Search results for: return flow ratio (RR)

Authors: Jorge Ramírez-Ortiz, Jorge Medina-Valtierra, Merced Martínez Rosales

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Biodiesel production with used frying by transesterification reaction with methanol, using a commercial kaolinite thermally-activated solid acid catalyst was investigated. The surface area, the average pore diameter and pore volume of the kaolinite catalyst were 10 m2/g, 13.0 nm and 30 mm3/g, respectively. The optimal conditions for the transesterification reaction were determined to be oil/methanol, in a molar ratio 1:31, temperature 160 ºC and catalyst concentration of 3% (w/w). The yield of fatty acids methyl esters (FAME) was 92.4% after 2 h of reaction. This method of preparation of biodiesel can be a positive alternative for utilizing used frying corn oil for feedstock of biodiesel combined with the inexpensive catalyst.

Keywords: Biodiesel, frying corn oil, kaolinite, transesterification

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Authors: Young-Seok Choi

Abstract:

The Adaptive Line Enhancer (ALE) is widely used for enhancing narrowband signals corrupted by broadband noise. In this paper, we propose novel ALE methods to improve the enhancing capability. The proposed methods are motivated by the fact that the output of the ALE is a fine estimate of the desired narrowband signal with the broadband noise component suppressed. The proposed methods preprocess the input signal using ALE filter to regenerate a finer input signal. Thus the proposed ALE is driven by the input signal with higher signal-to-noise ratio (SNR). The analysis and simulation results are presented to demonstrate that the proposed ALE has better performance than conventional ALE’s.

Keywords: Adaptive filter, adaptive line enhancer, noise, feedback.

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Authors: N. Lassouaoui, L. Hamami, N. Nouali

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The tracking allows to detect the tumor affections of cervical cancer, it is particularly complex and consuming time, because it consists in seeking some abnormal cells among a cluster of normal cells. In this paper, we present our proposed computer system for helping the doctors in tracking the cervical cancer. Knowing that the diagnosis of the malignancy is based in the set of atypical morphological details of all cells, herein, we present an unsupervised genetic algorithm for the separation of cell components since the diagnosis is doing by analysis of the core and the cytoplasm. We give also the various algorithms used for computing the morphological characteristics of cells (Ratio core/cytoplasm, cellular deformity, ...) necessary for the recognition of illness.

Keywords: Cervical cell, morphological analysis, recognition, segmentation.

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Authors: Asim N., M. Mazhar Manzoor, Shariq A.

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Knowledge is renowned as a significant component for sustaining competitive advantage and gives leading edge in business. This study emphasizes towards proper and effectuate utilization of internal and external (both either explicit or tacit) knowledge comes from stakeholders, highly supportive to combat with the challenges and enhance organizational productivity. Furthermore, it proposed a model under context of IRSA framework which facilitates the organization including flow of knowledge and experience sharing among employees. In discussion section an innovative model which indulges all functionality as mentioned in analysis section.

Keywords: Effective Decision-Making, Internal & ExternalKnowledge, Knowledge Management, Tacit & Explicit Knowledge.

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Authors: Eldin Wee Chuan Lim

Abstract:

The mixing behaviors of dry and wet granular materials in gas fluidized bed systems were investigated computationally using the combined Computational Fluid Dynamics and Discrete Element Method (CFD-DEM). Dry particles were observed to mix fairly rapidly during the fluidization process due to vigorous relative motions between particles induced by the flow of gas. In contrast, due to the presence of strong cohesive forces arising from capillary liquid bridges between wet particles, the mixing efficiencies of wet granular materials under similar operating conditions were observed to be reduced significantly.

Keywords: Computational Fluid Dynamics, Discrete Element Method, Gas Fluidization, Mixing, Wet particles

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Authors: Atul K. Desai

Abstract:

To increase the maximum span of cable-stayed bridges, Uwe Starossek has developed a modified statical system. The basic idea of this new concept is the use of pairs of inclined pylon legs that spread out longitudinally from the foundation base or from the girder level. Spread-pylon cable-stayed bridge has distinct advantage like reduction of sag of cables and oscillation of cable during earthquake over traditional cable-stayed bridges. Spread-pylon also improves seismic performance of deck during strong ground motion.

