Line Arrangements Research Articles

Production Track Balance Analysis Using The Moodie Young Method

The purpose of this study was to find out the efficiency level of the production line by using the Moodie Young method. Where the method was used to determine the balance level of the production line consisted of 3 parts, namely: Line Efficiency, Balance Delay, and Smooth Index.The results showed that in the actual production line arrangement, there were 5 workstations with 7 work elements with Line Efficiency results of 40.29 %, Balance Delay of 59.70%, and Smoothness Index of 9578.22.

Bending-active kirigami

Kirigami techniques use prescribed arrangements of cuts and fold lines to transform 2D sheet materials into complex 3D forms. These sheet transformations occur via elastic deformations, rigid folding motions, and/or pop-up mechanisms; design techniques for kirigami patterns are correspondingly based on mechanics, kinematics, and physical prototyping. This paper proposes a new family of pop-up kirigami patterns termed ‘bending-active kirigami’, which transform flat sheets into approximated double-curved surfaces using a simple 1-DOF actuation mechanism. A pattern design technique is first developed from a combination of the well-known ‘elastica’ solution for the large elastic deformation of slender rods, with the kinematic constraints imposed by a kirigami pop-up mechanism. This combination creates a rapid and intuitive design method for specification of a formed surface and its constituent kirigami pattern. An extended family of patterns are then developed based on other elastica solutions and pop-up mechanism types. Finally, a bending-active kirigami pattern is applied to the design of a deployable structure, with measurements of a physical prototype used to verify the developed design method.

The initial degree of symbolic powers of Fermat-like ideals of planes and lines arrangements

We explicitly compute the least degree of generators of all symbolic powers of the defining ideal of Fermat-like configuration of lines in except for the second symbolic powers, where we provide bounds for them. We will also explicitly compute those numbers for ideal determining the singular locus of the arrangement of lines given by the pseudoreflection group A 3. As direct applications, we verify Chudnovsky’s(-like) Conjecture, Demailly’s(-like) Conjecture and Harbourne-Huneke Containment problem as well as calculate the Waldschmidt constant and (asymptotic) resurgence number.

Peru: 2022 Article IV Consultation-Press Release; Staff Report; and Statement by the Executive Director for Peru

After being hit very hard by the pandemic in 2020, both in terms of health and economic outcomes, Peru experienced an equally strong economic rebound in 2021. A new administration was inaugurated in July 2021 with a program focused on reducing inequality and improving social conditions, but limited support from Congress and lack of cohesion heightened political uncertainty. While real GDP surpassed its pre-pandemic level by 2021, labor force participation and total employment have not fully recovered yet. Poverty increased significantly in 2020 and, despite some improvement in 2021, remains higher than in 2019. On May 27, 2021, the IMF Executive Board completed the mid-term review of Peru’s continued qualification under the Flexible Credit Line (FCL) arrangement.

Some open questions about line arrangements in the projective plane

Despite that the study of line arrangements in the projective plane is old and elemental, there is still a long list of intriguing open questions and applications to modern mathematics. Our goal is to discuss part of that list, focusing on the connection with Chern invariants and pointing towards configurations of rational curves.

Point line geometry in the tropical plane

We study the classical result by Bruijn and Erdős regarding the bound on the number of lines determined by a n-point configuration in the plane, and in the light of the recently proven Tropical Sylvester-Gallai theorem, come up with a tropical version of the above-mentioned result. In this work, we introduce stable tropical lines, which help in answering questions pertaining to incidence geometry in the tropical plane. Projective duality in the tropical plane helps in translating the question for stable lines to stable intersections that have been previously studied in depth. Invoking duality between Newton subdivisions and line arrangements, we are able to classify stable intersections with shapes of cells in subdivisions, and this ultimately helps us in coming up with a bound. In this process, we also encounter various unique properties of linear Newton subdivisions which are dual to tropical line arrangements.

Research on the Heating of Woven Carbon Fiber Fabrics Using Thin-Film Solar Cells

Abstract This study attempted to fabricate heating fabrics using thin-film solar cells. A lightweight and flexible thin-film solar cell was used as the power supply, and fabric samples made of carbon fiber heating lines were used as heating elements. Single-factor experiments of three factors (solar cell voltage, heating time, and carbon fiber heating line arrangement) were conducted, and their influence on the heating effect was analysed. Orthogonal experiments and variance tests were used to determine the influence of the three factors and the optimal heating process. All influential factors were shown to be statistically significant. This kind of heating fabric can be used in warm clothing or for heated clothing.

