Complex Calculations Research Articles

Effect of Column Deformation for Steel Frames with Semi-rigid Connection

As semi-rigid behaviour will give a more economical design, it should be applied in the structural steel design. The properties of semi-rigid connection may affect the column design and is the main focus in this study. Complex calculation with semi-rigid consideration in design may cause unfavourable time consuming. Therefore, a simplified column design is needed to eliminate complicated procedures while accommodating the semi-rigid condition. In this analysis, the validated finite element procedure has been used for the analysis of a semi-rigid column in a non-sway frame. Parametric study was performed within variables of types of connection, loading patterns, locations of investigated column and column base fixity. The influences of column slenderness and beam flexibilities were also included and the implications towards the column design were then identified.

Investigation of Criteria for Comparing of Natural and LED Radiation Spectral Distribution

The difference in the spectral composition of artificial and natural lighting can negatively affect health, as well as lead to a distorted perception of the color of surrounding objects. At the same time, a certain correction of the spectral composition of visible radiation in medical institutions and workplaces has a positive effect on human health, while can be carried lighting control out taking into account the data of personal sensor devices that determine the human condition. The purpose of the research was to select criteria for comparing natural and LED optical and visible radiation by spectral composition and by the visibility of color differences in natural and LED lighting. The effectiveness of the application of known and developed criteria for assessing the difference in the spectral composition of optical and visible radiation from natural and LED sources was investigated, as well as for the visibility of color differences in natural and LED lighting. To minimize the values of criteria are proposed additive and subtractive methods for calculating LED parameters. Their comparison allowed us to conclude that a more complex calculation algorithm, but higher performance for an additive technique than for a subtractive one with the same minimization results.It was found that to simulate the spectral composition of natural radiation using LEDs, it is most effective to use the criteria "standard deviations of the relative differences between the optical and visible spectral components of natural and LED radiation". A comparison of the criteria for the visibility of color differences in natural and LED lighting showed approximately the same effectiveness of using the criteria "small color differences" and "standard deviation by photoreceptors" at the present stage and the prospects for applying the second criterion, provided that its acceptable values are established.

Data Processing of Bridge IoT Monitoring Based on Task Scheduling of Cloud Service Listening Signal

For the long-term continuous monitoring of bridge-related indicators, it is necessary to arrange relatively perfect acquisition equipment on the bridge, which can feedback various information parameters of the bridge. However, there are many parameters to feedback the bridge information, which leads to the complex and overstaffed structure of the monitoring system. Furthermore, the huge amount of data collected and the complex calculation process also increase the difficulty of the operation of the monitoring system. In this regard, we should choose more scientific and reasonable indicators, lightweight data structure, stable data transmission, and analysis programs to improve the accuracy of continuous monitoring. To establish a stable and efficient bridge monitoring system, we use the distance coefficient-effective independent algorithm to optimize. Then, we calculate the relevant information of the strain environment with the help of a neural network model, strengthen the training of deep learning through the YOLOv5s model, and improve the task scheduling strategy of attention concentration. Through that, we solve the problem of embedded systems with relatively low computing power. Different weights are assigned to each fused feature map, and the nodes at the highest level and the lowest level are deleted so that a concise and efficient lightweight network model is constructed. Multiple iterations are performed to achieve deeper feature fusion. Therefore, the complexity of the model is effectively reduced, and the monitoring performance can be effectively improved. Finally, through the experimental analysis, it is proved that compared with the traditional fusion model, the number of parameters of the improved fusion network structure in bridge health monitoring is reduced by 7.37%. The detection speed is increased by 18.2%. The amount of computation is reduced by 42.92%, and the average detection accuracy is required to reach 95.33%. It is verified that the proposed method can effectively improve the accuracy and risk control ability of the detection data by learning from the samples with small labels. It also has great practical significance and market value for the design and optimization of the bridge health monitoring system, which is suitable for the monitoring data of large-scale construction projects.

