Josefina Barnachea Janier

Denoising solar radiation data using Meyer wavelets

Signal processing is important in solar energy data analysis since the received solar radiation data fluctuates continuously. Some of the fluctuations can be considered as noise, and need to be filtered out before the signal will be used for other analysis. There exist various methods in order to filter the noise and one of the promising methods is wavelets transform. This paper utilized the use of wavelet transform method for solar radiation denoising. The Meyer wavelets have been utilized, instead of the usual sinusoidal or Gaussian type functions. Since Meyer wavelets are obtained directly from its Fourier transform which is in terms of sinusoidal functions, optimized Meyer wavelets may give a good indication of the solar radiation data. Results showed Heuristic Stein Unbiased Estimate of Risk (SURE) and SURE gave better denoised results as compared to Minimax and Fixed Form methods.

Denoising solar radiation data using coiflet wavelets

Signal denoising and smoothing plays an important role in processing the given signal either from experiment or data collection through observations. Data collection usually was mixed between true data and some error or noise. This noise might be coming from the apparatus to measure or collect the data or human error in handling the data. Normally before the data is use for further processing purposes, the unwanted noise need to be filtered out. One of the efficient methods that can be used to filter the data is wavelet transform. Due to the fact that the received solar radiation data fluctuates according to time, there exist few unwanted oscillation namely noise and it must be filtered out before the data is used for developing mathematical model. In order to apply denoising using wavelet transform (WT), the thresholding values need to be calculated. In this paper the new thresholding approach is proposed. The coiflet2 wavelet with variation diminishing 4 is utilized for our purpose. From numerical results it can be seen clearly that, the new thresholding approach give better results as compare with existing approach namely global thresholding value.

N-mean kernel filter and normalized correlation for face localization

Recently, Template matching approach has been widely used to locate faces with various pose, illumination and clutter background. Normalized Cross-correlation (NCC) is an effective and simple measurement method to compute the similarity matching between the stored faces templates and the rectangular blocks of the input image to locate the face position. However, localization error occurs very often due to some rectangular blocks which have more face than correct blocks because of the effect of matrices values of these blocks. In this paper we proposed a simple preprocessing method before the use of NCC. This is to reduce the effects of such problems by increasing the values of the input image pixels. The result showed a significant improvement in localization accuracy compared with the use of NCC alone which is only up to 11%. Yale University database was used to evaluate our proposed method.

Quantification of asphaltene precipitation by scaling equation

Asphaltene precipitation from crude oil is one of the issues for the oil industry. The deposition of asphaltene occurs during production, transportation and separating process. The injection of carbon dioxide (CO2) during enhance oil recovery (EOR) is believed to contribute much to the precipitation of asphaltene. Precipitation can be affected by the changes in temperature and pressure on the crude oil however, reduction in pressure contribute much to the instability of asphaltene as compared to temperature. This paper discussed the quantification of precipitated asphaltene in crude oil at different high pressures and at constant temperature. The derived scaling equation was based on the reservoir condition with variation in the amount of carbon dioxide (CO2) mixed with Dulang a light crude oil sample used in the experiment towards the stability of asphaltene. A FluidEval PVT cell with Solid Detection System (SDS) was the instrument used to gain experimental knowledge on the behavior of fluid at reservoir conditions. Two conditions were followed in the conduct of the experiment. Firstly, a 45cc light crude oil was mixed with 18cc (40%) of CO2 and secondly, the same amount of crude oil sample was mixed with 27cc (60%) of CO2. Results showed that for a 45cc crude oil sample combined with 18cc (40%) of CO2 gas indicated a saturation pressure of 1498.37psi and asphaltene onset point was 1620psi. Then for the same amount of crude oil combined with 27cc (60%) of CO2, the saturation pressure was 2046.502psi and asphaltene onset point was 2230psi. The derivation of the scaling equation considered reservoir temperature, pressure, bubble point pressure, mole percent of the precipitant the injected gas CO2, and the gas molecular weight. The scaled equation resulted to a third order polynomial that can be used to quantify the amount of asphaltene in crude oil.Asphaltene precipitation from crude oil is one of the issues for the oil industry. The deposition of asphaltene occurs during production, transportation and separating process. The injection of carbon dioxide (CO2) during enhance oil recovery (EOR) is believed to contribute much to the precipitation of asphaltene. Precipitation can be affected by the changes in temperature and pressure on the crude oil however, reduction in pressure contribute much to the instability of asphaltene as compared to temperature. This paper discussed the quantification of precipitated asphaltene in crude oil at different high pressures and at constant temperature. The derived scaling equation was based on the reservoir condition with variation in the amount of carbon dioxide (CO2) mixed with Dulang a light crude oil sample used in the experiment towards the stability of asphaltene. A FluidEval PVT cell with Solid Detection System (SDS) was the instrument used to gain experimental knowledge on the behavior of fluid at reservoir...

