Specific System Design Research Articles

AC ripple on DC voltage: Experimental and theoretical investigation of the impact on accelerated ageing in electrical insulation

AbstractWith the increasing penetration of DC systems into the high voltage and medium voltage power industry, DC voltage is becoming common for distribution/transmission and to supply different typologies of loads. The allowable extent of AC ripple superimposed to DC, and its effect on insulation ageing, is a long‐term discussed topic. The most harmful phenomenon causing extrinsic ageing acceleration and insulation system premature failure is partial discharges (PD); thus, the risk of incepting PD due to AC ripple could become a primary issue for electrical asset equipment reliability. In this work, the impact of AC sinusoidal ripple on insulation system life and reliability is dealt with, considering both intrinsic and extrinsic ageing but focusing on the latter, that is, the PD aspect. Experiments are performed to assess how the jump voltage (due to AC ripple) and the DC component impact on PD activity in terms of amplitude and repetition rate. For the first time, the correlation between the magnitude of jump voltage associated with ripple and PD inception is established, shedding a light on the allowable ripple extent which does not impact significantly on ageing and premature insulation failure. This approach can provide straightforward tools for design specification and ageing inference of insulation systems.

Economic Evaluation of Using Ultracapacitors in Electric Vehicles

The main challenge of hybridizing ultracapacitors (UCs) with batteries in electric vehicles is their uncertain economic viability, besides their complexity and weight, which should be fully addressed. Therefore, this article determines the general condition for achieving a justified economic system, which is held when the average annual cost (AAC) of a battery‐UC system over a vehicle's useful life is lower than the annual cost of a sole‐battery for a specific system design, energy management strategy, vehicle type, and driving style. As such, the energy storage system is designed in a case study vehicle, and the optimal current distribution is found by dynamic programming (DP) under UDDS, HWFET, and US06 driving cycles. Then, by economic analysis, it is indicated that although adding an UC incurs additional costs, it saves the AAC by improving the battery health and prolonging its lifespan up to a maximum of 15‐year calendar life, which proves its economic justification. Investing in UCs is more economically viable for vehicles with severe driving cycles and high current stress. Finally, the DP optimal trajectory is implemented into an experimental setup under the US06 driving cycle to verify the evaluated strategy.

Future rescue management: Design specifications for a 5G-enabled emergency response information system

Today, access to real-time information from emergency scenes is still limited for emergency medical services, fire departments, and their professionals, also called first responders. Emergency Response Information Systems (ERISs) have recently been discussed in the literature as a potential solution to this problem. Using the Design Science Research (DSR) paradigm, we present a novel 5G-enabled ERIS (5G-ERIS) design that leverages 5G mobile network technologies to offer diverse real-time information. We provide a user-centered examination of design specifications for a 5G-ERIS based on a smart city digital twin. Based on literature and qualitative expert interviews with several first responders in Germany, we derive how emergency medical services and fire departments can improve their decision-making with this 5G-ERIS. Based on existing 5G application architectures, we structure our identified design specifications into four system layers. Our findings provide an essential knowledge base for the successful development, deployment, and long-term use of 5G-ERISs. We stimulate a broader discussion on the design objectives and specifications of 5G-ERISs in theory and practice.

Optimal performance and preliminary parameter matching for hydrogen fuel cell powertrain system of electric aircraft

Fuel cells are true net-zero carbon emission power sources for aircraft, which is highly sensitive to weight. In the initial phase of adapting hydrogen fuel cell systems for aircraft powertrains, preliminary design parameter matching remains premature. An explicit method for the performance optimization of aircraft hydrogen fuel cell powertrain systems and a process of preliminary parameter matching are proposed to address this problem. Performance and weight models of the fuel cell stack and its auxiliaries, the cathode air compressor subsystem, and the cooling subsystem are designed, and system performance at various altitudes and power output levels is calculated. The aircraft flight mission performance is synthesized and considered in the optimization process. The optimization result of system performance and the corresponding design parameters are then graphically illustrated as tern plots. Unlike the traditional iterative preliminary system parameter matching and optimization method, which explores the design space non-directionally and converges to a single local optimal point, the proposed explicit method sweeps the design space globally and obtains a group of design points with acceptable optimality. The system design process is boosted by a compact iterative loop. In the optimization practice, the cruise powertrain specific energy is improved by 6.5%. The relationship between specific system design parameters and system performance is displayed globally by the resulting tern plots. Multiple design guidelines are observed and proposed, and design scenarios are directly obtained from the graphs for further engineering processes.

