Minimum Weight Research Articles

Associated varieties of minimal highest weight modules

Let g \mathfrak {g} be a complex simple Lie algebra. A simple g \mathfrak {g} -module is called minimal if the associated variety of its annihilator ideal coincides with the closure of the minimal nilpotent coadjoint orbit. The main result of this paper is a classification of minimal highest weight modules for g \mathfrak {g} . This classification extends the work of Joseph [Ann. Sci. École Norm. Sup. (4) 31 (1998), 17–45], which focused on categorizing minimal highest weight modules annihilated by completely prime ideals. Furthermore, we have determined the associated varieties of these modules. In other words, we have identified all possible weak quantizations of minimal orbital varieties.

System Identification for Robust Control of an Electrode Positioning System of an Industrial Electric Arc Melting Furnace

Through system identification for robust control methods and utilizing real-time experimental field data, a comprehensive mathematical model is derived that represents the dynamic performance of a single electrode positioning system (EPS) in an industrial electric arc melting furnace (EAF). This EPS is characterized by large, time-varying dynamic parameters, which fluctuate based on operating conditions, specifically as the electrode weight changes within its operational range. The system identification methodology for robust control is developed in four main steps, progressing from experimental design to model validation. This approach yields a nominal model of the actual system and provides a trustworthy estimate of the region of uncertainty of the model, bounded by models of the real system under maximum and minimum electrode weight conditions (limit operating models). The methodology generates three fourth-order time-delay models using an ARMAX structure. The results are promising, as system identification for robust control enables the derivation of mathematical models specifically tailored for designing robust controllers. These controllers significantly enhance the EPS control system’s performance and substantially reduce energy consumption and environmental emissions.

Pemodelan Sistem Pemilihan Tempat POI Terdekat di Wilayah Klaten Kota Menggunakan Metode Dijkstra oleh PT. Telkom Klaten

The Point of Interest (POI) represents a specific geographic location defined by its coordinates, including longitude and latitude, and holds value as a site of interest or utility. Examples of POIs include tourist attractions, hotels, restaurants, ATMs, pharmacies, health centers, retail shops, gas stations, and other categories integral to modern navigation systems. PT. Telkom Klaten has faced increased demands to conduct POI surveys efficiently, driven by advancements in technology that call for faster and more streamlined processes. A primary challenge in these surveys is the selection of an optimal route that minimizes time, costs, and fuel consumption, given that the company currently relies on manual input in Google Maps to determine distance and travel time. This manual approach may hinder survey efficiency and increase operational costs. To address this, an application employing the Dijkstra algorithm was developed to determine the shortest route effectively. The Dijkstra algorithm, known for selecting edges with minimal weight to connect sequential nodes, requires defined origin and destination points, thereby generating the most efficient route between them. This study applies the Dijkstra algorithm to optimize survey routes by modeling them as graph-based routes, aiming to identify the shortest and most efficient paths between multiple POI locations. The findings indicate that the Dijkstra algorithm significantly reduces travel distance and time, thereby achieving notable savings in fuel and operational time for POI surveys.

Further results on outer independent triple Roman domination

An outer-independent triple Roman dominating function (OI[3]RDF) on a graph G = ( V , E ) is function f : V → { 0 , 1 , 2 , 3 , 4 } having the property that (i) if f ( v ) = 0 , then v must have either a neighbor assigned 4 or two neighbors one of which is assigned 3 and the other at least 2 or v has three neighbors all assigned 2; (ii) no two vertices assigned 0 are adjacent; (iii) if f ( v ) = 1 , then v must have either a neighbor assigned at least 3 or two neighbors assigned 2; (iv) if f ( v ) = 2 , then v must have one neighbor assigned at least 2. The weight of an OI[3]RDF is the sum of its function value over the whole set of vertices, and the outer-independent triple Roman domination number of G is the minimum weight of an OI[3]RDF on G. In this paper, we continue the study of outer-independent triple Roman domination number in graphs. First, we characterize all graphs with small or large outer-independent triple Roman domination number, and then we establish relationships with some other related parameters. Finally we present a sharp upper bound for the outer-independent triple Roman domination number of trees.

