Multiple Loops Research Articles

A system dynamics model based on ISM for risk perception in emergency by employees in chemical industrial parks

Risk perception is one of the factors that guide human behavior in the workplace. In accident prevention and emergency response, the risk perception of employees affects the safety behaviour and efficiency of emergency disposal. Besides, risk perception is a complicated process restricted by many influencing factors. The study aims to identify the most important factors affecting risk perception. This study had three phases. In the first, factors affecting the risk perception were extracted based on the questionnaire survey and the expert scoring. Then, the Interpretive Structure Model (ISM) was used to stratify the 14 influencing factors of risk perception and obtain a hierarchical structure chart. Finally, by analyzing the influence paths in the ISM, the system dynamics feedback loop diagram was constructed. The model took the state variable “risk perception→ risk response→ risk identification→ risk communication→ risk perception” as the main circular loop, and was supplemented and perfected by multiple feeder loop circuits. Research indicates risk experience is the most fundamental factor affecting risk perception. In the aspect of sensitivity analysis, the study shows that the risk perception of employees is related to the distance of the risk source. Its effectiveness in quantifying qualitative data, identifying influential factors, and establishing cause-effect relationships make it a valuable tool for enhancing risk perception in chemical industry park.

Research on parameter optimization method of thrust vector/aerodynamic rudder composite control law based on singular value method

Advanced aircraft with thrust vectoring/aerodynamic rudder layout have significant control coupling problems. The traditional single-loop control parameter design method cannot take into account the performance of multiple control loops in this scenario. Therefore, a control law parameter optimization method based on the singular value of the hysteresis matrix is proposed. First, the control parameter optimization interval is determined using the time domain control performance index. Then, the singular value method is used to measure the stability margin of the multiple-input multiple-output (MIMO) system on this basis, and the corresponding optimal objective function is established to optimize the controller parameters. The feasibility of this method is verified by numerical simulation. The results show that the designed control parameter optimization algorithm has better time domain control performance and larger system stability margin than the traditional single-loop control parameter design method.

Optimal iterative learning PI controller for SISO and MIMO processes with machine learning validation for performance prediction

The multivariable process plays a significant role in industrial applications, and designing a controller for the Multi-Input Multi-Output process is challenging due to dynamic process changes and interactions between system variables. Traditionally, the PI family of controllers has been used for its simple design, easy tuning, and quick deployment. However, these processes require complex control actions due to multiple loops in process plants. Thus, this paper proposes an Iterative Learning Controller Dead-time compensating PI, which utilizes the newly developed hybrid Simulated Annealing-Ant Lion Optimization algorithm for Single-Input Single-Output process simulation and real-time experimentation on the Quadruple Tank System. To validate the effectiveness of the developed controller, Machine Learning techniques such as regression and ensemble trees are used to accurately predict the actual system response using error values from respective processes. The simulation and experimental results demonstrate that the proposed controller achieved better performance. The regression and ensemble tree algorithm models effectively predicted the actual response. The obtained data shows that the proposed controller improved system stability and robustness by minimizing nearly half of the overshoot and improving settling time, with an average of 29.9596% faster than the other controller in the SISO process and 14.6116% in the MIMO process.

Prospective Observational Study Of The Outcome Of Pregnancies With Sonologically Detected Nuchal Cord At Term

