LUTPub (LUT University)
Not a member yet
24632 research outputs found
Sort by
Replacing PI-type current controllers using reinforcement learning
Get PDFThe usage of various learning-based solutions across fields has increased in the recent years. This umbrella term includes any method where a system learns patterns or behavior from data, such as supervised, unsupervised, and reinforcement learning. Such rapidly rising interest is driven by the recent expansion of computational power and capacities, novel algorithms, and available training data. Reinforcement learning approaches, in particular, have become prominent across various domains for their ability to handle uncertainty in their environment and adapt to high-dimensional spaces through continuous interactions, which represent a trial-and-error approach. This utility is applied in fields such as robotics, behavioral science, and control engineering, among many others. In the latter field specifically, these methods replace the existing controllers for parameter tuning, current control, etc.
This thesis contributes to the research of learning-based solutions of current control. Throughout this work, a literature review is conducted on the replacement of existing proportional-integral (PI) controller with a reinforcement learning approach. Particularly, an axial active magnetic bearing scenario is used as the example for the sake of demonstrating the flexibility of this application. Comparison of both approaches takes place and architectures are evaluated. We then propose a process of creating an architecture of the system to replacement of a traditional PI current controller with a reinforcement learning one
Flow-pakkausten kokonaiskustannusten mallintaminen : paperi vs. muovi
No full textThis thesis investigates the total cost of ownership (TCO) of paper- and plastic-based flow packaging in a comparative manner. Consumer preferences, changes in regulation, and the ambition of plastic reduction are driving an increased interest of plastic to fibre substitution. To assess where this substitution could occur, the understanding of total costs is critical.
The objective of this thesis is to understand the total costs and cost structures of paper- and plastic-based flow packaging. A constructive design science research (DSR) approach is adopted, combining a literature review with semi-structured interviews, and developing a TCO model. The literature review encompasses theory on cost management and modelling, as well as packaging material converting technologies. Additionally, it includes an overview of the relevant regulatory items affecting packaging costs. Interviews were conducted on industry experts to refine and benchmark the model, as well as provide its main inputs.
As a result, a modular TCO calculation model rooted in theory and refined by expert opinions was developed. The modelling encompasses complete flow packaging value chains, including material costs, printing and packaging operations, logistics, shelf-life, and disposal costs. The model provides the total costs and cost structures with detailed breakdowns, based on chosen input parameters by the user. The modelling results reveal packaging as the value chain phase incurring the highest costs, with packaging speed identified as the main driver. Paper-based packaging is found to be approximately 19 % more expensive than traditional plastic due mainly to its increased weight and slower packaging speeds.
The thesis contributes to the limited knowledge bases of packaging costs and value chain TCO modelling. For practitioners, it provides a comprehensive, customisable, and collaborative tool for data-driven decision making.Tämä diplomityö tutkii paperi- ja muovipohjaisten flow-pakkausten kokonaiskustannuksia (TCO). Kuluttajien mieltymykset, muuttuva lainsäädäntö ja halu vähentää muovinkäyttöä kasvattavat kiinnostusta muovin korvaamiseen kuitupohjaisilla ratkaisuilla. Tunnistaakseen soveltuvat tilanteet korvaamiselle, on tärkeää ymmärtää pakkausten kokonaiskustannukset.
Työn tavoitteena on ymmärtää paperi- ja muovipohjaisten flow-pakkausten kokonaiskustannusrakenteet. Tutkimus hyödyntää suunnittelutieteellistä metodologiaa, yhdistäen kirjallisuuskatsauksen ja puolistrukturoidut haastattelut, ja kehittäen TCO-mallin. Kirjallisuuskatsaus kattaa teoriaa kustannusjohtamisesta ja mallinnuksesta, sekä pakkausmateriaalien konvertointiteknologioista. Lisäksi se sisältää katsauksen merkittävimpiin lainsäädännöllisiin tekijöihin, jotka vaikuttavat pakkauskustannuksiin. Alan asiantuntijoita haastateltiin mallin säätämistä ja vertailua, sekä syöttötietoja varten.
