uncertainty analysis in the data assimilation framework, specifically for ensemble based methods where the effect of sampling errors is alleviated by localization. Finally, we study the uncertainty in numerical weather prediction models coming from approximate descriptions of physical processes. / Ph. D. / Computational models are used to understand the behavior of the natural phenomenon. Models are used to approximate the evolution of the true phenomenon or reality in time. We obtain more accurate forecast for the future by combining the model approximation together with the observation from reality. Weather forecast models, oceanography, geoscience, etc. are some examples of the forecasting models. However, models can only approximate the true reality to some extent and model approximation of reality is not perfect due to several sources of error or uncertainty. The noise in measurements or in observations from nature, the uncertainty in some model components, some missing components in models, the interaction between different components of the model, all cause model forecast to be different from reality. The aim of this study is to explore the techniques and approaches of modeling the error and uncertainty of computational models, provide solution and remedies to reduce the error of model forecast and ultimately improve the model forecast. Taking the discrepancy or error between model forecast and reality in time and mining that error provide valuable information about the origin of uncertainty in models as well as the hidden dynamics that is not considered in the model. Statistical and machine learning based solutions are proposed in this study to identify the source of uncertainty, capturing the uncertainty and using that information to reduce the error and enhancing the model forecast. We studied the error modeling, error or uncertainty quantification and reduction techniques in several frameworks from chemical models to weather forecast models. In each of the models, we tried to provide proper solution to detect the origin of uncertainty, model the error and reduce the uncertainty to improve the model forecast.

The importance of fire safety design has been realised due to the ever increasing loss of properties and lives caused by structural failures during fires. In recognition of the importance of fire safety design, extensive research has been undertaken in the field of fire safety of buildings and structures especially over the last couple of decades. In the same period, the development of fire safety engineering principles has brought significant reduction to the cost of fire protection. However the past fire research on steel structures has been limited to heavier, hot-rolled structural steel members and thus the structural behaviour of light gauge cold-formed steel members under fire conditions is not well understood. Since cold-formed steel structures have been commonly used for numerous applications and their use has increased rapidly in the last decade, the fire safety of cold-formed steel structural members has become an important issue. The current design standards for steel structures have simply included a list of reduction factors for the yield strength and elasticity modulus of hot-rolled steels without any detailed design procedures. It is not known whether these reduction factors are applicable to the commonly used thin, high strength steels in Australia. Further, the local buckling effects dominate the structural behaviour of light gauge cold-formed steel members. Therefore an extensive research program was undertaken at the Queensland University of Technology to investigate the local buckling behaviour of light gauge cold-formed steel compression members under simulated fire conditions. The first phase of this research program included 189 tensile coupon tests including three steel grades and six thicknesses to obtain the accurate yield strength and elasticity modulus values at elevated temperatures because the deterioration of the mechanical properties is the major parameter in the structural design under fire conditions. The results obtained from the tensile tests were used to predict the ultimate strength of cold-formed steel members. An appropriate stress-strain model was also developed by considering the inelastic mechanical characteristics. The second phase of this research was based on a series of more than 120 laboratory experiments and corresponding numerical analyses on cold-formed steel compression members to investigate the local bucking behaviour of the unstiffened flange elements, stiffened web elements and stiffened web and flange elements at elevated temperatures up to 800°C. The conventional effective design rules were first simply modified considering the reduced mechanical properties obtained from the tensile coupon tests and their adequacy was studied using the experimental and numerical results. It was found that the simply modified effective width design rules were adequate for low strength steel members and yet was not adequate for high strength cold-formed steel members due to the severe reduction of the ultimate strength in the post buckling strength range and the severe reduction ratio of the elasticity modulus to the yield strength at elevated temperatures. Due to the inadequacy of the current design rules, the theoretical, semi-empirical and empirical effective width design rules were developed to accurately predict the ultimate strength of cold-formed steel compression members subject to local buckling effects at elevated temperatures. The accuracy of these new design methods was verified by comparing their predictions with a variety of experimental and numerical results. This thesis presents the details of extensive experimental and numerical studies undertaken in this research program and the results including comparison with simply modified effective width design rules. It also describes the advanced finite element models of cold-formed steel compression members developed in this research including the appropriate mechanical properties, initial imperfections, residual stresses and other significant factors. Finally, it presents the details of the new design methods proposed for the cold-formed steel compression members subject to local buckling effects at elevated temperatures.

