Mohana Sundaram Muthuvalu

PC Based Energy Efficient Wireless Transceiver Module with ZigBee

The aim of this research is to develop a low power, low cost and energy efficient transceiver model which is integrated with programmable microcontroller and ZigBee transponder. A combination of programmable microcontroller with ZigBee transponder is used to control the transceiver module with computer commands. It has b een simulated for transmitting and receiving the communication signals from any movable device with more efficiently and use low power consumption. ZigBee Transponder is preferable as compared to radio frequency identification (RFID) due to IEEE 802.15.4 standard that promises stable data transmission with low power consumption device and having higher network flexibility. PIC 16F877A programmable microcontroller with coding in Mikro C software is simulated and used with computer control instructions. Series of experiments has been conducted to ensure the stability and low power consumption of this model.

A New Strategy for Multiple Chillers Plant Operation Using Fuzzy Inference System

Reducing energy consumption is one of the most important things for optimal operation of the multiple-chillers. The storage system for chilled-water is used for cooling demand and shifting load consumption at peak hours. The case study in this work is based on the existing system for chillers plant in an industrial building. This paper adopts Fuzzy Inference System, in order to adjust the operating points setting for a period of 24 hours to keep the cooling demand satisfied. This is based on a new strategy for the scheduled operation of the chillers. The results have shown the effectiveness for the energy savings and also satisfying the cooling demand. This proposed control system has been simulated in Matlab and the simulation result is compared with the measured data from the existing system.

Mathematical modelling for the drying method and smoothing drying rate using cubic spline for seaweed Kappaphycus Striatum variety Durian in a solar dryer

The solar drying experiment of seaweed using Green V-Roof Hybrid Solar Drier (GVRHSD) was conducted in Semporna, Sabah under the metrological condition in Malaysia. Drying of sample seaweed in GVRHSD reduced the moisture content from about 93.4% to 8.2% in 4 days at average solar radiation of about 600W/m2 and mass flow rate about 0.5 kg/s. Generally the plots of drying rate need more smoothing compared moisture content data. Special cares is needed at low drying rates and moisture contents. It is shown the cubic spline (CS) have been found to be effective for moisture-time curves. The idea of this method consists of an approximation of data by a CS regression having first and second derivatives. The analytical differentiation of the spline regression permits the determination of instantaneous rate. The method of minimization of the functional of average risk was used successfully to solve the problem. This method permits to obtain the instantaneous rate to be obtained directly from the experimental data. The drying kinetics was fitted with six published exponential thin layer drying models. The models were fitted using the coefficient of determination (R2), and root mean square error (RMSE). The modeling of models using raw data tested with the possible of exponential drying method. The result showed that the model from Two Term was found to be the best models describe the drying behavior. Besides that, the drying rate smoothed using CS shows to be effective method for moisture-time curves good estimators as well as for the missing moisture content data of seaweed Kappaphycus Striatum Variety Durian in Solar Dryer under the condition tested.

Optimal Operation of Multi-Chillers for Energy Saving Using a Multi-Fuzzy Inference System

The demand for cooling and air-conditioning is growing due to increasing demand for comfort level and cooling loads. The chilled-water systems (chillers) are one of the energy consuming appliances that consume large amount of energy in buildings. Under these circumstances, energy management system carried out to achieve the objective of using the minimum possible energy, while maintaining the comfort levels and the production rates in factories. This paper proposes an optimal operation for the chillers with the partial load ratio (PLR) and partial storage system (PSS) based on Fuzzy Inference System (FIS). Simulation results are presented to show the effectiveness of technique for energy saving of the Screw Chillers in large building as compared with ON-OFF control system.

Implications of drying temperature and humidity on the drying kinetics of seaweed

A Low Temperature and Humidity Chamber Test tested in the Solar Energy Laboratory, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Selangor, Malaysia. Experiments are attempted to study the effect of drying air temperature and humidity on the drying kinetics of seaweed Kappaphycus species Striatum besides to develop a model to estimate the drying curves. Simple method using a excel software is used in the analysis of raw data obtained from the drying experiment. The values of the parameters a, n and the constant k for the models are determined using a plot of curve drying models. Three different drying models are compared with experiment data seaweed drying at 30, 40, 50 and 60°C and relative humidity 20, 30 and 40% for seaweed. The higher drying temperatures and low relative humidity effects the moisture content that will be rapidly reduced. The most suitable model is selected to best describe the drying behavior of seaweed. The values of the coefficient of determination (R2), mean bias error (MBE) and root mean square error (RMSE) are used to determine the goodness or the quality of the fit. The Page model is showed a better fit to drying seaweed. The results from this study crucial for solar dryer development on pilot scale in Malaysia.

