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Borsa Istanbul 100 Index, known as BIST100, is the main indicator to measure the performance of the 100 highest stocks publicly traded in Borsa Istanbul concerning market and trading volume. BIST 100 index prediction is a popular research domain for its complex data structure caused by stock price, commodity, interest rate and exchange rate effects. The study proposed hybrid models using both Genetic, Particle Swarm Optimization, Harmony Search and Greedy algorithms from metaheuristic algorithms approach for dimension reduction, and MARS for prediction.

This paper aims to model in the simplest way through metaheuristic algorithms hybridized with the MARS model the effects of stock, commodity, interest and exchange rate variables on BIST 100 during the Covid-19 pandemic period (in the process of closing) between January 2020 and June 2021.

The most suitable hybrid model was chosen as PSO & MARS by calculating the RMSE, MSE, GCV, MAE, MAD, MAPE and R2 measurements of training, test and overall dataset to check every model's efficiency. Empirical results demonstrated that the proposed PSO & MARS hybrid modeling procedure gave results both as good as the MARS model and a simpler and non-complex model structure.

Using metaheuristic algorithms as a supporting tool for variable selection can help to identify important independent variables and contribute to the establishment of more non-complex models.ing, test and overall dataset to check every model's efficiency.

This paper aims to discuss the complexities and foresight of Mars colonization. There are many pioneers competing in a space race to Mars, for example, Elon Musk – SpaceX, Jeff Bezos – Blue Origin and Richard Branson – Virgin Orbit. The analyses are focused on the aerospace industry – the process of space adventures to Mars.

This study offers new methodological approaches – the development of a complexity metric and system innovation mode – to analyze how the complexities relate to the systemic nature of innovation. The complexity metric and system innovation model can be applied in various industries. These analysis tools can help gain insights into the strategies for achieving the diffusion of commercial space.

The analyses of findings have shown that, despite various attempts among the pioneers in a space race to colonize Mars (Elon Musk – SpaceX, Jeff Bezos – Blue Origin and Richard Branson – Virgin Orbit, among others), the aerospace industry has not yet reached a stage of commercialization. The commercial space to Mars is of low systemic nature at present. Many companies compete in a space race to develop technologies on a proprietary basis. However, the highest complexity level suggests a multinational and intergovernmental collaboration to achieve economies of scale and economies of scope as well as accelerate the process of technology diffusion – successful commercial space for the interplanetary settlement.

The main contribution that shows originality and value of this paper is the development of a complexity metric and system innovation model which can be used to explore how the complexities relate to the systemic nature of innovation and how they relate to the strategies in managing technological innovations. The new methodological approaches can be used and applied to various industries.

This paper aims to explore the financing mechanisms towards Mars commercialisation and SpaceX’s Mars mission programme to achieve the interplanetary settlement. This study also suggests the path to avoid the failure of space commercialisation.

This research uses a case study methodology (Eisenhardt, 1989; Yin, 2013). The analysis is based on the construct of technology S-curves and attempts to answer the research question: What are the financing mechanisms to achieve successful aerospace financing for Mars mission? This research used semi-structured questionnaire and conducted 51 in-depth interviews. The interview data were supported by an examination of secondary data to provide a cross check on the validity of research (Yin, 2013). The research findings provide lessons and insights into the challenges of aerospace financing to Mars.

This study has shown that financing via cryptocurrency and initial coin offering as well as crowdfunding (particularly donation- and equity-based crowdfunding) provide promising financial solutions to achieve Mars commercialisation. The implementation of Mars programme demonstrates the fifth generation of innovation development model – systems integration and extensive networking model.

Given a dearth of study focusing on the links between S-curves and technology financing of aerospace commercialisation, this research study attempts to fill a gap in this neglected area with a focus on exploring the financing mechanisms towards Mars commercialisation.

This paper aims to identify computational thinking (CT) in 4th to 6th grade students in the context of project-based problem-solving while engaged in an after-school program.

This case study approach was selected due to its suitability for answering “how” or “why” questions about real-world phenomena within a set context (Creswell and Poth, 2018; Yin, 2018). This was an appropriate fit given the context of an after-school program and the research question asked how to identify learners’ demonstrated CT through project-based learning hands-on activities and problem-solving in a naturalistic environment.

