Large Order Research Articles

Harmonic generation from silicon membranes at visible and ultraviolet wavelengths.

Nonlinear silicon photonics offers unique abilities to generate, manipulate and detect optical signals in nano-devices, with applications based on field localization and large third order nonlinearity. However, at the nanoscale, inefficient nonlinear processes, absorption, and the lack of realistic models limit the nano-engineering of silicon. Here we report measurements of second and third harmonic generation from undoped silicon membranes. Using experimental results and simulations we identify the effective mass of valence electrons, which determines second harmonic generation efficiency, and oscillator parameters that control third order processes. We can then accurately predict the nonlinear optical properties of complex structures, without introducing and artificially separating the effective χ(2) into surface and volume contributions, and by simultaneously including effects of linear and nonlinear dispersions. Our results suggest that judicious exploitation of the nonlinear dispersion of ordinary semiconductors can provide reasonable nonlinear efficiencies and transformational device physics well into the UV range.

An optimal control strategy for execution of large stock orders using long short-term memory networks

We simulate the execution of a large stock order with real data and a general power law in the Almgren and Chriss model. The example we consider is the liquidation of a large position executed over the course of a single trading day in a limit order book. Transaction costs are incurred because large orders walk the order book (that is, they consume order book liquidity beyond the best bid/ask price). We model the order book with a power law that is proportional to trading volume, and thus transaction costs are inversely proportional to a power of the trading volume. We obtain a policy approximation by training a long short-term memory (LSTM) neural network to minimize the transaction costs accumulated when execution is carried out as a sequence of smaller suborders. Using historical Standard & Poor’s 100 price and volume data, we evaluate our LSTM strategy relative to strategies based on the time-weighted average price (TWAP) and volume-weighted average price (VWAP). For execution of a single stock, the input to the LSTM is the cross-section of data on all 100 stocks, including prices, volumes, TWAPs and VWAPs. By using this data cross-section, the LSTM should be able to exploit interstock codependence in volume and price movements, thereby reducing transaction costs for the day. Our tests on Standard & Poor’s 100 data demonstrate that in fact this is so, as our LSTM strategy consistently outperforms TWAP- and VWAP-based strategies.

A review of different deep learning techniques for sperm fertility prediction

<abstract> <p>Sperm morphology analysis (SMA) is a significant factor in diagnosing male infertility. Therefore, healthy sperm detection is of great significance in this process. However, the traditional manual microscopic sperm detection methods have the disadvantages of a long detection cycle, low detection accuracy in large orders, and very complex fertility prediction. Therefore, it is meaningful to apply computer image analysis technology to the field of fertility prediction. Computer image analysis can give high precision and high efficiency in detecting sperm cells. In this article, first, we analyze the existing sperm detection techniques in chronological order, from traditional image processing and machine learning to deep learning methods in segmentation and classification. Then, we analyze and summarize these existing methods and introduce some potential methods, including visual transformers. Finally, the future development direction and challenges of sperm cell detection are discussed. We have summarized 44 related technical papers from 2012 to the present. This review will help researchers have a more comprehensive understanding of the development process, research status, and future trends in the field of fertility prediction and provide a reference for researchers in other fields.</p> </abstract>

Ivanovo-Voznesensk War Industry Committee in 1915–1917: Problems and Achievements

The article examines the activities of the Ivanovo-Voznesensk military-industrial committee in 1915– 1917. Close attention to the object of study is determined by the fact that Ivanovo-Voznesensk was the center of the largest textile region in Russia, and the local military-industrial committee united enterprises with a total number of more than 30 thousand workers. On the basis of the analysis of the archival documents of the committee, the author comes to the conclusion that the sole direction of its activity was the supply of the army with military equipment: the production of grenade and shell cases, and the production of asphyxiant gas. For this, special enterprises (shell and phosgene plants) were founded, generously financed by the members of the Committee. They regularly carried out deliveries for the military department. On the other hand, the local textile enterprises, which fulfilled large defense orders for the supply of fabrics, found themselves outside the sphere of influence of the military-industrial committee. All factories received orders and reported on them independently. Based on this, the thesis is confirmed that the military-industrial committees were not monopolists in the distribution of military orders. Even the attempts of local manufacturers, with the help of the military-industrial committee, to ensure the allocation of additional labor, raw materials, fuel and equipment were not very successful. As a result, no more than 40 % of the capacities of the Ivanovo-Voznesensk textile industry were mobilized for “defense production”. In addition, there is absolutely no trace of the role of the local military-industrial committee in the political organization of the bourgeoisie in Ivanovo-Voznesensk. This can be attributed to the fact that, on the one hand, the committee solved mainly economic problems, and, on the other hand — that the local bourgeoisie had other economic and political organizations that had operated long before the committee was created.

