Scaling of average receiving time on double-weighted polygon networks

In this paper, we introduce a class of double-weighted polygon networks with two different meanings of weighted factors [Formula: see text] and [Formula: see text], which represent path-difficulty and path-length, respectively, based on actual traffic networks. Picking an arbitrary node from the hub nodes set as the trap node, and the double-weighted polygon networks are divided into [Formula: see text] blocks by combining with the iterative method. According to biased random walks, the calculation expression of average receiving time (ART) of any polygon networks is given by using the intermediate quantity the mean first-passage time (MFPT), which is applicable to any [Formula: see text] ([Formula: see text]) polygon networks. What is more, we display the specific calculation process and results of ART of the double-weighted quadrilateral networks, indicating that ART grows exponentially with respect to the networks order and the exponent is [Formula: see text] which grows with the product of [Formula: see text]. When [Formula: see text] increases, ART increases linearly ([Formula: see text]) or sublinearly ([Formula: see text]) with the size of networks, and the smaller value of [Formula: see text], the higher transportation efficiency.

Reasoning Method Based on Intervals with Symmetric Truncated Normal Density

Error parameters are inevitable in systems. In formal verification, previous reasoning methods seldom considered the probability information of errors. In this article, errors are described as symmetric truncated normal intervals consisting of the intervals and symmetric truncated normal probability density. Furthermore, we also rigorously prove lemmas and a theorem to partially simplify the calculation process of truncated normal intervals and independently verify the formulas of variance and expectation of symmetric truncated interval given by some scholars. The mathematical derivation process or verification codes are provided for most of the key formulas in this article. Hence, we propose a new reasoning method that combines the probability information of errors with the previous statistical reasoning methods. Finally, an engineering example of the reasoning verification of train acceleration is provided. After simulating the large-scale cases, it is shown that the simulation results are consistent with the theoretical reasoning results. This method needs more calculation, while it is more effective in detecting non-error’s fault factors than other error reasoning methods.

Designing a Document Retrieval Method for University Digital Libraries Based on Hadoop Technology

With the development of big data, all walks of life in society have begun to venture into big data to serve their own enterprises and departments. Big data has been embraced by university digital libraries. The most cumbersome work for the management of university libraries is document retrieval. This article uses Hadoop algorithm to extract semantic keywords and then calculates semantic similarity based on the literature retrieval keyword calculation process. The fast-matching method is used to determine the weight of each keyword, so as to ensure an efficient and accurate document retrieval in digital libraries, thus completing the design of the document retrieval method for university digital libraries based on Hadoop technology.

Kinematics of Articulated Planar Linkages

This paper proposes a kinematics algorithm in screw coordinates for articulated linkages. As the screw consists of velocity and position variables of a joint, the solutions of the forward and inverse velocities are the functions of position coordinates and their time derivatives. The most prominent merit of this kinematic algorithm is that we only need the first order numerical differential interpolation for computing the acceleration. To calculate the displacement, we also only need the first order numerical integral of the velocity. This benefit stems from the screw the coordinates of which are velocity components. Both the forward and the inverse kinematics have the similar calculation process in this method. Through examples of planar open-chain linkage, single closed-chain linkage and multiple closed-chain linkage, the kinematics algorithm is validated. It is particularly fit for developing numerical programmers for forward and inverse kinematics in the same procedures, including the velocity, displacement and acceleration which provide the fundamental information for dynamics of the linkage.

WHY YACHT RUDDERS BREAK

For most sailing yachts, losing a rudder is probably the most catastrophic structural failure other than losing the keel. Rudder failure happens with distressing regularity. This paper examines the hypothesis that the underlying reason is design failure. There are many qualitative decisions to be taken in the design calculation process. Example calculations are presented which show that the maximum rudder force generated in steady state conditions is easily underestimated. For a typical spade rudder of a typical modern production sailing yacht, the normal rudder force should be calculated using a boat speed of at least 125% hull speed, and a force coefficient of at least 1.3. Care must be taken in selecting an appropriate value for the allowable stress of the material used for the stock.