Shelter Effect of Pedestrian Wind behind Row Trees in a Line Arrangement

Flow past a single-line arrangement of evenly-spaced row trees, in an open territory, was numerically simulated under the action of a boundary-layer type of oncoming flow, with a strength of “strong breeze”, based on the Beaufort scale. By selecting Koelreuteria henryi as the demonstrated tree species, the spatial wind speed variations behind row trees at the pedestrian level, at various tree heights and tree spaces, were analyzed to investigate the corresponding downstream shelter effects from a systematic basis. Based on the results of the analyses, the tendency of stream-wise wind speed variations behind the row trees was presented so as to provide additional insights into row-tree planning for protection against ground wind. Moreover, in other cases of row trees with similar crown shapes and properties, resulting flow fields for various tree heights and tree spaces can provide referable quantitative information, which can be readily used to conduct tentative shelter effect assessments and pedestrian comfort evaluations in a preliminary planning stage.

Validation of Stability-Indicating RP-HPLC Method and Determination of Impurities by LC-QTOF-MS for Adenosine in Eye Drops

Presently, there is no validated method for stability-indicating related substances of adenosine used in the treatment of cataracts and found in different combined eye drop products. A stability-indicating related substances analytical method for adenosine used in the treatment of cataracts and found in different combined eye drop products should be developed and validated. A new reverse phase-HPLC method of determination for adenosine-related compounds has been developed and validated according to the International Council for Harmonisation. In this method, all impurities were easily detected for adenosine, which is found in combination with different active ingredients such as nicotinic acid and nicotinamide. The impurities obtained by a stress test were purified and their structures were characterized by mass spectroscopy (LC-QTOF-MS). The concentration range for linearity was evaluated as 0.06-4.27 µg/mL for adenosine, 0.15-4.27 µg/mL for uridine, 0.15-4.17 µg/mL for inosine, 0.13-4.35 µg/mL for guanosine, and 0.12-4.26 µg/mL for adenine. Good linearity was achieved for each component, and it was determined that the correlation coefficient (r) met the acceptance criterion r ≥ 0.99. The accuracy of the method was good-to-excellent recoveries at each concentration level (from LOQ to 120% of the specification limit) were achieved within the limit range of 80.0-120.0%, and RSD of recoveries was found below 10.0% for both formulations. With this economical and simple method validated in accordance with the ICH Q2 (R1) guideline, a new method has been created for adenosine, which is suitable for routine analysis. The validated method is a very simple and suitable method for green chemistry without any pre-processing, and the structure of the impurities obtained as a result of stress studies was confirmed by LC-QTOF-MS.

Concept for Construction of Unmanned Ferry Lines on Russia’s Inland Waterways

This article considers the prospects of building highly automated ferry lines on the internal waterways of Russia. To do this, the authors used the engineering-cybernetical approach to determine the basic provisions of the concept for the construction of unmanned ferry lines. The key provisions of the concept account for the integration of unmanned ferry lines in the river information and communications triad based on the hierarchical principle: the corporate river information and communications service - the river information service - the automated ship-traffic control system. The authors consider the prospects of using unmanned ferry lines on rivers where the navigation and information support for the unmanned ferry can be provided using radio technical facilities covering both the points of departure and destination. The authors also reviewed the arrangement of unmanned ferry lines for situations where the departure point and the destination are far from each other. This type of unmanned ferry line is suitable for reservoirs or large lakes.Finally, the research work also provides a rationalization of the selection of the automation level for unmanned ferry lines following the terminology used by the work team for inland water transport of the Committee for the Inland Water Transport of the UN Economic Commission for Europe (UNECE).

