Empirical modelling of activated sludge process via system identification

Activated sludge process is an important stage in Wastewater Treatment Plant (WWTP). In this study, model of the activated sludge process from Bunus Regional Sewage Treatment Plant Kuala Lumpur, Malaysia is developed. This paper focuses on modelling and model reduction of the WWTP system. The model with best fits of higher than 80 and the order of less than 10 is selected. For modelling purposes, data obtained is stimulated and modelled using System Identification technique which employ linear model ARX. For model reduction purposes, the high order model is reduced using model order reduction (MOR) of a combination of Singular Perturbation Approximation (SPA) and Frequency Domain Gramian based Model Reduction (FDIG) method. From the modelling results obtained, the ARX model with best fit of 85.11 is selected. Meanwhile, for the MOR FD-SPA technique, a 9th order model is selected with 2.5 x 10-2 reduction error between frequencies 0.05 rad/s and 1.4 rad/s

Development of Kaya Slice (coconut jam slice): evaluation of physicochemical, sensory evaluation and macronutrients composition when cooperated with gelatin

Kaya Slice is a nutritious traditional breakfast-on-the-go that was innovated from the traditional kaya. In this study, the traditional kaya was transformed into square shape gelatin to make it a more convenient and ready-to-eat breakfast. A total of six formulations were developed by using commercial and fresh coconut milk together with different percentages of gelatin (2%, 4%, and 6%). This insight was investigated by sensory evaluation using a 9-point hedonic and scoring test in descriptive data set. The best formulation obtained from the evaluation of 35 panellists was then characterized in terms of physicochemical properties (Texture Profile Analysis (firmness), Brix, Protein, Fat, Fiber, and Calories). From the descriptive data, all formulations were accepted by the panellist. Nevertheless, ANOVA analysis indicated that C2 (commercial coconut milk + 4% of gelatin) is the best formulation. In macronutrient analysis, Kaya Slice was found to have good dietary fibre content (0.11 g/100 g), high-fat content (0.49 g/100 g), protein content (0.32 g/100 g) compare to the commercial kaya (0.00 g/100 g), (1.00 g/100 g), and (0.00 g/100 g) respectively. Low-calorie content in Kaya Slice with 45 % of °Brix value is the minimal degree of Brix and the texture was softer (hardness) (significantly different (p<0.05)) to commercially processed cheese slice as standard. Overall, Kaya Slice has a great potential in becoming new emergent of traditional nutritious breakfast on the go

Target Localization in MIMO OFDM Radars Adopting Adaptive Power Allocation among Selected Sub-Carriers

Multiple-input multiple-output (MIMO) radar has been introduced to enhance the performance of classical radar systems. Nevertheless, radar cross sections (RCS) fluctuations remains a known problem in radars. Target localization using narrowband signal produces reduced accuracy due to RCS fluctuations. One of the solution to this problem is utilization of frequency diversity of wideband signal. This paper presents target localization in MIMO radars using an adaptive orthogonal frequency division multiplexing (OFDM) waveform for effective frequency diversity utilization. Each transmitting antenna transmits an OFDM signal in different time slots and received by the each receiving antenna in the receiver array. A joint direction-of-departure (DOD) and direction-of-arrival (DOA) estimation scheme is applied to each of the OFDM sub-carrier using two-way multiple signal classification (MUSIC) algorithm. The estimation results at each sub-carrier are combined based on majority decision using angle histogram (non-parametric approach) to formulate the final wideband angle estimation. In addition, an adaptive power allocation among the sub-carriers is implemented, where the system evaluates the signal quality at each sub-carrier and consequently formulates a feedback to the MIMO transmitting side. The following transmission will comprise of OFDM waveform that focuses the transmit power at selected sub-carriers only. The sub-carrier selection is based on singular values obtained from singular value decomposition operation at each of the sub-carrier. The performance of the proposed scheme is evaluated through numerical simulations as well as validation by experiments in a radio anechoic chamber. It was demonstrated that the usage of larger number of sub-carriers improves the angle estimation accuracy

Multi-Layer Perceptron (MLP)-Based Nonlinear Auto-Regressive with Exogenous Inputs (NARX) Stock Forecasting Model