Keywords: Different geometry of cable stayed bridge, seismic time history analysis, earthquake displacement ratio, response mode shape.

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Authors: Stelian Petrescu, Adina Frunzâ, Camelia Petrescu

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A method to determine experimentally the melting rate, rm, and the heat transfer coefficients, αv (W/(m3K)), at convective melting in a fixed bed of particles under adiabatic regime is established in this paper. The method lies in the determining of the melting rate by measuring the fixed bed height in time. Experimental values of rm, α and α v were determined using cylindrical particles of ice (d = 6.8 mm, h = 5.5 mm) and, as a melting agent, aqueous NaCl solution with a temperature of 283 K at different values of the liquid flow rate (11.63·10-6, 28.83·10-6, 38.83·10-6 m3/s). Our experimental results were compared with those existing in literature being noticed a good agreement for Re values higher than 50.

Keywords: Convective melting, fixed bed, packed bed, heat transfer, ice melting.

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Authors: R. Bourziza, A. Hammani, M. Kuper, A. Bouaziz

Abstract:

In oases, the surface water resources are becoming increasingly scarce and groundwater resources, which generally have a poor quality due to the high levels of salinity, are often overexploited. Water saving have therefore become imperative for better oases sustainability. If drip irrigation is currently recommended in Morocco for saving water and valuing, its use in the sub-desert areas does not keep water safe from high evaporation rates. An alternative to this system would be the use of subsurface drip irrigation. This technique is defined as an application of water under the soil surface through drippers, which deliver water at rates generally similar to surface drip irrigation. As subsurface drip irrigation is a recently introduced in Morocco, a better understanding of the infiltration process around a buried source, in local conditions, and its impact on plant growth is necessarily required. This study aims to contribute to improving the water use efficiency by testing the performance of subsurface irrigation system, especially in areas where water is a limited source. The objectives of this research are performance evaluation in arid conditions of the subsurface drip irrigation system for young date palms compared to the surface drip. In this context, an experimental test is installed at a farmer’s field in the area of Erfoud (Errachidia Province, southeastern Morocco), using the subsurface drip irrigation system in comparison with the classic drip system for young date palms. Flow measurement to calculate the uniformity of the application of water was done through two methods: a flow measurement of drippers above the surface and another one underground. The latter method has also helped us to estimate losses through evaporation for both irrigation techniques. In order to compare the effect of two irrigation modes, plants were identified for each type of irrigation to monitor certain agronomic parameters (cumulative numbers of palms and roots development). Experimentation referred to a distribution uniformity of about 88%; considered acceptable for subsurface drip irrigation while it is around 80% for the surface drip irrigation. The results also show an increase in root development and in the number of palm, as well as a substantial water savings due to lower evaporation losses compared to the classic drip irrigation. The results of this study showed that subsurface drip irrigation is an efficient technique, which allows sustainable irrigation in arid areas.

Keywords: Subsurface drip irrigation, Water conservation, Arid areas, Young date palms.

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Authors: Farhat Hajer, Khir Tahar, Ammar Ben Brahim

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This work presents a study on the influence of the main operating variables on the gas turbine cycle. A numerical simulation of a gas turbine cycle is performed for a real net power of 100 MW. A calculation code is developed using EES software. The operating variables are taken in conformity with the local environmental conditions adopted by the Tunisian Society of Electricity and Gas. Results show that the increase of ambient temperature leads to an increase of Tpz and NO_x emissions rate and a decrease of cycle efficiency and UHC emissions. The CO emissions decrease with the raise of residence time, while NO_x emissions rate increases and UHC emissions rate decreases. Furthermore, both of cycle efficiency and NOx emissions increase with the increase of the pressure ratio.