Problems involving optimal sequential making in uncertain dynamic systems arise in domains such as engineering, science and economics. Such problems can often be cast in the framework of Markov Decision Process (MDP). Solving an MDP requires computing the optimal value function and the optimal policy. The idea of dynamic programming (DP) and the Bellman equation (BE) are at the heart of solution methods. The three important exact DP methods are value iteration, policy iteration and linear programming. The exact DP methods compute the optimal value function and the optimal policy. However, the exact DP methods are inadequate in practice because the state space is often large and in practice, one might have to resort to approximate methods that compute sub-optimal policies. Further, in certain cases, the system observations are known only in the form of noisy samples and we need to design algorithms that learn from these samples. In this thesis we study interesting theoretical questions pertaining to approximate and learning algorithms, and also present an interesting application of MDPs in the domain of crowd sourcing. Approximate Dynamic Programming (ADP) methods handle the issue of large state space by computing an approximate value function and/or a sub-optimal policy. In this thesis, we are concerned with conditions that result in provably good policies. Motivated by the limitations of the PBE in the conventional linear algebra, we study the PBE in the (min, +) linear algebra. It is a well known fact that deterministic optimal control problems with cost/reward criterion are (min, +)/(max, +) linear and ADP methods have been developed for such systems in literature. However, it is straightforward to show that infinite horizon discounted reward/cost MDPs are neither (min, +) nor (max, +) linear. We develop novel ADP schemes namely the Approximate Q Iteration (AQI) and Variational Approximate Q Iteration (VAQI), where the approximate solution is a (min, +) linear combination of a set of basis functions whose span constitutes a subsemimodule. We show that the new ADP methods are convergent and we present a bound on the performance of the sub-optimal policy. The Approximate Linear Program (ALP) makes use of linear function approximation (LFA) and offers theoretical performance guarantees. Nevertheless, the ALP is difficult to solve due to the presence of a large number of constraints and in practice, a reduced linear program (RLP) is solved instead. The RLP has a tractable number of constraints sampled from the original constraints of the ALP. Though the RLP is known to perform well in experiments, theoretical guarantees are available only for a specific RLP obtained under idealized assumptions. In this thesis, we generalize the RLP to define a generalized reduced linear program (GRLP) which has a tractable number of constraints that are obtained as positive linear combinations of the original constraints of the ALP. The main contribution here is the novel theoretical framework developed to obtain error bounds for any given GRLP. Reinforcement Learning (RL) algorithms can be viewed as sample trajectory based solution methods for solving MDPs. Typically, RL algorithms that make use of stochastic approximation (SA) are iterative schemes taking small steps towards the desired value at each iteration. Actor-Critic algorithms form an important sub-class of RL algorithms, wherein, the critic is responsible for policy evaluation and the actor is responsible for policy improvement. The actor and critic iterations have deferent step-size schedules, in particular, the step-sizes used by the actor updates have to be generally much smaller than those used by the critic updates. Such SA schemes that use deferent step-size schedules for deferent sets of iterates are known as multitimescale stochastic approximation schemes. One of the most important conditions required to ensure the convergence of the iterates of a multi-timescale SA scheme is that the iterates need to be stable, i.e., they should be uniformly bounded almost surely. However, the conditions that imply the stability of the iterates in a multi-timescale SA scheme have not been well established. In this thesis, we provide veritable conditions that imply stability of two timescale stochastic approximation schemes. As an example, we also demonstrate that the stability of a widely used actor-critic RL algorithm follows from our analysis. Crowd sourcing (crowd) is a new mode of organizing work in multiple groups of smaller chunks of tasks and outsourcing them to a distributed and large group of people in the form of an open call. Recently, crowd sourcing has become a major pool for human intelligence tasks (HITs) such as image labeling, form digitization, natural language processing, machine translation evaluation and user surveys. Large organizations/requesters are increasingly interested in crowd sourcing the HITs generated out of their internal requirements. Task starvation leads to huge variation in the completion times of the tasks posted on to the crowd. This is an issue for frequent requesters desiring predictability in the completion times of tasks specified in terms of percentage of tasks completed within a stipulated amount of time. An important task attribute that affects the completion time of a task is its price. However, a pricing policy that does not take the dynamics of the crowd into account might fail to achieve the desired predictability in completion times. Here, we make use of the MDP framework to compute a pricing policy that achieves predictable completion times in simulations as well as real world experiments.