The prediction of stocks in the stock market is important in investment as it would help the investor to time buy and sell transactions to maximize profits. In this paper, a Multi-Layer Perceptron (MLP)-based Nonlinear Auto-Regressive with Exogenous Inputs (NARX) model was used to predict the prices of the Apple Inc. weekly stock prices over a time horizon of 1995 to 2013. The NARX model belongs is a system identification model that constructs a mathematical model from the dynamic input/output readings of the system, and predicts the future behaviour of the system based on the constructed mathematical model. The One Step Ahead (OSA) and correlation tests were used to test validate the model. Results demonstrate the predictive ability of the model while producing Gaussian residuals (indicating the validity of the model)

Development of portable magnetic clampingfor lathe machine

Chuck is a device used to clamp any material that operates with the turning of the machine and it is connected to the headstock spindle of the lathe. However, the limitation is that the thickness of the workpiece must not be less than the area of clamping on the chuck. In this a new magnetic clamping for attaching and detaching the workpiece on the chuck and is able to clamp small and thin workpieces is developed. The chuck is made by using mild steel and has a few intercepts with brass. Magnetic mechanism is placed in the chuck. Several cutting processes were done with the convectional chuck and the magnetic clamping on a different thickness of workpiece. Next, all the workpieces were tested with several parameters on specimen and perform surface roughness testing to compare and finalize the effectiveness of the magnetic clamping. From the obtained result, the use of the magnetic clamping produces much better result of surface roughness on thin workpiece. Thus, using magnetic clamping as the clamping method for thin workpiece is much effective in turning machine

Differential Responses to Blood Pressure and Oxidative Stress in Streptozotocin-Induced Diabetic Wistar-Kyoto Rats and Spontaneously Hypertensive Rats: Effects of Antioxidant (Honey) Treatment

Oxidative stress is implicated in the pathogenesis and/or complications of hypertension and/or diabetes mellitus. A combination of these disorders increases the risk of developing cardiovascular events. This study investigated the effects of streptozotocin (60 mg/kg; ip)-induced diabetes on blood pressure, oxidative stress and effects of honey on these parameters in the kidneys of streptozotocin-induced diabetic Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Diabetic WKY and SHR were randomized into four groups and received distilled water (0.5 mL) and honey (1.0 g/kg) orally once daily for three weeks. Control SHR had reduced malondialdehyde (MDA) and increased systolic blood pressure (SBP), catalase (CAT) activity, and total antioxidant status (TAS). SBP, activities of glutathione peroxidase (GPx) and glutathione reductase (GR) were elevated while TAS was reduced in diabetic WKY. In contrast, SBP, TAS, activities of GPx and GR were reduced in diabetic SHR. Antioxidant (honey) treatment further reduced SBP in diabetic SHR but not in diabetic WKY. It also increased TAS, GSH, reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio, activities of GPx and GR in diabetic SHR. These data suggest that differences in types, severity, and complications of diseases as well as strains may influence responses to blood pressure and oxidative stress

Development of Shoe Dryer system using Microcontroller with GSM Module

This paper describes the design and development of a shoe dryer using a microcontroller. Nowadays, people often travel and sometimes in rainy day, they need to dry their shoe in a very short time anywhere. However, very rare of places including shopping mall and hotel provide a shoe dryer. The shoe dryer is designed to help people who are in hurry to dry their shoe on the go. A temperature sensor is used to measure the temperature inside the shoe dryer, while a program is uploaded in the microcontroller for reading and data collection. The programming includes the activation of shoe dryer with the GSM module, thus it can be controlled using a mobile phone. An experiment was conducted to test the performance of the shoe dryer. The optimum performance was obtained when the temperature is set at 36°C, and timer at 60 seconds with normal room temperature. The temperature and timer need to be adjusted accordingly based on the shoe condition in order to get very satisfying results. This paper proved that the shoe dryer was successfully designed, implemented and analyzed

CMOS ring oscillator delay cell performance: a comparative study

A common voltage-controlled oscillator (VCO) architecture used in the phase locked loop (PLL) is the ring oscillator (RO). RO consist of number of inverters cascaded together as the input of the first stage connected to the output of the last stage. It is important to design the RO to be work at desired frequency depend on application with low power consumption. This paper presents a review the performance evaluation of different delay cell topologies the implemented in the ring oscillator. The various topologies analyzed includes current starved delay cell, differential delay cell and current follower cell. Performance evaluation includes frequency range, frequency stability, phase noise and power consumption had been reviewed and comparison of different topologies has been discussed. It is observed that starved current delay cell have lower power consumption and the different of the frequency range is small as compared to other type of delay cell