Background: Nuchal cord refers to the condition where the umbilical cord wraps around the fetal neck, potentially leading to complications during pregnancy and delivery. The prevalence of nuchal cords at delivery ranges between 6% and 37%, with possible adverse outcomes including fetal asphyxia, hypoxia, and in severe cases, stillbirth. The current study aims to evaluate the impact of nuchal cord detection via ultrasound in fullterm pregnancies and assess its prognostic significance concerning perinatal outcomes. Materials and Methods: This prospective observational study involved a cohort of pregnant women at term (37- 42 weeks of gestation) with sonologically detected nuchal cords. Ultrasound evaluations were conducted to determine the presence and characteristics of nuchal cords, including the number of loops and tightness. The outcomes measured included the mode of delivery, fetal distress, Apgar scores, and neonatal complications such as hypoxic-ischemic encephalopathy (HIE) and meconium aspiration syndrome (MAS). Statistical analysis was performed to assess the correlation between nuchal cord characteristics and perinatal outcomes. Results: The study found that the presence of nuchal cords was associated with an increased rate of cesarean deliveries and a higher incidence of fetal distress during labor. However, the degree of tightness and the number of loops significantly influenced the severity of outcomes. Neonates with tightly looped nuchal cords showed a higher incidence of low Apgar scores and required more intensive neonatal care. The study also observed a slight increase in the occurrence of neonatal complications, including MAS and HIE, among those with multiple nuchal cord loops. Conclusion: The detection of nuchal cords at term via ultrasound is a valuable tool in predicting potential delivery complications. While many nuchal cords do not adversely affect perinatal outcomes, those with multiple loops or tight cords pose a higher risk of complications. This study emphasizes the importance of careful monitoring and tailored management strategies for pregnancies complicated by nuchal cords to optimize maternal and fetal outcomes.

Main heat transport system configuration influence on steam drum level control and safety for a pressure tube type boiling water reactor with multiple interconnected loops

Abstract NCABWR (Natural-Circulation-Advanced-Boiling-Water-Reactor) is a pressure-tube-type BWR with multiple inter-connected Main-Heat-Transport (MHT) system loops and steam drums (SDs). SD-Level-Control is related to, the MHT coolant inventory and sustained heat removal, hence the overall safety of the Nuclear-Power-Plant (NPP). SD-Level is vital for ensuring presence of adequate coolant-inventory with sufficient and prolonged cooling of fuel, for normal-operation and accidents. In the initial-MHT-configuration of NCABWR the four MHT-loops are, inter-connected at the Common-Reactor-Inlet-Header (CRIH), which influences the SDLC adversely; such occurrences are, not reported in the open literature. Open loop (without SD-level-controllers) step-change response showed that initial MHT-configuration response is stable, non-oscillatory and non-diverging even for a high-magnitude step-change in the feed-flows. Closed-loop (with SD-level-controllers) response, even to minor disturbances leads to diverging SD-Levels due to CRIH-MHT-configuration (Gaikwad, A.J., Vijayan, P., Iyer, K., Bhartiya, S., Kumar, R., Lele, H.G., Ghosh, A.K., Kushwaha, H.S., and Sinha, R.K. (2009). Effect of loop configuration on steam drum level control for a multiple drum interconnected loops pressure tube type boiling water reactor. IEEE Trans. Nucl. Sci. 56: 3712–3725). CRIH is required to overcome Postulated-Initiating-Event (PIE) for single-accumulator-failure-LOCA. A hypothetical MHT-configuration with partitioning of CRIH will isolate each loop from one another and lead to a stable SDLC, but then for the above-mentioned PIE safety is not met. LOCA in one of the four ECCS header-compartments require a mandatory interconnection among, the four MHT-Loops at CRIH. Solution to SDLC issue were explored with changes in MHT-configuration and with innovative solution-schemes for feed-water-system and SDLCs. In the present study the pioneering solution-schemes with individual SD pressure control for SD level control and the Split/Double baffle are proposed, implemented and the performance was tested with simulation are discussed in details with other solution schemes.

6452 Hybrid Closed Loop Insulin Pump Therapy (Omnipod-5, T-Slimx2, Medtronic 780G) in uncontrolled type 1 Diabetes previously treated with multiple daily injections or open loop pumps

6452 Hybrid Closed Loop Insulin Pump Therapy (Omnipod-5, T-Slimx2, Medtronic 780G) in uncontrolled type 1 Diabetes previously treated with multiple daily injections or open loop pumps

Study of intricate extraordinary Hall effect and magnetization switching behavior in graded GdFeCo ferrimagnet