1 + 1 > 2? Information, Humans, and Machines

Our study, conducted through a field experiment with a major Asian microloan company, examines the interaction between information complexity and machine explanations in human–machine collaboration. We find that human evaluators’ loan approval decision-making outcomes are significantly enhanced when they are equipped with both large information volumes and machine-generated explanations, underscoring the limitations of relying solely on human intuition or machine analysis. This blend fosters deep human engagement and rethinking, effectively reducing gender biases and increasing prediction accuracy by identifying overlooked data correlations. Our findings stress the crucial role of combining human discernment with artificial intelligence to improve decision-making efficiency and fairness. We offer specific training and system design strategies to bolster human–machine collaboration, advocating for a balanced integration of technological and human insights to navigate intricate decision-making scenarios efficiently. Specifically, the study suggests that, whereas machines manage borderline cases, humans can significantly contribute by reevaluating and correcting machine errors in random cases (i.e., those without explicitly congruent feature patterns) through stimulated active rethinking triggered by strategic information prompts. This approach not only amplifies the strengths of both humans and machines, but also ensures more accurate and fair decision-making processes.

Pectin-based emulsion gels prepared by acidic and ionotropic methods for intestinal targeted delivery in vitro

Considering the different potential roles of the small intestine and colon in the functions of bioactive components, this study was performed to design a pectin-based controlled delivery system targeting different intestinal sections according to emulsification gelation methods (i.e., pectin gelated with acidified ethanol, iron, and calcium: PE-H, PE-Fe, and PE-Ca, respectively). The properties and targeted delivery of pectin-based emulsion gels were compared. All emulsion gels exhibited similar diameter and acceptable roundness with naringin encapsulation efficiency of approximately 90%. Cross-sections of PE-H, PE-Fe, and PE-Ca exhibited loose networks, large voids, and dense structures, resulting in diverse time dependence during digestion. Furthermore, PE-Ca showed the fastest completion of gelation and exhibited excellent hardness properties, suggesting that it would have the strongest anti-digestive effect. PE-Fe showed time- and pH-dependent swelling behavior in simulated intestinal fluid. Simulated digestion experiments indicated burst release and slow release of naringin from PE-H and PE-Fe, respectively, due to their differences in pH responsiveness and time dependence; a similar amount of naringin was released from PE-Ca after enzyme-triggered digestion in simulated colon fluid. Overall, distinct emulsion gels achieved targeted disintegration in intestinal sites. PE-H and PE-Fe would contribute to the rapid and sustained release of naringin in the small intestine, respectively, whereas PE-Ca would contribute to naringin release in the colon. These findings provide new insights for the future design of specific delivery systems that can be used in the functional food industry; they indicate the robust potential for including pectin in emulsion-based foods with targeted functions.

잠재적 고객만족 개선 지수(PCSI Index)를 활용한 학습관리 시스템(LMS)의 품질만족 인식에 관한 연구

This paper aims to analyze the satisfaction and perception of university students regarding the quality of Learning Management Systems (LMS) utilized in mobile environments. The analysis is conducted through Timko's Customer Satisfaction Coefficient and the PCSI Index. To achieve this goal, the definitions and concepts of smart learning and LMS are examined, and a survey on the quality satisfaction of LMS functionalities based on the Kano model is conducted among 127 university students. Through this process, Critical considerations for improving the quality of LMS in mobile environments are analyzed, including the prevention of information misperception errors, acquisition of course-related materials, and avoidance of repetitive unnecessary information. It is hoped that the directional insights derived from this study will serve as a basis for the development and design of specific LMS systems.

