Contribuições de modelagem de equações estruturais na análise de dados em modelos comportamentais de destino turístico

A fragilidade brasileira quanto à competitividade turística é um fato observável nos dados da Organização Mundial do Turismo. O Brasil caiu em 2011, da 45ª para a 52ª posição, apesar de liderar no atributo recursos naturais e estar colocado na 23° em recursos culturais. Assim, grandes interesses e esforços têm sido direcionados para o estudo da competitividade dos produtos e destinos turísticos. O destino turístico é caracterizado por um conjunto complexo e articulado de fatores tangíveis e intangíveis, apresentando alta complexidade, dados de elevada dimensionalidade, não linearidade e comportamento dinâmico, tornando-se difícil a modelagem desses processos por meio de abordagens baseadas em técnicas estatísticas clássicas. Esta tese investigou modelos de equações estruturais e seus algoritmos, aplicados nesta área, analisando o ciclo completo de análise de dados, em um processo confirmatório no desenvolvimento e avaliação de um modelo holístico da satisfação do turista; na validação da estrutura do modelo de medida e do modelo estrutural, por meio de testes de invariância de múltiplos grupos; na análise comparativa dos métodos de estimação MLE, GLS e ULS para a modelagem da satisfação e na realização de segmentação de mercado no setor de destino turístico utilizando mapas auto-organizáveis de Kohonen e sua validação com modelagem de equações estruturais. Aplicações foram feitas em análises de dados no setor de turismo, principal indústria de serviços do Estado do Rio Grande do Norte, tendo sido, teoricamente desenvolvidos e testados empiricamente, modelos de equações estruturais em padrões comportamentais de destino turístico. Os resultados do estudo empírico se basearam em pesquisas com a técnica de amostragem aleatória sistemática, efetuadas em Natal-RN, entre Janeiro e Março de 2013 e forneceram evidências sustentáveis de que o modelo teórico proposto é satisfatório, com elevada capacidade explicativa e preditiva, sendo a satisfação o antecedente mais importante da lealdade no destino. Além disso, a satisfação é mediadora entre a geração da motivação da viagem e a lealdade do destino e que os turistas buscam primeiro à satisfação com a qualidade dos serviços de turismo e, posteriormente, com os aspectos que influenciam a lealdade. Contribuições acadêmicas e gerenciais são mostradas e sugestões de estudo são dadas para trabalhos futuros.

Contribuições ao estudo de modelagem de equações estruturais na avaliação da satisfação do cliente de serviços de comunicações móveis

No mercado de telecomunicações as transformações tecnológicas das últimas décadas aliaram-se a um cenário formado por empresas de alta tecnologia que caracterizam o setor de comunicações móveis pessoais em todo mundo. Neste contexto, as empresas deste setor preocupam-se cada vez mais com a competitividade, oferta de serviços, área de atendimento, demanda reprimida e a lealdade do cliente. Estudos de comportamento do consumidor pesquisam a satisfação e lealdade de clientes como fatores básicos para relações bem sucedidas e duradouras com as empresas. A complexidade das relações entre variáveis na avaliação da satisfação do cliente em comunicações móveis pode ser adequadamente pesquisada com a utilização de métodos estatísticos multivariados. Essa tese analisou as relações causais envolvendo os antecedentes e consequentes associados à satisfação do cliente, no segmento de comunicações móveis, bem como desenvolveu e validou um modelo comportamental do cliente no uso deste serviço, buscando explicar as relações entre os construtos envolvidos: satisfação, qualidade dos serviços, valor percebido, imagem da marca, lealdade e reclamação. Foi estabelecida uma ampla base teórica para avaliar a importância estratégica do modelo que relaciona a influência na satisfação do serviço com as percepções dos clientes e avaliada a precisão deste modelo, por meio de uma análise comparativa a utilização de três métodos de estimação dos seus parâmetros, MLE, GLS, e ULS, com o emprego de modelagem de equações estruturais. Foram feitas aplicações em análises de dados, sendo testada e avaliada empiricamente, a influência do gênero na satisfação do cliente deste setor, além de uma segmentação de mercado utilizando mapas auto-organizáveis e a correspondente validação deste processo, com modelagem de equações estruturais.Os resultados do estudo empírico produziram uma boa qualidade de ajustamento para o modelo teórico proposto, com evidências do estabelecimento de uma adequada capacidade explicativa e preditiva, destacando-se a relevância da relação causal entre a satisfação e lealdade, em consonância com diversos estudos realizados para os mercados de comunicações móveis.