Tensile fracture of blunt V-notches in rectangular plates additively manufactured from Acrylonitrile Butadiene Styrene with different raster angles

In this research, the tensile fracture behavior of rectangular specimens made of Acrylonitrile Butadiene Styrene (ABS) containing double-edge blunt V-notches is evaluated. The specimens are printed using the fused deposition modeling (FDM) technique with five different raster angles and three different notch tip radii. To simplify the complex calculations related to the anisotropic behavior of these specimens, the Virtual Isotropic Material Concept (VIMC) is used in conjunction with three well-known linear elastic notch fracture mechanics (LENFM) criteria, i.e., the mean stress (MS), point stress (PS), and averaged strain energy density (ASED) criteria as well as the extended finite element method (XFEM). It is shown that all these fracture models can predict the load-bearing capacity of the 3D-printed notched specimens by acceptable accuracies, where the best predictions belong to the MS criterion with the critical distance obtained directly from the finite element method, and the least accurate predictions belong to the XFEM method.

Inspector Gadget

We introduce InspectorGadget, an Open-Source Python-based software for assessing and comparing the complexity of masking gadgets. By providing a limited set of characteristics of a hardware platform, our tool allows to estimate the cost of a masking gadget in terms of cycle count equivalent and memory footprint. InspectorGadget is highly flexible. It enables the user to define her own estimation functions, as well as to expand the set of gadgets and predefined microcontrollers. As a case-study, we produce a fair comparison of several masked versions of Kyber compression function from the literature, together with novel alternatives automatically generated by our tool. Our results confirm that an interesting middle ground exists between theoretical performance measures (asymptotic complexity or operations count) and real implementations benchmarks (clock cycle accurate evaluations). InspectorGadget offers both simplicity and genericity while capturing the main performance-related parameters of a hardware platform.

Copy Number Profiling Implicates Thin High-Grade Squamous Intraepithelial Lesions as a True Precursor of Cervical Human Papillomavirus-Induced Squamous Cell Cancer

Full-thickness high-grade squamous intraepithelial lesions (HSIL) are precursors of invasive cervical squamous cell carcinoma (SCC). The World Health Organization and Lower Anogenital Squamous Terminology Standardization Project for human papilloma virus (HPV)–associated lesions divide full-thickness HSIL of the cervix into thin HSIL with thickness of 1 to 9 cell layers and the typical full-thickness HSIL of >10 cell layers. Although HPV oncogene transcripts and p16ink4a overexpression, as markers of transforming HPV infection, are detectable in thin HSIL, the biological significance of thin HSIL in cervical carcinogenesis remains poorly understood. To further characterize thin HSIL, we performed a comparative study of chromosomal copy number variations (CNV), an analysis of dysregulated genes present in the segments with CNV, and a generalized genetic complexity calculation for 31 thin HSIL, 31 thick HSIL, 24 microinvasive SCC (pT1a SCC), and 22 highly invasive SCC samples. Thin HSIL share various CNV and specific dysregulated gene pathways with thick HSIL and invasive SCC. Thin HSIL exhibited an average CNV of 11.6% compared with 14.1% for thick HSIL, 15.5% for pT1a SCC, and 26.6% for highly invasive SCC. The CNV included gains at 1q and 3q (40% and 43%, respectively), partial loss of 3p, and loss of chromosomes 11 (18%), 16 (50%), 20 (35%), and 22 (40%). Pathways affected solely in thin HSIL were those enhancing immune evasion and primarily involved the (interleukin) IL6, IL21, and IL23 genes. ILs are transiently upregulated in response to infection and play a crucial role in mounting antitumor T-cell activity. Deregulation reflects an attempt by the HPV to evade the initial immune response of the host. The primary pathways shared by thick HSIL and invasive SCC were interactions between lymphoid and nonlymphoid cells, NOTCH2 signaling, tight junction interactions (primarily of the claudin family), and FGR2 alternative splicing. Our results show that thin HSIL carry similar genetic changes as thick HSIL and SCC, indicating that thin HSIL are true precursor lesions that can progress to thick HSIL and SCC.