Results show that heuristics, algorithms and conditional logic were observed more than other components of CT such as data collection, simulations and modeling. Descriptions of common activities in a naturalistic learning environment are presented to illustrate how the students practiced CT over time, which could help readers develop an understanding of CT in conjunction with hands-on problem-solving activities in elementary students. Identifying and classifying CT in this study focused on students’ learning process.

This study contributes to the challenging field of evaluating CT while focusing on observable behaviors and problem-solving activities with various degrees of teacher’s facilitation instead of final artifacts. Implications for researchers and educators interested in integrating CT in K-12 learning and its assessment are discussed.

An accurate prediction of the deformation of retaining structures is critical for ensuring the stability and safety of braced deep excavations, while the high nonlinear and complex nature of the deformation makes the prediction challenging. This paper proposes an explainable boosted combining global and local feature multivariate regression (EB-GLFMR) model with high accuracy, robustness and interpretability to predict the deformation of retaining structures during braced deep excavations.

During the model development, the time series of deformation data is decomposed using a locally weighted scatterplot smoothing technique into trend and residual terms. The trend terms are analyzed through multiple adaptive spline regressions. The residual terms are reconstructed in phase space to extract both global and local features, which are then fed into a gradient-boosting model for prediction.

The proposed model outperforms other established approaches in terms of accuracy and robustness, as demonstrated through analyzing two cases of braced deep excavations.

The model is designed for the prediction of the deformation of deep excavations with stepped, chaotic and fluctuating features. Further research needs to be conducted to expand the model applicability to other time series deformation data.

The model provides an efficient, robust and transparent approach to predict deformation during braced deep excavations. It serves as an effective decision support tool for engineers to ensure the stability and safety of deep excavations.

The model captures the global and local features of time series deformation of retaining structures and provides explicit expressions and feature importance for deformation trends and residuals, making it an efficient and transparent approach for deformation prediction.

The gender composition of teams remains an important yet complex element in unlocking the success of collaboration and performance in the metaverse. In this study, the authors examined the collaborations of same- and mixed-gender dyads to investigate how gender composition influences perceptions of the dyadic collaboration process and outcomes at both the individual and team levels in the metaverse.

Drawing on expectation states theory and social role theory, the authors hypothesized differences between dyads of different gender compositions. A blocked design was utilized where 432 subjects were randomly assigned to teams of different gender compositions: 101 male dyads, 59 female dyads and 56 mixed-gender dyads. Survey responses were collected after the experiment.

Multilevel multigroup analyses reveal that at the team level, male dyads took on the we-impress manifestation to increase satisfaction with the team solution. In contrast, female and mixed-gender dyads adopted the we-work-hard-on-task philosophy to increase satisfaction with the team solution. At the individual level, impression management is the key factor associated with trust in same-gender dyads but not in mixed-gender dyads.

As one of the pioneering works on gender effects in the metaverse, our findings shed light on two fronts in virtual dyadic collaborations. First, the authors offer a theoretically grounded and gendered perspective by investigating male, female and mixed-gender dyads in the metaverse. Second, the study advances team-based theory and deepens the understanding of gender effects at both the individual and team levels (multilevel) in a virtual collaboration environment.

This study, a conceptual paper, analyses the growth of curation in tourism and hospitality and the curator role in selecting and framing products and experiences. It considers the growth of expert, algorithmic, social and co-creative curation modes and their effects.

Narrative and integrative reviews of literature on curation and tourism and hospitality are used to develop a typology of curation and identify different curation modes.

Curational techniques are increasingly used to organise experience supply and distribution in mainstream fields, including media, retailing and fashion. In tourism and hospitality, curated tourism, curated hospitality brands and food offerings and place curation by destination marketing organisations are growing. Curation is undertaken by experts, algorithms and social groups and involves many of destination-related actors, producing a trend towards “hybrid curation” of places.

Research is needed on different forms of curation, their differential effects and the power roles of different curational modes.

Curation is a widespread intermediary function in tourism and hospitality, supporting better consumer choice. New curators influence experience supply and the distribution of consumer attention, shaping markets and co-creative activities. Increased curatorial activity should stimulate aesthetic and stylistic innovation and provide the basis for storytelling and narrative in tourism and hospitality.