Keywords: CO, efficiency, gas turbine, NOx, UHC.

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Authors: R. Joseph Raviselvan, K. Ramanathan, P. Perumal, M. R. Thansekhar

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Hard coatings are widely used in cutting and forming tool industries. Titanium Nitride (TiN) possesses good hardness, strength, and corrosion resistance. The coating properties are influenced by many process parameters. The coatings were deposited on steel substrate by changing the process parameters such as substrate temperature, nitrogen flow rate and target power in a D.C planer magnetron sputtering. The structure of coatings were analysed using XRD. The hardness of coatings was found using Micro hardness tester. From the experimental data, a regression model was developed and the optimum response was determined using Response Surface Methodology (RSM).

Keywords: Hardness, RSM, sputtering, TiN XRD.

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Authors: E. F. Ochulor, S. O. Adeosun, S. A. Balogun

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Effect of sprue/metal head height on mould filling, microstructure and mechanical properties of TWDI casting is studied. Results show that metal/sprue height of 50 mm is not sufficient to push the melt through the gating channel, but as it is increased from 100-350 mm, proper mould filling is achieved. However at higher heights between 200 mm and 350 mm, defects associated with incomplete solidification, carbide precipitation and turbulent flow are evident. This research shows that superior UTS, hardness, nodularity and nodule count are obtained at 100 mm sprue height.

Keywords: Melt pressure and velocity, nodularity, nodule count, sprue height.

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Authors: Khalid Al-Tahat, Khaled Zuhair Mahmoud, Ahmad Al-Mughrabi

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This paper proposes a novel methodology for enabling debugging and tracing of production web applications without affecting its normal flow and functionality. This method of debugging enables developers and maintenance engineers to replace a set of existing resources such as images, server side scripts, cascading style sheets with another set of resources per web session. The new resources will only be active in the debug session and other sessions will not be affected. This methodology will help developers in tracing defects, especially those that appear only in production environments and in exploring the behaviour of the system. A realization of the proposed methodology has been implemented in Java.

Keywords: Live debugging, web application, web resources, inconsistent bugs, tracing.

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Authors: Riad Saraiji, Scott Sizer, Emily Yance-Houser, Felix Bermejo

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The use of a Geographic Information System (GIS) in roadway lighting to show the state of street-lighting and nighttime accident is demonstrated. Geographical maps were generated showing colored streets based on how much of the street's length is illuminated. The night to daytime accidents ratio at intersections were found along with the state of lighting at those intersections. The result is a method to show the state of street-lighting at roads and intersections and a quick guide for decision makers to implement strategies for better street-lighting to reduce night time traffic accidents in a particular district.

Keywords: GIS. Roadway lighting, Traffic Accidents

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Authors: H. Binti Ya’akob, C. Siew Chin, A. Abd Aziz, I. Ware, M. Fauzi Abd Jalil, N. Rashidah Ahmed, R. Sabtu

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Labisia pumila (LP) plant extract has the potential to be applied in cosmeceutical products due to its anti-photoaging properties. The main purpose of this study was to improve transdermal delivery of LP by encapsulating LP in niosomes. Niosomes loaded LPs were prepared by coacervation phase separation method using non-ionic surfactant (Span 60), labrasol, and cholesterol. The optimum formula obtained were Span 60, labrasol and cholesterol at the mole ratio of 6:1:4. At the optimum formulation, the niosome obtained significantly improved the quality of transdermal penetration of LP compared to free LP.

Keywords: Labisia pumila, niosomes, transdermal, quality.

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Authors: Tomasz M. Jankowski

Abstract:

The basis of this paper is the assumption, that graviton is a measurable entity of molecular gravitational acceleration and this is not a hypothetical entity. The adoption of this assumption as an axiom is tantamount to fully opening the previously locked door to the boundary theory between laminar and turbulent flows. It leads to the theorem, that the division of flows of Newtonian (viscous) fluids into laminar and turbulent is true only, if the fluid is influenced by a powerful, external force field. The mathematical interpretation of this theorem, presented in this paper shows, that the boundary between laminar and turbulent flow can be determined theoretically. This is a novelty, because thus far the said boundary was determined empirically only and the reasons for its existence were unknown.