A blind deconvolution algorithm based on backward automatic differentiation and its application to rolling bearing fault diagnosis

Blind deconvolution (BD) is an effective algorithm for enhancing the impulsive signature of rolling bearings. As a convex optimization problem, the existing BDs have poor optimization performance and cannot effectively enhance the impulsive signature excited by weak faults. Moreover, the existing BDs require manual derivation of the calculation process, which brings great inconvenience to the researcher's personalized design of the maximization criterion. A new BD algorithm based on backward automatic differentiation (BAD) is proposed, which is named BADBD. The calculation process does not require manual derivation so a general solution of BDs based on different maximization criteria is realized. BADBD constructs multiple cascaded filters to filter the raw vibration signal, which makes up for the deficiency of single filter performance. The filter coefficients are determined by Adam algorithm, which improves the optimization performance of the proposed BADBD. BADBD is compared with classic BDs by synthesized and real vibration signals. The results reveal superior capability of BADBD to enhance the impulsive signature and the fault diagnosis performance is significantly better than the classic BDs.

Sistem Pendukung Keputusan Pemilihan Sales Terbaik Menggunakan Metode Rank Order Centroid (ROC) dan Additive Ratio Assessment (ARAS) Berbasis Web

Setiap tahun, CV. Anugerah Wangi melakukan pemilihan sales terbaik untuk memotivasi para sales dalam memberikan pelayanan dan peningkatan penjualan sepeda motor. Proses pemilihan sales terbaik masih dilakukan secara manual dengan mengumpulkan data seluruh sales dalam 1 tahun. Pekerjaan ini tentu tidak efektif dan efisien. Selain itu, perhitungan yang dilakukan juga menjadi sulit karena mencakup banyak kriteria penilaian. Karena itulah perlu dibuat suatu sistem pendukung keputusan dalam pemilihan sales terbaik pada CV. Anugerah Wangi yang dapat memudahkan pimpinan untuk melakukan proses perhitungan. Sistem Pendukung Keputusan Pemilihan Sales Terbaik dibuat dengan menggunakan metode Rank Order Centroid (ROC) dan Additive Ratio Assessment (ARAS). Penggabungan metode ROC dan ARAS dapat mengoptimalkan terhadap pembobotan dalam setiap kriteria yang digunakan. Adapun kriteria yang digunakan dalam pemilihan sales terbaik yaitu, jumlah penjualan (C1), penilaian pelayanan (C2), jumlah penjualan (C3), masa bekerja (C4) dan kedisiplinan (C5). Dari penelitian ini, dilakukan uji coba terhadap 23 data sales yang kemudian dilakukan perhitungan sehingga mendapatkan hasil rangking teratas yang menjadi sales terbaik yaitu Faizur Rohman dengan nilai 0,916. Abstract Every year, CV. Anugerah Wangi selects the best sales to motivate sales in providing services and increasing motorcycle sales. The process of selecting the best sales is still done manually by collecting data on all sales in 1 year. This work is certainly not effective and efficient. In addition, the calculations made also become difficult because it includes many assessment criteria. That why it is necessary to make a decision support system in selecting the best sales for CV. Anugerah Wangi. So, it can make it easier for leaders to carry out the calculation process. The Best Sales Selection Decision Support System was made using the Rank Order Centroid (ROC) and Additive Ratio Assessment (ARAS) methods. The combination of ROC and ARAS methods can optimize the weighting in each of the criteria used. The criteria used in the selection of the best sales are the number of sales (C1), service assessment (C2), number of sales (C3), years of service (C4), and discipline (C5). From this study, a trial was carried out on 23 sales data which was then calculated so that the top-ranking results were the best sales, namely Faizur Rohman with a value of 0.916.

