Functional Requirements Research Articles

A novel method of refining the performance of rail systems: an evaluation of system dynamics using discrete event simulation

PurposeThis paper aims to trial a novel method of improving the performance of rail systems. Accordingly, an evaluation of rail system dynamics (SD) using discrete event simulation (DES) will be undertaken. Globally, cities and their transportation systems face ongoing challenges with many of these resulting from complicated rail SD. To evaluate these challenges, this study utilized DES as the basis of the analysis of Melbourne Metro Rail's SD. The transportation SD processes including efficiency and reliability were also developed.Design/methodology/approachUsing DES, this research examines and determines the Melbourne Metro Rail's SD. Although the Melbourne Metro Rail is still in progress, the DES developed in this research examined the system requirements of functionality, performance and integration. As the basis of this examination, the Melbourne Metro Rail's optimization was simulated using the developed DES. As the basis of the experiment, a total of 50 trials were simulated. This included 25 samples for each of efficiency and reliability. The simulation not only scrutinized the SD but also underlined some of its shortfalls.FindingsThis study found that information and communication technology (ICT) was the pinnacle of system application. The DES development highlighted that both efficiency and reliability rates are the essential SD and thus fundamental for Melbourne Metro Rail system functionality. Specifically, the three elements of SD, capacity, continuity and integration are considered critical in improving the system functionality of Melbourne Metro Rail.Research limitations/implicationsThis particular mega rail infrastructure system was carefully analyzed, and subsequently, the DES was developed. However, since the DES is at its inception, the results are relatively limited without inclusive system calibration or validation process. Nonetheless, with some modifications, such as using different KPIs to evaluate additional systems variables and setting appropriate parameters to test the system reliability measures at different intensities, the developed DES can be modified to examine and evaluate other rail systems. However, if a broader system analysis is required, the DES model subsequently needs to be modified to specific system parameters.Practical implicationsThrough evaluation of Melbourne's Metro Rail in the manner described above, this research has shown the developed DES is a useful platform to understand and evaluate system efficiency and reliability. Such an evaluation is considered important when implementing new transport systems, particularly when they are being integrated into existing networks.Social implicationsEfficient rail networks are critical for modern cities and such systems, while inherently complex, aid local economies and societal cohesion through predictable and reliable movement of people. Through improved system functionality and greater efficiencies, plus improved passenger safety, security and comfort, the traveling public will benefit from the enhanced reliability of the transportation network that results from research as that provided in this paper.Originality/valueThis research paper is the first of its kind specifically focusing on the application of DES on the Melbourne Metro Rail System. The developed model aligns with the efficiency optimization framework, which is central to rail systems. The model shows the relationship between increased efficiency and optimizing system reliability. In comparison with more advanced mathematical modeling, the DES presented in this research provides robust, but yet rapid and uncomplicated system enhancements. These findings can better prepare rail professionals to adequately plan and devise appropriate system measures.

Discrepancies of Functional Requirements of Façade Opening System between Real-Life Public and Built Environment Experts Focusing on Thermal Comfort and Ventilation

A survey was conducted to analyze the discrepancies of the functional requirements of the façade system in residential units among 605 of the real-life public and 73 experts. Personal and housing information, resident life patterns, public façade usage behavior, and functional requirements were collected from the respondents. Both the public and experts recognized insulation as the main function of façade opening systems. More than 85% of the public and experts opened windows for ventilation, but ventilation was ranked 3rd amongst the public and 4th amongst experts in the main functions list of façade systems. The public cited the inflow of fine dust as the main reason for dissatisfaction with opening windows. In contrast, the experts cited a decrease in thermal comfort due to the inflow of external moisture as the reason for dissatisfaction with opening windows. The results showed that discrepancies exist between the public and experts’ perceptions of the main function of housing façade systems. Analyzing the common points and differences between the public and experts’ perception can help in developing façade system design and control technology.

