625 research outputs found
A new multistage lattice vector quantization with adaptive subband thresholding for image compression
Lattice vector quantization (LVQ) reduces coding complexity and computation due to its regular structure. A new multistage LVQ (MLVQ) using an adaptive subband thresholding technique is presented and applied to image compression. The technique concentrates on reducing the quantization error of the quantized vectors by "blowing out" the residual quantization errors with an LVQ scale factor. The significant coefficients of each subband are identified using an optimum adaptive thresholding scheme for each subband. A variable length coding procedure using Golomb codes is used to compress the codebook index which produces a very efficient and fast technique for entropy coding. Experimental results using the MLVQ are shown to be significantly better than JPEG 2000 and the recent VQ techniques for various test images
Multiple Description Coding Using A New Bitplane-LVQ Scheme.
In this paper, a novel Bitplane-LVQ technique to compress subbands bitplane coefficients is proposed for multiple description coding (MDC) system
Optical Fiber Bending Detection on Long Distance OPGW using OTDR
In Malaysia, thousands of kilometers of Optical Ground Wire (OPGW) have been installed by a utility company. For long distance fiber cable, there is a possibility of optical fiber to bend with very small radius especially in joint closures which caused optical power to attenuate. This attenuation is known as ‘bend losses. Bend loss increases the total power attenuation of optical fiber. In addition, for long distance fiber cable, it is important to avoid any extra loss as the fiber itself attenuates 0.2 to 0.35 dB/km and splice loss about 0.1 dB each. Hence, in this study, the method of detecting bend loss as well as optical fiber bending is presented. The result of this study is expected to allow fiber industry players to determine the exact location and proper rectification can be done to solve bend loss problem
Study: The Performance FFT and Wavelet Packet of OFDM Systems from through Demonstrated Numerical Examples
A major goal of the next-generation wireless communication systems is the development of a reliable highspeed wireless communication system that supports high user mobility. Multi-Carrier Modulation (MCM) technique is an attractive approach for high-speed digital radio communication systems in order to achieve a high spectral efficiency and to combat the frequency selectivity of the channel. Orthogonal frequency division multiplexing (OFDM) is a kind of MCM techniques. As proven by the success of OFDM, multicarrier modulation has been recognized as an efficient solution for wireless communications. Waveform bases other than sine functions could similarly be used for multicarrier systems in order to provide an alternative to OFDM. Wavelet Packet Modulation (WPM) was proposed as one of the multicarrier transmission methods like OFDM. Since it is a multicarrier transmission method. In this paper, we study the performance of FFT-OFDM and wavelet Packet (WP)- OFDM from through demonstrated numerical examples, and evaluation of FFT-OFDM and DWPT-OFDM in AWGN channel , Flat fading channel and Selective Fading Channel
Autocorrelated process control: Geometric Brownian Motion approach versus Box-Jenkins approach
Existing of autocorrelation will bring a significant effect on the performance and
accuracy of process control if the problem does not handle carefully. When dealing with
autocorrelated process, Box-Jenkins method will be preferred because of the popularity.
However, the computation of Box-Jenkins method is too complicated and challenging which
cause of time-consuming. Therefore, an alternative method which known as Geometric
Brownian Motion (GBM) is introduced to monitor the autocorrelated process. One real case of
furnace temperature data is conducted to compare the performance of Box-Jenkins and GBM
methods in monitoring autocorrelation process. Both methods give the same results in terms of
model accuracy and monitoring process control. Yet, GBM is superior compared to Box-Jenkins
method due to its simplicity and practically with shorter computational time
Implementation of cryptography algorithms in SCADAKratos application
This paper studies cryptography algorithms to be implemented into the SCADAKratos application of thermal vacuum chamber (TVC) system. SCADAKratos application is used to control and monitor the operations of the TVC which is a satellite test equipment that is located at the Malaysia Space Centre, Banting, Malaysia. The security features had been put aside during the development as it was claimed that there is no threat to the system since the system is operated internally. However, during service and troubleshooting by the manufacturer, the system will be accessed through public network. Besides that, the system also can be accessed remotely during operation for control and monitoring purpose. In addition, the testing data results also need to be transferred to the customer through the internet as it is easier and faster. The remote access through public network will cause the TVC system to face a risk to any threat and attack. Therefore, the implementation of cryptography algorithm into TVC system is needed in order to secure and protect the system from unauthorized access. This paper explains the architecture of SCADAKratos application of TVC system and how the cryptography algorithms could be implemented through this application. Secure Hash Algorithm (SHA-1) and AES algorithm (AES) are chosen as the encryption technique which will be applied in the TVC system. Simulation result shows that this technique is feasible for the mentioned implementation
The relationship between ICT adoption and business performance in Malaysia and Indonesia
This paper reviews the relationship of information communication technology adoption (ICT) and
Business Performance (BP) from women entrepreneur perspective in Malaysia and Indonesia. The aim of
this paper is to identify the dimension of ICT adoption and BP to develop a conceptual framework for
further study about the relationship to identify those that can determine women entrepreneur success. To
achieve this objective, literature review is conducted by extend number of literature in ICT, BP, and
women entrepreneur. Related studies are review and analyze by using literature table. The finding of this
paper reveals a proposed conceptual framework and hypothesis that gain support from literature. The
significant of this study is expected to provide guideline for women entrepreneurs in Malaysia and
Indonesia who wish to adopt ICT in their business and help them to evaluate the relationship with BP.
This study can assist women entrepreneurs in considering the adoption of Electronic commerce (EC) and
Mobile commerce (MC) to embark themselves in technology and innovation. Further efforts are to test
this conceptual framework and hypothesis by using Structural Equation Modelling (SEM) to develop a
research model
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