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Tangerang, Indonesia

Saputra K.V.I.,Pelita Harapan University
International Journal of Bifurcation and Chaos | Year: 2015

We investigate a dynamical system having a special structure namely a codimension-one invariant manifold that is preserved under the variation of parameters. We derive conditions such that bifurcations of codimension-one and of codimension-two occur in the system. The normal forms of these bifurcations are derived explicitly. Both local and global bifurcations are analyzed and yield the transcritical bifurcation as the codimension-one bifurcation while the saddle-node-transcritical interaction and the Hopf-transcritical interactions as the codimension-two bifurcations. The unfolding of this degeneracy is also analyzed and reveal global bifurcations such as homoclinic and heteroclinic bifurcations. We apply our results to a modified Lotka-Volterra model and to an infection model in HIV diseases. © 2015 World Scientific Publishing Company. Source


Hardjono B.,Pelita Harapan University
Proceedings of the International Conference on Sensing Technology, ICST | Year: 2016

This paper shows that our novel method, Virtual Detection Zone (VDZ) system with CCTV snap shots can provide the empirical data needed to construct Fundamental Diagrams and to calibrate a chosen model. VDZ system is better than the traditional system which uses loop detectors, as it is able to show zero speeds at totally jammed density, which is an essential parameter for macroscopic traffic model. Real data set have been obtained by using only seven VDZ agents who have carried GPS enabled smart phones, together with snapshots from fifteen existing CCTV, on Tangerang to Jakarta highway (a distance of 21 km). The test, carried out without the use of any intrusive sensors, has produced data which is in agreement with previous traditional method. By adopting and modifying Cell Transmission Model or CTM, a variant Macro model, it is shown that simulated speeds for AM cluster generated by CTM can be calibrated to follow real traffic data. Its Mean Absolute Percentage Error or MAPE can be improved from 93.8 to 48.8% and improved further by 5.1% using type test method. © 2015 IEEE. Source


Saputra K.V.I.,Pelita Harapan University | Quispel G.R.W.,La Trobe University | Van Veen L.,University of Ontario Institute of Technology
Journal of Physics A: Mathematical and Theoretical | Year: 2010

In this paper we develop an integrating factor matrix method to derive conditions for the existence of first integrals. We use this novel method to obtain first integrals, along with the conditions for their existence, for two- and three-dimensional Lotka-Volterra systems with constant terms. The results are compared to previous results obtained by other methods. © 2010 IOP Publishing Ltd. Source


Murwantara I.M.,Pelita Harapan University
Proceedings of the International Conference on Uncertainty Reasoning and Knowledge Engineering, URKE 2011 | Year: 2011

Product Line Architecture is the key success of Software Product Line Engineering. Product Line Architecture prepares the design of architectures for members of product line. Architecture design is the most essential activities of a Product Line Architecture development. It prepares the corner stone of variability decision. The architecture design need to produce specific architecture from product members' assets in a Software Product Line. Representing variability explicitly is the most challenging one. Moreover, the architecture must cope to the diversity of products, and take the behaviour into account. This paper introduces some approaches to address the architecture design problems. Features' grouping with specific concern is the starting point. Then, models the component and interaction element composition, based on its capability. This paper also introduces logics that link the interaction element and component. Using layers, the product line architecture can be established. © 2011 IEEE. Source


Strut-and-Tie models are well-known worldwide as valuable tool in designing D-Regions of Reinforced Concrete members. It has been adopted in many Concrete Structural Codes in many countries. Recently strut-and-tie-models have been included in Indonesia Concrete Structural Code (SNI-03-2847-2012). In this paper, it will be shown how a Strut-and-Tie Model can be developed for various structural concrete deep beams using Evolutionary Structural Optimization. As a tool for this study the author used Bi-Directional Evolutionary Structural Optimization (BESO2D) computer programs, developed by X. Huang and Y.M. Xie [1]. Three tested concrete beams with small, medium, and large opening [2] will be taken as the case study. It will be shown the optimal topology of a plane stress of continuum structures produced from BESO2D can be taken as the basic strutand- tie-model. For design process the best strut-and-tie-model can be delivered from the optimal topology structure only with the deep knowledge of the basic load transfer from loading to support point. © 2015 The Authors. Published by Elsevier Ltd. Published by Elsevier Ltd. Source

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