Functional-Combination-Based Comprehensive Benefit Evaluation of Energy Storage Projects under Source-Grid-Load Scenarios via Super-Efficiency DEA

As an important support for power systems with high penetration of sustainable energy, the energy storage system (ESS) has changed the traditional model of simultaneous implementation of electricity production and consumption. Its installed capacity under the source-grid-load scenario is rising year by year, contributing to sustainable development, but it faces the problems of insufficient utilization and benefits. This study analyzes the functional combination of ESS under source-grid-load scenarios. A comprehensive benefit evaluation method of energy storage projects (ESPs), based on a fuzzy decision-making trial and evaluation laboratory (DEMATEL) and super-efficiency data envelopment analysis (DEA), is proposed. Firstly, the functional requirements of energy storage in source-grid-load scenarios are explored, and the characteristics of various functions are analyzed to form eight functional combination schemes. Secondly, index modeling is carried out from three aspects—the whole life cycle cost, functional combination benefits, and social and environmental benefits—and a comprehensive benefit evaluation index system of ESP is proposed. Then, the intuitionistic trapezoidal fuzzy number (ITFN) is combined with DEMATEL to form an effective analysis method for the input–output relationship of the indices, and the comprehensive evaluation is realized based on the SE-DEA model. Compared with other methods, this model can ensure the objectivity and stability of the evaluation results in ESP evaluation. Finally, the effectiveness of the proposed evaluation method and the rationality of the functional combination are verified under source-grid-load scenarios. The calculation results show that in the application scenario of source-grid-load, after adopting the functional combination scheme formulated in this article, the comprehensive investment benefits of ESPs have been improved. Moreover, the source side effect is at its best, with an efficiency value of 2.209.

Conceptual design of shore station for an innovative waste collecting vessel

Marine environment protection legislation in the EU requires ships to return waste they generate on voyages to waste-reception facilities in ports. In many harbors there is a need to expand the port infrastructure to enable the operation of Waste Collecting Vessels (WCVs). In addition, these vessels can perform new functions of cleaning port basins and adjacent waterways. A novelty in the presented research on the conceptual design of the shore station is the inclusion of new requirements for an autonomy and modularization of the vessel. The shore station was designed in the form of a floating pontoon, taking into account the various functional requirements addressed in the ship's conceptual design stage. The pontoon consists of modules corresponding to the ship segments moored in them. The conceptual design was intentionally defined in a generalized form to allow for further development and adaptation to local requirements at individual ports.

Analysis and design framework for the development of indoor scene understanding assistive solutions for the person with visual impairment/blindness

This paper discusses the challenges of the current state of computer vision-based indoor scene understanding assistive solutions for the person with visual impairment (P-VI)/blindness. It focuses on two main issues: the lack of user-centered approach in the development process and the lack of guidelines for the selection of appropriate technologies. First, it discusses the needs of users of an assistive solution through state-of-the-art analysis based on a previous systematic review of literature and commercial products and on semi-structured user interviews. Then it proposes an analysis and design framework to address these needs. Our paper presents a set of structured use cases that help to visualize and categorize the diverse real-world challenges faced by the P-VI/blindness in indoor settings, including scene description, object finding, color detection, obstacle avoidance and text reading across different contexts. Next, it details the functional and non-functional requirements to be fulfilled by indoor scene understanding assistive solutions and provides a reference architecture that helps to map the needs into solutions, identifying the components that are necessary to cover the different use cases and respond to the requirements. To further guide the development of the architecture components, the paper offers insights into various available technologies like depth cameras, object detection, segmentation algorithms and optical character recognition (OCR), to enable an informed selection of the most suitable technologies for the development of specific assistive solutions, based on aspects like effectiveness, price and computational cost. In conclusion, by systematically analyzing user needs and providing guidelines for technology selection, this research contributes to the development of more personalized and practical assistive solutions tailored to the unique challenges faced by the P-VI/blindness.

The Analysis of Intelligent Functions Required for Inland Ships

Sorting out the requirements for intelligent functions is the prerequisite and foundation of the top-level design for the development of intelligent ships. In light of the development of inland intelligent ships for 2030, 2035, and 2050, based on the analysis of the division of intelligent ship functional modules by international representative classification societies and relevant research institutions, eight necessary functional modules have been proposed: intelligent navigation, intelligent hull, intelligent engine room, intelligent energy efficiency management, intelligent cargo management, intelligent integration platform, remote control, and autonomous operation. Taking the technical realization of each functional module as the goal, this paper analyzes the status quo and development trend of related intelligent technologies and their feasibility and applicability when applied to each functional module. At the same time, it clarifies the composition of specific functional elements of each functional module, puts forward the stage goals of China’s inland intelligent ship development and the specific functional requirements of different modules under each stage, and provides reference for the Chinese government to subsequently formulate the top-level design development planning and implementation path of inland waterway intelligent ships.