Keywords: Freed gravitons, free gravitons.

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Authors: M. Nili, S. Tavasoli, A. R. Yazdandoost

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In this paper, an experimental investigation on the effect of Isfahan Ground Granulate Blast Furnace Slag (GGBS) on the compressive strength development of self-consolidating concrete (SCC) and normal concrete (NC) was performed. For this purpose, Portland cement type I was replaced with GGBS in various Portions. For NC and SCC Mixes, 10*10*10 cubic cm specimens were tested in 7, 28 and 91 days. It must be stated that in this research water to cement ratio was 0.44, cement used in cubic meter was 418 Kg/m³ and Superplasticizer (SP) Type III used in SCC based on Poly-Carboxylic acid. The results of experiments have shown that increasing GGBS Percentages in both types of concrete reduce Compressive strength in early ages.

Keywords: Compressive strength, GGBS, normal concrete, self-consolidating concrete.

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Authors: Won Mok. Choi, Tae Su. Kwon, Hyun Sung. Jung, Jin Sung. Kim

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The aim of this paper is to confirm the effect of key design parameters, the punch radius and punch angle, on rupture of the expansion tube using a finite element analysis with a ductile damage model. The results of the finite element analysis indicated that the expansion ratio of the tube was mainly affected by the radius of the punch. However, the rupture was more affected by the punch angle than the radius of the punch. The existence of a specific punch angle, at which rupture did not occur, even if the radius of the punch was increased, was found.

Keywords: Expansion tube, Ductile damage, Shear failure, Stress triaxiality.

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Authors: Vanchai Laemlaksakul, Sompoap Talabgaew

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This research studied the appropriate factors and conditions for laminated bamboo bending by Design of Experiments (DOE). The interested factors affecting the spring back in laminates bamboo were (1) time, (2) thickness, and (3) frequency. This experiment tested the specimen by using high frequency machine and measured its spring back immediately and next 24 hours for comparing the spring back ratio. Results from the experiments showed that significant factors having major influence to bending of laminates bamboo were thickness and frequency. The appropriate conditions of thickness and frequency were 4 mm. and 1.5 respectively.

Keywords: Bamboo, bending, spring back, design of experiments.

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Authors: K. J. Kachiashvili

Abstract:

The Comparison analysis of the Wald-s and Bayestype sequential methods for testing hypotheses is offered. The merits of the new sequential test are: universality which consists in optimality (with given criteria) and uniformity of decision-making regions for any number of hypotheses; simplicity, convenience and uniformity of the algorithms of their realization; reliability of the obtained results and an opportunity of providing the errors probabilities of desirable values. There are given the Computation results of concrete examples which confirm the above-stated characteristics of the new method and characterize the considered methods in regard to each other.

Keywords: Errors of types I and II, likelihood ratio, the Bayes Type Sequential test, the Wald's sequential test, averaged number of observations.

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Authors: Ammar Abbas, Ibrahim M. Hussain, Osama M. Hussain

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The IEEE 802.11e which is an enhanced version of the 802.11 WLAN standards incorporates the Quality of Service (QoS) which makes it a better choice for multimedia and real time applications. In this paper we study various aspects concerned with 802.11e standard. Further, the analysis results for this standard are compared with the legacy 802.11 standard. Simulation results show that IEEE 802.11e out performs legacy IEEE 802.11 in terms of quality of service due to its flow differentiated channel allocation and better queue management architecture. We also propose a method to improve the unfair allocation of bandwidth for downlink and uplink channels by varying the medium access priority level.

Keywords: Wireless, IEEE 802.11e, EDCA, Throughput, QoS, MAC.