This diploma thesis is focused on influence of reduced tillage technology of soil processing on it´s near-surface soil layer (0 to 10 cm). The research was carried out on agricultural land near Šardičky village, where company ZEMO spol. s r.o. provides long-term use of reduced tillage technology. In 2016 the soil quality in this site was evaluated by using physical and hydrophysical parameters, results are presented in the previous bachelor thesis "Selected hydrophysical parameters as indicators of soil quality.". In diploma thesis in addition chemical and other hydrophysical properties have been evaluated to provide a comprehensive assessment of soil quality. In 2016, poppy seed was grown on this site and spring barley was grown in 2017 and 2018. Grab samples and intact soil cores were taken during the vegetation period of the crop. After three years of experimental research, in which I participated, it is possible to assess the development of individual parameters and the influence of reduced tillage technology on near-surface soil layer. The theoretical part of the diploma thesis deals with the description of the reduced tillage technology and problematics of the determination of soil parameters, which are used for evaluation of the quality of the near-surface layer. The practical part deals with evaluation of these parameters according to various authors and describes the development of soil quality during years 2016, 2017 and 2018.

Many companies have a large collection of different model variants and results. Hexagon's (formerly MSC Software) software Odyssee helps to find out what information is contained in this data. New calculations can sometimes be avoided because the results for new parameter combinations can be predicted from the existing calculations. This is particularly interesting for non-linear or large models with long run times. The software also helps when setting up new DOEs and offers a variety of options for statistical displays. In the lecture, the number-based and image-based methods are compared. / Viele Firmen können auf eine große Sammlung vorhandener Rechnungen für verschiedene Modellvarianten zurückgreifen. Die Software Odyssee von Hexagon (früher MSC Software) hilft herauszufinden, welche Informationen in diesen Daten stecken. Neue Rechnungen kann man sich teilweise ersparen, weil die Ergebnisse für neue Parameterkombinationen aus den vorhandenen Rechnungen vorhergesagt werden können. Dies ist besonders interessant für nichtlineare oder große Modelle mit langer Rechenzeit. Die Software hilft auch beim Aufsetzen neuer DOEs und bietet vielfältige Möglichkeiten für statistische Darstellungen. In dem Vortrag werden die zahlenbasierte und bildbasierte Methode gegenübergestellt.