Abstract This study delves into the unique properties of the GdFeCo Hall bar with a vertical composition gradient. Our exploration includes a detailed analysis of the temperature-dependent extraordinary Hall effect (EHE) response and magnetization-switching behavior. The findings reveal a FeCo-rich state at room temperature, characterized by an asymmetric drop at 20 Oe and a magnetic compensation temperature (Tcomp) around 150 K. The presence of triple hysteresis loops at 280 K and 270 K, along with unexpected changes in the EHE resistance difference (ΔRXY) at temperatures distant from Tcomp, hint at complex compositional effects similar to the artificial skyrmion-like Hall effect. The temperature points for zero ΔRXY values at ±30 kOe and ±4 kOe show a difference of 18 K, suggesting a spin-flop effect at compensation. Detailed analysis near Tcomp uncovers multiple loops, indicating coexisting Gd and FeCo sublattices with varied compositions. The magnetization switching experiments demonstrate field-driven switching and a limited role of electrical current in the system. These unique findings enhance our understanding of compositionally controlled ferrimagnets for spintronic applications.

Genome-wide identification of clock-associated genes and circadian rhythms in Fragaria × ananassa seedlings

Flowering time in plants is regulated by a photoperiod-responsive mechanism. Some plant species use a circadian clock-based control mechanism to adapt to variable environments. Strawberry is a horticultural crop that responds to certain photoperiods and temperatures to induce flowering. However, clock-associated genes in octoploid cultivated strawberry (Fragaria × ananassa) have not been defined, and their regulatory mechanism for responding to photoperiods is unclear. We herein targeted 12 clock-associated genes reported in other plant species and performed a genome-wide analysis and expression comparison in F. × ananassa seedlings. Seventy-eight sequences were selected from the F. × ananassa genome. The major domains and cis-acting elements were conserved in each sequence. Transcripts were clearly expressed under continuous light conditions in F. × ananassa seedlings (‘Yotsuboshi’) acclimated to long days. Among them, 9 genes maintained their unique autonomous circadian rhythms and may function as clock genes. LHY (LATE ELONGATED HYPOCOTYL) had the Myb domain and LHY expression peaked in the dawn. PRR (PSEUDO-RESPONSE REGULATOR) family members (PRR9, PRR7, PRR5, and TOC1 (TIMING OF CAB EXPRESSION 1)) had a pseudo-receiver domain and CCT domain, and peak expression times began sequentially from the afternoon for PRR9 to the evening for TOC1. LUX (LUXARRHYTHMO) had a Myb domain, and LUX expression peaked in evening with ELF3 (EARLY FLOWERING 3). FKF1 (FLAVIN-BINDING KELCH REPEAT F BOX 1) had PAS and F-box domains, and FKF1 expression peaked in the afternoon. GI (GIGANTEA) expression also peaked in the afternoon. F. × ananassa (‘Yotsuboshi’) appears to have multiple feedback loops comprising clock-associated genes. Although the rhythmic expression of CHE (CCA1 HIKING EXPEDITION) and ZTL (ZEITLUPE) was not observed, they had conserved domains, CHE with the TCP domain and ZTL with the PAS and F-box domains. The present results provide basic information on the circadian clock for the control of F. × ananassa flowering.

Joint optimization of production, inspection, and maintenance under finite time for smart manufacturing systems

Given the flexible and configurable characteristics of smart manufacturing systems with a limited time per manufacturing task, the assumption of infinite time for prostems is no longer applicable to the joint-control strategy. Consequently, a joint-control model that considers production, inspection, and maintenance within a finite-time scenario for smart manufacturing systems is proposed in this paper. The objective is to optimize overall production and maintenance functions to minimize the total system cost. Comparing the joint strategy under infinite time with the proposed finite-time approach reveals significant differences in unit costs between the two scenarios. To enhance the effectiveness of the model, a discrete iterative algorithm with multiple loops was developed. Through a case study, it was observed that 1) joint strategies implemented within a finite time horizon were more cost-effective than those under infinite time, thus emphasizing the need for business managers to develop strategies within a finite time frame; 2) different production planning and efficiency levels had varying effects on the final joint strategy, necessitating customized strategies based on different production durations. Overall, the research gap regarding joint strategies within a finite-time context was addressed in this research, serving as a methodological foundation for practitioners to develop various strategies that minimize total costs across diverse real-world scenarios.