Using irreducible polynomials for random number generation

A method is presented for generating random numbers with uniform distribution using linear recurrence sequences with very large period lengths. This method requires an irreducible polynomial modulo 2 to define the sequence. A suitable method for generating an infinite number of such polynomials is presented. The polynomials generated in this way can have an arbitrarily large degree, and a large enough order to make them suitable for practical applications.

Theory and Experiment of Spatial Light Modulation and Demodulation With Multi-Plane Diffraction and Applications

Spatial light modulation enhances capacity of optical communications by modulating spatial amplitude, phase and polarization degrees of freedom with recent success of orbital angular momentum based architectures. There is a hardware challenge to demodulate large symbol families or high order symbols requiring a general design of spatial light demodulation. Multi-plane diffraction (MPD) recently introduced for improving spatial modulation capabilities in free space optical channels promises utilization at the receiver side as a demodulator. In this article, we theoretically model, numerically simulate and experimentally implement spatial light demodulation based on MPD. Numerical simulations and experimental implementations verify capabilities of MPD for increasing inter-symbol distances at the detector front-end. We obtain approximately two times improvement compared with direct detection for basic design including three diffraction planes as a proof-of-concept and improved performance with increasing number of diffraction planes compared with state-of-the-art single-plane diffraction (SPD) based interferometric receivers. Besides that, we perform, for the first time, experimental implementation of MPD based spatial light modulation. In addition, symmetric-key cryptography application of the proposed system is theoretically presented with low decoder complexity while numerical simulations promise high performance security against intruders. MPD based design is practically applicable and promising for diverse optical architectures including both communications and cryptography as a low-cost, low hardware complexity, passive and high performance design.

New family of root-finding algorithms based on inverse rational interpolation

Inverse interpolation with rational functions is investigated for the use in iterative refinement of the root approximation. A new family of optimal methods of arbitrary large order of convergence for solving nonlinear equations is presented. Experiments are conducted to check the influence of polynomial degrees in numerator and denominator on convergence properties of the proposed methods. Wolfram Mathematica 12 software was used to carry the computation due to its capabilities of arbitrary large precision arithmetic.

Cyclic coverings of graphs. Counting rooted spanning forests and trees, Kirchhoff index, and Jacobians

The purpose of this survey is to describe invariants of cyclic coverings of graphs. The covered graph is assumed to be fixed, and the cyclic covering group has an arbitrarily large order. A classical example of such a covering is a circulant graph. It covers a one-vertex graph with a prescribed number of loops. More sophisticated objects representing the family of cyclic coverings include $I$-, $Y$-, and $H$-graphs, generalized Petersen graphs, sandwich-graphs, discrete tori, and many others. We present analytic formulae for counting rooted spanning forests and trees in cyclic coverings, establish their asymptotics, and study the arithmetic properties of these quantities. Moreover, in the case of circulant graphs we give exact formulae for computing the Kirchhoff index and present structural theorems for the Jacobians of such graphs. Bibliography: 95 titles.

Unification of Tarekat in Indonesia: A Critical Review

This study aims to conduct a critical review of a dissertation on the unification of tarekat in Indonesia. To understand how critical review works, a summary will be made of the dissertation that is used as the object of study. The critical review work step is carried out by trying to present an overview of the dissertation that will be critically reviewed to provide an overview of the material being analyzed. Content analysis is a characteristic of this study, with which opinion interpretations are carried out. The findings of the study explain that this dissertation explains that the Sufistic thoughts of Ahmad Khatib Sambas are considered unique compared to other Sufis, because Ahmad Khatib Sambas succeeded in combining two large orders, namely the Qadiriyah and Naqsyabandiyah Orders which then taught them separately. Apart from that, this tarekat has a quite prominent spirit of activism, as evidenced by several resistance movements against colonialism sponsored by followers of the Qadiriyah and Naqsyabandiyah Tarekat. The results of the critical review show that this research has not succeeded in answering what is at the core of the research problem. The research findings presented are too broad, so they do not focus on the main discussion. In addition, this study also failed to present novelty from previous studies.