Influência das condições ambientais no verdor da vegetação da caatinga frente às mudanças climáticas

The Caatinga biome, a semi-arid climate ecosystem found in northeast Brazil, presents low rainfall regime and strong seasonality. It has the most alarming climate change projections within the country, with air temperature rising and rainfall reduction with stronger trends than the global average predictions. Climate change can present detrimental results in this biome, reducing vegetation cover and changing its distribution, as well as altering all ecosystem functioning and finally influencing species diversity. In this context, the purpose of this study is to model the environmental conditions (rainfall and temperature) that influence the Caatinga biome productivity and to predict the consequences of environmental conditions in the vegetation dynamics under future climate change scenarios. Enhanced Vegetation Index (EVI) was used to estimate vegetation greenness (presence and density) in the area. Considering the strong spatial and temporal autocorrelation as well as the heterogeneity of the data, various GLS models were developed and compared to obtain the best model that would reflect rainfall and temperature influence on vegetation greenness. Applying new climate change scenarios in the model, environmental determinants modification, rainfall and temperature, negatively influenced vegetation greenness in the Caatinga biome. This model was used to create potential vegetation maps for current and future of Caatinga cover considering 20% decrease in precipitation and 1 °C increase in temperature until 2040, 35% decrease in precipitation and 2.5 °C increase in temperature in the period 2041-2070 and 50% decrease in precipitation and 4.5 °C increase in temperature in the period 2071-2100. The results suggest that the ecosystem functioning will be affected on the future scenario of climate change with a decrease of 5.9% of the vegetation greenness until 2040, 14.2% until 2070 and 24.3% by the end of the century. The Caatinga vegetation in lower altitude areas (most of the biome) will be more affected by climatic changes.

State-space modelling of geolocation data reveals sex differences in the use of management areas by breeding northern fulmars

We thank Orkney Islands Council for access to Eynhallow and Talisman Energy (UK) Ltd and Marine Scotland for fieldwork and equipment support. Handling and tagging of fulmars was conducted under licences from the British Trust for Ornithology and the UK Home Office. EE was funded by a Marine Alliance for Science and Technology for Scotland/University of Aberdeen College of Life Sciences and Medicine studentship and LQ was supported by a NERC Studentship. Thanks also to the many colleagues who assisted with fieldwork during the project, and to Helen Bailey and Arliss Winship for advice on implementing the state-space model.

State-space modelling of geolocation data reveals sex differences in the use of management areas by breeding northern fulmars

We thank Orkney Islands Council for access to Eynhallow and Talisman Energy (UK) Ltd and Marine Scotland for fieldwork and equipment support. Handling and tagging of fulmars was conducted under licences from the British Trust for Ornithology and the UK Home Office. EE was funded by a Marine Alliance for Science and Technology for Scotland/University of Aberdeen College of Life Sciences and Medicine studentship and LQ was supported by a NERC Studentship. Thanks also to the many colleagues who assisted with fieldwork during the project, and to Helen Bailey and Arliss Winship for advice on implementing the state-space model.

Exploring the cardiovascular disease continuum: blood pressure and target organ damage

Introduction The objectives of this thesis are to: (1) examine how ambulatory blood pressure monitoring (ABPM) refines office blood pressure (BP) measurement; (2) determine if absolute ambulatory BP or dipping status is better associated with target organ damage (TOD); (3) explore the association of isolated nocturnal hypertension (INH) with TOD; and (4) investigate the association of night-time BP with ultrasound markers of cardiovascular damage. Methods Data from the Mitchelstown Cohort Study was analysed to deliver objectives 1 and 2. Objective 3 was addressed by a systematic review and analysis of data from the Mitchelstown Study. A sample of participants from the Mitchelstown Study underwent an echocardiogram for speckle tracking analysis and carotid ultrasound to achieve objective 4. Results ABPM reclassifies hypertension status in approximately a quarter of individuals, with white coat and masked hypertension prevalence rates of 11% and 13% respectively. Night-time systolic BP is better associated with TOD than daytime systolic BP and dipping level. In multi-variable models the odds ratio (OR) for LVH was 1.4 (95% CI 1.1 -1.8) and for albumin:creatinine ratio ≥ 1.1 mg/mmol was 1.5 (95% CI 1.2 – 1.8) for each 10 mmHg rise in night-time systolic BP. The evidence for the association of INH with TOD is inconclusive. Night-time systolic BP is significantly associated with global longitudinal strain (GLS) (beta coefficient 0.85 for every 10 mmHg rise, 95% CI 0.3 – 1.4) and carotid plaques (OR 1.9 for every 10 mmHg rise, 95% CI 1.1 – 3.2) in univariable analysis. The findings persist for GLS in sex and age adjusted models but not in multivariable models. Discussion Hypertension cannot be effectively managed without using ABPM. Night-time systolic BP is better associated with TOD than daytime systolic BP and dipping level, and therefore, may be a better therapeutic target in future studies.