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Authors: Alia Alghosoun, Nabil El Moçayd, Mohammed Seaid

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Modeling dam-break flows over non-flat beds requires an accurate representation of the topography which is the main source of uncertainty in the model. Therefore, developing robust and accurate techniques for reconstructing topography in this class of problems would reduce the uncertainty in the flow system. In many hydraulic applications, experimental techniques have been widely used to measure the bed topography. In practice, experimental work in hydraulics may be very demanding in both time and cost. Meanwhile, computational hydraulics have served as an alternative for laboratory and field experiments. Unlike the forward problem, the inverse problem is used to identify the bed parameters from the given experimental data. In this case, the shallow water equations used for modeling the hydraulics need to be rearranged in a way that the model parameters can be evaluated from measured data. However, this approach is not always possible and it suffers from stability restrictions. In the present work, we propose an adaptive optimal control technique to numerically identify the underlying bed topography from a given set of free-surface observation data. In this approach, a minimization function is defined to iteratively determine the model parameters. The proposed technique can be interpreted as a fractional-stage scheme. In the first stage, the forward problem is solved to determine the measurable parameters from known data. In the second stage, the adaptive control Ensemble Kalman Filter is implemented to combine the optimality of observation data in order to obtain the accurate estimation of the topography. The main features of this method are on one hand, the ability to solve for different complex geometries with no need for any rearrangements in the original model to rewrite it in an explicit form. On the other hand, its achievement of strong stability for simulations of flows in different regimes containing shocks or discontinuities over any geometry. Numerical results are presented for a dam-break flow problem over non-flat bed using different solvers for the shallow water equations. The robustness of the proposed method is investigated using different numbers of loops, sensitivity parameters, initial samples and location of observations. The obtained results demonstrate high reliability and accuracy of the proposed techniques.

Keywords: Optimal control, ensemble Kalman Filter, topography reconstruction, data assimilation, shallow water equations.

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Authors: J. R. Wang, S. W. Chen, Y. Chiang, W. S. Hsu, J. H. Yang, Y. S. Tseng, C. Shih

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In this research, the HABIT analysis methodology was established for Maanshan nuclear power plant (NPP). The Final Safety Analysis Report (FSAR), reports, and other data were used in this study. To evaluate the control room habitability under the CO₂ storage burst, the HABIT methodology was used to perform this analysis. The HABIT result was below the R.G. 1.78 failure criteria. This indicates that Maanshan NPP habitability can be maintained. Additionally, the sensitivity study of the parameters (wind speed, atmospheric stability classification, air temperature, and control room intake flow rate) was also performed in this research.

Keywords: PWR, HABIT, habitability, Maanshan.

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Authors: Esmaeil Asadzadeh, Mehtab Alam

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Progressive collapse of the layered hyperbolic tower shells are studied considering the influences of changes in the supporting columns’ types and angles. 3-D time history analyses employing the finite element method are performed for the towers supported with I-type and ᴧ-type column. It is found that the inclination angle of the supporting columns is a very important parameter in optimization and safe design of the cooling towers against the progressive collapse. It is also concluded that use of Demand Capacity Ratio (DCR) criteria of the linear elastic approach recommended by GSA is un-conservative for the hyperbolic tower shells.

Keywords: Progressive collapse, cooling towers, finite element analysis, crack generation, reinforced concrete.

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Authors: P. Mounnarath, U. Schmitz, Ch. Zhang

