An improved support vector regression and its modelling of manoeuvring performance in multidisciplinary ship design optimization

In this paper, the combination of the Laplace loss function and Support Vector Regression (SVR) are presented for the estimation of manoeuvring performance in multidisciplinary ship design optimization, and a new SVR algorithm was proposed, which has only one parameter to control the errors and automatically minimized with v, and adds b2/2 b to the item of confidence interval. It is shown that the proposed SVR algorithm in conjunction with the Laplace loss function can estimate the ship manoeuvring performance appropriately compared to the simulation results with Napa software and other approximation methods such as Artificial Neural Network (ANN) and classic SVR. In this article, we also gather enough ship information about the offshore support vessel; the Latin Hypercube Design is employed to explore the design space. Instead of requiring the evaluation of expensive simulation codes, we establish the metamedels of ship manoeuvring performance; all the numerical results show the effectiveness and practicability of the new approximation algorithms

Approaching quantum anomalous Hall effect in proximity-coupled YIG/graphene/h-BN sandwich structure

Quantum anomalous Hall state is expected to emerge in Dirac electron systems such as graphene under both sufficiently strong exchange and spin-orbit interactions. In pristine graphene, neither interaction exists; however, both interactions can be acquired by coupling graphene to a magnetic insulator (MI) as revealed by the anomalous Hall effect. Here, we show enhanced magnetic proximity coupling by sandwiching graphene between a ferrimagnetic insulator yttrium iron garnet (YIG) and hexagonal-boron nitride (h-BN) which also serves as a top gate dielectric. By sweeping the top-gate voltage, we observe Fermi level-dependent anomalous Hall conductance. As the Dirac point is approached from both electron and hole sides, the anomalous Hall conductance reaches 1/4 of the quantum anomalous Hall conductance 2e2/h. The exchange coupling strength is determined to be as high as 27 meV from the transition temperature of the induced magnetic phase. YIG/graphene/h-BN is an excellent heterostructure for demonstrating proximity-induced interactions in two-dimensional electron systems

Nonlinear photonic crystals near the supercollimation point

We uncover a strong coupling between nonlinearity and diffraction in a photonic crystal at the supercollimation point. We show this is modeled by a nonlinear diffraction term in a nonlinear schroedinger type equation, in which the properties of solitons are investigated. Linear stability analysis shows solitons are stable in an existence domain that obeys the Vakhitov-Kolokolov criterium. In addition, we investigate the influence of the nonlinear diffraction on soliton collision scenarios.Comment: 16 pages, 3 figures, being published in Optics Letter

Experimental study of needle-tissue interaction forces: effect of needle geometries, insertion methods and tissue characteristics.

A thorough understanding of needle-tissue interaction mechanics is necessary to optimize needle design, achieve robotically needle steering, and establish surgical simulation system. It is obvious that the interaction is influenced by numerous variable parameters, which are divided into three categories: needle geometries, insertion methods, and tissue characteristics. A series of experiments are performed to explore the effect of influence factors (material samples n=5 for each factor) on the insertion force. Data were collected from different biological tissues and a special tissue-equivalent phantom with similar mechanical properties, using a 1-DOF mechanical testing system instrumented with a 6-DOF force/torque (F/T) sensor. The experimental results indicate that three basic phases (deformation, insertion, and extraction phase) are existent during needle penetration. Needle diameter (0.7-3.2mm), needle tip (blunt, diamond, conical, and beveled) and bevel angle (10-85°) are turned out to have a great influence on insertion force, so do the insertion velocity (0.5-10mm/s), drive mode (robot-assisted and hand-held), and the insertion process (interrupted and continuous). Different tissues such as skin, muscle, fat, liver capsule and vessel are proved to generate various force cures, which can contribute to the judgement of the needle position and provide efficient insertion strategy

Distributed constraint optimization for discrete-time multiagent systems with event-triggered communication

This paper investigates the distributed optimization problem (DOP) with equality constraint in discrete-time multiagent systems (MASs) in which the global optimization objective is constituted by the summation of local objective functions. Firstly, by employing the Lagrange multiplier method, we convert the convex optimization problem with equality constraint into a consensus problem of MASs. Secondly, to reduce the communication burden, a type of event-triggered control protocol is proposed to enable all agents achieving consensus. Thirdly, by employing the Lyapunov function method and a set of inequality techniques, we establish some sufficient conditions to ensure that all agents converge to consensus and successfully solve the original DOP. Finally, a numerical simulation example is presented to validate the effectiveness of the theoretical analysis

