Technical Perspective Research Articles

Design and analysis of an ideal scramjet flowpath

The current work presents a novel conceptual framework for the fluid and gasdynamics that govern the design and performance of an ideal scramjet flowpath. These include a theoretical comparison between ram and scram modes, the physics of thrust loss during inlet unstart, and the design of an optimal scramjet flowpath. We present a unique explicit, closed-form relation for the wall divergence of an ideal scramjet combustor. The accompanying derivations and discussions, which leverage this formulation, seek to address uncertainties and misconceptions regarding the dominant fluid processes present in these engines. It is shown that scram and ram modes exhibit theoretical similitude for maximum thrust potential at conditions beyond the one-dimensional Rayleigh choking limit but can diverge below the global choking threshold. Additionally, it is shown that even for an ideal scramjet heat engine cycle, thermodynamic efficiencies at various flight conditions deviate from those of the classical Brayton cycle. These insights and accompanying theoretical analyses are meant to establish a foundation for the thermodynamics and gasdynamics relevant to the performance of dual-mode scramjet engines. The resulting work offers an intuitive technical perspective on supersonic combustion and the fundamentals of dual-mode scramjet operation that can be applied across a wide range of scramjet-related experimental and computational studies and design efforts in the future.

Understanding institutional layers and modes of change for energy transitions: Analysis of Norway's electricity sector reforms

AbstractInstitutions have significant implications for whether and how energy systems restructure, evolve, and successfully transition. Yet, literature analyzing energy sector reforms often approach transitions from economic or technical perspectives, with much less attention to the underlying roles and influences of institutions. This paper explores the roles and influence of institutions on the speed, direction, timing, and sequence of energy transitions. A conceptual framework integrating the hierarchy of institutions with an historical institutionalist approach is developed and applied to explore transitions in Norway's electricity sector as a case study. Results show that conversion followed by layering emerge as the dominant modes of institutional change in Norway's electricity sector reform, illustrating the importance of alignment between institutions in creating the conditions for large‐scale energy transitions and the importance of boundaries to maintain alignment between levels of institutions. Governments can minimize potential gaps between transition intentions and outcomes through effective conversion and layering of institutional arrangements, but layering challenges emerge when institutional change introduces new actors or energy arenas to existing policy paradigms.

Technical Perspective: Hiding Secrets in Programs

Technical Perspective: Hiding Secrets in Programs

Formalizing ethical principles within AI systems: experts’ opinions on why (not) and how to do it

AbstractAI systems are increasingly put into contexts where computed decisions must be guided by ethical considerations. To develop ethically grounded algorithms and technologies, scholars have suggested computational ethics as an essential frontier, which aims to translate ethical principles into computer code. However, computational ethics has received little attention in academic literature so far, with existing work mainly focusing on its technical implementation, while many open questions concerning its (societal and ethical) implications still need to be resolved. Therefore, in this study, we interviewed 12 experts from philosophy, AI and cognitive sciences to shed light on computational ethics beyond a technical perspective. Findings suggest that indicated supporting and opposing arguments can be clustered into pragmatic/practical, societal and epistemic reasons, all of which need to be contemplated when engaging in computational ethics and developing resulting artificial moral agents. Furthermore, the mentioned recommendations for companies’ technological design and development, for industry’s governance measures and academia’s research endeavors are recapitulated and summarized in a holistic framework that aims to facilitate a reflected implementation of ‘ethics in and by design’ in the future.

Assessing Malaysia’s Internet of Things (IoT) Readiness Based On CREATE-IoT Key Performance Indicators

The current nationwide deployment of Internet of Things (IoT) in Malaysia has never been assessed nor benchmarked against any Key Performance Indicators (KPIs). A proven IoT assessment standard called CREATE-IoT has successfully driven IoT projects in European countries, and it is hence used as a benchmarking tool in this research. The assessment that includes both technical and business perspectives concludes that 42 out of 50 KPIs (84%) in Malaysia are in the advanced state. Malaysia is thus rated as an IoT-ready country. However, rooms for improvement exist in the scopes of providing expected duration for completing an IoT service transaction to predict the level of customer satisfaction when using the service – and the ability to produce IoT sensors and devices locally to have sustainable, scalable, and economical continuous IoT deployments.