Thermal analysis of mortar based on crushed dune sand

This study investigates the thermal decomposition behavior of mortars formulated using crushed dune sand and thixotropic polyester resin. Thermal analysis techniques, including Differential Scanning Calorimetry (DSC), Differential Thermal Analysis (DTA), and Gravimetric Thermal Analysis (GTA), were employed to characterize the thermal transitions, decomposition stages, and stability of these mortars. Results indicate that crushed dune sand maintains consistent glass transition (Tg) and crystallization temperatures (Tc) when integrated into the mortar matrix, highlighting its thermal stability. However, the melting point (Tm) varies due to the presence of the resin, which significantly influences the composite’s thermal behavior. Decomposition analysis reveals two major weight loss stages: water evaporation between 200°C to 400°C and organic decomposition of the resin between 700°C to 800°C, with minimal weight change beyond 800°C, indicating thermal stability. The DTA results exhibit distinct endothermic reactions related to dehydration and dehydroxylation, along with a pronounced exothermic peak around 400°C, signifying resin decomposition. Elemental analysis confirms that the crushed dune sand is predominantly silica with minimal impurities, making it suitable for construction applications. This research contributes to a deeper understanding of the thermal behavior of polymer-modified mortars, with implications for enhancing thermal and mechanical properties in construction materials.

The Exposure Height of Silicon Particle with Round Edges Effect on the Tribological Property of Al-Si Alloy Cylinder Liner

In order to improve the wear resistance of Al-Si alloy cylinder liners, surface treatment is usually used. The Al-Si alloy cylinder liner samples were prepared by mechanical grinding and laser finishing. The mechanical grinding samples were carried out by the independent design and development of a grinding machine. The laser finishing samples were laser-heated by a CO2 continuous transverse-flow laser. Both of the two surface treatments could provide the surfaces of protruding silicon particles with round edges to improve the wear resistance. However, in the exposure height of silicon particles with round edges, the study was lacking. The exposure height of silicon particles is important to the tribological properties of the Al-Si alloy cylinder liner, and should be analyzed in detail. The wear tests were completed by a contraposition reciprocating wear test rig under lubrication. It was found that when the silicon particles were exposed on the surface of the Al-Si alloy cylinder liner sample by 1.2 μm, the mechanical grinding samples and laser finishing samples all exhibited minimum friction coefficients and weight losses. This paper confirms that a suitable exposure height of silicon particles would reduce the probability of adhesion wear and abrasive wear of Al-Si alloy cylinder liners and increase the lubrication. It presents an excellent tribological property. However, when the exposure height of silicon particles is too high, the silicon particle is easily prone to plastic deformation or even falls off during the friction process due to the high stress and larger plastic contact index.

PangeBlocks: customized construction of pangenome graphs via maximal blocks

BackgroundThe construction of a pangenome graph is a fundamental task in pangenomics. A natural theoretical question is how to formalize the computational problem of building an optimal pangenome graph, making explicit the underlying optimization criterion and the set of feasible solutions. Current approaches build a pangenome graph with some heuristics, without assuming some explicit optimization criteria. Thus it is unclear how a specific optimization criterion affects the graph topology and downstream analysis, like read mapping and variant calling.ResultsIn this paper, by leveraging the notion of maximal block in a Multiple Sequence Alignment (MSA), we reframe the pangenome graph construction problem as an exact cover problem on blocks called Minimum Weighted Block Cover (MWBC). Then we propose an Integer Linear Programming (ILP) formulation for the MWBC problem that allows us to study the most natural objective functions for building a graph. We provide an implementation of the ILP approach for solving the MWBC and we evaluate it on SARS-CoV-2 complete genomes, showing how different objective functions lead to pangenome graphs that have different properties, hinting that the specific downstream task can drive the graph construction phase.ConclusionWe show that a customized construction of a pangenome graph based on selecting objective functions has a direct impact on the resulting graphs. In particular, our formalization of the MWBC problem, based on finding an optimal subset of blocks covering an MSA, paves the way to novel practical approaches to graph representations of an MSA where the user can guide the construction.

