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Editorial: Artificial Intelligence and Metaheuristic Optimization Methods in Engineering and Biomedical
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An Adversarial Approach to Adaptive Model Predictive Control
Get PDFThis paper presents a novel approach to introducing adaptation in Model Predictive Control (MPC). Assuming limited a priori knowledge about the process, we consider a finite set of possible models (a dictionary), and use the theory of adversarial multi-armed bandits to develop an adaptive version of MPC called adversarial adaptive MPC (AAMPC). Under weak assumptions on the dictionary components, we then establish theoretical bounds on the performance of AAMPC and show its empirical behaviour via simulation examples
Behavior in Oxidation at 1000°C of Carbon-Containing Equimolar CoNiFeMnCr Alloys Added with Hafnium or Tantalum with High Contents
Get PDFIn this work, HfC–and TaC–reinforced cast versions of the equimolar CoNiFeMnCr alloy (Cantor) were tested in oxidation at 1000°C in laboratory air. Chromium seemingly shared, with manganese, its role as a selectively oxidized element. The principal oxide to form externally was an M2O3 one in which Mn and Cr were present in various proportions depending on the proximity with the alloy’s surface. The HfC carbides close to the oxidation front were oxidized in situ in HfO2, with the release of carbon diffusing inwards after that and inducing the solid-state precipitation of blocky or acicular chromium carbides. The behavior of the TaC carbides present close to the oxidation front was different since they dissolved, and Ta diffused towards the oxidation front to form CrTaO4 oxides. Even after 50 hours at 1000°C, the subsurfaces were more or less deeply impoverished in Cr and Mn, with minimal contents meager, especially for Mn. The evaluation of the Cr and Mn quantities and the exploitation of results in terms of equivalent oxide thickness and kinetic oxidation constant demonstrates that the resistance of the alloys against oxidation is feeble and must be significantly improved to allow benefiting of the superior high-temperature mechanical resistances of such alloys in practical application. For that, some ways are proposed
Reflection of the Freedom Movements on the Relationship between Political Power and Architecture in Paris: Architectural Competitions
Get PDFAs its most prominent financier and employer, architecture is closely related to religious, political, and economic power. According to Lefebvre, representation spaces are established to permanently represent politics and ideology and their transmission to new generations. The democratic attitude of the political power will only change the perception known with the representation spaces. Therefore, this study deals with the example of Paris, which was indicated as the capital of the freedom movements initiated in the 1960s, to demonstrate how the relationship between political power and ideology with architecture transformed under the influence of democracy and freedom movements. For this purpose, political ideology between 1960-90 formed in the De Gaulle period and reached the highest level in the Mitterrand time, attracting the entire world's attention, and its relationship with architecture is investigated.
Democratic, pluralistic, participatory, and transparent approaches in politics brought architectural competitions to the agenda by seeking transparency, pluralism, and participation in the production method of architecture above all. These architectural competitions were organized for Paris to reflect the ideological perspective. The crucial result of the libertarian perspectives concerning the city is the importance of publicity as a factor containing the shared spaces of people. The important results concerning the field of architecture are the support of the formation of new ideas, the production of buildings that are the leading symbols of new movements, and providing equality of opportunity for architects
Bioactivity and Prospects of Using Ethanolic Extracts of Some Plants and Bee Glue (Propolis) to Control the Greater Wax Moth Galleria mellonella (L) (Lepidoptera: Pyralidae)
Get PDFThe greater wax moth (Galleria mellonella) is one of the most important pests of stored or unattended combs that cause severe damage to bee broods, threatening the development of apiculture in various countries, especially Sudan. A laboratory experiment was conducted in the College of Agricultural Studies, Sudan University of Science and Technology, Shambat, Sudan, to explore the potency of ethanolic extract (EE) of different parts of three different plants and bee glue against the third larval instar of greater wax moth. The experiment was laid out in Randomized Complete Block Design and replicated five times. The percentage of mortality of GWM was recorded after 24, 48, 72, and 96 hours post-treatment. Analysis of the variance of the obtained data revealed significant differences regarding insecticidal effect between the EEs of the four test products and the control. The EE of Eucalyptus camaldulensis, Propolis, Nigella sativa, and Carum carvi have bioactivity action against the third instar larvae of GWM with an increased percentage of mortality according to the increase of concentration as well as elapse of time. Hence, the highest concentration (15%) caused 86.7%, 83.3%, 73.3 and 66.7% larval mortality after 96 hours for EE of leaves of E. camaldulensis, powder of bee glue (Propolis), seeds of N. sativa and seeds of C. carvi respectively. The results also clearly demonstrated that the EE of the powder of Propolis is significantly more toxic than E. camaldulensis, N. sativa, and C. carvi, where the LC50 values were 3.1% for Propolis, 5.0% for E. camaldulensis, 7.0 % for N. sativa and 7.7% for C. carvi. The products mentioned above at the mentioned concentration are environmental friendly, safe for honeybees, economically feasible, and affordable for small beekeepers
Visual Analysis of Activity Construction Based on Bibliometrics