Post-Harvest Handling of Eucheumatoid Seaweeds

The post-harvest handling of cultivated seaweed biomass is a crucial stage in the whole value-chain of the carrageenophyte industry. The quantity and quality of carrageenan derived from any given biomass depends largely on the post-handling treatment and management of the supply-chain for the harvested seaweeds. Since the successful farming of Kappaphycus and Eucehuma began in the early 1970s in the Philippines, the generally low technologies and cheaper conventional methods of drying the harvested seaweeds (i.e. hanging, platform, shade drying, ‘sauna-like method,’ etc.) are still prefered by the majority of farmers. However, these methods pose serious problems for carrageenophyte quality. A new day is coming when the traditional methods will not be sufficient in order to add value to the biomass. Recently, new methods for the drying of various eucheumatoid seaweeds were introduced, e.g. passive drying (chimney and greenhouse-based solar houses), active drying (de-humidifier drier) and hybrid (wind turbine, double-pass solar collectors with fins and v-groove, solar driers). However, these are still in their early stages of development and technology transfer to the industry.

Maximum Likelihood Inference for Univariate Delay Differential Equation Models with Multiple Delays

This article presents statistical inference methodology based on maximum likelihoods for delay differential equation models in the univariate setting. Maximum likelihood inference is obtained for single and multiple unknown delay parameters as well as other parameters of interest that govern the trajectories of the delay differential equation models. The maximum likelihood estimator is obtained based on adaptive grid and Newton-Raphson algorithms. Our methodology estimates correctly the delay parameters as well as other unknown parameters (such as the initial starting values) of the dynamical system based on simulation data. We also develop methodology to compute the information matrix and confidence intervals for all unknown parameters based on the likelihood inferential framework. We present three illustrative examples related to biological systems. The computations have been carried out with help of mathematical software: MATLAB® 8.0 R2014b.

Performance Analysis of 2-Point Explicit Group (2-EG) Method for Solving Second-Order Composite Closed Newton-Cotes Quadrature System

In this paper, the effectiveness of 2-Point Explicit Group (2-EG) iterative method with second-order composite closed Newton-Cotes (2-CCNC) quadrature scheme for solving second kind linear Fredholm integral equations is investigated. The formulation and implementation of the proposed method are presented. In addition, computational complexity analysis and numerical results of test examples are also included to verify the performance of the proposed method.

A maximum likelihood estimation framework for the exponential Differential Equation Model

In this paper we propose the maximum likelihood method of estimation for Delay Differential Equation Model governed by unknown delay and other parameters of interest. As an example we consider the Exponential Differential Equation Model. A grid based estimation framework is proposed. Our methodology estimates correctly the delay parameter as well as the initial starting value of the dynamical system based on simulation data.

Simulation and development of ZigBee based wireless stakeout system controlled by PC

Wireless technology has become a new emerging technology in stakeout and security concerns industries. Study of wireless communication with energy efficiency is also a one of the most important research area. Therefore this paper presents an efficient computerized stakeout system (CSS) for stakeout and recognition purposes with the use of energy efficient ZigBee based transceiver. The designed model entails a combination of programmable microcontrollers, relay circuitry, DC motors and sharp camera eye to control the model through another wireless transceiver module which is connected with personal computer. In the operation of each sensor node in wireless and movable stakeout system, battery is also a most limiting factor for the whole system performance and lifetime so it is obtained that ZigBee transponders are capable in providing wider transmission range and efficient compare to RF and Wi-Fi due to low usage of power during data gathering transmission. The computer commands are used to control the motion and visual feedback is used to provide the precision control. The CSS system is capable of positioning at tedious and hazardous work space as instructed through command to get the actual visual feedback. The results are in good agreement with theoretical understandings and show a greater efficiency, with low power consumption and reduction in complexity.