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Fragility analysis is an effective tool for the seismic vulnerability assessment of civil structures in the last several years. The design of the expansion joints according to various bridge design codes is almost inconsistent, and only a few studies have focused on this problem so far. In this study, the influence of the expansion joint clearances between the girder ends and the abutment backwalls on the seismic fragility assessment of continuous integral bridge frames is investigated. The gaps (ranging from 60 mm, 150 mm, 250 mm and 350 mm) are designed by following two different bridge design code specifications, namely, Caltrans and Eurocode 8-2. Five bridge models are analyzed and compared. The first bridge model serves as a reference. This model uses three-dimensional reinforced concrete fiber beam-column elements with simplified supports at both ends of the girder. The other four models also employ reinforced concrete fiber beam-column elements but include the abutment backfill stiffness and four different gap values. The nonlinear time history analysis is performed. The artificial ground motion sets, which have the peak ground accelerations (PGAs) ranging from 0.1 g to 1.0 g with an increment of 0.05 g, are taken as input. The soil-structure interaction and the P-Δ effects are also included in the analysis. The component fragility curves in terms of the curvature ductility demand to the capacity ratio of the piers and the displacement demand to the capacity ratio of the abutment sliding bearings are established and compared. The system fragility curves are then obtained by combining the component fragility curves. Our results show that in the component fragility analysis, the reference bridge model exhibits a severe vulnerability compared to that of other sophisticated bridge models for all damage states. In the system fragility analysis, the reference curves illustrate a smaller damage probability in the earlier PGA ranges for the first three damage states, they then show a higher fragility compared to other curves in the larger PGA levels. In the fourth damage state, the reference curve has the smallest vulnerability. In both the component and the system fragility analysis, the same trend is found that the bridge models with smaller clearances exhibit a smaller fragility compared to that with larger openings. However, the bridge model with a maximum clearance still induces a minimum pounding force effect.

Keywords: Expansion joint clearance, fiber beam-column element, fragility assessment, time history analysis.

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Authors: M. Khaouani, A. Guen-Bouazza, B. Bouazza, Z. Kourdi

Abstract:

The integrity and issues related to electrostatic performance associated with scaling Si MOSFET bulk sub 10nm channel length promotes research in new device architectures such as SOI, double gate and GAA MOSFET. In this paper, we present some novel characteristic of horizontal rectangular gate\gate all around MOSFETs with dual metal of gate we obtained using SILVACO TCAD tools. We will also exhibit some simulation results we obtained relating to the influence of some parameters variation on our structure, that having a direct impact on their threshold voltage and drain current. In addition, our TFET showed reasonable I_ON/I_OFF ratio of (10⁴) and low drain induced barrier lowering (DIBL) of 39 mV/V.

Keywords: GAA, SILVACO, QUANTUM, MOSFETs.

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Authors: Ehan Sabah Shukri, Wirachman Wisnoe

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The influence of twist arrangement on the temperature distribution in an annular diffuser fitted with twisted rectangular hub is investigated. Different pitches (Y = 120 mm, 100 mm, 80 mm, and 60 mm) for the twist arrangements are simulated to be compared. The geometry of the annular diffuser and the inlet condition for the hub arrangements are kept constant. The result reveals that using twisted rectangular hub insert with different pitches will force the temperature to distribute in a circular direction. However, temperature distribution will be enhanced with the length pitch increases.

Keywords: Numerical simulation, twist arrangement, annular diffuser, temperature distribution, swirl flow, pitches.

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Authors: A. Shaygani, R. Saifi, M. S. Saidi, M. Sani

Abstract:

Particle size distribution, the most important characteristics of aerosols, is obtained through electrical characterization techniques. The dynamics of charged nanoparticles under the influence of electric field in Electrical Mobility Spectrometer (EMS) reveals the size distribution of these particles. The accuracy of this measurement is influenced by flow conditions, geometry, electric field and particle charging process, therefore by the transfer function (transfer matrix) of the instrument. In this work, a wire-cylinder corona charger was designed and the combined fielddiffusion charging process of injected poly-disperse aerosol particles was numerically simulated as a prerequisite for the study of a multichannel EMS. The result, a cloud of particles with no uniform charge distribution, was introduced to the EMS. The flow pattern and electric field in the EMS were simulated using Computational Fluid Dynamics (CFD) to obtain particle trajectories in the device and therefore to calculate the reported signal by each electrometer. According to the output signals (resulted from bombardment of particles and transferring their charges as currents), we proposed a modification to the size of detecting rings (which are connected to electrometers) in order to evaluate particle size distributions more accurately. Based on the capability of the system to transfer information contents about size distribution of the injected particles, we proposed a benchmark for the assessment of optimality of the design. This method applies the concept of Von Neumann entropy and borrows the definition of entropy from information theory (Shannon entropy) to measure optimality. Entropy, according to the Shannon entropy, is the ''average amount of information contained in an event, sample or character extracted from a data stream''. Evaluating the responses (signals) which were obtained via various configurations of detecting rings, the best configuration which gave the best predictions about the size distributions of injected particles, was the modified configuration. It was also the one that had the maximum amount of entropy. A reasonable consistency was also observed between the accuracy of the predictions and the entropy content of each configuration. In this method, entropy is extracted from the transfer matrix of the instrument for each configuration. Ultimately, various clouds of particles were introduced to the simulations and predicted size distributions were compared to the exact size distributions.