Ilmiöiden automaattinen ennustaminen hakukonetilastojen avulla

Web-hakukoneiden merkitys tiedonhaussa on noussut merkittävään asemaan viimeisten vuosikymmenten aikana. Vaikka tiedonhaku hakukoneella on hyvin suoraviivaista, ihmiset käyttäytyvät hakukoneissa eri tavoilla. Tämän tutkielman aiheena on tutkia ihmisten hakukonekäyttäytymistä ja yrittää löytää tapoja hyödyntää näitä tutkimustuloksia. Tutkielmassa käytetään aineistona keskeisiä hakukoneiden perusteita käsitteleviä teoksia, joiden avulla käydään läpi hakukoneiden toimintalogiikkaa sekä hakukonetilastojen hyödyntämismahdollisuuksista löytyvää kirjallisuutta. Tutkielman tutkimusosuus hyödyntää Googlen tarjoamia työkaluja, joiden avulla päästään käsiksi ihmisten hakukonekäyttäytymiseen avainsanojen ja näiden hakuajankohtien osalta. Tutkimusosuudessa aiheena on ennustaa vuoden 2015 eduskuntavaalien viiden suurimman puolueen ääniosuudet. Ennustus tehtiin tutkimalla ihmisten hakukonekäyttäytymistä viiden edeltävän vaalin aikana ja suhteuttamalla nämä käyttäytymismallit tiedettyihin vaalituloksiin. Tehtiin hypoteesi, että suurempi hakuvolyymi johtaa suurempaan ääniosuuteen ja valittiin lineaarinen regressio ennustusmalliksi. Ennustusmalli toimi hyvin ja keskimääräinen virhemarginaali ääniosuuden ennustuksessa oli 2,90 %-yksikköä. Perussuomalaisten tulos oli yllätyksellinen ja ilman sitä ennustuksen keskimääräinen virhemarginaali oli 1,34 %-yksikköä. Tutkimustulosten perusteella nähdään hakukonetutkimusten potentiaali. Vaikka vaalitulosten ennustamiseen käytetty tietomäärä oli hyvin suppea, saatiin silti aikaan julkaisukelpoisia tuloksia. Näiden tulosten mukaan näyttää siltä, että Googlen hakutilastojen avulla on mahdollista ennustaa ihmisten valinnoista riippuvia nykymaailman tapahtumia lähitulevaisuuteen.

Suhteelliseen ilmaantuvuuteen perustuvan kovarianssirakenteen bayesiläinen MCMC-estimointi valikoituneessa perheaineistossa

Tässä tutkielmassa rintasyövän ja ruoansulatuselinten syöpien perheittäistä kertymistä ja perimäosuutta estimoitiin lapsena tai nuorena syövän sairastaneiden suomalaisten perheaineistoissa. Perheet poimittiin siten, että jokaisessa perheessä on vähintään yksi alle 40-vuotiaana diagnosoitu syöpätapaus vuosina 1970-2012. Rintasyöpäaineisto koostui 4921 perheestä, joissa oli kaikkiaan 26 259 henkilöä. Ruoansulatuselinten aineisto puolestaan koostui 3328 perheestä ja 22 441 henkilöstä. Syövän perimäosuuden suhteellista ilmaantuvuutta mallinnettiin hierarkkisella bayesiläisellä Poisson-regressio sekamallilla, jossa sairastumisalttiuden vaihtelu jaettiin ympäristön, perimän ja ylihajonnan komponentteihin. Parametrien yhteisposteriorijakaumaa arvioitiin MCMC-otannan avulla JAGS-ohjelmalla. Lisäksi syöpien kertymistä tarkasteltiin estimoimalla sukulaisuussuhteiden mukaan ositettuja suhteellisia syöpäilmaantuvuuksia. Simulaatiotutkimuksella arvioitiin tilastollisen mallin satunnaiskomponenttien estimoituminen ja tarkasteltiin harhan korjauksen vaikutusta tutkimusasetelmaan. Rintasyöpäaineistossa nuorten syöpäpotilaiden perheenjäsenillä havaittiin 739 syöpää ja perheenjäsenten keskimääräinen syöpäriski oli 81% (95%:n todennäköisyysväli 68-94%) suurempi kuin vastaavalla väestöllä. Rintasyövän perimäosuus oli 26% (0-57%). Ruoansulatuselinten syöpiä havaittiin perheenjäsenillä 574 ja perheenjäsenten syöpäriski oli 60% (48-73%) suurempi kuin väestöllä ja sen perimäosuudeksi estimoitiin 63% (37-88%). Tutkielman tulosten mukaan ympäristötekijöiden merkitys rintasyöpäaineistossa on suuri. Vastaavasti ruoansulatuselinten syövissä ympäristötekijöiden merkitys on pienempi ja perimän osuus selvästi suurempi.