A new method to enhance the magnetocaloric effect in (Sc,Ti)Fe2 via magnetic phase separation

Magnetic refrigeration based on the magnetocaloric effect (MCE) is a novel refrigeration technology that will replace traditional vapor-compression refrigeration in the future. Improvement in the performance of MCE materials is crucial for the development of magnetic refrigeration technology. This study presents a new method that enhances the MCE performance of (Sc,Ti)Fe2 via magnetic phase separation. The maximum magnetic entropy change induced by the coexistence of an in-plane ferromagnetic phase (FMab) and a canting antiferromagnetic phase (CAFM) in Sc0.3Ti0.7Fe2 is twice that found in other (Sc,Ti)Fe2 compounds. Variable-temperature neutron diffraction experiments directly reveal that the large magnetic entropy change in Sc0.3Ti0.7Fe2 is dominated by the transformation from a highly ordered FMab state to a CAFM state with a lower magnetic order. The magnetic phase separation is a direct transition from a higher-ordered state with a larger lattice to a lower-ordered state with a smaller lattice that induces a large magnetic order change and lattice contraction. The combination of the metamagnetic transition and negative thermal expansion leads to enhanced MCE. This study suggests the possibility that magnetic phase separation can be an effective approach to achieving and controlling a large MCE in magnetic materials.

Newton’s method and its visualization

Relevance of work. Mathematical modulation in various fields of science and technology often leads to nonlinear equations or systems of such equations. Far from always, these equations can be solved by exact methods. More often it is necessary to use approximate methods. One of the most popular of them is Newton's method. In modern works, Newton's method often serves as the basis for the development of new approximate methods that accelerate the convergence of iterative processes or are used to solve systems of large orders. The goal of the work. Visualize the work of the algorithm for solving the equation, as well as the system of equations according to Newton's method, so that the results of this work could be used when compiling electronic textbooks on the study of this method. Another goal is to study the method in the case when the system has several solutions; to study the possibility of using the method for equations with an infinite number of solutions.

Business-startups in Ukraine: current state and development prospects

Due to the war in Ukraine, all sectors of the economy suffered in one way or another. At the same time, the IT industry remains the most stable sector, which brings a large share of taxes to the budget and thus supports the economy of our country. It is this industry that receives large orders from foreign customers, attracts investors, including large corporations. Any business that is barely born or exists only at the level of an idea and the first organizational steps, provided the necessary expert and financial support, can very soon show dizzying results. Especially if it is an innovative project in the field of IT technologies, marketing, telecommunications, electronic commerce, biotechnology. This is where business incubators come from, which provide support (office, consulting, investment) to startups at all stages from development to commercialization of an idea in exchange for a share in future profits. Perfection has no limits. Innovators take pride in implementing complex solutions, they like to overcome difficulties and use advanced technologies. But, every new project has its price. After all, every strategic decision must be well justified from the business side. Otherwise, it can lead to unplanned costs and release delays. Over the past decade, the Ukrainian startup ecosystem has grown significantly and “grown up”, which has enabled Ukraine to be stable in the technological field in the face of today's challenges. E-commerce, social media, 3D printing, mobile applications – it's no secret that the wealthiest investors willingly invest in these industries. But there are less obvious areas that attract more and more capital every year. Despite the large-scale military actions in Ukraine, European investors are still interested in Ukrainian startups. The secret lies in the mentality of Ukrainians: hard work, dedication and the ability to concentrate under any circumstances. The war changed not only the agenda, but also perspectives. It is the investments that drive Ukraine's recovery and development. Today, the Ministry of Digital Transformation is busy attracting investments for the development of the startup ecosystem, digitalizing Ukraine by introducing innovations on the Diya platform and legalizing the crypto sector. All this is necessary to accelerate the economic recovery of the country already now, without waiting for victory in the war.

Information Capacity of Turbulent and Absorptive Underwater Wireless Link with Perfect Laguerre–Gaussian Beam and Pointing Errors

The model of information capacity for underwater wireless optical communication (UWOC) links with pointing errors and the carrier of perfect Laguerre–Gaussian (PLG) beam in absorbed and weakly turbulent seawater is modeled. Using this model, the influence of channel parameters on the propagation of PLG beams is numerically analyzed. We show that the pointing error significantly reduces the performance of the optical transmission system. Large topological charge and radial orders are not conducive to high information capacity transmission. Additionally, the information capacity decreases with the increase in the spectral absorption coefficient of seawater. With higher transmission power, the transmission of an optical transmission system with high average capacity can be realized. The information capacity is affected by both signal wavelength and seawater absorption coefficient. That is, in the case of small seawater absorption and short message channel, the channel capacity loss of the link with long signal wavelength is smaller. In the case of long channels and strong seawater absorption, the influence of signal wavelength on the average capacity can be ignored. The information capacity of the communication link is the highest, which is composed of the carrier with the OAM topological charge, and the radial orders are both 1, and the wavelength is 410 nm.