Tuloksena kehitettiin teoriaan perustuva modulaarinen TCO-laskentamalli, joka on säädetty asiantuntijoiden näkemysten mukaisesti. Mallinnus kattaa koko pakkausarvoketjun, sisältäen materiaalikustannukset, painatus ja pakkausoperaatiot, logistiikan, säilyvyyden ja hävityskulut. Malli tuottaa kokonaiskustannukset ja kustannusrakenteet yksityiskohtaisesti jaoteltuina, perustuen käyttäjän syöttämiin tietoihin. Mallinnustulokset paljastivat pakkausvaiheen aiheuttavan eniten kustannuksia, pakkausnopeuden ajamana. Paperipohjaiset pakkaukset ovat noin 19 % muovisia kalliimpia, johtuen ensisijaisesti paperin painavuudesta ja hitaammasta pakkausnopeudesta.
Työ osallistuu tällä hetkellä vähäiseen tieteelliseen keskusteluun pakkauskustannusten ja arvoketjujen kokonaiskustannusten mallintamisen aloilla. Käytännön toimijoille se tarjoaa kattavan, muokattavan ja yhteistyötä tukevan työkalun datavetoiseen päätöksentekoon
Biomethane and acidogenic potential of agri-food waste streams : towards the production of volatile fatty acids (VFAs)
Get PDFDark fermentation results in an appropriate alternative in the valorization of residues derived from agri-food industry, through the transformation of simple sugars into value-added products. CLAMBER R&D Biorefinery is a public Spanish research center that is currently working on the assessment of agri-food residues to produce volatile fatty acids (VFAs), which then might be used in the production of bioplastics such as poly3-hydroxybutyrate-co-valerate (PHBV). This study investigates the acidogenic potential of agri-food residues as precursors in the production of VFAs. Four agri-food wastes (AFW) (Dairy Industry Residues (AFW1), Winery Industry Residues (AFW2), and two fruits and vegetable residues (AFW3 & AFW4) ) were initially characterized to determine physico-chemical and biological properties. Centrifugation and thermal hydrolysis were applied to liquid and solid residues, respectively, as pretreatment prior to the dark fermentation experiments, which were carried out under mesophilic conditions (35°C). Experiments were run for residues with and without pretreatment, as well as for operating conditions with and without pH control. Quantification of VFAs was performed by using HPLC Chromatography, and kinetic parameters of the study were estimated using a second-order model. Results showed an important improvement on the final VFA yield for the four residues when pH control was implemented, with a percentage increase of 423% for AFW1, 367% for AFW2, 103% for AFW3 and 33% for AFW4 in comparison with experiments without pH control. Centrifugation resulted in a proper option for pretreatment of liquid residues, with improvement of 24% for AFW1 and 53% for AFW2 in VFA yield. Thermal hydrolysis showed poor potential as a pretreatment of solid residues, with a decrease of 4% for AFW3 and 25% for AFW4 in VFA yield. The maximum VFAs yield was determined for each residue, resulting in values of 0.927 gVFAs/gVS for AFW1, 0.668 gVFAs/gVS, for AFW2, 0.936 gVFAs/gVS for AFW3 and 0.841 gVFAs/gVS for AFW4. The results of this work provide useful information about the potential of the four tested residues, becoming products of interest for implementation in further analysis to produce PHBV
Cosine Phase Based Representation of Signals for Remote Monitoring in Multiuser Wireless Networks
Get PDFIn this paper, we investigate a novel representation of a band-limited and continuous-time signal using a sequence of impulses or events. To begin with, we evaluate the mean squared error between the original signal and its reconstructed version assuming that: (i) the signal samples are transmitted at the Shannon channel capacity; (ii) the signal representation using the cosine phase method is done before its transmission. The proposed approach is then compared with an existing approach based on the signal transmission of quantized samples. Finally, we provide some representative examples through Monte Carlo simulations, consistently revealing the superiority of the proposed signal representation approach over the existing one regarding transmission bandwidth and peak-to-peak value of the original signal.Post-print / Final draf
Cost management in a digitalized business environment
No full textTämän kandidaatintutkielman tavoitteena oli selvittää kustannusjohtamisen roolin merkitystä digitalisoituneessa liiketoimintaympäristössä. Tutkimuksen pääpaino oli siinä, miten kustannusjohtamisen keskeisiä työkaluja hyödynnetään nykyisessä ympäristössä, minkälaisia haasteita yritykset kohtaavat käytännössä ja minkälaisia tulevaisuuden mahdollisuuksia digitalisaatio avaa päätöksenteolle jatkossa.