Project development methodologies applied to capital projects focused on non-renewable and renewable energy sources: bibliometric analysis

This article aims to demonstrate the main results of bibliometric analysis related to current publications that disclose the energy transition from fossil sources, primarily natural gas, to renewable sources. It also covers publications involving the production of gaseous fuels such as biogas, biomethane, synthetic natural gas, and synthesis gas derived from biomass. Additionally, it explores how these topics relate to recent economic organization concepts, such as Circular Economy, Industrial Ecology, Short Supply Chain, etc. Notably, the article presents methodologies from a technical, economic, and financial perspective for the development of capital projects in this sector. These methodologies are widely used in academic research and development but may not necessarily align with established market practices.

Lean Technical Factors and Customer Relations: An Assessment of Readiness to Deploy Lean Manufacturing within SMEs

The study aims to assess lean readiness level within manufacturing SMEs from technical perspective by examining the relationship between process management and planning & control on customer relations. The research applied quantitative survey approach by administering questionnaire to SMEs managers. Responses received were analyzed using SMART-PLS 4 to examine measurement model, structural model, and path coefficient. The findings of the study show that process management and planning & control have a positive and significant relationship on customer relations. The study implies that manufacturing SMEs in Nigeria have an appreciable lean readiness from technical perspective. It also indicates that processes, planning and control activities within SMEs are compatible with lean practices and techniques. The study is among the few that assess lean readiness from technical perspective, hence given a new insight in evaluation of lean readiness

Optimal performance of stand-alone hybrid microgrid systems based on integrated techno-economic-environmental energy management strategy using the grey wolf optimizer.

Recently, global interest in organizing the functioning of renewable energy resources (RES) through microgrids (MG) has developed, as a unique approach to tackle technical, economic, and environmental difficulties. This study proposes implementing a developed Distributable Resource Management strategy (DRMS) in hybrid Microgrid systems to reduce total net percent cost (TNPC), energy loss (Ploss), and gas emissions (GEM) while taking the cost-benefit index (CBI) and loss of power supply probability (LPSP) as operational constraints. Grey Wolf Optimizer (GWO) was utilized to find the optimal size of the hybrid Microgrid components and calculate the multi-objective function with and without the proposed management method. In addition, a detailed sensitivity analysis of numerous economic and technological parameters was performed to assess system performance. The proposed strategy reduced the system's total net present cost, power loss, and emissions by (1.06%), (8.69%), and (17.19%), respectively compared to normal operation. Firefly Algorithm (FA) and Particle Swarm Optimization (PSO) techniques were used to verify the results. This study gives a more detailed plan for evaluating the effectiveness of hybrid Microgrid systems from a technical, economic, and environmental perspective.

An assessment framework for underground construction methods in the pre-construction stage: a technical perspective

The selection of an appropriate underground construction method plays a crucial role during the pre-construction phase as it must consider various aspects, such as safety, technical feasibility, and cost-effectiveness. However, there is still a lack of technical assessments for selecting suitable underground construction methods in the research field. Therefore, this study aims to build an assessment model to technically assess such methods in the pre-construction stage. Firstly, technical assessment factors were obtained from literature reviews, expert consultations and survey results. Factor analysis was performed to reveal the underlying significance of each factor. The Fuzzy Analytic Hierarchy Process (Fuzzy AHP) model was then constructed to assess the relative importance of each factor. Finally, the assessment model was validated by seeking experts’ opinions on its performance in a practical project. The study resulted in a Fuzzy AHP model established from a list of 8 groups of factors with 35 refined factors, covering many aspects from documents and resources to geology and hydrology. The validation results demonstrated the model’s effectiveness in assisting contractors to make informed decisions. This study has contributed to construction literature by introducing a novel framework for underground construction methods, offering a practical tool for pre-construction planning and decision-making.