Review on Fragility Analysis of Building Structure in Seismic Prone Area

In general, using a steel bracing system is the most effective choice for enhancing the resistance of reinforced concrete frames to lateral loads. Steel bracing offers notable advantages over other methods, including greater strength and stiffness, cost-effectiveness, a smaller footprint, and minimal additional weight on existing structures. Both empirical and analytical fragility curves have been taken into account. Strengthening seismically deficient reinforced concrete frames with steel bracing systems is a practical solution for improving earthquake resilience. Nearly all structural analysis software, such as ETABS and SAP2000, supports linear and nonlinear static analysis for high-rise structures. Key parameters include fragility curves, the P-Δ effect, base shear, lateral displacement, axial force, and story drift, among others. The findings showed that bracing systems significantly reduce lateral displacement in frames. Fragility curves were developed based on peak ground acceleration (PGA) for various limit states—slight, moderate, major, and collapse-assuming a lognormal distribution. This study aims to develop analytical fragility curves for high-rise building structures.

Direct Alcoholysis of Glucose into Alkyl Levulinates Catalysed by Metal-Doped Sulfonated Activated Carbon

Lignocellulosic biomass is widely studied to produce alkyl levulinate through alcoholysis catalysed by acid catalyst, which potentially used as a biofuel additive. However, the poor properties of homogeneous catalyst have prompted this study to focus on enhancing the yield of alkyl levulinate by using sulfonated activated carbon (AC-S) doped with different metals as a heterogeneous catalyst with co-existence of Brønsted and Lewis acidic sites. The activated carbon (AC) precursor was modified via sulfonation and impregnated with iron (Fe), copper (Cu) and cobalt (Co) metals, which were further characterised to evaluate their physicochemical properties as a catalyst. Their catalytic activity was evaluated for glucose alcoholysis in a stainless-steel batch reactor at 180 ˚C for 4 h, by charging 0.6 g of glucose, 40 mL of alcohol (methanol and ethanol) and 0.3 g of catalyst. From the result, the catalyst properties were improved after sulfonation and metal doping. Among the employed heterogeneous catalysts, AC-S-Cu exhibited the highest catalytic activity, which was contributed mainly by its co-existence of Brønsted and Lewis acidic sites with significant Brønsted acidity, higher thermal stability with minimum weight loss up to 200 ˚C (<2 wt%), better morphology, and larger surface area (928 m2/g). The maximum alkyl levulinate yield (15.04 wt%) was obtained for ethyl levulinate production under conditions of 180 ˚C, 4 hr, 0.6 g of glucose, 0.3 g of AC-S-Cu and 40mL of ethanol. The outcome of this study provides an insight on the potential of AC-S-Cu in facilitating the direct alcoholysis of glucose to alkyl levulinate

Using of Grasshopper Optimization Algorithm Approach for Optimal Weight Design Problem of the Spur Gear

Gears are undoubtedly the most important parts of motion transmission. One way to increase the motion performance of the system is to reduce the weights of the gears without sacrificing the strength capability. Today, various optimization techniques that rely heavily on analytical and heuristic approaches are used for this problem. In this study, the gear optimization problem in accordance with the minimum weight was solved with Grasshopper Optimization Algorithm (GOA). Introduced in recent years, GOA is a meta-heuristic optimization technique that stands out with its successful performance in engineering applications. This approach was used in a spur gear formation case as per the minimum weight for the first time. Compared to previous studies, the results obtained in this paper show that it is possible to design a lighter gear with GOA.