A filtering system to solve the large-scale shared autonomous vehicles Dial-a-Ride Problem

Shared autonomous vehicles are rapidly becoming one of the most popular topics in the fields of transportation and operations research. This paper studies a prospective transportation system in which shared autonomous vehicles (SAVs) providing Dial-a-Ride services in urban and rural areas must meet a large number of passenger requests (at least 105 per day). We consider those SAVs likely to replace, in the future, most of the individual vehicles inside urban areas. We address this very large-scale problem with a greedy insertion heuristic that involves a specific filtering system design in order to speed up the decision process and relies on an original network-driven encoding of the routes. Experimental results show that en-route vehicles can be drastically reduced by such systems using a fleet of SAVs of capacity 10, decreasing the vehicle number by more than 98%, compared to a situation where all travel demands would rely on personal vehicles. In addition, thanks to the filtering system, the total execution time can be reduced by almost 97% compared to the classic best-fit insertion heuristic, while maintaining the quality of the solution. This opens the way to the adaptation of our algorithms to a dynamic real-time context.

Numerical analysis of injuries of e-scooter riders in frontal impacts against SUVs

The rising popularity of e-scooters in urban areas highlights the importance of understanding potential collision dynamics and consequences to enhance rider safety, especially since 80% of fatalities for these vulnerable road users result from incidents involving motor vehicles. This study aims to identify potential injury mechanisms of e-scooter riders involved in frontal impacts against Sports Utility Vehicles (SUVs) using Finite Element Analysis (FEA) and a Human Body Model (HBM). Six impact scenarios at 25 km/h were simulated: on the passenger's side door (1-SD), on the trunk door (2-TD), on the bonnet (3-FB), on the bonnet from the side (4-SB), on the windshield from the side (5-SW), and finally, on the bonnet with an offset (6-FO). A wide range of Injury Risk Criteria (IRCs) was analyzed, including A3MS, HIC15, BrIC, DAMAGE, Cmax and PC Score, and head contact forces were output. Injury Risk Curves were then used to calculate the probability and severity of the sustained injuries predicted by the mentioned IRCs. Overall, the results corresponding to the most injurious scenarios suggested serious (30% to 40% overall probability) and critical (45% probability for the 4-SB scenario) brain, moderate head (30% probability for scenarios 1-SD and 2-TD), and serious thoracic (26% to 78% overall probability) injuries. Additionally, in two scenarios (1-SD and 2-TD), the e-scooter rider's mandible impacted against the vehicle's roof side rail and rear spoiler, involving potential anterior-posterior serious mandible fractures. The conclusions reached in this study help to understand potential injury sources and provide valuable information for the design of specific safety systems or the creation or improvement of e-scooter legislation.

Telemonitoring: ethical lessons from the COVID-19 pandemic

BackgroundThe COVID-19 pandemic accelerated the development and application of telemonitoring, enabling health care providers to continue to provide medical care. Telemonitoring oftentimes replaced face-to-face health care services instead of as being offered as a supplement to regular medical care. Given that pressure on hospitals is expected to remain, telemonitoring is seen as an important means of alleviating those pressures. In this paper, we consider the intensified deployment of telemonitoring during the pandemic as an excellent opportunity to learn how telemonitoring can be implemented in a morally responsible way.ResultsIn order to gain concrete, contextual and in-depth knowledge of the ethical issues raised by telemonitoring during the corona pandemic, we explore telemonitoring for two conditions: COVID-19 and Idiopathic pulmonary fibrosis. We conducted interviews with patients and professionals on five important ethical themes: 1. a shift in responsibilities, 2. empowerment and self-management, 3. the value of face-to-face consultations, 4. inclusivity and equal access, and 5. privacy and big data. Based on the findings of this empirical study and medical ethical principles, we formulate lessons for responsible implementation and upscaling: 1. ensure explicit and realistic allocation of responsibilities and avoid expectations that monitoring is more direct and continuous than it actually is; 2. create opportunities for an optimal form of self-management—in particular for patients with chronic conditions—and for meaningful conversations; 3. integrate telemonitoring within an established HCP – patient trust relation and stimulate research on the conditions for face-to-face consultations; 4. take vulnerability into account in inclusion & exclusion criteria and involve patients in design and implementation processes; 5. concerns of collection of data are beyond privacy and identify the risks of dependency on commercial companies.ConclusionsOur findings show that offering patients choices for telemonitoring will not necessarily result in increased and equal accessibility, good quality of care and patient autonomy. Whether or not these aims and promises will be fulfilled, and the ethical challenges adequately met, is highly dependent on choices regarding the design of specific monitoring systems, the development process and the embeddedness in a trusting physician–patient relationship.