Teoreettinen viitekehys rakentuu kustannusjohtamisen teorian ympärille, jossa avataan keskeisimmät menetelmät ja käsitteet digitalisoitunut ympäristö huomioiden. Empiirinen osio tutkimuksesta toteutettiin kvalitatiivisina teemahaastatteluina, joissa kerättiin tietoa kolmelta alalla toimivalta asiantuntijalta.
Haastattelututkimuksen perusteella nousi esille, että vaikka digitalisaatio mahdollistaa entistä tehokkaamman tiedonkäsittelyn älykkäämmissä järjestelmissä, tuo se mukanaan haasteita liittyen tekoälyn murrosvaiheeseen.
Tutkielman johtopäätöksissä esitetään lopuksi konkreettisia jatkotutkimusehdotuksia liittyen taloudelliseen päätöksentekoon nopeasti muuttuvassa digitaalisessa ympäristössä.This bachelor’s thesis aimed to examine the role and significance of cost management in a digitalized business environment. The study primarily investigated how core cost management tools are utilized in the current landscape, what practical challenges companies face, and what kinds of opportunities digitalization opens for future decision-making.
The theoretical framework is based on cost management theory, outlining the key methods and concepts relevant to a digitalized organizational context. The empirical part of the research was conducted through qualitative thematic interviews, gathering insights from three industry professionals.
Based on the interview data, it became evident that while digitalization enables the faster processing of extensive datasets, it also introduces challenges related to the current transformation driven by artificial intelligence.
In the conclusion chapter, the thesis presents concrete suggestions for future research, particularly concerning financial decision-making in a rapidly evolving digital environment
Solving the job shop problem using an evolutionary algorithm
No full textKonepajaongelma on yleinen optimointi ongelma, jolla on useita eri ratkaisu menetelmiä. Ongelmassa on tavoitteena löytää optimaalinen suoritusjärjestys kappaleille ja niiden työvaiheille. Ongelman ratkaisemisessa ja menetelmän valitsemisessa pitää ottaa huomioon eri tapausten erilaiset rajoitteet. Erilasisissa ongelmissa voi olla paljon erilaisia rajoitteita ja menetelmä tulee valita rajoitteet huomioiden. Optimaalinen suoritusjärjestys mahdollistaa konepajan toiminnan mahdollisimman tehokkaasti.
Tässä työssä tarkasteltiin evoluutioalgoritmin soveltuvuutta konepajaongelman ratkaisemisessa. Evoluutioalgoritmi inspiroituu biologisesta evoluutiosta. Algoritmi aloittaa satunnaisilla järjestyksillä ja muokkaa niitä sukupolvien myötä mahdollisimman tehokkaiksi. Algoritmi säilyttää parhaat järjestykset ja vertaa niitä keskenään. Uusia ehdokkaita parhaalle järjestykselle muodostetaan risteyttämällä aikaisempia järjestyksiä.