Effect of Y2O3 content on the corrosion behavior of Cu-10W composites prepared by spark plasma sintering

Cu-W composites with good mechanical properties, electrical properties and corrosion resistance are still rare. In this study, Y2O3 reinforced Cu-10W composites were prepared by spark plasma sintering. The effects of different Y2O3 contents on the corrosion resistance of Cu-10W composites were studied by static immersion corrosion and electrochemical corrosion. The results show that, the incorporation of Y2O3 makes the microstructure of Cu-10W composites dense and grain refinement. The minimum weight loss value can be obtained when Y2O3 content is 2 wt%. Y2O3 can effectively increase the self-corrosion potential and corrosion current density of Cu-10W composites and enhance the electrochemical impedance level. And Y2O3 can increase the resistivity ring radius, which leads to the increase of charge transfer resistance Rct and the decrease of Warburg impedance Zw.

Weight change does not impact long-term outcomes following cryoballoon pulmonary vein isolation

Abstract Background Weight loss has been suggested to reduce frequency and burden of atrial fibrillation (AF) in overweight patients (pts). However, there are limited data on weight loss impact on outcomes in pts with AF who have undergone pulmonary vein isolation (PVI). Purpose To understand the impact of weight change on long-term outcomes, as assessed by freedom from recurrent AF in pts undergoing cryoballoon (CB) PVI. Methods We enrolled consecutive pts with AF who underwent CB PVI; all had implantable loop recorders (ILR) for long-term ECG monitoring. The cohort was divided into 4 groups based on weight change 1-year post ablation: (1) optimal weight loss (OWL) – weight decrease ≥ 10%; (2) minimal weight loss (MWL) - weight loss (WL) 3-9% weight decrease; (3) no weight change (NWC) - weight change < 3%, (4) weight gain (WG) ≥ 3% weight increase. We assessed for AF recurrence after excluding a 3-month post-ablation blanking period. Results Out of a total of 322 pts who underwent ablation, 241 (75%) pts (69 ± 10 years; 159 (66%) male; 133 (55%) PAF; CHA2DS2-VASc 2.7 ± 1.5; BMI 30 ± 5) had weight information available at ablation and last follow-up. All were off antiarrhythmics by 1 year. There were no differences in the 4 cohorts with respect to baseline characteristics. During the first year, about ¼ of pts were able to lose ≥ 3% of weight but only 8 pts (3%) were able to lose ≥ 10%. AF recurred in 153 (63%); they were older, more likely to have persistent AF (PeAF), and a higher CHA2DS2-VASc score. However, weight change did not impact outcome (Figure). In a multivariate Cox Regression hazards analysis, PAF vs. PeAF at ablation was the only factor associated with any recurrence at follow-up (Figure). Conclusions Post CB PVI only about ¼ of pts are able to lose weight. Weight changes in the first-year post ablation in obese pts did not alter outcomes with respect to likelihood of recurrent AF. These data should be taken into account when considering catheter ablation.

Weight Minimization of Truss Using Strain Energy Density and Genetic Algorithm for Single and Multiple Load Cases

Weight Minimization of Truss Using Strain Energy Density and Genetic Algorithm for Single and Multiple Load Cases

Enhancing Network Security in Distributed Systems Using Middle Roman Dominating Functions

A Middle Roman dominating function (MRDN) on a graph G = (V,E) is a function f:v→{0,1,2,3} satisfying the condition that every vertex u with f(u)=0 is adjacent to at most one vertex v with f(v)=2 or 3. Further if a vertex is assigned 2, then at most two of its vertices can be assigned 0 and if a vertex is assigned 3, then all its neighbours can be assigned 0. The weight of a MRDF is the value f(V(G))=∑_uϵV▒〖f(u〗). The Middle Roman domination number γ_MR (G) is the minimum weight of a MRDF on G. In this paper, we introduce Middle Roman Domination number denoted as γ_MR (G), study the properties of the function, present some characterization and determine γ_MR (G)-value for some graphs. Middle Roman Dominating Functions (MRDFs) present a unique approach within graph theory, with significant implications for various fields in computer science. By assigning values to vertices under specific constraints, MRDFs enable the optimization of resources, enhancing network security, load balancing, and energy efficiency in distributed systems. This paper explores the application of MRDFs in scenarios such as intrusion detection, resilient network design, task scheduling, and sensor activation. By minimizing the overall weight while maintaining functional requirements, MRDFs provide an effective strategy for addressing challenges in network topology, resource allocation, and fault tolerance. The versatility of MRDFs makes them a valuable tool in the development of robust and efficient computing systems.