Sotilaan moraalisuus: Kyselytutkimus suomalaisten rauhanturvaajien asenteista käskyjen tottelemiseen

Tässä pro gradu -tutkielmassa selvitetään kyselytutkimuksen keinoin suomalaisten rauhanturvaajien käsityksiä sotilaan velvollisuudesta totella käskyjä moraalisesti tai laillisesti epäselvissä tilanteissa. Kyselyssä selvitetään, onko sotilas velvollinen tottelemaan käskyjä, jotka ovat vastoin tämän omaa moraalikäsitystä. Toisaalta kohdejoukolta kysytään mielipiteitä siihen, kuuluisiko sotilaan olla laillisessa vastuussa tekemistään sotarikoksista, mikäli rikos on tehty esimiehen käskystä. Tutkimuksen teoreettisena taustana on oikeutetun sodan teorian piirissä käyty debatti niin sanotun traditionaalisen ja moraalisen näkökulman välillä. Asetetut tutkimuskysymykset ovat: 1) Millaiset ovat näkemykset käskyjen tottelemisesta niiden suomalaisten sotilaiden joukossa, jotka todennäköisimmin joutuvat kosketukseen aseistetun vihollisen kanssa, ja 2) Mitkä taustatekijät vaikuttavat näihin näkemyksiin. Kohdejoukkona on vuosina 2006 ja 2007 KFOR-kriisinhallintaoperaatiossa palvellut suomalainen jääkärikomppania sekä vuosien 2012 ja 2013 aikana UNIFIL-operaatioon Libanoniin sijoitetun irlantilais-suomalaisen pataljoonan suomalaiskontingentti. Kyselyyn vastasi 211 rauhanturvaajaa. Tutkimuksen hypoteesit ovat (H1) Ne sotilaat, jotka identifioituvat voimakkaimmin sotilasyhteisöön, tottelevat käskyjä todennäköisimmin tilanteesta riippumatta, ja (H2) Hyvin koulutetut ja kokeneimmat sotilaat tottelevat varmimmin käskyjä moraalisesti epäselvissä tilanteissa, mutta kieltäytyvät tottelemasta laitonta käskyä. Hypoteesien testaamisessa selitettävinä muuttujina ovat vastaajien mielipiteet kolmeen esitettyyn väittämään, jotka koskevat sotilaan velvollisuutta totella käskyjä eri tilanteissa. Selittävinä muuttujina ovat yleisimpien sosiodemografisten muuttujien lisäksi esimerkiksi vastaajan viihtyminen sotilasyhteisössä, urasuuntautuminen, aikaisempi rauhanturvakokemus ja näkemys oman sotilaskoulutuksen riittävyydestä. Käytettävät tilastoanalyysimenetelmät ovat Spearmanin järjestyskorrelaatio ja ordinaalinen logistinen regressio. Analyysin tulokset antavat osittaista tukea asetetuille hypoteeseille. Suomalaisrauhanturvaajista suuri enemmistö ei ole valmiita tottelemaan sodan oikeussääntöjen vastaisia käskyjä, mutta mielipiteissä on huomattavaa hajontaa suhteessa yksilön omien moraalikäsitysten vastaisten käskyjen tottelemiseen. Vastaajan viihtymisellä sotilasyhteisössä on tilastollisesti merkitsevä yhteys taipuvaisuuteen totella käskyjä moraalisesti epäselvissä tilanteissa. Toisaalta analyysin tuloksista ilmenee, että ne sotilaat, jotka näkevät olevansa saamansa koulutuksen perusteella valmiita taistelu- ja kriisinhallintatehtäviin, eivät pidä esimiehen käskyä rikosoikeudellisesta vastuusta vapauttavana tekijänä, mikäli sotilas on käskyä noudattaessaan syyllistynyt sotarikokseen.