SLAM for Multiple Extended Targets using 5G Signal

5th Generation (5G) mobile communication systems operating at around 28 GHz have the potential to be applied to simultaneous localization and mapping (SLAM). Most existing 5G SLAM studies estimate environment as many point targets, instead of extended targets. In this paper, we focus on the performance analysis of 5G SLAM for multiple extended targets. To evaluate the mapping performance of multiple extended targets, a new mapping error metric, named extended targets generalized optimal sub-pattern assignment (ET-GOPSA), is proposed in this paper. Compared with the existing metrics, ET-GOPSA not only considers the accuracy error of target estimation, the cost of missing detection, the cost of false detection, but also the cost of matching the estimated point with the extended target. To evaluate the performance of 5G signal in SLAM, we analyze and simulate the mapping error of 5G signal sensing by ET-GOPSA. Simulation results show that, under the condition of SNR = 10 dB, 5G signal sensing can barely meet to meet the requirements of SLAM for multiple extended targets with the carrier frequency of 28 GHz, the bandwidth of 1.23 GHz, and the antenna size of 32

Persepsi Masyarakat terhadap Alun-alun Kota Bandung sebagai Ruang Terbuka Publik

Bandung merupakan sebuah kota yang strategis yang memiliki nilai sejarah yang cukup panjang dalam masa perjuangan. Alun alun Bandung merupakan hasil warisan ciri kota tradisional yang dibangun oleh penguasa kolonial yang merupakan pusat ruang terbuka kota. Dari masa kemasa Alun-alun kota Bandung telah mengalami beberapa kali Perubahan, baik bentuk maupun fungsinya sehingga mengakibatkan degradasi makna terhadap fungsinya bagi masyarakat Kota Bandung itu sendiri. Maka fenomena tersebut mengarahkan kepada pertanyaan penelitian yaitu bagaimana persepsi masyarakat terhadap Alun-alun Kota Bandung ditinjau sebagai ruang terbuka publik. Tujuan penelitian ini adalah untuk mengetahui persepsi masyarakat terhadap Alun-alun Kota Bandung. Dari tujuan tersebut maka sasaran yang dilakukan adalah mengidentifikasi karakter dan fungsi ruang terbuka publik yaitu fungsi ekologis, arsitektural, dan sosial. Dari hasil analisis dengan menggunakan kuesioner yaitu uji sampel dengan regresi linear sederhana dengan pendekatan analisis pengguna dan analisis karakteristik ruang terbuka publik. Hasil penelitian ini menghasilkan penilaian baik terhadap korelasi variabel bebas yaitu persepsi masyarakat terhadap variabel terikat yaitu Alun-alun Kota Bandung, setiap kali pertanyaan yang berkenaan dengan Persepsi masyarakat terhadap Alun-alun Kota Bandung akan mempengaruhi nilai hasil pengujian yang cenderung meningkat akan keberadaan Alun-alun itu sendiri. Hasil penelitian ini bisa dimanfaatkan untuk mengangkat kembali citra Alun-alun Kota Bandung sebagai ruang publik atau (Central Square).[Public Perception of The Alun-alun Bandung as Public Open Space] Bandung is a city that has a value that strategic long history in the struggle. Alun Bandung square is the result of inherited traits of traditional town built by the colonial rulers which is the center of the city open space. Over time, Bandung town square has undergone several changes, both form and function, resulting in degradation of the meaning of the function for the city of London itself. The phenomenon then leads to the research question is how the public perception of the square is the city of Bandung reviewed as public open space for the present study tries to analyze the function of the existence of Bandung City Square as a public space. The purpose of this study was to determine the public perception of the square is the city of Bandung. From these objectives, the target does is identify the character and function of public open space that is the function of ecological, architectural and social. From the analysis by using a questionnaire that test samples with a simple linear regression analysis approach and analysis of the characteristics of users of public open space. The results of this study resulted in better assessment of the correlation of the independent variable is the public perception of the dependent variable is the town square of Bandung, every time queries regarding the public\u27s perception of the town square Bandung will affect the value of the test results are likely to increase in the existence Square itself. the results of this study can be used to lift the image of Bandung city square as a public space or (Central Square)