Get PDFChina has a well-developed active structure, with the continuous expansion of the scale of engineering construction and the continuous extension to the complex geological areas, especially the tectonic areas that are still active or will still be active in the future. Related projects are faced with many new challenges. The summative achievements on the problems related to active tectonics in China still need to be made available. This paper uses CNKI and WOS as data sources, and the documents related to active tectonics and geology from 2003 to 2022 are taken as objects. The scientific knowledge graph is visualized and analyzed by the bibliometrics software CiteSpace. The results show that: (1) the number of research literature on active tectonics at home and abroad is on the rise as a whole, (2) the number of articles published in the field of active tectonics in China is highly proportional to the number of earthquake disasters in China each year, and (3) the United States is in an absolute leading position in this field. It can help researchers in related fields to obtain the classical achievements of nearly 20 years quickly, and it is easy to find the bottleneck of current research. It can also expand the field of vision to find new research directions
Detection, Location and Quantification of Structural Faults in a Two-Story Building Using the Artificial Immunological System
Get PDFLarge buildings and skyscrapers are vulnerable to environmental, temporal, and anthropological stresses, generating wear and tear that can lead to this social and economic impediment's collapse. The technological improvements of the fourth industrial revolution have resulted in changes in the connection between physical space and man, known as the cyber physic model, which necessitates monitoring systems to protect the structural branch and so correct this structural vulnerability. Thus, the structural health monitoring system is the exact measure of the evolution required by the cyber physic model in construction and the protection of the monumental buildings, ensuring not only their economic development but also the safety of society. Therefore, this research work presents the innovative proposal of the cyber-physical structural health monitoring system aimed at buildings and skyscrapers, based on and differentiated by intelligent computing techniques, using the negative selection algorithm to perform the analysis and monitoring of structural integrity, overcoming the existing traditional work. The cyber-physical structural health monitoring system will be applied to experimental data obtained from the shear building model that represents these imposing skyscrapers. An artificial immune system will be developed and used in the decision-making process based on the acquisition and processing of the obtained signals to perform the identification, localization, and quantification of possible structural damage. Observing the results, this work proved to be efficient, robust, and economically feasible, having high performance and overcoming the shortcomings of traditional techniques. It represents the perfect measure of cyber physics in the monitoring of large buildings and skyscrapers
Optimization of Tuned Mass Damper for Submerged Floating Tunnel with Frequency-Domain Dynamics Simulation
Get PDFIn this study, the Tuned Mass Damper (TMD) optimization is carried out to reduce the resonant motion of Submerged Floating Tunnel (SFT) under wave excitations. The SFT dynamics is evaluated in frequency domain; a new approach to cost-effectively optimizing TMD parameters for a moored system is suggested. Discrete-Module-Beam (DMB) method is used to model the Tunnel; mooring lines are included as equivalent stiffness matrix through static-offset tests by the fully coupled model. Since the frequency-domain dynamics simulation model is employed, a significant reduction in optimization time can be achieved. TMD is installed at the tunnel’s mid-length to mitigate the lateral motion of the Tunnel and coupled with the Tunnel with translational and rotational springs and dampers. The optimization process for TMD parameters is performed through the Genetic Algorithm (GA). The GA generates the TMD mass and spring and damping coefficients. The dynamics simulation is performed under wave conditions and this process is repeated until the stopping criteria is satisfied. Results demonstrate that TMD with optimized parameters significantly reduces the lateral motion, especially near the system’s lowest lateral natural frequency. This frequency-domain optimization also works as intended with significantly decreased optimization time
Combustion Performance of Hydrogen Direct Injection under Lean-burn Conditions for Power Generation
Get PDFThis paper studies the combustion phenomenon of hydrogen (H2) direct injection (DI) in a modified spark ignition (SI) engine. As we known, ignition timing strongly correlates with combustion performance, especially for power output and efficiency. Therefore, different ignition timing varying among -20, -15, -10, -5, 0, 5, 10, 15, and 20 deg top dead center (TDC) are tested in this research. Besides, different H2 injection timings and injection pressures are also compared in this study. Moreover, as H2 usually favors lean-burn combustion, λ at 3, 3.5, and 4 are tested to find the lean-burn limitation. In order to obtain the engine speed influences on power output, finally 1500, 2000, and 2500 revolutions per minute (rpm) are evaluated in this study. Finally, thermal brake efficiency (BTE) and power output are analyzed. Results showed that power output and efficiency increase with the delay of ignition timing from -20 to 5 deg TDC and then decrease with delaying timing from 5 to 20 deg TDC. However, injection timing has less effect on the H2 combustion phenomenon. H2 lean-burn limitation is found that when λ is larger than 3, the efficiency decreases sharply. Moreover, both power output and efficiency firstly increase then decrease with higher engine speed and 2000 rpm is the best option for this small engine. Finally, by evaluating the contribution index, ignition timing and engine speed should be optimized first to achieve higher efficiency
Compositions for Limestone Restoration
Get PDFInformation about the lime composition used for the restoration of limestone is given. It has been shown that using a polysilicate mortar to formulate a lime composition contributes to an increase in water resistance, adhesion strength of the composition to the base, and acceleration of curing. A primer composition is proposed, including liquid sodium glass and calcium chloride