SP2.10 - Early outcomes with the Insides Chyme Reinfusor (ICR) device in the management of parenteral nutrition dependent high output stomas (PN-HOS)

Abstract Aims PN-HOS represent a complex challenge, requiring input from surgical, gastroenterology and nutritional teams. Length of stay (LOS) is prolonged with difficulties in achieving output control and adequate nutrition with other associated risks. ICR is a modified stoma bag/mechanical pump and catheter device, reinfusing chyme into the distal limb, maintaining gut continuity, preserving enteral nutrient absorption and preventing distal limb atrophy. ICR may accelerate establishment of nutritional autonomy and reduce costs associated with PN/LOS. We report the largest study of ICR outcomes Methods Prospective study of ICR outcomes in patients with PN-HOS. Analysis included LOS, duration of PN, establishment of nutritional autonomy, nutritional markers, adverse ICR effects. Results Sixteen patients were trained to use the ICR (6M:10F). Median age 60yr. 75% achieved independent use (median 5.6 days). Overall usage was 395 days (median 32 days). Nutritional autonomy achieved in nine patients (pre-reversal). ICR increased median albumin 10.5 g/l. Adverse events included changing difficulties, spillage, noise, and discomfort. Two patients discontinued ICR because of pain/reflux. One patient died from unrelated post-operative complications. One patient with multiple loop stomas was successfully established on dual ICR. Nursing experience with ICR demonstrated ease of use and straightforward patient education. Cost analysis PN £5000/mth v ICR 1800/mth. Anecdotally at the time of reversal, surgical opinion was of much favourable bowel for anastomosis and return to function. Conclusions The ICR device is safe and contributes to restoration of nutritional autonomy. It reduces PN dependence with cost-benefits and acceptable adverse effects. At time of initial surgery distal limb should be fashioned to allow potential use of ICR.

The quasi-stochastic nature of hail growth: Hail trajectory clusters in simulations of the Kingfisher, OK hailstorm

Abstract Current methods that incorporate synoptic, meso-alpha, and even some storm-scale processes to distinguish among storms that produce significantly severe versus merely severe hail have not been highly successful. These results suggest that smaller-scale processes, such as meso-beta, meso-gamma, and microscale, have a larger impact on hail production than previously theorized. Relatedly, previous research, often using hail trajectories driven by steady-state model fields, has also frequently painted hail trajectories as having simple, relatively uniform motions within a supercell. This study uses a Lagrangian hail trajectory model embedded in two idealized supercell simulations and updated every model timestep, in conjunction with a trajectory clustering technique, to examine the variability of hail trajectories both within and across the two simulations. The clustering method identified 11 distinct clusters in both supercell simulations. Clusters sourced embryos from almost all quadrants around the updraft core. Trajectories in both simulations exhibited complex and highly variable behavior, occasionally including multiple vertical loops. Cluster trajectories could follow similar paths but produce different distributions of mass at the surface, or conversely, could follow different paths but result in similar mass distributions at the surface. An aggregate review of all trajectories showed the larger hail in each simulation was somewhat more likely to be produced in regions with less strong peak updraft speeds, but other environmental profile information was more mixed, particularly for the simulation producing the largest hail. In sum, storm-scale information is highly impactful on hail trajectories, and needs to be considered in forecasting applications. Future hail trajectory modeling studies also need to incorporate more realistic storm-scale information.

Unidirectional and hierarchical on-chip interconnected architecture for large-scale hardware spiking neural networks

Spiking Neural Networks (SNNs) exhibit the strong capability to address spatiotemporal dynamic problems. Recent research has explored the hardware SNN systems to solve the spatiotemporal problems in real-time. The Network-on-Chip (NoC) is an effective scheme for building large-scale hardware SNNs. However, for the existing NoC-based hardware SNNs, large area overhead and hardware power are consumed by their interconnections, because of complex topologies and router structures. Therefore, in this work a novel Unidirectional and Hierarchical on-Chip Interconnected Architecture (UHCIA) is proposed to address this problem. The proposed UHCIA mainly combines the novel hybrid topology of unidirectional multiple loops and rings, and uses a deflection router technique. Experimental results show that compared to other works, the UHCIA achieves ∼23.6X of area reduction and ∼6.4X of power reduction, with high system throughput and biological real-time computations.

