Ruki Harwahyu

Low-rate ring backbone with dual-hop coverage ZigBee network

In this paper, we present a new concept of ZigBee backbone by utilizing ZigBee technology for the use of low-rate wireless medium-distance link. The backbone is mainly used for connecting sensor devices around the backbone location to the gateway device. Non-beacon enabled ZigBee operation mode is considered in this backbone with ring topology enhanced by dual-hop coverage setting. We present an analytical model to evaluate the performance of the backbone in term of its success transmission probability and suggest the optimal backbone configuration. The accuracy of the model is confirmed using computer-based simulation.

Implementation of Color-Blind Aid System

Color-blind is a physical defect causing patient lo ses the ability to recognize colors either particul ar or the whole of them. This disability is problematic in da ily life, moreover in some specific areas that requ ire carefulness eyesight. We propose a vision aid kit w ith improved user experience, such as finger pointe r and voice command-and-response. Our work proofs the design and implementation of color-blind aid system fo r embedded and mobile device. This study used Windows Embedded Standard 2009, Windows Phone 7, Speech API library, Open CV library and EmguCV wrapper. The performance of each functionality is evaluated. From various testing that are conducted, the system can best detect color samples with prec ision level of 90.67% on embedded device implementation and 95.33% on mobile device implementation. The best fingertip detection rate attained is 89.6% wit h normal lighting condition. The voice command works with detection rate of 75.87%, meanwhile for the sy nthesized speech response, 88, 33% respondents can understood the words well.

Performance estimation of AODV variant with trust mechanism

Several research effort in recent years has shown its significant interest in the development of security measure in the routing of Mobile Ad-hoc Network (MANET). Ad-hoc On-demand Distance Vector (AODV) routing protocol has been one of the basic protocol that is modified to cope with security demands. This paper present an analytical model to evaluate the performance of AODV variant that is developed to be secure with malicious node detection and trust mechanism. Since the performance of MANET is tightly depends on the underlying topology of the nodes, route establishment may fail due to nodes movement or malicious activity. The analytical model aims to provide the basic performance insight in the form of the route establishment probability of the MANET with and without malicious nodes. The model is important for MANET designer to optimize the connectivity for all nodes.

Implementing Speech Feature for Embedded System to Support Color Blind People

Speech feature can be an alternative interaction model for embedded device that is designed without many buttons for control. In this work, we create colorblind aid system. This paper compares speech feature created using SAPI5.1 with speech feature created manually using phoneme concatenation and DTW, and assess their performance in WinCE6 and WES09 embedded OS environment. The testing for speech feature is conducted by 10 respondents to identify words synthesized by systems and to say words to be recognized by systems. Testing for the OS is conducted by observing size, boot time, and their support for the speech feature. As the result, speech feature created using SAPI5.1 is better than the manually-created one, with success rate 88, 33% for speech synthesis and 75, 87% and 74, 76% subsequently for speech recognition in silent and noisy condition. The second test shows that WES09 is more suitable for this particular system due to its support for .NET and SAPI5.1.

Dual hop multicast ping method for node failure detection in ZigBee loop network

This paper reviews node failure detection method in ZigBee loop network. ZigBee network was popularly used for low power and low cost implementation of wireless data transmission. Node failure detection is needed in order to maintain the network reliability. Common node failure detection methods are based on ZigBee mesh networking capability. But in many application areas which have simple loop topology, ZigBee will not get much benefit from its mesh networking capability. We propose a multicast ping with dual hop grouping for failure detection and protection in ZigBee loop network, in order to give simple node management, efficient processing resource, and uniform firmware implementation. This method has been simulated in Network Simulator (NS2) tools. The result has validated that dual hop multicast ping method can be used in ZigBee loop network for accurate node failure detection. The simulation shows that the implementation of method also increases average end-to-end delay from 0.06 second to 0.08 second as trade off to network performance.