Strict Scenario Research Articles

Nonlinear adaptive pose motion control of a servicer spacecraft in approximation with an accelerated tumbling target

Removing a limited number of large debris can significantly reduce space debris risks. These bodies are generally exposed to extreme environmental disturbance torques or consecutive accidents due to their large wet area, which causes them to experience accelerated high-rate tumbling motion. The existing literature has adequately explored the approximation operations with non-cooperative targets exhibiting 3-axis tumbling motion. However, the research gap lies in the lack of attention given to addressing this approximation for targets undergoing accelerated motion. Agile, accurate, and large-angle maneuvers are three common necessities for safely capturing such targets. Changes in the moment of inertia brought on by fuel slushing cannot be disregarded during such a maneuver. To deal with nonlinearities, adverse coupling effects, actuator saturation constraints, time-varying moment of inertia, and external disturbances that worsen during accelerated agile large-angle maneuvers, a novel adaptive control approach is developed in this paper. The controller's main advantage is its adjustable desired acceleration, which maintains its performance even when dealing with accelerated motion. The control law is directly synthesized from the nonlinear relative equations of motion, without any linearization or simplification of the system dynamics, making it robust to a variety of orbital elements and target behaviors. Adaptation laws are extracted from the Lyapunov stability theorem in a way that guarantees asymptotic stability. Moreover, control actuator roles (delay, saturation, and allocation) are accounted for in modeling and simulation. Finally, a comprehensive numerical simulation based on three different realistic and strict scenarios is carried out to demonstrate the effectiveness and performance of the proposed control approach. The controller's robustness against time-varying dynamic parameters (sharp and sudden change, smooth and slow change, and periodic change) is extensively demonstrated through simulation.

Analyses for graphical records for a total solar eclipse in May 1230: a possible reference for the “Medieval Grand Maximum”

Abstract Datable graphical records of total solar eclipses allow us to assess contemporaneous variability of Earth's rotation speed, solar coronal structure, and solar-wind conditions. Such records are known back to the early 18th century. Here, we examine Matthew Paris’ medieval manuscript, an eyewitness account of a total solar eclipse just after local sunrise, and analyse his eclipse drawings on 14 May 1230. We philologically identify his observational site as St. Albans and compute local eclipse visibility. To locate St. Albans in the totality path, our analysis requires ΔT in 555 s < ΔT < 923 s (loose scenario), consistent with the latest published ΔT spline curve, which indicates that only the upper part of the eclipsed Sun should have been visible in this case. The eclipsed Sun sould have been entirely visible over the local horizon if we set the ΔT margins to 555 s < ΔT < 571 s (strict scenario), which requires slightly modifying the latest ΔT spline curve. Matthew Paris’ drawing of the total solar eclipse showed streamer-like structures similar to solar-minimum-type coronal streamers, consistent with the local tilt of the apparent solar equator. This is morphologically consistent with the minimum-type solar coronal streamers predicted from the open solar flux reconstructed from the 14C dataset. This record potentially demonstrates a similarity in solar cycles between the ‘Medieval Grand Maximum’ and modern solar cycles. Collectively, historical eclipse records could be used to assess Earth's rotation speed, solar coronal dynamics, and background solar dynamo activity on a millennial timescale.

S10.2d Fungal beta-glucans and mannan performances in HIV-associated histoplasmosis