Analysis of hysteresis loops and dielectric performance in the ovalene-like system: Monte Carlo study

This Monte Carlo study offers a comprehensive analysis of the ovalene-like system, emphasizing its dielectric behavior, thermal performance and hysteresis loops. The investigation reveals intricate dynamics influenced by diverse parameters, contributing to a nuanced understanding of the system’s response. Additionally, the study scrutinizes the impact of various physical parameters on the thermal behavior of polarizations and susceptibilities. The examination thoroughly explores the influence of these parameters on loop characteristics, coercive field, and saturation behavior, unveiling the formation of multiple loops and polarization plateaus on the electric hysteresis. In summary, this study advances our understanding of the ovalene-like system’s dielectric response, thermal characteristics and hysteresis dynamics, providing valuable insights for future research and applications, particularly in advanced electronic devices.

TEADASH: Implementing and Evaluating a Teacher-Facing Dashboard Using Design Science Research

The benefits of teacher-facing dashboards are incontestable, yet their evidence is finite in terms of long-term use, meaningful usability, and maturity level. Thus, this paper uses design science research and critical theory to design and develop TEADASH to support teachers in making decisions on teaching and learning. Three cycles of design science research and multiple small loops were implemented to develop the dashboard. The tool was then deployed and evaluated in real time with the authentic courses. Five courses from two Swedish universities were included in this study. The co-design with teachers is crucial to the applicability of this dashboard, while letting teachers use the tool during their courses is more important to help them to recognize the features they actually use and the tool’s usefulness for their teaching practices. TEADASH can address the prior matters, align with the learning design, and meet teachers’ needs. The technical and co-design aspects, as well as the advantages and challenges of applying TEADASH in practice, are also discussed here.

Dielectric behavior of graphene-type nanolattice: Monte Carlo simulations

In this study, we used Monte Carlo simulations to explore the dielectric properties of a graphene-type nanolattice, revealing significant effects on blocking temperature. The ferroelectric interaction and external electric field parameters greatly influence the nanolattice's dielectric and thermal properties. We observed a polarization plateau and multiple hysteresis loops, indicating stability and various polarization states. Unexpected ferroelectric behavior in graphene-based systems was confirmed experimentally in moiré heterostructures, validating theoretical predictions. This aligns with models like the Ising model and enhances material stability and response, offering insights for precise control over dielectric properties in nanotechnology.

Community detection in social networks using machine learning: a systematic mapping study

AbstractOne of the important issues in social networks is the social communities which are formed by interactions between its members. Three types of community including overlapping, non-overlapping, and hidden are detected by different approaches. Regarding the importance of community detection in social networks, this paper provides a systematic mapping of machine learning-based community detection approaches. The study aimed to show the type of communities in social networks along with the algorithms of machine learning that have been used for community detection. After carrying out the steps of mapping and removing useless references, 246 papers were selected to answer the questions of this research. The results of the research indicated that unsupervised machine learning-based algorithms with 41.46% (such as k means) are the most used categories to detect communities in social networks due to their low processing overheads. On the other hand, there has been a significant increase in the use of deep learning since 2020 which has sufficient performance for community detection in large-volume data. With regard to the ability of NMI to measure the correlation or similarity between communities, with 53.25%, it is the most frequently used metric to evaluate the performance of community identifications. Furthermore, considering availability, low in size, and lack of multiple edge and loops, dataset Zachary’s Karate Club with 26.42% is the most used dataset for community detection research in social networks.

Principles for delivering transformative co‐design methodologies with multiple stakeholders for achieving nature recovery in England

AbstractAchieving successful multi‐stakeholder collaboration for sustainable outcomes is complex. This paper provides key principles for future co‐design projects aimed at fostering an inclusive approach to research. These have been developed based on a novel methodology that co‐designed the essential components of a long‐term, collaborative agreement for a nature recovery scheme in England. Using an assortment of iterative, deliberative participatory methods, this research engaged a wide variety of stakeholders to produce a template agreement for an agri‐environmental policy. We demonstrate that a flexible, highly reflective approach resulted in positive engagement with previously marginalised stakeholders. The approach also successfully navigated the unequal power dynamics seen both within and between groups. Finally, multiple feedback loops allowed participants to continually build on previous interactions as they developed and reviewed the agreement. By drawing out the complexities of the co‐design process, this paper explains how co‐design efforts can produce potentially transformative outputs. We hope that the principles introduced here offer a useful starting point for those planning to undertake multi‐stakeholder co‐design.