Keskeiset havainnot työssä olivat, että evoluutio algoritmi toimii hyvin konepajaongelman optimointiin ja on hyvin sovellettavissa erilaisiin ongelmiin. Evoluutio algoritmin etu on sen soveltuvuus monimutkaisissa ja laajoissa ongelmissa, joiden ratkaisemisessa muut menetelmät voisivat olla hitaita tai liian epäkäytännöllisiä.The machine shop problem is a general optimization problem that has several different solution methods. The goal of the problem is to find the optimal execution order for parts and their work steps. When solving the problem and choosing a method, the different constraints of different cases must be taken into account. There can be many different constraints in different problems and the method must be chosen taking the constraints into account. The optimal execution order enables the machine shop to operate as efficiently as possible.
This work examined the applicability of the evolutionary algorithm in solving the machine shop problem. The evolutionary algorithm is inspired by biological evolution. The algorithm starts with random orders and modifies them as efficiently as possible over generations. The algorithm stores the best orders and compares them with each other. New candidates for the best order are formed by crossing previous orders.
The key findings in the work were that the evolutionary algorithm works well for optimizing the machine shop problem and is well applicable to various problems. The advantage of the evolutionary algorithm is its applicability to complex and large-scale problems that other methods might be slow or too impractical to solve
Hiilidioksidin käsittely talteenoton jälkeen : kuuman kaliumkarbonaattiprosessin jälkeisen hiilidioksidin käsittelyn mallinnus ja teknistaloudellinen arviointi
No full textThis thesis studied technologies for processing CO₂ from post-combustion and oxy-fuel combustion sources. Processing of CO₂ includes compression, dehydration, purification and liquefaction. It was found that a wide range of technologies may be utilized for all the process steps, depending on the CO₂ composition and requirements. For compression and dehydration, multi-stage centrifugal compressors and temperature swing adsorption were found to be the most common. Closed-cycle liquefaction was found to be slightly more economical than open-cycle options. The main impurities of concern in the CO₂ were found to be non-condensable gases, acid gases, heavy metals, and dust. For removal of non-condensables and mercury, cryogenic distillation and fixed bed adsorption were the common technologies. For acid gas removal, several different options were proposed, with no clear preferred technology.
A CPU configuration after a HPC carbon capture system was presented and modelled. The performance of the CPU was found to vary greatly depending on the purity of the captured CO₂. Especially the performance of the refrigeration and cryogenic distillation systems was found to decrease at high non-condensable gas contents. The CPU recovery ratio was found to be in the range of 93.2-99.5 %, and electricity consumption between 129 and 161 kWh/tonCO₂ . A techno-economic assessment of the modelled system was performed. The levelized cost of the CO₂ was found to be between 21.8-31.3 C/tonCO₂ . Major contributors to electricity consumption and capital expenses were found to be the compression and refrigeration systems.Diplomityössä tutkittiin hiilidioksidin käsittelyä happipolton ja polton jälkeisen talteenoton jälkeen. Hiilidioksidin käsittely sisältää paineistuksen, kuivatuksen, puhdistuksen ja nesteytyksen. Selvisi, että prosessivaiheiden toteuttamiseen on olemassa useita eri teknologioita riippuen hiilidioksidin koostumuksesta ja vaatimuksista. Paineistukseen sekä kuivatukseen yleisimmät vaihtoehdot ovat monivaiheinen keskipakokompressori ja lämpötilan muutokseen perustuva adsorptio. Suljetun nesteytysjärjestelmän havaittiin olevan taloudellisesti hieman kannattavampi verrattuna avoimeen järjestelmään. Hiilidioksidin tärkeimmät epäpuhtaudet olivat lauhtumattomat kaasut, happamat kaasut, raskasmetallit ja tuhka. Yleisimmät teknologiat lauhtumattomien kaasujen ja elohopean puhdistukseen havaittiin olevan kryogeeninen tislaus ja kiintopetiadsorptio. Happamien kaasujen puhdistukseen löytyi useita eri vaihtoehtoja ilman selkeää ensisijaista teknologiaa.