No existence of a linear algorithm for the one-dimensional Fourier phase retrieval

Fourier phase retrieval, which aims to reconstruct a signal from its Fourier magnitude, is of fundamental importance in fields of engineering and science. In this paper, we provide a theoretical understanding of algorithms for the one-dimensional Fourier phase retrieval problem. Specifically, we demonstrate that if an algorithm exists which can reconstruct an arbitrary signal x∈CN in Poly(N)log⁡(1/ϵ) time to reach ϵ-precision from its magnitude of discrete Fourier transform and its initial value x(0), then P=NP. This partially elucidates the phenomenon that, despite the fact that almost all signals are uniquely determined by their Fourier magnitude and the absolute value of their initial value |x(0)|, no algorithm with theoretical guarantees has been proposed in the last few decades. Our proofs employ the result in computational complexity theory that the Product Partition problem is NP-complete in the strong sense.

Cryptanalysis of the cryptosystems based on the generalized hidden discrete logarithm problem

In this paper, we will solve an important form of hidden discrete logarithm problem (HDLP) and a generalized form of HDLP (GHDLP) over non-commutative associative algebras (FNAAs). We will reduce them to discrete logarithm problem (DLP) in a finite field through analyzing the eigenvalues of the representation matrix. Through the analysis of computational complexity, we will show that HDLP and GHDLP are not good improvements of DLP. With all the instruments in hand, we will break a series of corresponding schemes. Thus, we can conclude that all ideas of constructing cryptographic schemes based on the two solved problems are of no practical significance.

Parameterized complexity of candidate nomination for elections based on positional scoring rules

Consider elections where the set of candidates is partitioned into parties, and each party must nominate exactly one candidate. The Possible President problem asks whether some candidate of a given party can become the unique winner of the election for some nominations from other parties. We perform a multivariate computational complexity analysis of Possible President for several classes of elections based on positional scoring rules. We consider the following parameters: the size of the largest party, the number of parties, the number of voters and the number of voter types. We provide a complete computational map of Possible President in the sense that for each choice of the four possible parameters as (i) constant, (ii) parameter, or (iii) unbounded, we classify the computational complexity of the resulting problem as either polynomial-time solvable or NP-complete, and for parameterized versions as either fixed-parameter tractable or W[1]-hard with respect to the parameters considered.

A Practical Approach to Alignment and Error Feedback Control for Long-Span Arch Bridges

The accurate installation of long-span arch bridges’ arch ribs remains a challenge due to the complex calculations required for cable forces and arch rib displacements, as well as the significant influence of environmental and construction loads. In this study, we propose a practical approach to alignment and error feedback control for long-span arch bridges. Cable forces were optimized using multiple control objectives based on influence matrix principles. The impact of temperature on the next segment to be installed was analyzed using the metastatic GM(1, 1) model and fitting results. Several tunable parameters were employed to account for parameter errors and environmental interference. These parameters were adjusted based on the deviations between practical and theoretical alignments for different arch rib segments, achieving a model output of an offset-free-tracking arch rib structure. This technology was applied to monitor the construction of the Tian’e Longtan Grand Bridge. Compared to conventional alignment control approaches, the proposed method achieved excellent arch ring alignment after the closure of the high-accuracy arch rib and cable release, as well as effective control of cable force uniformity and tower deviation. Field measurement data indicate that the closing deviation of the arch ring is only 3 mm. This study provides a valuable reference for the construction control of long-span arch bridges.

Secure multiparty computation protocol based on homomorphic encryption and its application in blockchain

Blockchain technology is a key technology in the current information field and has been widely used in various industries. Blockchain technology faces significant challenges in privacy protection while ensuring data immutability and transparency, so it is crucial to implement private computing in blockchain. To target the privacy issues in blockchain, we design a secure multi-party computation (SMPC) protocol DHSMPC based on homomorphic encryption in this paper. On the one hand, homomorphic encryption technology can directly operate on ciphertext, solving the privacy problem in the blockchain. On the other hand, this paper designs the directed decryption function of DHSMPC to resist malicious opponents in the CRS model, so that authorized users who do not participate in the calculation can also access the decryption results of secure multi-party computation. Analytical and experimental results show that DHSMPC has smaller ciphertext size and stronger performance than existing SMPC protocols. The protocol makes it possible to implement complex calculations in multi-party scenarios and is proven to be resistant to various semi-malicious attacks, ensuring data security and privacy. Finally, this article combines the designed DHSMPC protocol with blockchain and cloud computing, showing how to use this solution to achieve trusted data management in specific scenarios.

