KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Settings

Author: search.filters.author.Worasawate, Denchai

Search Results

Now showing 1 - 4 of 4
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    An improvement of an RFID indoor positioning system using one base station
    (2009-01-01)
    Hatthasin, Upady
    ;
    Thainimit, Somying
    ;
    Vibhatavanij, Kemathat
    ;
    Premasathian, Nol
    ;
    Worasawate, Denchai
    The proliferation of mobile computing devices and wireless positioning networks has fostered a growing interest in location-aware systems and devices. Most technologies such as Radio Frequency IDentification (RFID), RADAR, etc, use at least three Base Station (BS) for calculating position of target objects. This paper describes an improvement of the previous OneBS algorithm [13]. The proposed system uses only one BS based on the RFID infrastructure for positioning target tags amid the clutter of indoor interference environments. We proposed to fuse the Round-trip Time of Flight (RTOF) and the Received Signal Strength (RSS) in the positioning algorithm. Both information are kept in an intersection Box (iBox). The RTOF information is used to focus a target tag's position among groups of four-nearestneighbor reference tags kept within iBox. Then, the RSS information is weighted using the weighted center of gravity technique to estimate a location of the target tags. Our experiments are based on Three Dimension (3D) materials within interference environments. The interference environments are simulated based on Uniform Geometrical Theory of Diffraction (UTD), for measuring signals in each specific area. Our proposed algorithm gains 50 percents better average distance error compared to the OneBS algorithm.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Magnetic field distributions of two-slot array antenna on a concentric sectoral cylindrical resonator excited by a coupling slot
    (2008-12-01)
    Wounchoum, Phairote
    ;
    Worasawate, Denchai
    ;
    Phongcharoenpanich, Chuwong
    ;
    Krairiksh, Monai
    in this paper, the magnetic field distribution of two-slot array antenna on a concentric sectoral cylindrical resonator excited by a coupling slot is presented. The correlations between the field distributions of the antenna and the mode-based field distributions are presented. The radiation pattern, magnetic field distribution and magnitude of S11 are investigated in the terms of the length of the sectoral resonator. It shows that the TE112 mode has degenerated to the magnitude of S11 for the circumferential slot array antenna. The results provide useful information for the design of switched-beam array antenna on the concentric sectoral cylindrical resonators. ©2008 IEEE.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Radiation characteristics of two-slot array antenna on a concentric sectoral cylindrical resonator excited by a coupling slot
    (2007-12-01)
    Wounchoum, Phairote
    ;
    Phongcharoenpanich, Chuwong
    ;
    Worasawate, Denchai
    ;
    Krairiksh, Monai
    This paper presents the radiation characteristics of two-slot array antenna on a concentric sectoral cylindrical resonator excited by a coupling slot. The magnetic fields inside the sectoral cylindrical resonator for the first few modes are presented with sectoral angle of 60 degrees. It shows that the appropriate mode for a slot array antenna on a concentric sectoral cylindrical resonator is the TM<inf>110</inf> mode. The radiation patterns of two-slot array antenna on a concentric sectoral cylindrical resonator for single sector are illustrated. The location of the coupling slot is considered to find the appropriate radiation pattern. The results provide useful information for the design of switched-beam array antenna on the concentric sectoral cylindrical resonators.
  • Loading...
    Thumbnail Image
    Some of the metrics are blocked by your 
    consent settings
    Item type:Publication,
    Durian maturity identification using radar equation based on support vector classification
    (2007-12-01)
    Worasawate, Denchai
    ;
    Ampungart, Atitaya
    ;
    Krairiksh, Monai
    This paper presents a method to identify the maturity of durian using radar equation. The measurement system consists of two identical square patch antennas acting as a transmitter and a receiver. The return loss of the transmitter and the transmission coefficient at the receiver are measured using network analyzer. These measured data are used to determine the ratio of the effective reflection coefficients for two different frequencies at the interface between air and durian. In this step, the radar equation is applied. In this experiment, ten mature and ten immature durians are chosen by an experienced farmer. The measured data of fourteen durians are used for training the system using the support vector classification. The measured data of another six durians are used for testing the system. The results show that the performance of the system is acceptable.