A Specific Emitter Identification System Design for Crossing Signal Modes in the Air Traffic Control Radar Beacon System and Wireless Devices.

To improve communication stability, more wireless devices transmit multi-modal signals while operating. The term 'modal' refers to signal waveforms or signal types. This poses challenges to traditional specific emitter identification (SEI) systems, e.g., unknown modal signals require extra open-set mode identification; different modes require different radio frequency fingerprint (RFF) extractors and SEI classifiers; and it is hard to collect and label all signals. To address these issues, we propose an enhanced SEI system consisting of a universal RFF extractor, denoted as multiple synchrosqueezed wavelet transformation of energy unified (MSWTEu), and a new generative adversarial network for feature transferring (FTGAN). MSWTEu extracts uniform RFF features for different modal signals, FTGAN transfers different modal features to a recognized distribution in an unsupervised manner, and a novel training strategy is proposed to achieve emitter identification across multi-modal signals using a single clustering method. To evaluate the system, we built a hybrid dataset, which consists of multi-modal signals transmitted by various emitters, and built a complete civil air traffic control radar beacon system (ATCRBS) dataset for airplanes. The experiments show that our enhanced SEI system can resolve the SEI problems associated with crossing signal modes. It directly achieves 86% accuracy in cross-modal emitter identification using an unsupervised classifier, and simultaneously obtains 99% accuracy in open-set recognition of signal mode.

Reducing High Temperature System Development Cycle Time and Cost with Additively Manufactured Connectors

Connectors are a fundamental part of Ozark IC’s high temperature modules from characterization and test packages to Ozark IC’s XNode® data acquisition and single-board computing modules. Development of rugged high temperature electronic systems requires the co-development of similarly rugged high temperature connectors. The design and development of connector solutions enable test and evaluation of high temperature systems which would otherwise require fulfillment of a commercial connector order. There is a nascent supply chain of rugged, high temperature-rated connector designs but manufacturer lead times for such commercial products can exceed an entire design, prototype, and test cycle. Such delays are incompatible with rapid design iterations and fail-fast strategies employed in the development of extreme environment electronics – especially when the design and test cycles can change the requirements or specifications of the connectors. Polymer and ceramic additive manufacturing techniques enable in-house connector fabrication and support a connector co-development cycle that complements the pace and interdependent requirements of high temperature system development. These solutions are simple and reliable under laboratory conditions, operating for thousands of hours at 200 °C [1] and hundreds of hours at 800 °C [2]. The use of proprietary connectors manufactured with additive techniques and digital tooling lends an extra degree of freedom to system design and enables the trade-off of connector with system design specifications that greatly accelerates system ruggedization. Electrical connectors represent the final interface between an electronics module and the outside world. A failure of a connector is a failure of packaging that makes the module opaque to the tester and renders the power and robustness of any electronic system moot.

A co-simulation of superconducting qubit and control electronics for quantum computing.

As the number of qubits in quantum computing increases, the scalability of existing qubit circuit structures and control systems may become insufficient for large-scale expansion and high-fidelity control. To address this challenge, we propose a behavioral-level model of a superconducting qubit and its control electronics, followed by a co-simulation to evaluate their performance. In this paper, we present the modeling process, simulation procedure, and resulting design specifications for the qubit control system. Our co-simulation approach utilizes MATLAB and Simulink, enabling us to derive critical circuit design specifications, such as the required Digital-to-Analog Converter (DAC) resolution, which should be 8 bits or higher, to achieve high-fidelity control. By taking into account factors such as DAC sampling rates, integral and differential nonlinearities, and filter characteristics, we optimize the control system for efficient and accurate qubit manipulation. Our model and simulation approach offer a promising solution to the scalability challenges in quantum computing, providing valuable insights for the design of large-scale superconducting quantum computing systems.