Modeling of ice-matrix composite fracture

This article discusses the results of a study that used the structural approach to conduct multiscale modeling of composite materials. These materials are composed of an ice matrix that has been enhanced with high-strength basalt fibers. The research involved numerical modeling to analyze the fracture process of composite materials made by freezing fresh water with added basalt fibers. The analysis included experimental data from samples of pure ice and composites with different amounts of filler. The effective modulus of elasticity of the composites was determined by considering the quantity of basalt fiber reinforcement. The discrepancy between the strength obtained by finite element complex ANSYS numerical calculation and the experimental data was revealed by a series of macroscopic test calculations of the composite material sample, according to which the effective modulus of elasticity of the composite was recalculated and corrections were introduced into the Voight and Reuss models, taking into account the non-uniform distribution of the fibers and the non-ideal adhesion between the fibers and water ice. A stochastic model of crack growth at the micro level was also used with the data on the diameter and length of basalt fibers and their random distribution in the layers of the composite material. Using the newly acquired effective elastic moduli and the SmartCrackGrowth algorithm, a satisfactory agreement of the crack growth rate with the obtained by stochastic calculation was achieved. The refined method of effective elastic moduli and multilevel model of stress-strain state calculation of composite materials are recommended for assessing the strength of ice cover and designing winter roads with high load-bearing capacity and long operational duration in the Arctic and Subarctic environments.

Explicit unsupervised feature selection based on structured graph and locally linear embedding

Numerous redundant and irrelevant features are usually contained in high-dimensional data whose presence, if ignored, can bring detrimental effects on the performance of data processing tasks. Unsupervised feature selection (UFS) as a trending topic in a great deal of domains has been greatly concerned, which can effectively filter out redundant and irrelevant features in the unlabeled data. The majority of existing UFS methods mainly focus on building the parameterized model in the original feature space or some certain low-dimensional feature subspace, which cannot fully capture the information of the target space. In this work, we propose a novel UFS method that unifies the explicit feature selective matrix and structured graph into a learning framework. An explicit selection matrix, whose scale, bound of the elements and structure are considered, is tailored for UFS. Furthermore, we take into account the local consistency so that the low dimensional manifold structures can be preserved to a better degree. Instead of using the pre-defined similarity matrix to construct graph, we make use of the way of learning to obtain the adaptive graph. Besides, for the purpose of exploiting the cluster structure of data, we impose a rank constraint on the graph. Notably, both the explicit selection matrix and intrinsic structure are learned in the target feature subspace, and thus the proposed methodology is more straightforward and effective. We present an effective and efficient algorithm for the resulting problem based on alternative optimization strategy, and establish its convergence and computational complexity analysis. The experimental results show that our proposed approach has improved by over 5.28% and 5.79% on average in terms of clustering accuracy (ACC) and Normalized Mutual Information (NMI) compared with comparison methods, which demonstrates its superiority.

Coding all clauses in L2 data: A call for consistency

Linguistic complexity is considered a hallmark of language proficiency (Norris & Ortega, 2009), and it is often a focus of second language (L2) research (Pallotti, 2015). Within the construct of complexity, syntactic complexity considers the combination of words and clauses. The term clause, however, is underspecified in the field, and L2 researchers only occasionally define how clause is operationalized in the coding. After a review of the importance of consistent clause coding, this commentary argues that coordinated verb phrases, nonfinite clauses, and verbal small clauses can reach the complexity of finite clauses by the production of another element, making these constructions commensurate with subordinate finite clauses. Since these constructions are structurally similar to accepted clauses (e.g., imperatives), their exclusion from the clausal complexity calculation threatens the validity and reliability of the coding. Because a narrow definition requires an arbitrary division along a continuum of complex verbal constructions, the field should adopt this broader definition of clause. Further, researchers should clarify their methodology choices and acknowledge coding challenges, which are common in L2 data, especially L2 speech data. The increased transparency in research methodology supports the interpretation of research results and facilitates comparisons across L2 studies.