Microstructure evolution and local mechanical properties of friction stir additively manufactured (FSAM) AA5083/AA6061/AA7075 gradient composite.

The current study is focused on the successful fabrication and characterization of microstructure and properties gradient composite made of 3 mm thick sheets of AA5083-O, AA6061-T6, and AA7075-T6 alloys using friction stir additive manufacturing (FSAM) technique. Two combinations of four layered FSAM builds (6756 and 7567) were fabricated successfully without any major defects at the optimized process parameters of 850 rpm (tool rotational speed) and 55 mm/min (tool transverse speed). The material mixing, interfacial bonding features, microstructure evolution, and mechanical performance within the stir zones (SZ) were thoroughly examined using advanced characterization techniques. Electron backscatter diffraction (EBSD) analysis confirmed a gradient microstructure along the build depth in both FSAM builds, with average grain sizes decreasing from 52 μm (AA5083), 46 μm (AA6061), and 40 μm (AA7075) in base metals to ∼ 4 to 7 μm within the SZ. The remarkable grain refinement within the SZ was mainly attributed to the dominant presence of the continuous dynamic recrystallization (CDRX) mechanism. Texture analysis corresponding to pole figures (PFs) and orientation distribution function (ODF) plots reveals the crystallographic texture evolution along the build depth. The prevalent existence of B/ and C textures throughout all regions of the FSAM builds affirms the presence of ample shear strain during the FSAM procedure. Through thickness miniature tensile and microhardness tests depict the gradient in mechanical performance for both the FSAM builds along the build depth. Microhardness gradients in the range from 80 HV0.1 to 145 HV0.1 were observed along the build depth. The axial sample in the build direction shows appreciable strength (265 MPa and 224 MPa) and uniform elongation (28% and 24 %) for 6756 and 7567 FSAM build, respectively. Furthermore, remarkable strain hardening behaviour corresponding to hardening capacity (Hc) and hardening exponent (n) was noticed for both the axial build samples compared to AA6061-T6 and AA7075-T6 base metals. These findings underscore the potential of FSAM in fabricating functionally gradient composite materials tailored to specific functional requirements.

Automating Fault Test Cases Generation and Execution for Automotive Safety Validation via NLP and HIL Simulation

The complexity and the criticality of automotive electronic implanted systems are steadily advancing and that is especially the case for automotive software development. ISO 26262 describes requirements for the development process to confirm the safety of such complex systems. Among these requirements, fault injection is a reliable technique to assess the effectiveness of safety mechanisms and verify the correct implementation of the safety requirements. However, the method of injecting the fault in the system under test in many cases is still manual and depends on an expert, requiring a high level of knowledge of the system. In complex systems, it consumes time, is difficult to execute, and takes effort, because the testers limit the fault injection experiments and inject the minimum number of possible test cases. Fault injection enables testers to identify and address potential issues with a system under test before they become actual problems. In the automotive industry, failures can have serious hazards. In these systems, it is essential to ensure that the system can operate safely even in the presence of faults. We propose an approach using natural language processing (NLP) technologies to automatically derive the fault test cases from the functional safety requirements (FSRs) and execute them automatically by hardware-in-the-loop (HIL) in real time according to the black-box concept and the ISO 26262 standard. The approach demonstrates effectiveness in automatically identifying fault injection locations and conditions, simplifying the testing process, and providing a scalable solution for various safety-critical systems.