The loop-linking number of line arrangements

In his Ph.D. thesis, Cadegan-Schlieper constructs an invariant of the embedded topology of a line arrangement which generalizes the \(\mathcal {I}\)-invariant introduced by Artal, Florens and the author. This new invariant is called the loop-linking number in the present paper. We refine the result of Cadegan-Schlieper by proving that the loop-linking number is an invariant of the homeomorphism type of the arrangement complement. We give two effective methods to compute this invariant, both are based on the braid monodromy. As an application, we detect an arithmetic Zariski pair of arrangements with 11 lines whose coefficients are in the 5th cyclotomic field. Furthermore, we also prove that the fundamental groups of their complements are not isomorphic; it is the Zariski pair with the fewest number of lines which have this property. We also detect an arithmetic Zariski triple with 12 lines whose complements have non-isomorphic fundamental groups. In the appendix, we give 29 combinatorial types which lead to similar ordered arithmetic Zariski pairs of 11 lines. To conclude this paper, we give a additivity theorem for the union of arrangements. This first allows us to prove that the complements of Rybnikov’s arrangements are not homeomorphic, and then leads us to a generalization of Rybnikov’s result. Lastly, we use it to prove the existence of homotopy-equivalent lattice-isomorphic arrangements which have non-homeomorphic complements.

Arrangements of Approaching Pseudo-Lines

We consider arrangements of n pseudo-lines in the Euclidean plane where each pseudo-line ell _i is represented by a bi-infinite connected x-monotone curve f_i(x), x in mathbb {R}, such that for any two pseudo-lines ell _i and ell _j with i !<! j, the function x !mapsto ! f_j(x) !-! f_i(x) is monotonically decreasing and surjective (i.e., the pseudo-lines approach each other until they cross, and then move away from each other). We show that such arrangements of approaching pseudo-lines, under some aspects, behave similar to arrangements of lines, while for other aspects, they share the freedom of general pseudo-line arrangements. For the former, we prove:There are arrangements of pseudo-lines that are not realizable with approaching pseudo-lines.Every arrangement of approaching pseudo-lines has a dual generalized configuration of points with an underlying arrangement of approaching pseudo-lines. For the latter, we show:There are 2^{Theta (n^2)} isomorphism classes of arrangements of approaching pseudo-lines (while there are only 2^{Theta (n log n)} isomorphism classes of line arrangements).It can be decided in polynomial time whether an allowable sequence is realizable by an arrangement of approaching pseudo-lines. Furthermore, arrangements of approaching pseudo-lines can be transformed into each other by flipping triangular cells, i.e., they have a connected flip graph, and every bichromatic arrangement of this type contains a bichromatic triangular cell.

The Maximum-Level Vertex in an Arrangement of Lines

The Maximum-Level Vertex in an Arrangement of Lines

The Hochschild cohomology of the algebra of differential operators tangent to a central arrangement of lines

Given a central arrangement of lines \mathcal{A} in a 2 -dimensional vector space V over a field of characteristic zero, we study the algebra \mathscr{D}(\mathcal{A}) of differential operators on V which are logarithmic along \mathcal{A} . Among other things we determine the Hochschild cohomology of \mathscr{D}(\mathcal{A}) as a Gerstenhaber algebra, establish a connection between that cohomology and the de Rham cohomology of the complement M(\mathcal{A}) of the arrangement, determine the isomorphism group of \mathscr{D}(\mathcal{A}) and classify the algebras of that form up to isomorphism.

A Comparative Study between Polyline and Straight Line Arrangements of Antislide Piles Based on Soil Arching Effect

Considering the limitations of terrain and engineering expenses, antislide piles are sometimes arranged in polylines. Studies show that this arrangement adversely affects the mechanical characteristics of antislide piles. However, there is no in‐deep understanding of this issue and the structural design and calculation method of this arrangement have not been discussed in relevant standards. Aiming at resolving this shortcoming, the polylines pile arrangement is studied in this article to provide a scientific basis for designing and calculating antislide piles. To this end, the cantilever pile is taken as the research background, and the soil arching effect between piles is taken as the research object. Then the performances of the single‐row polyline pile layout and straight line pile layout are analyzed in the Dawanjiang landslide and the results are verified from the aspects of the landslide reinforcement and the influence on the antislide pile structure. The obtained results show that the polyline pile layout is disadvantageous to the safety of the antislide pile structure, and the soil arch between piles under the polyline pile layout condition is not uniform. Meanwhile, it is found that as the polyline pile layout angle increases, the stress concentration appears at the “inflection point.” Under this circumstance, the soil arch between piles is not uniform, and the stress concentration intensifies.