HPC talteenoton jälkeinen CPU konfiguraatio esitettiin ja mallinnettiin. CPU prosessin suorituskyvyn havaittiin vaihtelevan merkittävästi riippuen hiilidioksidin puhtaudesta. Etenkin kylmäkierron ja kryogeenisen tislauksen suorituskyvyn huomattiin laskevan merkittävästi korkeilla lauhtumattomien kaasujen pitoisuuksilla. CPU prosessin saantosuhteeksi saatiin 93,2-99,5%ja sähkönkulutukseksi 129-161 kWh/tonCO₂ . Mallinnetulle järjestelmälle tehtiin teknistaloudellinen arviointi. Hiilidioksidin tasoitetuksi hinnaksi saatiin 21,8-31,3 C/tonCO₂ . Sähkönkulutuksen ja pääomakustannuksen merkittävimmiksi aiheuttajiksi havaittiin paineistus ja kylmäkierto
Development of a pricing process in a logistics service company
No full textHinnoittelu on yksi yritysten merkittävimmistä strategisista ohjauskeinoista, sillä se vaikuttaa kannattavuuteen, kilpailuasemaan ja asiakassuhteisiin. Hinnoittelu ei ole vain taloudellinen päätös, vaan sillä voidaan myös vaikuttaa yrityksen asemaan markkinoilla. Digitalisaation myötä hinnoittelun luonne on muuttunut. Lisääntynyt data ja analytiikka mahdollistavat entistä tarkemman ja joustavamman hinnoittelun, mutta samalla asiakkaiden lisääntynyt hintatietoisuus asettaa yrityksille paineita perustella päätöksensä. Hinnoittelua käsittelevä tutkimus on pitkään painottunut kysymykseen hinnanmäärittämisestä, vaikka todellinen tarve on ymmärtää, miten hinnoitteluprosessi kytketään osaksi yrityksen strategista ja operatiivista toimintaa. Hinnoitteluprosessin kehittäminen ja systemaattinen hallinta on olennainen edellytys kannattavuuden ja kilpailukyvyn varmistamiselle.
Tämän diplomityön tavoitteena on kehittää suomalaiselle logistiikkapalveluyritykselle hinnoitteluprosessia tukeva laskentatyökalu. Työkalun suunnittelu perustuu prosessin nykytilan mallinnukseen, sen keskeisten haasteiden tunnistamiseen sekä kehitysehdotusten määrittelyyn. Tutkimus perustuu kirjallisuuskatsaukseen, jossa tarkastellaan hinnoitteluprosesseja, -menetelmiä ja -kyvykkyyttä. Empiirinen osuus toteutettiin kohdeyrityksessä haastattelujen avulla. Haastattelut tarjosivat syvällistä tietoa nykyisistä käytännöistä ja niiden haasteista, kuten tiedon hajanaisuudesta, henkilöriippuvaisuudesta ja jälkiseurannan puutteellisuudesta. Havaintojen pohjalta laadittiin kehitysehdotuksia hinnoitteluprosessin parantamiseksi ja kehitettiin laskentatyökalu hinnoittelun tueksi. Työkalu perustuu kustannusperusteiseen hinnoittelumenetelmään ja tarjoaa rakenteen hinnoittelun systemaattiselle toteuttamiselle.
Tutkimuksen johtopäätöksenä voidaan todeta, että hinnoittelun kehittäminen edellyttää prosessin selkeyttämistä ja hinnoittelukyvykkyyden vahvistamista eri osa-alueilla. Työssä esitetyt kehitysehdotukset ja kehitetty laskentatyökalu tarjoavat yritykselle käytännön välineet hinnoittelun systemaattiseen hallintaan. Näin hinnoittelu voidaan kytkeä tiiviimmin osaksi liiketoiminnan suunnittelua ja seurantaa, mikä parantaa kannattavuuden hallintaa ja tukee yrityksen strategisia tavoitteita. Diplomityö luo näin pohjan kohdeyrityksen hinnoittelun kehittämiselle ja tarjoaa samalla esimerkkejä muille palveluyrityksille, jotka pyrkivät kehittämään hinnoitteluaan.Pricing represents one of the most important strategic tools for companies, as it affects profitability, market position, and customer relationship. Pricing is not only a financial decision but also a way to position a company in the market. With digitalization, the nature of pricing has changed. The use of data and analytics enables more accurate and flexible pricing, but at the same time, customers are more aware of prices, which increases the pressure on companies to justify their decisions. Research on pricing has for a long time focused mainly on price setting, although the real need is to understand how the pricing process can be connected to a company’s strategic and operational management. Developing and systematically managing the pricing process is essential for ensuring profitability and competitiveness.