Essays on mixed-frequency data : forecasting and unit root testing

Doutoramento em Economia

Geographical literacy, attitudes, and experiences of freshman students: A qualitative study at Florida International University

The purpose of the study was to explore the geography literacy, attitudes and experiences of Florida International University (FIU) freshman students scoring at the low and high ends of a geography literacy survey. The Geography Literacy and ABC Models formed the conceptual framework. Participants were freshman students enrolled in the Finite Math course at FIU. Since it is assumed that students who perform poorly on geography assessments do not have an interest in the subject, testing and interviewing students allowed the researcher to explore the assumption. ^ In Phase I, participants completed the Geography Literacy Survey (GLS) with items taken from the 2010 NAEP Geography Subject Area Assessment. The low 35% and high 20% performers were invited for Phase II, which consisted of semi-structured interviews. A total of 187 students participated in Phase I and 12 in Phase II. ^ The primary research question asked was what are the geography attitudes and experiences of freshman students scoring at the low and high ends of a geographical literacy survey? The students had positive attitudes regardless of how they performed on the GLS. ^ The study included a quantitative sub-question regarding the performance of the students on the GLS. The students’ performance on the GLS was equivalent to the performance of 12th grade students from the NAEP Assessment. There were three qualitative sub-questions from which the following themes were identified: the students’ definition of geography is limited, students recall more out of school experiences with geography, and students find geography valuable. In addition, there were five emergent themes: there is a concern regarding a lack of geographical knowledge, rote memorization of geographical content is overemphasized, geographical concepts are related to other subjects, taking the high school level AP Human Geography course is powerful, and there is a need for real-world applications of geographical knowledge. ^ The researcher offered as suggestions for practice to reposition geography in our schools to avoid misunderstandings, highlight its interconnectedness to other fields, connect the material to real world events/daily decision-making, make research projects meaningful, partner with local geographers, and offer a mandatory geography courses at all educational levels.^

Performance determinants For Swedish Financial Monetary Institutions: Panel Data evidence between 2010-2014.

Due to the rapid changes that governs the Swedish financial sector such as financial deregulations and technological innovations, it is imperative to examine the extent to which the Swedish Financial institutions had performed amid these changes. For this to be accomplish, the work investigates what are the determinants of performance for Swedish Financial Monetary Institutions? Assumptions were derived from theoretical and empirical literatures to investigate the authenticity of this research question using seven explanatory variables. Two models were specified using Returns on Asset (ROA) and Return on Equity (ROE) as the main performance indicators and for the sake of reliability and validity, three different estimators such as Ordinary Least Square (OLS), Generalized Least Square (GLS) and Feasible Generalized Least Square (FGLS) were employed. The Akaike Information Criterion (AIC) was also used to verify which specification explains performance better while performing robustness check of parameter estimates was done by correcting for standard errors. Based on the findings, ROA specification proves to have the lowest Akaike Information Criterion (AIC) and Standard errors compared to ROE specification. Under ROA, two variables; the profit margins and the Interest coverage ratio proves to be statistically significant while under ROE just the interest coverage ratio (ICR) for all the estimators proves significant. The result also shows that the FGLS is the most efficient estimator, then follows the GLS and the last OLS. when corrected for SE robust, the gearing ratio which measures the capital structure becomes significant under ROA and its estimate become positive under ROE robust. Conclusions were drawn that, within the period of study three variables (ICR, profit margins and gearing) shows significant and four variables were insignificant. The overall findings show that the institutions strive to their best to maximize returns but these returns were just normal to cover their costs of operation. Much should be done as per the ASC theory to avoid liquidity and credit risks problems. Again, estimated values of ICR and profit margins shows that a considerable amount of efforts with sound financial policies are required to increase performance by one percentage point. Areas of further research could be how the individual stochastic factors such as the Dupont model, repo rates, inflation, GDP etc. can influence performance.

Development of Glomerella leaf spot is enhanced in virus-infected Maxi Gala apples.