This is the first study of curational strategies in tourism and hospitality, providing a definition and typology of curation, and linking micro and macro levels of analysis. It suggests the growth of choice-based logic alongside service-dominant logic in tourism and hospitality.

The purpose of this paper is to investigate the extent to which interdisciplinary (HASS, i.e. non-STEM) factors—in particular, accounting, stakeholder management and accountability—enable, influence and motivate large human exploration ventures, principally in maritime and space fields, utilizing Columbus’s and Chinese explorations of the 1400s as the primary setting.

The study analyzes archival data from narrative and interpretational history, including both academic and non-academic sources, that relate to two global historical events, the Columbus and Ming Chinese exploration eras (c. 1400–1500), as a parallel to the modern “Space Race”. Existing studies on pertinent HASS (Humanities and Social Sciences) and STEM (Science, Technology, Engineering and Mathematics) enablers, influencers and motivators are utilized in the analysis. The authors draw upon the concepts of stakeholder theory and the construct of accountability in their analysis.

Findings suggest that non-STEM considerations—politics, finance, accountability, culture, theology and others—played crucial roles in enabling Western Europe (Columbus) to reach the Americas before China or other global powers, demonstrating the pivotal importance of HASS factors in human advancements and exploration.

In seeking to answer those questions, this study identifies only those factors (HASS or STEM) that may support the success or failure in execution of the exploration and development of a region such as the New World or Space. Moreover, the study has the following limitation. Relative successes, failures, drivers and enablers of exploratory ventures are drawn almost exclusively from the documented historical records of the nations, entities and individuals (China and Europe) who conducted those ventures. A paucity of objective sources in some fields, and the need to set appropriate boundaries for the study, also necessitate such limitation.

It is observable that many of those HASS factors also appear to have been influencers in modern era Space projects. For Apollo and Soyuz, success factors such as the relative economics of USA and USSR, their political ideologies, accountabilities and organizational priorities have clear echoes. What the successful voyages of Columbus and Apollo also have in common is an appetite to take risks for an uncertain return, whether as sponsor or voyager; an understanding of financial management and benefits measurement, and a leadership (Isabella I, John F. Kennedy) possessing a vision, ideology and governmental apparatus to further the venture’s goals.

Whilst various historical studies have examined influences behind the oceangoing explorations of the 1400s and the colonization of the “New World”, this article takes an original approach of analyzing those motivations and other factors collectively, in interdisciplinary terms (HASS and STEM). This approach also has the potential to provide a novel method of examining accountability and performance in modern exploratory ventures, such as crewed space missions.

Using coconut shell aggregates (CSA) in concrete benefits agricultural waste management and reduces the demand for mineral resources. Several studies have found that concrete containing CSA can achieve strengths that are comparable to regular concrete. The purpose of the present work is to evaluate the concrete’s durability-related properties to supplement these earlier findings.

Cylindrical specimens were prepared with a constant water–cement ratio of 0.50 and CSA content ranging from 0% to 50% (at 10% increment) by volume of the total coarse aggregates. The specimens were cured for 28 days and then tested for density, surface hardness, electrical resistivity and water sorptivity. The surface hardness was measured to describe the concrete resistance to surface wearing, while the resistivity and sorptivity were evaluated to describe the material’s resistance to fluid penetration.

The results showed that the surface hardness of concrete remained on average at 325 Leeb and did not change significantly with CSA addition. The distribution of surface hardness was also similar across all CSA groups, with the interquartile range averaging 59 Leeb. These results suggest that the cement paste and gravel stiffness had a more pronounced influence on the surface hardness than CSA. On the other hand, concrete became lighter by about 9%, had lower resistivity by 80% and had significantly higher initial sorptivity by up to 110%, when 50% of its natural gravel was replaced with CSA. Future work may be done to improve the durability of CSA when used as coarse aggregate.

The present study is the first to show the lack of correlation between CSA content and surface hardness. It would mean that the surface hardness test may not completely capture the porous nature of CSA-added concrete. The paper concludes that without additional treatment prior to mixing, CSA may be limited only to applications where concrete is not in constant contact with water or deleterious substances.