The purpose of this thesis is to develop a calculation tool to support the pricing process of a Finnish logistics service company. The design of the tool is based on modeling the current state of the process, identifying its key challenges, and defining improvement proposals. The research builds on a literature review examining pricing processes, methods and capabilities. The empirical part was carried out in the case company through interviews that offered in depth insights into current practices and challenges, such as a fragmented information, reliance on individuals, and lack of follow-up. Based on these findings, development proposals for the pricing process were created and a calculation tool was developed to support pricing. The tool is based on a cost-based pricing method and provides a structured approach for implementing pricing systematically.
The results of the study indicate that improving pricing requires both clarifying the process and strengthening pricing capabilities across different dimensions. The proposed improvements and the developed calculation tool provide the company with practical means for systematic pricing management. This allows pricing to be more closely linked to business planning and monitoring, which improves profitability management and supports strategic goals. The thesis contributes by providing a concrete development framework for the case company, while also offering insights for the other service organizations seeking to advance their pricing capabilities
Antimatter meets lithium-ion batteries : unveiling cathode conduction mechanisms via positron annihilation spectroscopy and density functional theory
No full textCarbon coatings play a pivotal role in enhancing the performance of lithium-ion battery cathodes by improving conductivity and structural stability. However, the fundamental mechanisms behind fast charging, particularly at the buried interfaces between active materials and conductive carbon additives, remain unclear. In this work, we employ positron annihilation spectroscopy, in combination with two-component density functional theory (TCDFT), to study the ionic mobility, the electron transfer orbitals and electronic structure at the LiCoO2/carbon (LCO/C) composite cathodes interfaces. Positrons, selectively annihilating with low-momentum electrons, are shown to be highly sensitive to orbital and interfacial characteristics.
In Lithium-ion batteries, conduction involves a synergistic interplay between electronic transport along the collector circuit and ionic transport across the electrolyte. Achieving optimal performance requires both pathways to function efficiently. Experimentally, focusing on solid state LCO/C interfaces and thereby avoiding contamination from liquid electrolytes, we show that carbon coatings boost both ionic and electronic conductivities by two orders of magnitude, while carbon nanotube coated LCO shows a further two orders of magnitude. Positron lifetime measurements on LCO/C revealed two distinct annihilation lifetime components, theoretical calculations have further demonstrated that, in the LCO/C system, one lifetime corresponds to the bulk region, while the other is associated with surface states at the LCO/C interface.
Motivated by the experimental results, DFT simulations are carried out to investigate conducting mechanisms at buried LCO/C interfaces in the fully discharged state. Beginning with a graphene-stacked LCO heterostructure, a novel method that combines positron lifetime spectroscopy with TCDFT shows that the positron surface state serves as a reliable descriptor of rapid ionic mobility, underscoring the potential of positron annihilation techniques for probing ion transport dynamics. TCDFT calculations indicate that the heterostructure forms a p-type Schottky junction at the interface, with graphene’s Dirac point shifted down by approximately 1 eV from the Fermi level. Further analysis of Doppler broadening spectra and momentum distributions reveals spectral contributions from O-2p, C-2pz, and Co-3d electron transfer orbitals—components essential to redox and conduction processes. The significant O-2p and C-2pz contributions show that positron annihilation spectroscopy selectively probes the momentum-space features of 2p orbitals, which are often less distinguishable in conventional band and density of states analysis. In order to extend the analysis beyond graphene, we construct a linear combination of Doppler-broadening profiles and introduce a descriptor that quantifies the contribution of interfacial electron-transfer orbitals. The descriptor reliably ranks the effectiveness of diverse carbon coatings (graphene, C60, CNTs) without requiring constructing large first-principles heterostructure models. The descriptor, derived from both experimental and theoretical spectra, serves as an effective detection method of the electron transfer orbital contributions.