Quantitative MR Image Reconstruction Using Parameter-Specific Dictionary Learning With Adaptive Dictionary-Size and Sparsity-Level Choice.

We propose a method for the reconstruction of parameter-maps in Quantitative Magnetic Resonance Imaging (QMRI). Because different quantitative parameter-maps differ from each other in terms of local features, we propose a method where the employed dictionary learning (DL) and sparse coding (SC) algorithms automatically estimate the optimal dictionary-size and sparsity level separately for each parameter-map. We evaluated the method on a T1-mapping QMRI problem in the brain using the BrainWeb data as well as in-vivo brain images acquired on an ultra-high field 7 T scanner. We compared it to a model-based acceleration for parameter mapping (MAP) approach, other sparsity-based methods using total variation (TV), Wavelets (Wl), and Shearlets (Sh) to a method which uses DL and SC to reconstruct qualitative images, followed by a non-linear (DL+Fit). Our algorithm surpasses MAP, TV, Wl, and Sh in terms of RMSE and PSNR. It yields better or comparable results to DL+Fit by additionally significantly accelerating the reconstruction by a factor of approximately seven. The proposed method outperforms the reported methods of comparison and yields accurate T1-maps. Although presented for T1-mapping in the brain, our method's structure is general and thus most probably also applicable for the the reconstruction of other quantitative parameters in other organs. From a clinical perspective, the obtained T1-maps could be utilized to differentiate between healthy subjects and patients with Alzheimer's disease. From a technical perspective, the proposed unsupervised method could be employed to obtain ground-truth data for the development of data-driven methods based on supervised learning.

Toward a Comprehensive Evaluation on the Online Methods for Monitoring Transformer Turn-to-Turn Faults

Transformer winding turn-to-turn fault is the prominent cause of transformer total failure, so detecting the winding fault in real time to stop the failure development in advance is imperative. However, existing techniques entailing periodic offline inspections fail to continuously monitor transformer winding states while causing extra costs due to the outage during inspections. This has driven researchers to consider effective continuous online monitoring methods from several technical perspectives, including typically port voltage current analysis, online frequency response analysis, and vibration analysis. Since these methods are conventionally evaluated with qualitative comparisons focusing only on feasibility, quantitative assessments indispensable for the targeted improvement of the methods and the most suitable method decision in specific scenarios are still missing. To this end, we conduct a comprehensive evaluation on the three methods by leveraging both experiment and theoretical analysis. Specifically, a customized experiment platform has been designed to support data acquisition under different operating conditions. As conventional feature mining algorithms cannot process the monitoring data produced by different methods in a uniform manner, a feature extraction algorithm leveraging image mining is proposed to extract data features after mapping the test data into a high-dimensional image. This novel algorithm allows us to fully assess several fundamental aspects (i.e., sensitivity, repeatability, and anti-interference capability) of these monitoring methods.

Cooperative Exploration Model of Coal–Gallium Deposit: A Case Study of the Heidaigou Coal–Gallium Deposit in the Jungar Coalfield, Inner Mongolia, China

Gallium (Ga) is a typical scattered trace element that is irreplaceable in strategic sectors such as national defense, wireless communications, new materials, renewable energy, and healthcare. The coal–Ga deposit is an important complement to traditional Ga resources and has become a significant focus for Ga mineral resource exploration. Therefore, there is an urgent need to research the coal–Ga cooperative exploration model from both technical and economic perspectives. Taking the Heidaigou coal–Ga deposit as an example, the enrichment zone of coal–Ga is predominantly situated in the northern part of the exploration area, adjacent to the fault zone. The Ga concentration demonstrates a gradual decline from the north–central region towards the northeast and southeast. Similar vertical Ga distribution patterns are observed in adjacent drillings, with notably higher concentrations in the roof, floor, and parting layers. The cooperative exploration model for coal–Ga deposits is proposed based on the above features. The model employs a comprehensive set of cooperative technical methods, such as remote sensing, geological mapping, seismic exploration, drilling, petrogeochemistry, and well logging. The layout of exploration engineering and the concentration of Ga provide the basis for the estimation of Ga resources. Additionally, the model provides an important scientific basis for the improvement of the strategic coordination ability of Ga mineral resources.