Materials and manufacturing technology for high reliability rigid-flex multilayer PCB for space 3D-electronics packaging

Rigid-flex Multilayer PCB Technology enables the elimination of several connectors and bulky harness for interconnecting functional electronic systems. This minimizes packaging complexity and reduces performance degradation at high frequencies with an added advantage of reduced weight and volume in high-reliability space electronic packages. Here, only thermo-mechanically stable adhesiveless all polyimide flexible laminate cores and no-flow glass-polyimide prepregs are employed. To overcome the manufacturing issues like registration, coverlay protrusion into the rigid portions, and residual copper deposition at the intersections of flexible and rigid portions; a novel manufacturing process technology is proposed here. The technology has been successfully devised after choosing the most appropriate flexible, rigid, and low-flow prepreg materials. Herein, for the realization of rigid-flex multilayer PCB technology with 2-layers of flex and 8-layers of rigid to meet the functional requirements of the board is presented. The critical registration issues associated with the dissimilar rigid and flexible substrates are successfully addressed to achieve best-fit registration and obtain minimum annular rings of 50 μm in all the inner layers for high reliability. Experimental results manifest that incorporating rigid-flex multilayer PCB technology dramatically reduces weight (>30%) and volume (∼40%) to high-reliability space electronics 3D packaging for static and dynamic applications.

A home health management app designed in the post-epidemic era using empirical evidence based on the demand collection of elderly users

In the context of the epidemic, the daily routines of China’s elderly populace underwent substantial transformations. The implementation of home-based pandemic containment strategies led to heightened levels of social isolation and loneliness, exerting a discernible influence on the subjective well-being of this demographic. Consequently, residing in retirement apartments has emerged as a more advantageous alternative for elderly individuals capable of self-care. To meet their life and emotional needs and improve their sense of well-being, we used the KANO model to design a health management app for the self-care of older persons. We summarised the functional requirements for the self-care of elderly people, distributed questionnaires to generate a list of requirements, and conducted data analysis. We optimised the low-fidelity prototype based on the usability test results combined with relevant interface design elements to implement emotional interaction design practices for older persons’ self-care. Furthermore, we completed a design evaluation and program optimisation of the design practice to guide the final visual design. The research findings identify the core principles of interactive design for elderly users to enable visual design specifications for improving the lives of the elderly population. This research highlights the need to design more appropriate products that meet demographic characteristics. This work contributes to strengthening the connection between elderly people and society while bridging the ‘digital divide’ based on this population’s cautious approach to technologies and declining abilities to learn.

Targeting cellular cathepsins inhibits hepatitis E virus entry.

The hepatitis E virus (HEV) is estimated to be responsible for 70,000 deaths annually, yet therapy options remain limited. In the pursuit of effective antiviral therapies, targeting viral entry holds promise and has proven effective for other viruses. However, the precise mechanisms and host factors required during HEV entry remain unclear. Cellular proteases have emerged as host factors required for viral surface protein activation and productive cell entry by many viruses. Hence, we investigated the functional requirement and therapeutic potentials of cellular proteases during HEV infection. Using our established HEV cell culture model and subgenomic HEV replicons, we found that blocking lysosomal cathepsins (CTS) with small molecule inhibitors, impedes HEV infection without affecting replication. Most importantly, the pan-cathepsin inhibitor K11777 suppressed HEV infections with an EC50 of ~ 0.01 nM. Inhibition by K11777, devoid of notable toxicity in hepatoma cells, was also observed in HepaRG and primary human hepatocytes. Furthermore, through time-of-addition and RNAscope experiments, we confirmed that HEV entry is blocked by inhibition of cathepsins. Cathepsin L (CTSL) knockout cells were less permissive to HEV, suggesting that CTSL is critical for HEV infection. Finally, we observed cleavage of the glycosylated ORF2 protein and virus particles by recombinant CTSL. In summary, our study highlights the pivotal role of lysosomal cathepsins, especially CTSL, in the HEV entry process. The profound anti-HEV efficacy of the pan-cathepsin inhibitor, K11777, especially with its notable safety profile in primary cells, further underscores its potential as a therapeutic candidate.