In summary, this work establishes a quantum-based methodology for understanding and optimizing ionic and charge transport at electrode interfaces, bridging atomic-scale modeling with macroscopic battery performance. It offers a reproducible and scalable strategy for future materials design in high-rate LIBs, solid-state batteries, and energy conversion technologies.I rivestimenti carboniosi svolgono un ruolo fondamentale nel migliorare le prestazioni dei catodi per batterie agli ioni di litio, incrementando la conducibilità e la stabilità strutturale. Tuttavia, i meccanismi alla base della ricarica rapida, in particolare alle interface sepolte tra i materiali attivi e gli additivi conduttivi di carbonio, rimangono poco compresi. In questo lavoro impieghiamo la spettroscopia di annichilazione di positroni (PAS), in combinazione con la teoria della densità a due componenti (TCDFT), per sondare la mobilità ionica, gli orbitali di trasferimento elettronico e la struttura elettronica alle interfacce dei catodi compositi LiCoO2/carbonio (LCO/C). I positroni, che annichilano selettivamente con elettroni a basso momento, si rivelano estremamente sensibili alle caratteristiche orbitali e interfaciali.
Lavorando sperimentalmente su catodi LCO/C completamente solidi—eliminando così la contaminazione da elettroliti liquidi—mostriamo che i rivestimenti di carbonio aumentano di due ordini di grandezza sia la conducibilità ionica sia quella elettronica, mentre il LCO rivestito con nanotubi di carbonio (CNT) mostra un ulteriore incremento di due ordini di grandezza. Le misure di vita media dei positroni (PALS) su LCO/C hanno rivelato due componenti di annichilazione distinte; i calcoli teorici hanno dimostrato che, nel Sistema LCO/C, una vita media corrisponde alla regione di bulk mentre l’altra è associata a stati di superficie all’interfaccia LCO/C.
Motivati dai risultati sperimentali, sono state effettuate simulazioni per investigare i meccanismi di diffusione ionica e trasporto elettronico alle interfacce sepolte LCO/C nello stato completamente scarico. Iniziando da un eterostrato LCO impilato con grafene, un nuovo metodo che combina PALS con TCDFT dimostra che lo stato di superficie del positrone funge da descrittore affidabile della rapida mobilità ionica, evidenziando il potenziale delle tecniche di annichilazione di positroni per studiare la dinamica del trasporto ionico. I risultati TCDFT indicano che l’eterostrato forma una giunzione Schottky di tipo p il cui punto di Dirac si trova circa 1 eV al di sotto del livello di Fermi, conferendo un comportamento quasi metallico. Un’ulteriore analisi degli spettri di allargamento Doppler e delle distribuzioni di momento rivela contributi spettrali da orbitali di trasferimento elettronico O-2p, C-2pz e Co-3d—componenti essenziali per i processi redox e di conduzione. Le significative componenti O-2p e C-2pz dimostrano che la spettroscopia di annichilazione di positroni amplifica selettivamente le caratteristiche in spazio-momento degli orbitali 2p, spesso poco distinguibili nelle analisi convenzionali di bande e DOS.
Per generalizzare oltre il grafene, viene introdotta una combinazione lineare dei profili di allargamento Doppler, con il parametro β che funge da descrittore per quantificare il contributo degli orbitali di trasferimento elettronico interfaciali. β classifica in modo affidabile l’efficacia di diversi rivestimenti carboniosi (grafene, C60, CNT) senza la necessità di costruire estesi modelli di eterostrati ab initio. Il parametro β, derivato sia da spettri sperimentali sia teorici, si conferma dunque un indicatore robusto delle interazioni elettroniche interfaciali.