Analysis of carbon neutrality technology path selection in the steel industry under policy incentives

As an energy-intensive industry, the steel industry incentivizes carbon neutrality technology innovation through carbon neutrality policies, thereby promoting the industry's low-carbon transformation. However, how policy promotes technological innovation in the steel industry to achieve net zero emissions is an urgent practical and theoretical problem that needs to be solved. This study constructs a comprehensive model that combines steel demand forecasting, technology evaluation, and bottom-up technology selection models. Described the cost-effectiveness of emission reduction technologies from a technical and economic perspective, quantitatively analyzed the emission reduction potential and evolution path of carbon neutrality technology under policy incentives in the steel industry, and provided policy support and specific deployment time for different technologies. The results indicate that under the scenario of strong subsidies and carbon prices, by 2060, the share of traditional long-process steelmaking was only 25 %, and the CO2 emissions per unit of crude steel were 0.88t CO2/t. At the same time, the implementation of policies has increased the cumulative emission reduction of the steel industry by 1.56 times from 2022 to 2060.

Handbike for Daily Use, Sport, and Rehabilitation Purposes: A Literature Review of Actuation and Technical Characteristics

With respect to alternative devices like traditional wheelchairs, handbikes can offer advantages from biomechanical and physiological perspectives, to several kinds of users. Assuring high mechanical efficiency and homogeneous force distributions along cycles, and being suitable for indoor and outdoor activities, these systems are used for rehabilitation, sports, and daily applications. From a technical perspective, their main characteristics can vary with the device final purpose and operational context. This review aims to provide an overall outline of handbikes in the literature from a general and comprehensive point of view, up until 2022. The analysis is performed (i) with a systematic approach, without a priori limitations on document type and content focus, and (ii) to identify the areas of interest for the scientific development of these systems. A systematic evaluation method for the identification and analysis of the documents was designed and implemented and the selection criteria, as well as the rationale for the procedure, are described. A specific taxonomy was defined and applied for the subsequent analysis, and each category is specifically evaluated and described, detailing the main outcomes of the literature analysis and relative discussion. Particular attention is paid to actuation strategies and propulsion efficiency. Finally, the main results of the work and future developments for handbikes are briefly synthesized.

Elucidating Discrepancy in Explanations of Predictive Models Developed Using EMR.

The lack of transparency and explainability hinders the clinical adoption of Machine learning (ML) algorithms. While explainable artificial intelligence (XAI) methods have been proposed, little research has focused on the agreement between these methods and expert clinical knowledge. This study applies current state-of-the-art explainability methods to clinical decision support algorithms developed for Electronic Medical Records (EMR) data to analyse the concordance between these factors and discusses causes for identified discrepancies from a clinical and technical perspective. Important factors for achieving trustworthy XAI solutions for clinical decision support are also discussed.

Feasibility Study of Establishing a PV Power Plant to Generate Electricity in Saudi Arabia from Technical, Geographical, and Economical Viewpoints

PV power plants have been built the world over, and successfully proven as one of the important substitutes of alternative energy. Nowadays, there has been some series of movements in Saudi Arabia to find out solutions. This research aims to study the feasibility of design and construction of solar power plant using photovoltaic cells in Saudi Arabia from the geographic, economic and technical perspective.

Cost Benefit Analysis to select clean energy solutions in dairy farm milk collection posts in Azores.