Keywords: Aerosol Nano-Particle, CFD, Electrical Mobility Spectrometer, Von Neumann entropy.

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Authors: Baha Tulu Tanju, Kamil Kahveci

Abstract:

Buoyancy driven heat transfer of nanofluids in a cylindrical enclosure used as a control unit in the subsea hydrocarbon injection wells is investigated in this study. The governing equations obtained with the Boussinesq approximation are solved using Comsol Multiphysics finite element analysis and simulation software. The base fluid is water and CuO is used as nanoparticles. Solution is obtained for nanoparticle solid volume fraction of 8% and for Rayleigh number in the range of 105-107. The results show that nanoparticle usage in the cylindrical electronic control unit has a significant effect on the flow and heat transfer.

Keywords: CuO, enclosure, nanofluid, natural convection

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Authors: Carol Anne Hargreaves

Abstract:

A key issue in stock investment is how to select representative features for stock selection. The objective of this paper is to firstly determine whether an automated stock investment system, using machine learning techniques, may be used to identify a portfolio of growth stocks that are highly likely to provide returns better than the stock market index. The second objective is to identify the technical features that best characterize whether a stock’s price is likely to go up and to identify the most important factors and their contribution to predicting the likelihood of the stock price going up. Unsupervised machine learning techniques, such as cluster analysis, were applied to the stock data to identify a cluster of stocks that was likely to go up in price – portfolio 1. Next, the principal component analysis technique was used to select stocks that were rated high on component one and component two – portfolio 2. Thirdly, a supervised machine learning technique, the logistic regression method, was used to select stocks with a high probability of their price going up – portfolio 3. The predictive models were validated with metrics such as, sensitivity (recall), specificity and overall accuracy for all models. All accuracy measures were above 70%. All portfolios outperformed the market by more than eight times. The top three stocks were selected for each of the three stock portfolios and traded in the market for one month. After one month the return for each stock portfolio was computed and compared with the stock market index returns. The returns for all three stock portfolios was 23.87% for the principal component analysis stock portfolio, 11.65% for the logistic regression portfolio and 8.88% for the K-means cluster portfolio while the stock market performance was 0.38%. This study confirms that an automated stock investment system using machine learning techniques can identify top performing stock portfolios that outperform the stock market.

Keywords: Machine learning, stock market trading, logistic principal component analysis, automated stock investment system.

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Authors: Fayez M. Idris, Nehal I. AlZubaidi

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Breast cancer detection techniques have been reported to aid radiologists in analyzing mammograms. We note that most techniques are performed on uncompressed digital mammograms. Mammogram images are huge in size necessitating the use of compression to reduce storage/transmission requirements. In this paper, we present an algorithm for the detection of microcalcifications in the JPEG2000 domain. The algorithm is based on the statistical properties of the wavelet transform that the JPEG2000 coder employs. Simulation results were carried out at different compression ratios. The sensitivity of this algorithm ranges from 92% with a false positive rate of 4.7 down to 66% with a false positive rate of 2.1 using lossless compression and lossy compression at a compression ratio of 100:1, respectively.

Keywords: Breast cancer, JPEG2000, mammography, microcalcifications.

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