In sintesi, questo lavoro stabilisce una metodologia basata su principi quantistici per comprendere e ottimizzare il trasporto ionico ed elettronico alle interfacce degli elettrodi, colmando il divario tra modellazione atomistica e prestazioni macroscopiche delle batterie. Esso offre una strategia riproducibile e scalabile per il design di materiali in batterie LIB ad alta potenza, batterie allo stato solido e tecnologie di conversione energetica.ei tietoa saavutettavuudest
The impact of information sharing and availability on job satisfaction in remote work
No full textKoronaviruspandemian jälkeen etätyö on jäänyt suureksi osaksi työelämää. Viime vuosina eri tahot ovat pyrkineet kyseenalaistamaan etätyötä ja lisäämään läsnätyön määrää. Perusteena on käytetty tiedon jakamisen ja tiedon saatavuuden heikkenemistä ja sen vaikutuksia mm. innovaatio toimintaan, työn tuottavuuteen ja työtyytyväisyyteen. Toisaalta etätyötä ja etenkin hybridityötä vaaditaan työntekijöiden keskuudessa. Samaan aikaan työtyytyväisyys, joka on tärkeä organisaation menestyksen osa-alue, on ollut maailmanlaajuisesti laskussa. Työn tarkoituksena on tutkia tiedon jakamisen ja tiedon saatavuuden vaikutusta työtyytyväisyyteen, huomioiden etätyön tekeminen.
Tutkimus toteutettiin kvantitatiivisella kyselyllä kohde organisaation kaikille työntekijöille. Vastaukset analysoitiin Sata tilastointiohjelmistolla. Tuloksista tehtiin kuvailevaa tarkastelua ja teoreettiseen viitekehyksen mukaista korrelaatio- ja regressioanalyysia.
Tutkimuksen tuloksissa havaittiin, että tiedon jakamisella ja tiedon saatavuudella on positiivinen yhteys työtyytyväisyyteen. Etätyö ei tässä tutkimuksessa näyttänyt vaikuttavan kokonaisuuteen merkittävästi, sillä vastaajista suurin osa teki etätyötä yli 50 %: työajasta. Tuloksista voidaan myös tulkita, että tiedon jakaminen välittyy kokonaisuudessaan tiedon saatavuuden kautta työtyytyväisyyteen. Tulosten perusteella tiedon jakaminen ja tiedon saatavuus lisäävät kompetenssia, autonomiaa ja yhteenkuuluvuutta.
Yhteenvetona voidaan todeta, että tietojohtamisen näkökulmaa voidaan käyttää myös työtyytyväisyyden parantamiseen. Johtajille keskeinen havaintona on, että perehdytys ja työkuorma ovat tärkeitä tekijöitä tässä kokonaisuudessa.After COVID pandemic, remote work has remained a big part of working life. In recent years, there have been efforts from various quarters to question it and increase the amount of on-site work. The rationale behind this has been the deterioration of information sharing and access to information and the resulting impact on innovation, productivity, and job satisfaction, among other things. On the other hand, remote work, and hybrid work in particular, is in demand among employees. At the same time, job satisfaction, which is an important factor in the success of an organization, has been declining globally. The purpose of this study is to examine the impact of information sharing and availability on job satisfaction, taking into account remote work.
The study was conducted using a quantitative survey of all employees in the target organization. The responses were analysed using Sata statistical software. The results were examined descriptively, and correlation and regression analyses were performed in accordance with the theoretical framework.
The results of the study showed that there is a positive correlation between information sharing and information availability and job satisfaction. Remote work did not appear to have a significant impact on the overall results of this study, as the majority of respondents worked remotely for more than 50% of their working hours. The results can also be interpreted to mean that knowledge sharing is conveyed through knowledge availability to job satisfaction. Based on the results, knowledge sharing and knowledge availability fulfil competence, autonomy, and cohesion. In summary, it can be said that the knowledge management perspective can also be used to improve job satisfaction. For managers, a key finding is that induction and workload are important factors in utilising this approach