Diversity, duplication, and genomic organization of homeobox genes in Lepidoptera.

Homeobox genes encode transcription factors with essential roles in patterning and cell fate in developing animal embryos. Many homeobox genes, including Hox and NK genes, are arranged in gene clusters, a feature likely related to transcriptional control. Sparse taxon sampling and fragmentary genome assemblies mean that little is known about the dynamics of homeobox gene evolution across Lepidoptera or about how changes in homeobox gene number and organization relate to diversity in this large order of insects. Here we analyze an extensive data set of high-quality genomes to characterize the number and organization of all homeobox genes in 123 species of Lepidoptera from 23 taxonomic families. We find most Lepidoptera have around 100 homeobox loci, including an unusual Hox gene cluster in which the lab gene is repositioned and the ro gene is next to pb A topologically associating domain spans much of the gene cluster, suggesting deep regulatory conservation of the Hox cluster arrangement in this insect order. Most Lepidoptera have four Shx genes, divergent zen-derived loci, but these loci underwent dramatic duplication in several lineages, with some moths having over 165 homeobox loci in the Hox gene cluster; this expansion is associated with local LINE element density. In contrast, the NK gene cluster content is more stable, although there are differences in organization compared with other insects, as well as major rearrangements within butterflies. Our analysis represents the first description of homeobox gene content across the order Lepidoptera, exemplifying the potential of newly generated genome assemblies for understanding genome and gene family evolution.

Ancient origin and conserved gene function in terpene pheromone and defense evolution of stink bugs and hemipteran insects

Insects use diverse arrays of small molecules such as metabolites of the large class of terpenes for intra- and inter-specific communication and defense. These molecules are synthesized by specialized metabolic pathways; however, the origin of enzymes involved in terpene biosynthesis and their evolution in insect genomes is still poorly understood. We addressed this question by investigating the evolution of isoprenyl diphosphate synthase (IDS)-like genes with terpene synthase (TPS) function in the family of stink bugs (Pentatomidae) within the large order of piercing–sucking Hemipteran insects. Stink bugs include species of global pest status, many of which emit structurally related 15-carbon sesquiterpenes as sex or aggregation pheromones. We provide evidence for the emergence of IDS-type TPS enzymes at the onset of pentatomid evolution over 100 million years ago, coinciding with the evolution of flowering plants. Stink bugs of different geographical origin maintain small IDS-type families with genes of conserved TPS function, which stands in contrast to the diversification of TPS genes in plants. Expanded gene mining and phylogenetic analysis in other hemipteran insects further provides evidence for an ancient emergence of IDS-like genes under presumed selection for terpene-mediated chemical interactions, and this process occurred independently from a similar evolution of IDS-type TPS genes in beetles. Our findings further suggest differences in TPS diversification in insects and plants in conjunction with different modes of gene functionalization in chemical interactions.

Intrinsic oscillations of viscoelastic three-layer truncated conical shell

Conical shells are used in rocket engineering, construction, aircraft engineering and shipbuilding. The purpose of the present work is to carry out a technique, algorithm and programs for obtaining resonant frequencies and waveforms for circular viscoelastic three-layer conical shells. On the basis of the Lagrange variation equation integral-differential equations of own vibrations are obtained. Based on the method of finite elements, a method for solving the problem of eigen-wear oscillations of the truncated three-layer shell with handedly and freely resting edges was carried out. The problem comes down to solving algebraic equations a large order. Obtained a frequency equation with complex output parameters. The proper oscillations of truncated conical shells are investigated, some characteristic features are revealed. Solving the frequency equation by the Muller method, complex roots are determined. It is established that as the elastic modulus of the shell increases, the real and imaginary parts of the natural frequencies increase accordingly. Paying attention to the rheological properties allows you to increase the values of frequency up to 15%.

