Roberd Saragih

Smart city dashboard for integrating various data of sensor networks

Urban growth may lead to various problems. The increasing number of citizens at urban areas may lead the increasing of demand such as new residential, public health, public transport. A city require basic infrastructure such as educational facilities, housing, clean water, sanitation, solid waste, electricity, telecommunications and so on. In the socio-economic level the increasing of city residents must be supplied with availability of jobs. A city must be managed and planned well to handle problems such as traffic congestion, air quality, water quality, water supply, energy supplies, and public health quality and so on. At this paper, we proposed tool using information technology and communication (ICT) to help local government to monitoring what currently happened in the city. We proposed application for monitoring city in single dashboard to help summarize the current condition of city. The architecture system use network sensor consisting of sensor nodes that has function to capture city condition like temperature, air pollution, water pollution, traffic situation. Also we can add another information socio-economic situation like public health service, economic indicator, energy supplies, etc. We have successfully developed the prototype of the smart city dashboard the give more accurate information of Bandung City, one of big cities in Indonesia.

Environmental and disaster sensing using cloud computing infrastructure

The remote monitoring system is growing very rapidly due to the growth of supporting technologies as well. Problem that may occur in remote monitoring such as the number of objects to be monitored and how fast, how much data to be transmitted to the data center to be processed properly. This study proposes using a cloud computing infrastructure as processing center in the remote sensing data. This study focuses on the situation for sensing on the environment condition and disaster early detection. Where those two things, it has become an important issue, especially in big cities big cities that have many residents. This study proposes to build the conceptual and also prototype model in a comprehensive manner from the remote terminal unit until development method for data retrieval. We also propose using FTR-HTTP method to guarantee the delivery from remote client to server.

Designing active vibration control with minimum order for flexible structure

This paper concerned with the designing active control for flexible structure. The structure has 4 stories and each story is modeled such that it has a single degree of freedom in the transverse direction and one more degree of freedom in the angle of torsion around the centroid of the story. The model of structure, absorber and stroke are combined such that the number of state is 30. The order of state is reduced up to 7th order by using the balanced truncation. The active control is designed by using the H∞ -control theory.

Building crawler engine on cloud computing infrastructure

This paper is aimed to create implementation crawler engine or search engine using cloud computing infrastructure. This approach use virtual machines on a cloud computing infrastructure to run service engine crawlers and also for application servers. Based on our initial experiments, this research has successfully built crawler engine that runs on Virtual Machine (VM) of cloud computing infrastructure. The use of Virtual Machine (VM) on this architecture will help to ease setup or installation, maintenance or VM terminating that has been running with some particular service crawler engine as needed. With this infrastructure, the increasing or decreasing in capacity and capability of multiple engine crawlers could set easily and more efficiently.

Modification of a steepest descent control for output tracking of some class non-minimum phase nonlinear systems

The problem of output tracking for a class of nonlinear systems whose zero dynamics are not necessarily stable is addressed in this paper. To solve the problem, we transform the systems into a normal form which is minimum phase with respect to a virtual output, which is a linear combination of state variables. By applying the modified steepest descent control, the system output track to the desired output.

Model Reduction of Bilinear System Using Balanced Singular Perturbation

This paper is concerned with generalize model order reduction using the balanced singular perturbation for bilinear system. We first transform the bilinear system to be balanced realization and then we divide the state into the fast and the slow mode. By setting the velocity of the fast mode equal to zeros, we obtain the bilinear system with lower order. To verify the proposed method, the simulation is carried out on a nonlinear RC circuit and the results show that this method is able to approximate a high order model is similar to the balanced truncation method.

Robust H∞ Control for Bilinear Systems Using the Dynamic Takagi-Sugeno Fuzzy Models Based on Linear Matrix Inequalities

The robust H∞ control design for bilinear systems with multi inputs is presented in this paper. First, the bilinear system is represented as a dynamic Takagi-Sugeno (TS) fuzzy system by using sector nonlinearity approach. The dynamic TS fuzzy system is a convex combination of local linear systems. The local robust H∞ controller is designed for each local linear system. The controller synthesis for the local linear systems is then formulated in the bilinear matrix inequalities (BMIs) problem. After that, the BMIs problem is reduced to an equivalent parameter of linear matrix inequalities (LMIs) problem which has a feasible solution. The robust H∞ controller for bilinear systems as a convex combination of the local robust H∞ controllers is obtained by using defuzzyfication. The existence condition of the robust H∞ controller for the bilinear systems is also presented. The simulation results are given to clarify the proposed method for the robust H∞ control design of the bilinear systems.

Reduced order bilinear time invariant systems using singular perturbation

Model order reduction of bilinear time invariant systems based on H∞ norm or least upper bound of difference equation is presented in this paper. The difference equation of the bilinear time invariant system is presented as error transfer function between full order and reduced order of the bilinear time invariant system. The proposed method is graphically easier than using alteration of Hankel singular values. The least upper bound of the error transfer function and H∞ norm of difference bilinear system are a function of controllability gramian. In this paper, the reduced bilinear system is carried out by using singular perturbation method. The numerical simulation results are given to clarify the proposed method for selection of reduced order bilinear time invariant system.

Parameters optimization of flexible structure using genetic algorithm

This paper concerned with the problem of optimization of parameters for the flexible structure. The structure has 4 stories and each story is modeled such that it has a single degree of freedom in the transverse direction and one more degree of freedom in the angle of torsion around the centroid of the story. The model of structure, absorber and stroke are combined such that the number of state is 30. The process of optimization is to minimize the H∞ -norm from closed loop transfer function of the system which implies suppressing the magnitude peaks vibration of the frequency response. Parameters optimization of flexible structure system becomes an H∞ -output feedback problem. This problem is transformed to Bilinear Matrix Inequality problem and then it is solved by using the genetic algorithm.

Design of passive control for flexible structure using genetic algorithm

A Genetic Algorithm (GA) based approach for design of H∞ passive control for a flexible structure is presented. The flexible structure has six degrees of freedom and the control system is designed by using the H∞-control theory. The passive control is to minimize the H∞-norm from closed loop transfer function of the system which implies suppressing the magnitude peaks vibration of the frequency response. Parameters optimization of flexible structure system becomes an H∞-output feedback problem. This problem is transformed to Bilinear Matrix Inequality problem and then it is solved by using GA. The GA is distinguished by their parallel investigation of several areas of a search space simultaneously to locate a global extreme by manipulating a population with randomized operators. The numerical simulations are conducted for examining the performance of the passive control. From this result, we can conclude that the GA is better than Nguyen method.