Biofusion design and parameter optimization for a novel passive assisted knee exoskeleton robot based on eight-bar mechanism

Abstract In an effort to alleviate the issue of knee joint fatigue and injury during lower limb ambulation, a novel passive assisted exoskeleton robot with human–machine interaction is investigated to assist the movement of the human knee joint. The design of the exoskeleton configuration takes into consideration the physiological structure and gait function of the knee joint, ensuring that it satisfies the requirements for motion, force, and gait function of the knee joint. To explore the interaction between the wearer and the exoskeleton, a human–machine kinematic model after wearing exoskeleton is established, which is instrumental in analyzing the integration motion of the wearer and exoskeleton. In addition, the dynamic and static models of the knee joint after wearing the exoskeleton are established, utilizing the Newton–Euler method and force polygon method, respectively, to evaluate the effectiveness of the exoskeleton. Moreover, the size parameters and spring stiffness of the exoskeleton are optimized, using both human body kinematic model and mechanic model. Furthermore, the effectiveness of the exoskeleton in proving assistance is evaluated through human body simulation, using OpenSim. The results indicate that the exoskeleton significantly reduces the knee joint torque by 48.42%.

Water Tower Home transformation: bottom-up urban regeneration through a reality TV show

The article examines Wutopia Lab’s transformation of the Water Tower Home (shuita zhijia, also know as ‘House on the House’), a top-floor unit of a residential building converted from a water tower located in a Bulinli lilong neighbourhood in Shanghai. In 2015, the top-floor unit was transformed into a three-bedroom apartment, which was featured in a popular reality TV show Dream Home. Using the concept of ‘raumplan’ as the primary design strategy, the design deploys various heights and platforms to re-organise the internal space while largely maintaining the exterior appearance of the building. It deliberately avoided homogeneous visual control and accommodated the residents’ complex functional requirements within a highly restricted space. The research scrutinises various actors’ involvement during the production of the reality TV show and the transformation process. It highlights how the design team navigated the stakeholders’ complex needs and the rigid yet ambiguous policy related to the regeneration of Shanghai’s unofficial urban heritage. By reflecting upon the various formal and informal design practices in this structure and its eventual demolition, the article illustrates the dilemmas in bottom-up regeneration of the historic urban environment in contemporary China.

Building Information Modelling Facility Management (BIM-FM)

Defined digital Facilities’ Management (FM) systems will contribute to the realisation of the United Nations’ Sustainable Development Goal (SDG) 11. Of the available digital FM systems, Building Information Modelling (BIM) for FM, herein referred to as BIM-FM, is the least developed. Where BIM-FM varies from existing digital FM tools is its advanced 3D visualisation capabilities. A semi-structured literature review is undertaken to assess the current implementation of BIM-FM and identify opportunities to engender its increased adoption. This paper is part of an ongoing piece of research aimed at defining a standard methodology for the application of BIM to historically significant structures, otherwise known as Historic BIM (HBIM). Two existing approaches to BIM-FM, current and developing, are outlined. The potential value BIM-FM can provide according to the literature is discussed but there exists minimal practical evidence to justify these claims. Barriers to its adoption are discussed, with a key underlying barrier found to be a lack of defined user requirements. Consequently, functional, modelling and information requirements established within the literature are identified, and existing attempts at realising the requirements are discussed. Six information categories and two functional requirements are identified. It is theorised that the tendency to utilise simplified geometric models for FM is primarily due to software and practical limitations as opposed to actual end user needs, and it is suggested that this should be investigated further in future work. Attempts at realising BIM-FM user requirements using other advanced technologies, primarily Digital Twins, are investigated and found to be an area of increasing commonality. A new conception of BIM-FM is proposed.

Ex-ante LCA of magnet recycling: Progressing towards sustainable industrial-scale technology

To alleviate the pressure on the rare earth supply chain, new technologies are under development for recovering, recycling and remanufacturing NdFeB magnets. In this study, the anticipated environmental performance of large-scale recycling is investigated and compared to the production of primary magnets. To do so, this ex-ante life cycle assessment combines input from measurements of pilot processes, expert technology forecasts, thermodynamic modeling, and equipment data from manufacturers. We examined the effect of four technology developments: process changes, size scaling, internal recycling, and optimization.The results show that at pilot scale, recovered NdFeB powders have lower impacts than primary powders for almost all impact categories. This demonstrates that the recovery of NdFeB alloys is environmentally beneficial. Magnets from anticipated large-scale recycling have over 80% lower impacts than primary magnets in most of the impact categories analyzed. All four investigated types of technology development contributed to this improved performance. The final configuration was validated by comparison with an industrial reference and theoretical optimum configuration. Four magnet manufacturing routes (sintering, extrusion, metal injection molding, bonding) have distinct environmental profiles, but all can progress to similarly low levels of impact. The choice among routes should be primarily based on the functional requirements.

