OGY Control of Haken Like Systems on Different Poincare Sections

The Chua system, the Lorenz system, the Chen system and The L\"u system are chaotic systems that their state space equations is very similar to Haken system which is a nonlinear model of a optical slow-fast system. These Haken-Like Sys-tems have very similar properties. All have two slow but unstable eigenvalues and one fastest but stable eigenvalue. This lets that an approximation of slow manifold be equivalent with unstable manifold of the system. In other hand, control of discreet model of the system on a defined manifold (Poincare map) is main essence of some important control methods of chaotic systems for example OGY method. Here, by using different methods of defining slow manifold of the H-L systems the efficiency of the OGY control for stabilizing problem investigated.Comment: 4 page

Transformasi Digital Perusahaan Dengan Ekonomi 5.0 Melalui Iot

Ekonomi digital (Ekonomi 5.0) saat ini terus berkembang di dunia tak terkecuali di Indonesia, Ekonomi 5.0 telah mengubah paradigma bisnis secara fundamental dengan memanfaatkan teknologi digital, kecerdasan buatan, dan konektivitas yang semakin meningkat, hal ini ditandai dari meningkatnya pengguna internet. Awal tahun 2021 pengguna internet di Indonesia mencapai 202,6 juta jiwa meningkat 15,5 persen atau 27 juta jiwa jika dibandingkan pada Januari 2020. Terlebih saat pandemi covid-19 telah merubah mekanisme pelayanan jasa dan perilaku konsumen. Para pelaku usaha perlu berinovasi agar bagaimana bisa menyelaraskan kebiasaan baru para konsumen dari model jual beli konvensional menjadi e-commerce. Transformasi ekonomi digital adalah proses yang harus membutuhkan dukungan dari segala sektor internal di Indonesia untuk berinvestasi dalam teknologi informasi dan komunikasi. Bisnis dan pemerintah di seluruh dunia sedang aktif mengembangkan strategi untuk memanfaatkan potensi transformasi ekonomi digital untuk meningkatkan pertumbuhan ekonomi dan menciptakan peluang baru bagi masyarakat dan bisnis. Maka dari itu penulisan ini di tujukan untuk menjelaskan pengembangan, transformasi, tren dan inovasi serta dampak baik dan buruknya. Pada akhirnya banyak peluang yang akan di rasakan oleh pelaku bisnis di era digital ini terlebih untuk kemitraan gelobal dalam mengembangkan bisnisnya agar lebih efektif dan efisien. Meski demikian, tantangan melibatkan pemilihan alat Business Process Management (BPM) yang sesuai, resistensi praktisi BPM terhadap teknologi baru, dan integrasi yang kurang optimal dengan persyaratan IoT dengan mengidentifikasi praktik terbaik, dampak integrasi teknologi canggih (AI, Big Data, Cloud Computing), dan mengungkap tantangan operasional dengan mengelola proses bisnis dengan lebih efektif di tengah tantangan perubahan teknologi yang terus berkembang. Keywords: Dampak, Tantangan, Peluang, Transformasi digital, IoT, kemajuan perekonomian, BPM, Ekonomi 5.0, AI

Towards Integrating Hybrid DAEs with a High-Index DAE Solver

J.D. Pryce and N.S. Nedialkov have developed a Taylor series method and a C++ package, DaeTs, for solving numerically an initial-value problem differential-algebraic equation (DAE) that can be of high index, high order, nonlinear, and fully implicit. Numerical results have shown this method to be efficient and very accurate, and particularly suitable for problems that are of too high an index for present DAE solvers. However, DaeTs cannot be applied to systems of DAEs that change at points it time, also called hybrid or multi-mode DAEs. This paper presents methods for extending Daets with the capability to integrate hybrid DAEs. Methods for event location and consistent initializations are given. Daets is applied to simulate a model of a parallel robot: a hybrid system of index-3 DAEs with closed-loop control

IMPLEMENTATION OF PROJECT ORIENTED PROBLEM-BASED LEARNING (POPBL) MODEL INTEGRATED WITH STEM TO ENHANCE JUNIOR HIGH SCHOOL STUDENTS' SCIENCE CONCEPT MASTERY

The low ability of students to solve problems is in line with the low mastery of science concepts. In this study, Science, Technology, Engineering, and Mathematics (STEM) integrated Project Oriented Problem Based Learning (POPBL) learning models were implemented to improve the mastery of science concepts of junior high school students, especially on the topic of Environmental Pollution. The method used was a mixed-method. The STEM integrated STB learning model design framework consists of 3 stages: Onset Stage, Execution Stage, and Closure Stage. The concept of students is emphasized at the onset stage in the case study dissemination phase. In this phase, students analyze problems based on articles provided by the teacher. The more understanding the material, the more critical students will explore existing issues and find logical solutions to those problems. The results showed that there was a difference between the average pretest and posttest learning outcomes (t=-5,660; df = 53; Sig. (2-tailed) = 0,000). This indicates an increase in junior high school students' science concepts mastery after using the STEM integrated POPBL Learning Model. Improving students' mastery of concepts using a STEM integrated POPBL learning model is still in the low category with n-gain = 0.17. Although still in the low category, the POPBL learning model with the STEM approach can be optimized to improve students' mastery of concepts and skills on other science topics

Reconstructing the potential for the 1D Schrödinger equation from boundary measurements

International audienceWe consider the inverse problem of determining the potential in the dynamical Schrödinger equation on the interval by the measurement on the boundary. We use the Boundary Control method to recover the spectrum of the problem from the observation at either left or right end points. Using the specificity of the one-dimensional situation we recover the spectral function, reducing the problem to the classical one which could be treated by known methods. We apply the algorithm to the situation when only the finite number of eigenvalues are known and prove the convergence of the method

Photoassisted tunneling from free-standing GaAs thin films into metallic surfaces

The tunnel photocurrent between a gold surface and a free-standing semiconducting thin film excited from the rear by above bandgap light has been measured as a function of applied bias, tunnel distance and excitation light power. The results are compared with the predictions of a model which includes the bias dependence of the tunnel barrier height and the bias-induced decrease of surface recombination velocity. It is found that i) the tunnel photocurrent from the conduction band dominates that from surface states. ii) At large tunnel distance the exponential bias dependence of the current is explained by that of the tunnel barrier height, while at small distance the change of surface recombination velocity is dominant