Steel has played an indispensable role in shaping our contemporary world  and will persist to play that role for the foreseeable future. However, the steel industry currently is responsible for 7% of the global CO2-emissions, primarily due to the conventional carbon-based reduction process of iron ore. Fossil-free steel manufacturing, such as hydrogen direct reduction,  could essentially make the  CO2-emissions from primary steel production obsolete. The product from hydrogen-based direct reduction of iron ore is H-DRI, which subsequently are molten in an EAF to produce crude steel. Due to H-DRI  being   a   novel   product,   its   thermophysical   properties   are   not   well documented,  which  are  essential  when  investigating  the  heating  and dissolution behavior.  When  feeding  H-DRI  to  an  EAF,  ferrobergs  may  form,  which  consist  of unmolten material that interrupts the continuous melting process. It is not established whether the heat transfer of the pellets or the heat transfer to the pellets is the leading cause of ferroberg-formation. Modelling the melting process in an EAF is considered near impossible, therefore a simplified heating model of H-DRI was required. In the present thesis, H-DRI pellets were examined with heating experiments in a lab-scale vertical tube furnace to 1500°C  while  the  surface- and center  temperatures  of  the  pellets were  measured.  The measured  surface  temperatures  were  applied  as  varying boundary  conditions  in COMSOL  Multiphysics  heat transfer simulations of  H-DRI  and H-HBI.  The  thermal conductivity  function  was  utilized  as  an  adjustable  parameter to  fit  the  theoretical center temperatures from the heat transfer simulations with the experimental center temperatures to acquire the temperature dependent effective heat conductivity and thermal diffusivity of H-DRI. By establishing an estimate correlation between the heat conductivity of H-DRI and H-HBI, the thermal conductivity and thermal diffusivity of H-HBI could also be obtained. The experiments together with the heat transfer simulations proved to be effective and yielded successful results of the effective heat conductivity and thermal diffusivity of H-DRI  and  H-HBI,  which  can  be  used  in  process  design,  future  models,  and simulations. Furthermore, it is unlikely that ferroberg-formation is caused by slow heat transfer of the H-DRI. It is more likely that it is due to slow heat transfer to the H-DRI. Therefore, the focus should be to increase the heat transfer to the H-DRI pellets while melting in an EAF to avoid ferrobergs. / Stål har haft en oumbärlig roll i att forma vår samtida värld och kommer att fortsätta att inneha  den  rollen  under  en  överskådlig  framtid.  Men  stålindustrin  ansvarar närvarande  för  7%  av  den  totala  globala  CO2-utsläppen,  främst  på  grund  av den konventionella kolbaserade reduktionsprocessen av järnmalm. Fossilfri ståltillverkning, som direktreduktion av järnmalm med vätgas, kan i princip göra CO2-utsläppen   från   primärståltillverkning föråldrat.   Produkten   från   vätgasbaserad direktreduktion  av järnmalm  är  H-DRI,  som  sedan  smälts  i  en  ljusbågsugn  för att producera  råstål. Eftersom  H-DRI  är  en  ny  produkt  så  är  dess  termofysiska egenskaper,  som  är väsentliga  när  man  undersöker  dess  uppvärmnings-  och smältbeteende, inte väl dokumenterat. Vid matning av H-DRI till en ljusbågsugn kan det bildas  ferroberg  som består  av  osmält  material  som  hindrar  den  kontinuerliga smältningsprocessen. Det är inte fastställt om det är värmeöverföringen i pelletsen eller värmeöverföringen  till pelletsen  som  är  den  främsta  orsaken  till  att  ferroberg bildas. Modellering  av  smältprocessen  i  en  ljusbågsugn  anses  nästintill  omöjlig, därför krävdes en förenklad uppvärmningsmodell av H-DRI. I detta examensarbete undersöktes H-DRI-pellets med uppvärmningsexperiment i en vertikal rörugn till 1500°C samtidigt som yt- och centrumtemperaturerna för pelletsen mättes. De uppmätta yttemperaturerna  användes  som  varierande  randvillkor  i  COMSOL Multiphysics värmeöverföringssimuleringar  av  H-DRI  och  H-HBI.  Den  termiska konduktiviteten användes som en justerbar parameter för att anpassa de teoretiska centrumtemperaturerna från värmeöverföringssimuleringarna med de experimentella centrumtemperaturerna  för  att  erhålla  den  temperaturberoende effektiva  termiska konduktiviteten och termiska diffusiviteten för H-DRI. Genom  att   fastställa   en uppskattad korrelation mellan värmeledningsförmågan för H-DRI och H-HBI, kunde även den termiska konduktiviteten och termiska diffusiviteten för H-HBI erhållas. Experimenten  tillsammans  med  värmeöverföringssimuleringarna  visade  sig  vara effektiva och gav framgångsrika resultat av den effektiva termiska konduktiviteten och termiska  diffusiviteten  hos H-DRI och H-HBI,  som  kan  användas  i  processdesign, framtida modeller och simuleringar. Det är osannolikt att ferrobergbildning orsakas av långsam värmeöverföring  i H-DRI, utan det är mer troligt att det beror  på långsam värmeöverföring till H-DRI. Därför bör fokus vara att öka värmeöverföringen till H-DRI pellets i en ljusbågsugn för att undvika ferrobergbildning.