Characterizing the Steady-State Performance of AC Lines Through a Dimensionless Universal Model

This paper revisits the AC power line model. Based solely on three dimensionless parameters, a universal electrical model is first developed, which is valid for any kind of power line (overhead, underground/submarine or gas insulated), irrespective of its rated voltage and length. Then, by neglecting the shunt losses, compact expressions are obtained in terms of the two remaining parameters for all electrical magnitudes characterizing the steady-state behavior of any line, such as real and reactive power flows at both ends, losses, charging current, transmission capability, etc. As a result, universal parameterized curves are also provided, including the well-known PV and P- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\delta $ </tex-math></inline-formula> curves. Moreover, numerical ranges of defining parameters are obtained for a diversity of present or future line arrangements, rated voltages and lengths, which are then represented as clusters of points on the universal curves. Beyond educational purposes, the proposed formulation and the associated characteristic curves can be useful, at the planning or design stages, when a certain degree of parameter uncertainty is still present, in order to compare different designs, or when selecting the most suitable simplified model for a particular case study, before fully defining the line features (type of conductor, phase-to-phase clearance, type of configuration, insulation, etc.).

Divides with cusps and Kirby diagrams for line arrangements

The complement of a complexified real line arrangement is an affine surface. It is classically known that such a space has a handle decomposition up to 2-handles. We will describe the handle decomposition induced from Lefschetz hyperplane section theorem for such a space. To describe the Kirby diagram, we introduce the notion of the divide with cusps which is a generalization of the divide introduced by A'Campo.

A Greedy Algorithm to Compute Arrangements of Lines in the Projective Plane

We introduce a greedy algorithm optimizing arrangements of lines with respect to a property. We apply this algorithm to the case of simpliciality: it recovers all known simplicial arrangements of lines in a very short time and also produces a yet unknown simplicial arrangement with 35 lines. We compute a (certainly incomplete) database of combinatorially simplicial complex arrangements of hyperplanes with up to 50 lines. Surprisingly, it contains several examples whose matroids have an infinite space of realizations up to projectivities.

Research on UAV Three-Phase Transmission Line Tracking and Localization Method Based on Electric Field Sensor Array.

The tracking and positioning of transmission lines is a key element for UAVs (Unmanned Aerial Vehicles) to achieve autonomous inspection of transmission lines. Current methods are vulnerable to weather and environmental factors, have high costs, and have difficulties in data processing. Therefore, this paper proposes a transmission line tracking and localization method based on the electric field sensor array, which calculates the current UAV’s heading angle deflection angle, the distance between the transmission line and the UAV, and the elevation angle, providing a new idea to solve the problem of UAV inspection of transmission lines. At the same time, the electric field distribution of different arrangements of three-phase transmission lines was analyzed using COMSOL to determine the flight area of the UAV. By comparing the electric field distribution of the UAV flight area and single-phase transmission lines, it was verified that the current method is also applicable in the three-phase transmission line scenario, and it was further verified that the sensor array used can sense the change of the UAV position in the flight area, indicating that the electric field sensor array can realize the transmission line tracking and localization of transmission lines. The experimental results showed that, in the three-phase transmission line scenario, when the sensor array moves along the transmission straight wire, the maximum absolute error of the heading angle deflection angle calculated according to this method was 8.2°, the maximum absolute error of the distance between the array and the transmission line was 19.3 cm, and the maximum absolute error of the elevation angle was 11.37°; the error was within a reasonable range and can be used for the UAV to realize autonomous inspection.

Unity, Complexity, dan Intensity Lukisan Karya Yazid

This study discusses how to understand the unity, complexity, and intensity of Yazid's painting using Monroe Beardsley's theory. Yazid is a West Sumatran artist who is quite famous for his naturalist flow and cannot be separated from the concept of natural beauty. This study uses a qualitative method which includes observation, interviews, and literature study. The research was conducted in the cities of Padang, Padang Pariaman and Padangpanjang, West Sumatra. After conducting research, it was found that Unity (unity) in Yazid's paintings as a whole shows how the arrangement of lines, colors, and compositions are produced in a perfect shape so that it looks like a unity. This makes for distinctive strokes and soft colors and object capture. The complexity of Yazid's paintings can be seen in the lighting which is described as similar to what is captured by the five senses so that the object does not look simple. How Yazid tries to present the refraction of light that is shown in each of his paintings. The intensity (seriousness) in Yazid's paintings can be seen in the lighting as the key in each of his works.