Application of Q-learning algorithm based on heterogeneous sensor networks in higher education teaching management

With the rapid advancement of information technology and online technologies, it has become imperative for all colleges and universities to address the challenge of leveraging modern management methods to enhance management efficiency, level, and practices. In the realm of educational institution management, the learning management system stands as the cornerstone of contemporary campus management and the entire campus computer network. In this article, the Q-learning algorithm, specifically applied to a heterogeneous cellular network, is employed to investigate the issues pertaining to teaching management in colleges and universities.The design and implementation of the university teaching management system mainly uses heterogeneous cellular networks to establish a physical model of the Q-learning algorithm, and then in the Rayleigh channel, the coverage factor and the system rate expression are derived in a closed form, and in a closed form Derive the energy efficiency expression, and then optimize the density of the basic micro-station algorithm to maximize performance. In the process of system design, this paper uses an algorithm to analyze the current research status of university teaching management, then proposes the research purpose and subject content, and analyzes the university's teaching management function and potential future functional requirements. When designing the university learning management system, it describes in detail the overall design concept, key technologies, system structure, and operating system structure and system topology. This research mainly focuses on the research of campus information management and Q learning algorithm. Based on the cellular network, a large number of campus management cases were analyzed and data fitting at the same time, and a set of Q-learning algorithm teaching management system based on heterogeneous cellular network was designed.

Technical Systems Effectiveness Management Technique

Currently, the task of performing a target function by a technical system with minimal resource costs is urgent. Obtaining the beneficial effect of a vehicle depends on many factors, which can become the basis for the formation of a control effect on the functional part of the system. At the same time, it is necessary to take into account the importance of a useful (target) effect in order to manage the technical systems effectiveness. The purpose of this article is to describe an instrument that allows adaptively redistributing the resource spent on the implementation of a purposeful process in the vehicle, based on the requirements of the consumer function and the target effect. As a result of the conducted research, the article proposes a technique for redistributing the resource of a technical system in the interests of its effectiveness management. The features of the presented technique are the visibility of its results presentation, as well as the possibility of application in evaluating the effectiveness and it`s management in relation to various types of technical systems, which will allow to substantiate the practical significance of obtained results.

Explicit modelling of meso-scale damage in laminated composites – Comparison between finite fracture mechanics and cohesive zone model

The ability of carbon fibre reinforced polymers to respect functional requirements such as permeability is strongly related to their damage state. In order to identify the fracture properties on which transverse cracking kinetics depend, we combine experimental and virtual tests by explicitly modelling all transverse cracks. Two modelling methods are compared, the cohesive zone model (CZM) and finite fracture mechanics (FFM). Both models are based on a double criterion of energy and strength. Each potential crack is assigned a couple of material properties (fracture energy and strength) derived from a probability distribution. This study focuses on how modelling choice implies assumptions on energy dissipation and the cracking behaviour represented. The relevance of both modelling methods is also discussed. A methodology is provided for identifying fracture properties and predicting damage accumulation in an isolated ply.

A formulation platform for incorporating live probiotics into different food matrices

Drying technologies are often utilized to maximize microbial shelf-life stability of probiotics-based foods. However, these processes inadvertently induce stress on microorganisms and reduce probiotic viability. This work sought to develop suitable protection strategies to maintain viability of powdered probiotics in different foods. A formulation platform (set of pre-existing/initial formulation templates for application/adaptation to various products) consisting of six powder formulations was evaluated. Each template combination comprised a probiotic, at least one prebiotic and at least one coating material. The powder particles were small (d50: 4.92 ± 0.09 μm to 9.30 ± 1.09 μm) to ensure optimal incorporation in foods for desirable mouthfeel, while all powders were favorably moisture-stable (aw: 0.34–0.53) and less susceptible to moisture uptake than their unencapsulated counterpart. At least one species from the platform was able to satisfy the viability and/or functional requirements on various food matrices which thus demonstrated its utility in formulation development.

Organization of the cross-border marketing center: functions, tasks and areas of activity

Organization of the cross-border marketing center: functions, tasks and areas of activity