Finite Element Model Updating Method for Radio Telescope Antenna Based on Parameter Optimization with Surrogate Model

There are deviations between the radio telescope antenna finite element (FE) model, founded on the design stage, and the actual working antenna structure. The original FE model cannot accurately describe the antenna structure deformation characteristics under the environmental load, thereby compromising the accuracy of the active structural compensation. This article proposes an antenna FE model updating method founded on parameter optimization with a surrogate model. The updating method updates the modulus of elasticity parameters of different components of the antenna backup structure (BUS) to obtain finite element analysis (FEA) results consistent with the actual measurement of the antenna reflector surface shape. The surrogate model founded on the multi-quadratic radial basis function (RBF) improves the computational efficiency of FE model updating, replacing the complex and time-consuming finite element analysis and calculation process. This method is implemented on a radio telescope antenna with an aperture of 25 m. The results show a significant reduction in the mismatch between the antenna and the updated FE model. This method’s calculation time is significantly reduced compared with the updating method without using the surrogate model, with the RBF surrogate model taking 1% of the time of the finite element model in the FEA calculations. The proposed method can improve the antenna FE model calculation accuracy and significantly enhance the efficiency of FE model updating calculations. Thus, it can offer a reference for antenna engineering practice.

Analysis of visual communication elements in variable font design from the perspective of digital technology

With the maturity of digital technology, the effectiveness of information transmission has received extensive attention. Variable font design is regarded as an extension of graphic design in digital media art, and variable font design is studied from the perspective of information communication design. From the perspective of digital technology, based on the research theory of variable information communication design, combined with the specific methods of font design, the perception, cognitive methods, and aesthetic laws of aesthetic subject vision and psychology in the field of font variable design are discussed. Provide relevant theoretical support for information communication design activities with variable fonts. Based on artificial intelligence technology, a new interactive art expression method is proposed. By analyzing the main expression scenarios of interactive art, namely user information communication scenarios, interactive art push scenarios, interactive art promotion scenarios and personal service scenarios, it provides a scenario application basis for interactive expression, calculate the space complexity, space complexity and resource complexity, according to the complexity calculation results, carry out interaction design from three aspects of visual elements, multimedia elements, and human-computer interaction elements, integrate the topology structure after the interaction is realized, and in the network topology structure. The proposed model consists mainly of visual design, basic design elements, basic visual design, complete design and solution generation. It realizes the expression of interactive art of multimedia elements in display and control. The experimental results show that the interactive element extraction speed of the visual communication expression method based on artificial intelligence technology is increased by 30%, and the flexibility is stronger.

A simplified model for correcting the heating capacity of air source heat pumps in high-altitude plateau areas

The performance of air source heat pumps (ASHPs) is typically evaluated in plain areas, leaving limited insight into their performance in high-altitude plateau areas. To address this, a simplified fitting model is proposed to correct ASHP heating capacity in plateau areas. The structure of the fitting model is deduced based on physical principles. Then we regress the model on simulation data calculated by a complex model from previous study. Finally, the fitting model is validated by both simulation data and field test data from four ASHP projects comprehensively. Utilizing the fitting model, the influence of outdoor temperature and altitudes on the correction factor are fully discussed. Results show that the proposed fitting model is easy to facilitate in practical engineering. Only three sets of experiments are required to determine the constant coefficients of the fitting model, thus eliminating the necessity of establishing a complex calculation model for ASHP systems. The heating capacity and correction factors of ASHPs in the plateau areas can be accurately calculated by the proposed fitting model. The maximum error is around 0.5 % compared with the model in a previous study. When compared with the monitored data from real projects, approximately 80 %∼85 % of the points fall within the ±20 % error line. For every 1000 m increase in altitude, the heating capacity decreases by approximately 3.9 %–5.1 %. The proposed fitting model offers simplicity and convenience for designing ASHP heating systems in high-altitude plateau areas.