IDSV-GCN: Integrating Dual Syntactic Views Graph Convolutional Network for aspect-based sentiment analysis

Aspect-based sentiment analysis (ABSA) aims to predict the sentiment polarity towards given aspects in a sentence. Recent research has highlighted that graph neural networks based on syntactic dependency trees effectively convey rich syntactic information and are suitable for ABSA tasks. Most existing work typically adopt either dependency type or minimum distance between nodes in the original syntactic tree to construct different views. However, existing work overlooks the high-dimensional local feature information in dependency relations, resulting in inadequate exploration of this view. Meanwhile, most work ignores that the minimum distance view and the dependency view can be complementary and integrated in syntactic analysis. Unfortunately, directly adding the two views introduces noise issues, leading to unsatisfactory results after their integration. To address these issues, this paper introduces an integrating dual syntactic views graph convolutional network (IDSV-GCN) model that seamlessly integrates dependency type view and minimum distance view, enabling comprehensive utilization of syntactic structure and information. To better address the computation of weights in the dependency type view, we innovatively propose a fusion attention mechanism. This approach effectively captures both global and local feature information. To more effectively integrate the two views and reduce the impact of noise, we employ a syntactic mask layer to filter out noise in the dependency type view and highlighting important dependency feature information. Then, we construct a minimum distance weight matrix based on the matrix obtained from the dependency type view. Finally, we merge the two matrices and feed them into the GCN to facilitate the model’s learning of syntactic information. Experimental results on three widely-used benchmark datasets demonstrate that our proposed IDSV-GCN model outperforms state-of-the-art methods.

Rapid fabrication and corrosion behavior of 3D-porous Cu-Al-Si compounds via low-energy self-exothermic reaction

In this study, porous Cu-Al-Si intermetallic compounds with three-dimensional structures were rapidly prepared by a novel self-exothermic reaction. By this method, Si was successfully solid-solved into CuAl intermetallic compounds and achieved better fusion with them. The effects of Si addition on their oxidation resistance and corrosion resistance were compared. The findings indicate that the minimum weight gain of the Cu-Al-Si product is only 1.48 % after oxidation at 800 °C for 288 h. Si facilitates the creation of a continuous Al2O3 protective layer on the surface of the porous Cu-Al-Si intermetallics skeleton, thereby preserving its internal structure while significantly enhancing its oxidation resistance. The incorporation of Si to Cu-Al intermetallics enhances the stability of the passivation film on the material's surface, increases the resistance of the passivation film, and effectively restricts the electrochemical reaction between the material and the corrosive medium.

Economic viability and overall performance analysis of optimized Cu-Fe-ZSM-5 catalyst for NOx and particulate matter removal using NH3-SCR

The necessity of a broader working temperature range of NH3-SCR catalysts has been considered as the need of the hour to tackle air pollutants like NOx and particulate matter (PM). The catalysts currently being used pose varied difficulties in the form of sulphur poisoning, inadequate temperature range, catalyst regeneration etc. An innovative and economic bimetallic combination of Cu-Fe on ZSM-5 with minimum weight percentage of metals and optimum efficiency has been synthesized in this study. In this research, we further focus on this Cu-Fe combination, to understand its feasibility for commercial applications. This bimetallic combination, used on the self-synthesized zeolite (ZSM-5), showed a consistent NOx removal efficiency of above 90% over the entire test temperature range, when compared with a commercially available zeolite. This Cu-Fe combination catalyst performed outstandingly in resisting sulphur poisoning and had NOx and PM emission coefficients well below the standard emissions control of Taiwan. It showed a good N2 selectivity as well. The study also analyses the cost-benefit ratio for the production of this catalyst for industrial applications with an annual net profit of around 14,66,124.09 USD for five parallel units.