NanoSMAD – A First Order System Configuration Design Tool for Nano and Micro Satellites

The emergence of nano and micro satellites, which weigh less than 100 kg, is causing a significant transformation in the space industry. The existing Space Mission Analysis and Design (SMAD) tools, which are primarily designed for larger satellites, often become irrelevant for these smaller satellites in terms of spacecraft mass, power, pointing requirement, total mission duration, fault tolerance, and design cost. To address this, we have developed a web based nanoSMAD tool specifically for designers of nano and micro satellites. This tool utilizes a comprehensive database of approximately 140 nano and micro satellites along with their internal subsystem specifications. By using the nanoSMAD tool, designers can efficiently develop nano and micro satellite systems by entering their requirements, which then generates high-level system design and requirement specifications. This process enables the tool to provide a basic satellite configuration design and generates a Master Equipment List (MEL) of subsystems. To further customize the design, users can provide more specific parameter inputs or select components from a drop-down menu, resulting in an iterative custom design approach. The satellite database used by the nanoSMAD tool is regularly updated through online surveys, including web scraping, to gather information on the latest non-space-grade off-the-shelf nano and micro satellite subsystems. This ensures that the tool stays up-to-date with the newest advancements in the field. Additionally, the nanoSMAD tool offers a unique feature of verifying the electrical interface compatibility of subsystems, which is an innovative aspect of the tool. Novice small satellite communities will greatly benefit from the nanoSMAD tool as it seamlessly generates an initial nano and micro satellite system design, providing a first-order understanding of the satellite’s configuration and requirements.

Sistem Informasi Tunggakan Pajak pada Dinas Pendapatan Pengelolaan Keuangan dan Kekayaan Daerah (DPPKKD) Kota Sabang

At the Sabang City Regional Financial and Wealth Management Revenue Service (DPPKKD), tax data management still uses simple methods with Microsoft Excel, causing data duplication and errors in presenting and searching for data. To overcome this, this research designs a web-based information system using PHP and MySQL. This research aims to design a Tax Arrears Information System to increase the efficiency and accuracy of information. Research methods include field studies, FlowMap analysis, interviews, comparative analysis, system design, and hardware and software specifications. The results of the analysis show weaknesses in the data processing process, such as large operational costs, difficulty in managing data, and vulnerability to data duplication. Designing a new system involves program menu structures, program flowcharts, Entity Relationship Diagrams (ERD), and system input/output design. The required hardware and software specifications are also explained. In conclusion, the use of information systems can increase efficiency and accuracy in managing tax arrears data in the Sabang City DPPKKD.

THE PERFORMANCE COMPARISON OF RF LEVEL MULTIPLEXING AND OPTICAL LEVEL MULTIPLEXING IN RADIO OVER FIBER SYSTEMS WITH DIRECT OPTICAL MODULATION TECHNIQUES

Communication in the world is developing very rapidly, not only limited to voice but data communication. Many techniques have been used to support multimedia services. Radio over Fiber is expected to support communication for long distances. Therefore, a Comparison of Performance Analysis was carried out using optisystem. Radio over Fiber is simulated by radio frequency signals of 10 GHz and 15 GHz. Radio over Fiber technology for long-distance communication is very vulnerable to high BER and attenuation values, so it requires a mature system design and adequate equipment specifications.

A brief analysis of the theoretical logic and system operation of the downward shift of administrative law enforcement power

The downward transfer of administrative law enforcement power is one of the core contents of China's administrative law enforcement system reform, and it is also an important part of the modernization of the national governance system and governance capacity. However, due to the lack of internal written norms and insufficient supply of external systems, the current system has a tendency to deviate from the requirements of national policies and the rule of law in practice, so the reconstruction of its system is an inevitable choice to ensure the benign operation of the downward transfer of administrative law enforcement power. Before carrying out the institutional construction, it is necessary to return to the natural and actual logic of "administrative law enforcement power downward" itself to describe the ideal goal of this system construction, reflect on the risks and challenges it may bring in the context of the legality and rationality of administration and the social background of extensive grassroots social governance, and then explore the final foothold of its standardization and institutionalization. In terms of specific system construction, it is necessary to give full play to the significance of theoretical contents such as the limits, basic principles and management models of the downward transfer of administrative law enforcement power in reform practice, and on this basis, carry out specific system design from the aspects of law enforcement teams, institutional guarantees, and supervision systems, so as to realize the organic unity of the legality and rationality of the system of decentralization of administrative law enforcement power.

Lossy State Communication over Fading Multiple Access Channels.