Apples are commercially grown in Brazil in a subtropical environment that favors the development of fungal diseases such as Glomerella leaf spot (GLS) caused mainly by Glomerella cingulata (anamorph Colletotrichum gloeosporioides). The main objective of this work was to evaluate the effect of mixed infections by Apple stem grooving virus (ASGV) and Apple stem pitting virus (ASPV) on the infection and the colonization processes of C. gloeosporiodes in cv. Maxi Gala plants. Leaves of 16-month-old potted plants were spray-inoculated and both the disease incidence and lesion count were monitored over time and leaf severity was assessed in the final evaluation using an image analysis tool. Results showed that initial infection estimated from a monomolecular model fitted to progress of lesion count was higher and the incubation period (time to reach 50% incidence) was on average 10 h shorter in virus-infected plants compared to non-infected plants. It is hypothesized that initial events such as conidial germination and fungal penetration into plant cells were facilitated by the presence of viral infection. Also, final GLS severity was significantly higher in the virus-infected plants. Mixed infections by ASGV/ASPV seemed to make apple leaves more susceptible to the initial infection and colonization by C. gloeosporioides.

Active Control of the Acoustic Field in a Vehicle Cabin

In this thesis, a thorough investigation on acoustic noise control systems for realistic automotive scenarios is presented. The thesis is organized in two parts dealing with the main topics treated: Active Noise Control (ANC) systems and Virtual Microphone Technique (VMT), respectively. The technology of ANC allows to increase the driver's/passenger's comfort and safety exploiting the principle of mitigating the disturbing acoustic noise by the superposition of a secondary sound wave of equal amplitude but opposite phase. Performance analyses of both FeedForwrd (FF) and FeedBack (FB) ANC systems, in experimental scenarios, are presented. Since, environmental vibration noises within a car cabin are time-varying, most of the ANC solutions are adaptive. However, in this work, an effective fixed FB ANC system is proposed. Various ANC schemes are considered and compared with each other. In order to find the best possible ANC configuration which optimizes the performance in terms of disturbing noise attenuation, a thorough research of \gls{KPI}, system parameters and experimental setups design, is carried out. In the second part of this thesis, VMT, based on the estimation of specific acoustic channels, is investigated with the aim of generating a quiet acoustic zone around a confined area, e.g., the driver's ears. Performance analysis and comparison of various estimation approaches is presented. Several measurement campaigns were performed in order to acquire a sufficient duration and number of microphone signals in a significant variety of driving scenarios and employed cars. To do this, different experimental setups were designed and their performance compared. Design guidelines are given to obtain good trade-off between accuracy performance and equipment costs. Finally, a preliminary analysis with an innovative approach based on Neural Networks (NNs) to improve the current state of the art in microphone virtualization is proposed.

On making web accessibility more accessible: strategy and tools for social good

The world currently faces a paradox in terms of accessibility for people with disabilities. While digital technologies hold immense potential to improve their quality of life, the majority of web content still exhibits critical accessibility issues. This PhD thesis addresses this challenge by proposing two interconnected research branches. The first introduces a groundbreaking approach to improving web accessibility by rethinking how it is approached, making it more accessible itself. It involves the development of: 1. AX, a declarative framework of web components that enforces the generation of accessible markup by means of static analysis. 2. An innovative accessibility testing and evaluation methodology, which communicates test results by exploiting concepts that developers are already familiar with (visual rendering and mouse operability) to convey the accessibility of a page. This methodology is implemented through the SAHARIAN browser extension. 3. A11A, a categorized and structured collection of curated accessibility resources aimed at facilitating their intended audiences discover and use them. The second branch focuses on unleashing the full potential of digital technologies to improve accessibility in the physical world. The thesis proposes the SCAMP methodology to make scientific artifacts accessible to blind, visually impaired individuals, and the general public. It enhances the natural characteristics of objects, making them more accessible through interactive, multimodal, and multisensory experiences. Additionally, the prototype of \gls{a11yvt}, a system supporting accessible virtual tours, is presented. It provides blind and visually impaired individuals with features necessary to explore unfamiliar indoor environments, while maintaining universal design principles that makes it suitable for usage by the general public. The thesis extensively discusses the theoretical foundations, design, development, and unique characteristics of these innovative tools. Usability tests with the intended target audiences demonstrate the effectiveness of the proposed artifacts, suggesting their potential to significantly improve the current state of accessibility.