Need Analysis for Down Syndrome Children to Develop a Learning Material on Numbers with the Aid of Multimedia Technology

Down Syndrome (DS) is a common chromosomal abnormality in human and typically delay in cognitive ability and physical growth. This study investigated the skills of 19 DS children ages between 1-13 attending special sessions at Kiwanis Down Syndrome Foundation center at Ipoh, Perak. A 34 item survey checklist with 1-4 in the Likert scale was used and defined as 1-Never to 4-Always. The skills were categorized into cognitive, affective and psychomotor. From the responses of the teacher-in-charge and the parents, the results showed that the DS children have varied skills that can further be improved in order for them to become more independent. The identified skills were used as a bench mark in developing learning material on numbers from 1 to 10 using multimedia technology. The developed learning material is called SynMax and composed of 3 activities such as learning, matching and counting. It was based on some learning theories Dual Coding Theory and Schema Theory. The Synmax will be tested to the children with Down Syndrome to determine its suitability, for our future work.

Enhancing 3D visualization for learning volumes of solid, an application in integral calculus: A multimedia courseware development

Mathematics is one of the major subjects which now integrates multimedia technology to its instructional materials and has become a phenomenon all around the world. The difficulty of visualizing mathematical concepts has been one of the major factors for students who find mathematics challenging, especially in calculating volumes of solid under the topic of integration. The objectives of the paper are to investigate on the suitable technique to produce a 3-dimensional (3D) visualization to demonstrate volumes of solid, to develop a multimedia courseware prototype for it and to evaluate the user acceptance of the prototype. The focus is on the methods of calculating volumes of solid under the topic of integration, which is a topic in Calculus. A multimedia courseware using Macromedia Toolbook implementing 2D graphics has been previously developed to assist the foundation students in UTP to learn integration. To enhance the students visualization of calculating volumes of solid, a 3D graphics multimedia courseware has been developed using the ADDIE model. The tools that are used to develop the prototype are Blender for 3D modeling and SWiSH Max 4 for layout and interactivity of courseware. Questionnaire has been distributed to get feedback from 12 students pertaining to 3 categories which are visualization, navigation and content. The key findings from the analysis showed that the use of video, images, graph, audio and colour in the prototype is suitable. The user experience test performed on the UTP engineering students who have taken Calculus course resulted in a positive response whereby 90% of them agreed that the use of 3D images has helped them to understand better on how to calculate the volume of solids compared to referring only to 2D graphs like what they have learned previously. 77% of the respondents also said that they would use the courseware to support their learning of Calculus.

Auto Detection For High Level Water Content For Oil Well

Auto detection of high level water content for oil well is a system that measures the percentage of water in crude oil. This paper aims to discuss an auto detection system for measuring the content of water level in crude oil which is applicable for offshore and onshore oil operations. Data regarding water level content from wells can be determined by using automation thus, well with high water level can be determined immediately whether to be closed or not from operations. Theoretically the system measures the percentage of two‐ fluid mixture where the fluids have different electrical conductivities which are water and crude oil. The system made use of grid sensor which is a grid pattern like of horizontal and vertical wires. When water occupies the space at the intersection of vertical and horizontal wires, an electrical signal is detected which proved that water completed the circuit path in the system. The electrical signals are counted whereas the percentage of water is determined from the total elec...