ANALISIS KESULITAN PESERTA DIDIK DALAM MENYELESAIKAN SOAL-SOAL POKOK BAHASAN GARIS SINGGUNG LINGKARAN

AbstrakLatar belakang penelitian ini adalah rendahnya hasil belajar matematika peserta didik terhadap pokok bahasan garis singgung lingkaran di SMP Al-Islam Benteng Tellue. Penelitian ini bertujuan untuk mengetahui kesulitan-kesulitan yang dialami peserta didik dalam menyelesaikan soal-soal pokok bahasan garis singgung lingkaran. Pendekatan penelitian yang digunakan yaitu pendekatan kualitatif yang dipadukan dengan jenis penelitian deskriptif. Subjek penelitian yaitu sebanyak 10 orang peserta didik di kelas VIII SMP Al-Islam Benteng Tellue. Pengumpulan data dilakukan dengan menggunakan metode tes dan wawancara. Data dianalisis secara deskriptif. Hasil penelitian menunjukkan kesulitan-kesulitan yang dialami peserta didik dalam menyelesaikan soal-soal pokok bahasan garis singgung lingkaran yaitu kesulitan pemahaman maksud soal yang tergolong rendah; kesulitan pemahaman konsep yang tergolong tinggi; kesulitan proses perhitungan yang tergolong rendah. AbstractThe background of this research is the low achievement of students' mathematics learning outcomes on the subject of circle tangent at SMP Al-Islam Benteng Tellue. This study aims to determine the difficulties experienced by students in solving the tangents to circles. The research approach used is a qualitative approach combined with a descriptive type of research. The research subjects were 10 students in class VIII SMP Al-Islam Benteng Tellue. Data was collected using the test and interview methods. Data were analyzed descriptively. The results of the study indicate that the difficulties experienced by students in solving the questions of the tangent line of the circle are the difficulties in understanding the meaning of the questions are classified as low; the difficulty of understanding the concept is high; the difficulty of the calculation process is low.

A tool (SPOLERC) to guide the evaluation of phosphorus leaching for agricultural soil by using the change point value in the Xingkai Lake Basin, China

Background The soil P leaching change point (CP) has been widely used to evaluate soil P leaching risk. However, an automation calculation method for soil P leaching CP value, and an effective risk grading method performed for classifying soil P leaching risk evaluation have not been developed. Results This study optimized the calculation process for soil P leaching CP value with two different fitting models. Subsequently, based on the Python programming language, a computation tool named Soil Phosphorus Leaching Risk Calculator (SPOLERC) was developed for soil P leaching risk assessment. SPOLERC not only embedded the calculation process of the soil P leaching CP value, but also introduced the single factor index (SFI) method to grade the soil P leaching risk level. The relationships between the soil Olsen-P and leachable P were fitted by using SPOLERC in paddy soils and arid agricultural soils in the Xingkai Lake Basin, and the results showed that there was a good linear fitting relationship between the soil Olsen-P and leachable P; and the CP values were 59.63 and 35.35 mg Olsen-P kg−1 for paddy soils and arid agricultural soils, respectively. Additionally, 32.7, 21.8, and 3.64% of arid agricultural soil samples were at low risk, medium risk, and high risk of P leaching, and 40.6% of paddy soil samples were at low risk. Conclusions SPOLERC can accurately fit the split-line model relationship between the soil Olsen-P and leachable P, and greatly improved the calculation efficiency for the soil P leaching CP value. Additionally, the obtained CP value can be used for soil P leaching risk assessment, which could help recognize key area of soil P leaching.

Dual-Gratings Imaging Spectrometer

Common dispersive-type spectroscopic instruments include prism-type and grating-type, usually using a single dispersive element. The continuous imaging band is always limited by the dispersion angle. When it is necessary to image two wavebands with an ultra-spectral resolution that are far apart, the imaging is difficult due to the large diffraction angle. To broaden the spectral coverage of the imaging spectrometer, in this paper, we propose a dual-gratings imaging spectrometer with two independently rotating gratings. In this proposed system, two very far apart wavelength bands can be imaged in the adjacent areas by adjusting the angle of the dual gratings. This greatly expands the spectral coverage of the imaging spectrometer. Currently, the only application area considered for this instrument is solar applications. In this article, we present the optical system of the dual-gratings imaging spectrometer, illustrate several advantages of the new structure, and discuss new problems caused by the dual-gratings, which are referred to as overlap between two spectra and double image offset. We deduced the calculation process of the dual grating rotation angle, the relationship between the final acquired image and the slit, the relationship between the angle change between the dual gratings and the double image offset, and the relationship between the MTF upper limit reduction and the spatial frequency. This article also summarizes the shortcomings of this structure and studies the applicable fields under these shortcomings. At last, we simulate a dual-gratings imaging spectrometer system, compare this scheme with two traditional schemes, and conclude that this instrument has certain practical significance.