A Faster Third-Order Masking of Lookup Tables

Masking of S-boxes using lookup tables is an effective countermeasure to thwart side-channel attacks on block ciphers implemented in software. At first and second orders, the Table-based Masking (TBM) schemes can be very efficient and even faster than circuit-based masking schemes. Ever since the customised second-order TBM schemes were proposed, the focus has been on designing and optimising Higher-Order Table-based Masking (HO-TBM) schemes that facilitate masking at arbitrary order. One of the reasons for this trend is that at large orders HO-TBM schemes are significantly slower and consume a prohibitive amount of RAM memory compared to circuit-based masking schemes such as bit-sliced masking, and hence efforts were targeted in this direction. However, a recent work due to Valiveti and Vivek (TCHES 2021) has demonstrated that the HO-TBM scheme of Coron et al. (TCHES 2018) is feasible to be implemented on memory-constrained devices with pre-processing capability and a competitive online execution time. Yet, currently, there are no customised designs for third-order TBM that are more efficient than instantiating a HO-TBM scheme at third order.In this work, we propose a third-order TBM scheme for arbitrary S-boxes that is secure in the probing model and under compositions, i.e., 3-SNI secure. It is very efficient in terms of the overall running time, compared to the third-order instantiations of state-of-the-art HO-TBM schemes. It also supports the pre-processing functionality. For example, the overall running time of a single execution of the third-order masked AES-128 on a 32-bit ARM-Cortex M4 micro-controller is reduced by about 80% without any overhead on the online execution time. This implies that the online execution time of the proposed scheme is approximately eight times faster than the bit-sliced masked implementation at third order, and it is comparable to the recent scheme of Wang et al. (TCHES 2022) that makes use of reuse of shares. We also present the implementation results for the third-order masked PRESENT cipher. Our work suggests that there is a significant scope for tuning the performance of HO-TBM schemes at lower orders.

Nanoptera in Higher-Order Nonlinear Schrödinger Equations: Effects of Discretization

We consider generalizations of nonlinear Schrödinger equations, which we call “Karpman equations,” that include additional linear higher-order derivatives. Singularly-perturbed Karpman equations produce generalized solitary waves (GSWs) in the form of solitary waves with exponentially small oscillatory tails. Nanoptera are a special type of GSW in which the oscillatory tails do not decay. Previous research on continuous third-order and fourth-order Karpman equations has shown that nanoptera occur in specific settings. We use exponential asymptotic techniques to identify traveling nanoptera in singularly-perturbed continuous Karpman equations. We then study the effect of discretization on nanoptera by applying a finite-difference discretization to continuous Karpman equations and examining traveling-wave solutions. The finite-difference discretization turns a continuous Karpman equation into an advance–delay equation, which we study using exponential asymptotic analysis. By comparing nanoptera in these discrete Karpman equations with nanoptera in their continuous counterparts, we show that the oscillation amplitudes and periods in the nanoptera tails differ in the continuous and discrete equations. We also show that the parameter values at which there is a bifurcation between nanopteron solutions and decaying oscillatory solutions depends on the choice of discretization. Finally, by comparing different higher-order discretizations of the fourth-order Karpman equation, we show that the bifurcation value tends to a nonzero constant for large orders, rather than to 0 as in the associated continuous Karpman equation.

Learning specialists and market resilience

In this paper, I address the stochastic behavior of asset prices set by an imperfectly informed specialist who uses learning technology to refine her knowledge of the order flow. The specialist’s endogenous choice of an information structure is analyzed which fully characterizes her responses to large orders in the market. Specifically, large orders can either be of structural origin, i.e., a disturbance in the asset’s payoff, or an exogenous one associated with noise trading. A specialist with a large learning capacity optimally chooses a pricing function where structural shocks display high persistence, whereas exogenous shocks disappear rapidly. This market structure provides a natural setup to address market resilience, in the sense of the recovery speed of prices.

Room temperature quantum anomalous Hall insulator in honeycomb lattice, RuCS3, with large magnetic anisotropy energy

The quantum anomalous Hall (QAH) effect has attracted enormous attention since it can induce topologically protected conducting edge states in an intrinsic insulating material. For practical quantum applications, the main obstacle is the non-existent room temperature QAH systems, especially with both large topological band gap and robust ferromagnetic order. Here, according to first-principles calculations, we predict the realization of the room temperature QAH effect in a two-dimensional (2D) honeycomb lattice, RuCS3 with a non-zero Chern number of C = 1. Especially, the nontrivial topology band gap reaches up to 336 meV for RuCS3. Moreover, we find that RuCS3 has a large magnetic anisotropy energy (2.065 meV) and high Curie temperature (696 K). We further find that the non-trivial topological properties are robust against the biaxial strain. The robust topological and magnetic properties make RuCS3 have great applications in room temperature spintronics and nanoelectronics.