Алгоритм планирования маршрута БПЛА в условиях недостатка визуальных ориентиров

Today, unmanned aircraft is used to solve a variety of tasks. One of the problems that arise when using unmanned aerial vehicles (UAVs) is the problem of navigation, in particular, determining their exact location in space. Today, there are various methods to solve this problem. A promising way to solve it in conditions where it is impossible to use a satellite navigation system is video navigation systems that use visual landmarks to determine location. In this paper, an overview of the existing types of UAV video navigation systems was carried out. The peculiarities of the operation of video navigation systems using the comparison of visual landmarks with satellite maps were also highlighted. The task was set to find a route in conditions of a lack of visual landmarks, in which the problem of losing reference points may arise. The graph data format used is described, which stores the values of the metric of the diversity of the underlying surface, which characterizes the magnitude of the probability of the problem of losing reference points. The existing algorithms for finding a path in a graph are considered and the need to develop a new algorithm is justified. A theoretical description of the algorithm was proposed, in which the path search process is divided into two stages: first, a solution option is searched for with the maximum value of the metric of diversity of the underlying surface, and then a route with the minimum length is selected. Several options of the implementation of the proposed algorithm were also presented and their asymptotic complexity was estimated. Based on the theoretical description, a software implementation of the proposed algorithm was developed and an experimental verification of the correctness of its operation on a test card with various flight tasks was performed. According to the test results, the proposed algorithm has shown its effectiveness by constructing routes correctly in all test examples. In the future, this algorithm can be used as part of the UAV video navigation system. The main advantages and disadvantages of the proposed algorithm were also described and ways for its further improvement were proposed.

Complete area-coverage path planner for surface cleaning in hospital settings using mobile dual-arm robot and GBNN with heuristics

Complete area-coverage path planners are essential for robots performing tasks like cleaning, inspection, and surveying. However, they often involve complex calculations, mapping, and determining movement directions, leading to high computational or processing overheads and the risk of deadlocks. This paper proposes an approach for cleaning, i.e., by linear wiping of generic and discontinuous surfaces in hospital settings using inhouse assembled mobile dual-arm (MDA) robotic system. The proposed framework introduces key features: (a) a less resource-intensive approach for MDA positioning and cleaning surface mapping, (b) Modified Glasius Bioinspired Neural Network through use of heuristics (GBNN+H) to optimize surface linear wiping while obstacle avoidance, and traversal across discontinuous surfaces. The advantages of the proposed algorithm are highlighted in simulation with GBNN+H significantly reduces the number of steps and flight time required for complete coverage compared to existing algorithms. The proposed framework is also experimentally demonstrated in a hospital setting, paving the way for improved automation in cleaning and disinfection tasks. Overall, this work presents a generic and versatile, applicable to various surface orientations and complexities.

Experimental evaluation and design of fillet welds under in-plane eccentric loads

The principal objective of this investigation is to furnish equations to compute the design strength of fillet welds under in-plane eccentric loads suitable for load and resistance factor design (LRFD) applications. Over the years, experimental and analytical techniques have been used to arrive at safe estimates for the strength of such welds in common practical applications. The conventional elastic design (ED) method is very conservative and is not compatible with the LRFD design philosophy. In addition, the ED method neglects the weld group's ductility and strain compatibility. On the other hand, the instantaneous center of rotation (IC) method considers the above parameters but requires complex calculations. In the present study, a method for designing fillet welds under eccentric loading is introduced called the plastic design (PD) method. This method considers the inelastic properties of the welds in a simple manner while providing an accurate prediction of the weld group's capacity. The performance of the proposed PD method was compared with the IC method for several cases. The ultimate loads obtained were mostly within 10% difference on the conservative side and only marginally different for a few. Additionally, the fillet weld group's resistance under in-plane eccentric loads was evaluated experimentally using 12C-shaped specimens with the load applied at different angles of 0, 45, and 75°. The test results also confirmed the efficacy of the proposed PD method in evaluating the design strength of such weld groups.