S10.2 Fungal Infections in Transplant Patients, September 24, 2022, 10:30 AM - 12:00 PMObjectivesDiagnosis of histoplasmosis in people living with HIV (PLWHIV) remains challenging despite developments in Histoplasma antigen and molecular detection tools. Fungal markers such as Beta-(1,3)-D-glucan (BDG) and galactomannan Aspergillus antigen (GM) are widely available, but the experience is limited during PLWHIV workup for suspicion of histoplasmosis. Our objective was to evaluate and compare BDG and GM performances for the diagnosis of HIV-associated histoplasmosis.MethodsWe performed a diagnostic accuracy study using primary serum samples stored frozen in a certified biorepository (CRB Amazonie-DC-2021-4649). Samples consisted of consecutive hospitalized PLWHIV unexposed to oral antifungals during the previous month (EDIRAPHIS study-NCT01884779). All patients gave consent for biobanking and ancillary studies on fungal markers.Histoplasmosis cases, proven (EORTC/MSG criteria) and probable (polyclonal or monoclonal Histoplasma antigen detections in urines or serum), as well as negative controls, were randomly selected. Patients with a proven or suspected Pneumocystis jirovecii infection were excluded. Following manufacturers’ instructions, samples were blindly tested for BDG and GM using Fungitell® and PlateliaTM Aspergillus Ag assays, respectively.Gold standard definition used three scenarios: EORTC scenario (cases and controls defined according to the EORTC/MSG 2020 criteria for endemic mycoses); strict scenario with proven cases restricted to those positives to all three previous Histoplasma antigen detections, and controls conversely negatives for all methods; and a large scenario with proven or probable cases and controls negatives for all methods.ResultsWe included 121 samples, 92 HIV-associated histoplasmosis cases (34 proven and 58 probable), and 29 negative controls. Compared with controls, histoplasmosis cases were significantly younger and advanced in the course of HIV disease [median CD4 count level 33/mm3 (15-87) vs 116 (62-245)].BDG and GM median detection levels were significantly higher among histoplasmosis cases compared with controls across all scenarios [368 (176-441) pg/ml vs 142 (89-211) for BDG and 2.5 (1.3-4.8) vs 0.19 (0.14-0.36) for GM, in cases vs controls of the strict scenario, respectively].In the strict scenario, at 150 pg/ml and 0.5 for BDG and GM respectively, sensitivity, specificity, positive and negative likelihood ratios were respectively: 95% [95%confidence interval (CI), 85-100] vs 90% [77-100], 52% [34-70] vs 83% [69-97], 2 [1.4-3.0] vs 5.3 [2.4-12.0], and 0.1 [0.01-0.7] vs 0.12 [0.03-0.45]. ROC curves found AUCs of 0.82 [0.68-0.91] vs 0.92 [0.80-0.98], and optimal thresholds at 288 pg/ml and 1.29, for BDG and GM, respectively (Fig. 1). Post-test probabilities showed best performances at the lowest thresholds for negative testing of both BDG and GM, and at the 0.7 thresholds for a positive GM test (Fig. 2).ConclusionBDG and GM may not be used for the same objective when searching for HIV-associated histoplasmosis. Although a negative BDG test at the lowest thresholds should rule out histoplasmosis in a screening context, limitations of a positive BDG test, even at the highest thresholds, call for a consecutive positive GM test before starting patients on antifungal therapy targeting histoplasmosis. Still, when considering the highest costs of BDG testing, higher balanced diagnostic performances, and lower costs of GM testing alone, one may favor the use of GM, notably in resources-limited settings.

Land sustainability for public cemeteries in KHDTK Hambala: a preliminary study on the borrow-to-use forest area with a cooperation mechanism in Sumba, Indonesia

Deaths due to the COVID-19 pandemic in East Sumba raised the problem of limited burial grounds, so the government tried to provide a new location. The Hambala Special Purpose Forest Area (KHDTK) has a potential land to be used as a burial site by MoEF Regulation No.P.27/2018. The study analyzed the suitability of burial grounds using a GIS-based multi-criteria approach. Criteria and indicators cover the legality (license status of forests, policies), management (master plans, detailed plans), technical (human resources, infrastructure), socio-economic (pandemic, grave needs, economic impacts, culture, conflict), and ecological (topography, land cover, distance to water sources and settlements). A multi-criteria evaluation of the proposed use of KHDTK covering an area of 17 ha resulted in three scenarios of the burial land suitability map, namely the ‘strict scenario’ covering an area of 1.5 hectares; moderate scenario covering an area of 6.5 hectares, and ‘scenario loosely’ covering an area of 14.2 hectares. The third scenario as a reference for managers and stakeholders is lend-use of Forest Areas for burial grounds by government cooperation mechanism.

A Win–Win Mode: The Complementary and Coexistence of 5G Networks and Edge Computing

The emerging Internet of Things (IoT) services put forward higher demands on the bandwidth and latency performance of the traditional cloud computing. Cloud–edge collaboration and 5G cloud are two effective schemes to solve this problem. Adopting only one scheme may lead to the insufficiency of the performance in strict scenarios. So, the integration deployment of 5G networks and edge computing is significant. This article aims to provide a comprehensive survey on the complementarity and coexistence of 5G networks and edge computing. It reviews the evolving bonds of mobile communication technologies and edge computing and summarizes five scenarios where both 5G and edge computing can be applied. Based on the analysis of the key technologies and the tech-connections of 5G and edge computing, a win–win mode of them complementing each other is proposed. Finally, the potential challenges of the new mode, including security risks, heterogeneity issues, transition stage, and service orchestration, are summarized. This survey can provide rational assistance for researchers and developers focusing on the integration deployment of 5G networks and edge computing.

Development of a GIS tool for qualitative assessment of the Egyptian’s quality of life

A frame work was presented for the assessment of the quality of life through the development of different indicators applied for Egypt. This paper focuses on the assessment of the quality of life using previously developed indicators in the first part of the study. A GIS user-friendly interface was developed to enhance the presentation of the study. This enables non technical users to directly use the developed GIS application to explore different concerns. Three cases were demonstrated in this paper, where an assessment of the quality of life of farmers, civilians, and agricultural investors was attained under specific scenario in each case. Assessment for other cases can still be made by browsing through the dropdown menu for each interest group under the selected scenario. Based on the demonstrated results for the three groups of people, it was found that the quality of life for a certain group of people under the strict scenario is in general less than the quality of life for the same group under the relax scenario.