Association between Birth Weight of the Babies and Mode of Delivery: A Cross-Sectional Study

Background: Birth weight has significant short and long-term effects on health and survival and is a useful predictor of prenatal and postnatal development. Birth weight is likely to play a key role for the infant’s survival because it is one of the strongest predictors of infant mortality risk. The aim of the study was to find out the association between birth weight and mode of delivery. Methods: This was a cross-sectional study conducted at Combined Military Hospital, Ghatail from 15 March 2019 to 30 June 2019. Secondary data were used, which were collected from hospital register during the period of 01 January 2018 to 31 December 2018. The study population was all the newborn babies delivered in CMH, Ghatail during that period and mothers of the newborn babies were respondents of the study. Results: Out of 526 respondents majority (64.83%) were in the age group of 23-32 years with mean age 25.14(range: 18-40) years. Of the newborn babies around half (48.3%) were male. The mean birth weight was 2.92 kg with minimum weight 1.2 kg and maximum 4.2 kg. The data showed that the prevalence of Low Birth Weight (LBW) 13.1%. Majority (84.6%) of the mothers didn’t have any comorbidity, few (15.4%) suffered from comorbidity. 53.8% babies were born by caesarean section (CS) and 46.2% were delivered by normal vaginal delivery. Among the low birth weight babies 65.2% were born by CS. Statistically significant association was found between birth weight of the babies and mode of delivery (p<0.05). Conclusion: Caesarean section cannot be routinely recommended, unless there are other obstetric indications. Bangladesh Armed Forces Med J Vol 57 No (1) June 2024, pp 8-13

Corrosion resistance analysis of Al2O3-TiO2 composite ceramic coatings on carbon steel pipe surfaces

This study investigates the corrosion resistance of Al2O3-TiO2 composite coatings reinforced with multi-walled carbon nanotubes (MWCNTs) on carbon steel pipe surfaces. Coatings were deposited using atmospheric plasma spraying (APS) and high velocity oxy-fuel (HVOF) techniques. Microstructural analysis revealed that HVOF-sprayed coatings exhibited denser and more homogeneous structures compared to APS-sprayed coatings. Electrochemical tests in 3.5 wt% NaCl solution showed that the HVOF-sprayed Al2O3-13 wt% TiO2-1.5 wt% MWCNT coating demonstrated the lowest corrosion current density of 7.6 × 10−9 A/cm2 and the most positive corrosion potential. Hot corrosion tests in a simulated boiler environment (500°C, 1000 h) revealed that this coating also exhibited minimal weight gain (0.9 mg/cm2) and thickness loss (2 μm). The corrosion rate of the optimal coating was 0.05 mm/year, significantly lower than the bare carbon steel (2.45 mm/year). XRD analysis of corroded samples showed that HVOF-sprayed coatings maintained their original phase composition without detectable substrate corrosion products. The superior corrosion resistance of the HVOF-sprayed Al2O3-13 wt% TiO2-1.5 wt% MWCNT coating is attributed to its optimized composition, dense microstructure, and the reinforcing effect of MWCNTs. These findings provide valuable insights for developing advanced coating solutions to mitigate corrosion-related challenges in the oil and gas industry and other harsh industrial environments.

A Greedy Simulated Annealing-based Multiobjective Algorithm for the Minimum Weight Minimum Connected Dominating Set Problem

A Greedy Simulated Annealing-based Multiobjective Algorithm for the Minimum Weight Minimum Connected Dominating Set Problem