The aim of this paper is to evaluate the possibility of implementation of alternative renewable energy micro-generation installations in dairy farm milk collection posts, from the technical, economical and environmental perspectives. This work was performed through a dairy farm milk collection post energy audit, to perform energy profile characterization and demand requirements. Following that, a study of the weather conditions was done and the obtained data (through CLIMAAT and MacSIMAR projects) [11] was introduced in a renewable energy solutions calculator (HOMER). Moreover, a system design from the available portfolio of micro-generation devices was defined and a cost benefit analysis of the selected alternatives was done. In the end a comparison of the current implemented solution with alternative designs was performed. Results show that from the analyzed solutions for this case, the set of PV (20Kw) and Wind (3KW) with no batteries is the best one, since it presents the least cost of energy, the smallest initial capital and the highest Net Present Cost. The sensitivity analysis derive that wind micro-turbines should be installed except if the solar radiation is on its maximum value and that in no case the use of batteries is an advantage for the system operation. For systems requiring a certain degree of energy (in this case with an average of 350 kW/day), the implementation of micro generation systems, like the ones evaluated, will never be economically viable in terms of Total Economic Value, even with generous feed-in tariff schemes. It is preferable that the grid operator makes investments in renewable energy production. To improve the system energy performance, the options should be focused on energy efficiency measures.

Current Status and Analysis of the Clinical Application of Digital Technology in Oral Medicine

With the increasing maturity and popularization of digital technology in oral medicine, its application has now expanded to various clinical subspecialties of oral medicine. Digitalization has become one of the important development directions of oral medicine. What is the current development status of digital technology in oral medicine? In what ways is digital technology applied across various clinical specialties of oral medicine? Dentists are particularly concerned about these issues in their clinical work and research. In this paper, all the digital technologies applied in oral medicine are organized and categorized from a technical perspective. In this paper, we focused on presenting three-dimensional data acquisition technology, dental computer-aided design technology, dental computer-aided processing technology, and oral surgery implementation technology. Their technical principles, technical characteristics, applications in oral medicine, a secondary discipline of medicine, and the development status of domestically-developed technology are described and reviewed in detail. The other technologies such as oral digital materials, oral virtual simulation teaching, and oral multi-source data management are briefly discussed. We intend to provide references for dentists to apply digital technology in clinical practice and research.

Studi Kelayakan Bisnis Pada Pengembangan Usaha King MuayThai Camp Bandung

Muay Thai is a martial art originating from Thailand called "The Art of Eight Limbs". This research examines whether the development of the King Muay Thai business is feasible from a marketing perspective, whether the development of the King Muay Thai business is feasible from a technical and operational perspective, whether the development of the King Muay Thai business is technically feasible and operationally feasible. feasible from an organizational and management point of view, if the commercial development of King Muay Thai is feasible from a financial point of view. The aim to be achieved in this research is to produce a commercially viable plan through implementation aspects, from the marketing strategy aspect used by King Muaythai Camp, the implementation of operational technical aspects carried out at King Muaythai Camp, organizational structure management. aspects of survival at King Muaythai Camp and business feasibility with a focus on financial aspects at King Muaythai Camp Bandung. This research uses a quantitative method where we conducted direct interviews with the owner of King Muaythai Camp to obtain information on marketing aspects, technical and operational aspects, organizational and management aspects, and financial aspects at King Muaythai Camp.

Comparative analysis of cold in-place recycling for roadway maintenance and rehabilitation from the perspectives of technical-cost-environmental nexus

Cold-in-place recycling (CIR) is a sustainable road pavement maintenance technology for its on-site operation and complete reuse of reclaimed asphalt pavement. However, its sustainable performance has not been thoroughly investigated. This study aims to systematically assess and compare CIR against three alternative maintenance technologies from technical, cost and environmental perspectives, specially taking into account different numbers of repaired layers. The technical improvement in full-depth loading resistance is evaluated using a newly developed multi-sequenced repeated load (MSRL) test. Environmental impacts are assessed through life cycle assessment (LCA), while cost analysis is conducted using life cycle cost analysis (LCCA), with consistent system boundary applied. Additionally, a nexus analysis is performed using a modified Boston Consulting Group (BCG) matrix to comprehensively examine the sustainable performance of different treatments and further explore the synergies and trade-offs among various assessment aspects. The multi-dimensional sustainable assessment results reveal the influence factors in each perspective. Final BCG matrix shows that CIR can achieve the comparable technical performance to the conventional maintenance treatment, while reducing GHG emissions by 60.8% and cost by 45.8%. The methodology and findings of this study are expected to provide helpful insights for decision-makers in reducing negative impacts and promoting integrated management for sustainability.