Pure arterial malformation of the fetal PCA treated with flow diverter stent-case report and literature review.

Thirty-three-year-old female underwent diagnostic work-up for chronic headaches. Cerebral DSA on the right side showed fetal posterior cerebral artery (PCA) with unusually shaped arterial malformation on its proximal part. Malformation was formed by multiple convolutions and loops with no arteriovenous shunting. During endovascular procedure, flow diverter stent was placed in the right C6 segment. Patient was put on double antiaggregation therapy. Four weeks after procedure, patient was admitted to ER with signs of dyphasia. No recent ischemic lesions were detected on emergent magnetic resonance. Dyphasia resolved spontaneously. On follow-up magnetic resonance angiography 5 years after the procedure, main portion of malformation has diminished with slightly filling of posterior part supplied by right P1. Here, reported finding is consistent with previously described pure arterial malformation (PAM). Main intention of our treatment was to induce malformation remodeling with flow diverter placement. Two main risks arise when using flow diverters on fetal PCA region. Firstly, there is possibility of occluding fetal PCA alongside malformation. On the contrary, high flow through fetal PCA could hinder malformation thrombosis. Some case series reported high rate of fetal PCA occlusion without ischemic sequelae in the PCA teritory. Others consider flow diverters highly ineffective treatment for the fetal PCA aneurysms due to low rate of complete aneurysm occlusion. We presented first reported case in which flow diverter was used to treat PAM. Slow malformation thrombosis leaves enough time for collateral circulation to recruit and supply territory of the vessel affected by the malformation.

Comprehensive two-dimensional gas chromatography using a miniaturized multiloop splitter-based non-cryogenic artificial trapping (M-SNAT) modulation device for analysis of cannabis samples

Multiloop splitter-based non-cryogenic artificial trapping (M-SNAT) modulation technique was developed, miniaturized and applied in comprehensive two-dimensional gas chromatography (GC×GC) for analysis of cannabis samples. The approach employed deactivated fuse silica (DFS) columns configured into multiple loop splitter system halving the perimeters of the progressively upstream loops. This splitter device was located between the first (1D) semi-nonpolar column outlet and a microfluidic Deans switch (DS). Each splitter loop splits a peak into two subpeaks having the same area with different void times. Three loops were then applied resulting in the number of the split subpeaks (nsplit) of 8 for each peak, and retention time differences between any two adjacent subpeaks (∆tR,split) were the same. By applying periodic heartcut event (H/C) within every artificial modulation period (PAM) of nsplit×∆tR,split, comprehensive split-and-trapped modulation profiles of analytes could be selectively transferred onto the second (2D) polar column (30 m) without cryogen consumption. This artificial modulation system was applied for analysis of cannabis samples with enhanced 2D peak capacity (2nc∼15). The established method was applied to analyse cannabis extracts using vegetable oils with or without frying process. This reveals 454 different peaks with 76, 92, 35 and 70 specific components specifically observed by using olive oil extraction (OE), fried OE, coconut oil extraction (CE) and fried CE, respectively.

Self-consistent field theory for loop-containing polymers: A general algorithm for path-determination

An algorithm was developed for self-consistent field theory (SCFT) simulations of loop-containing polymers (LCPs), where the total number of independent loops (fundamental cycles in the polymer structure) is characterized by the “cycle rank.” Although various multi-ring and cage-like polymers have been reported, there is no explicit SCFT scheme for LCPs with multiple loops. An LCP was cut to open its fundamental cycles to form a pseudo-tree-like polymer. Conventional SCFT calculations for pseudo-tree-like polymers require extra spatial constraints on the pseudo-free endpoints generated by opening the fundamental cycle, which increases the computational cost. A reduction in the computational cost was observed, and the algorithm was applied to microphase-separated structures of small LCPs.