Joint communications and sensing functionalities integrated into the same communication network have become increasingly relevant due to the large bandwidth requirements of next-generation wireless communication systems and the impending spectral shortage. While there exist system-level guidelines and waveform design specifications for such systems, an information-theoretic analysis of the absolute performance capabilities of joint sensing and communication systems that take into account practical limitations such as fading has not been addressed in the literature. Motivated by this, we undertake a network information-theoretic analysis of a typical joint communications and sensing system in this paper. Towards this end, we consider a state-dependent fading Gaussian multiple access channel (GMAC) setup with an additive state. The state process is assumed to be independent and identically distributed (i.i.d.) Gaussian, and non-causally available to all the transmitting nodes. The fading gains on the respective links are assumed to be stationary and ergodic and available only at the receiver. In this setting, with no knowledge of fading gains at the transmitters, we are interested in joint message communication and estimation of the state at the receiver to meet a target distortion in the mean-squared error sense. Our main contribution here is a complete characterization of the distortion-rate trade-off region between the communication rates and the state estimation distortion for a two-sender GMAC. Our results show that the optimal strategy is based on static power allocation and involves uncoded transmissions to amplify the state, along with the superposition of the digital message streams using appropriate Gaussian codebooks and dirty paper coding (DPC). This acts as a design directive for realistic systems using joint sensing and transmission in next-generation wireless standards and points to the relative benefits of uncoded communications and joint source-channel coding in such systems.

A Smartwatch System for Continuous Monitoring of Atrial Fibrillation in Older Adults After Stroke or Transient Ischemic Attack: Application Design Study.

The prevalence of atrial fibrillation (AF) increases with age and can lead to stroke. Therefore, older adults may benefit the most from AF screening. However, older adult populations tend to lag more than younger groups in the adoption of, and comfort with, the use of mobile health (mHealth) apps. Furthermore, although mobile apps that can detect AF are available to the public, most are designed for intermittent AF detection and for younger users. No app designed for long-term AF monitoring has released detailed system design specifications that can handle large data collections, especially in this age group. This study aimed to design an innovative smartwatch-based AF monitoring mHealth solution in collaboration with older adult participants and clinicians. The Pulsewatch system is designed to link smartwatches and smartphone apps, a website for data verification, and user data organization on a cloud server. The smartwatch in the Pulsewatch system is designed to continuously monitor the pulse rate with embedded AF detection algorithms, and the smartphone in the Pulsewatch system is designed to serve as the data-transferring hub to the cloud storage server. We implemented the Pulsewatch system based on the functionality that patients and caregivers recommended. The user interfaces of the smartwatch and smartphone apps were specifically designed for older adults at risk for AF. We improved our Pulsewatch system based on feedback from focus groups consisting of patients with stroke and clinicians. The Pulsewatch system was used by the intervention group for up to 6 weeks in the 2 phases of our randomized clinical trial. At the conclusion of phase 1, 90 trial participants who had used the Pulsewatch app and smartwatch for 14 days completed a System Usability Scale to assess the usability of the Pulsewatch system; of 88 participants, 56 (64%) endorsed that the smartwatch app is "easy to use." For phases 1 and 2 of the study, we collected 9224.4 hours of smartwatch recordings from the participants. The longest recording streak in phase 2 was 21 days of consecutive recordings out of the 30 days of data collection. This is one of the first studies to provide a detailed design for a smartphone-smartwatch dyad for ambulatory AF monitoring. In this paper, we report on the system's usability and opportunities to increase the acceptability of mHealth solutions among older patients with cognitive impairment. ClinicalTrials.gov NCT03761394; https://www.clinicaltrials.gov/ct2/show/NCT03761394. RR2-10.1016/j.cvdhj.2021.07.002.

A computational study of trailing edge noise suppression with embedded structural compliance.

A unique concept for suppression of trailing edge noise scattering from a splitter plate in a low Reynolds number flow is proposed. The key idea of the concept is the adoption of a structural compliance system embedded with a finite number of elastic panels. Specific compliance system designs are devised for promotion of panel structural resonance that effectively absorbs broadband flow/acoustic fluctuation energy responsible for noise scattering. The concept is examined using high-fidelity direct aeroacoustic simulation together with spatiotemporal aeroacoustic-structural interaction analysis. The concept is confirmed feasible and outperforms many similar trailing edge noise reduction approaches reported in the literature.