Universiti Putra Malaysia
Download Latest Complete Journal - JST Vol. 26 (3) Jul. 2018
Foreword by the Chief Executive Editor
No.ArticlesDownloads
1
Full Article
(Downloads: 97)
Abstract (Viewed: 9)The mangrove forest ecosystem acts as a shield against the destructive tidal waves, preventing the coastal areas and other properties nearby from severe damages; this protective function certainly deserves attention from researchers to undertake further investigation and exploration. Mangrove forest provides different goods and services. The unique environmental factors affecting the growth of mangrove forest are as follows: distance from the sea or the estuary bank, frequency and duration of tidal inundation, salinity, and composition of the soil. These crucial factors may under certain circumstances turn into obstacles in accessing and managing the mangrove forest. One effective method to circumvent this shortcoming is by using remotely sensed imagery data, which offers a more accurate way of measuring the ecosystem and a more efficient tool of managing the mangrove forest. This paper attempts to review and discuss the usage of remotely sensed imagery data in mangrove forest management, and how they will improve the accuracy and precision in measuring the mangrove forest ecosystem. All types of measurements related to the mangrove forest ecosystem, such as detection of land cover changes, species distribution mapping and disaster observation should take advantage of the advanced technology; for example, adopting the digital image processing algorithm coupled with high-resolution image available nowadays. Thus, remote sensing is a highly efficient, low-cost and time-saving technique for mangrove forest measurement. The application of this technique will further add value to the mangrove forest and enhance its in-situ conservation and protection programmes in combating the effects of the rising sea level due to climate change. Geoinformation technology, mangrove, remote sensing, sustainable management, tropical forest
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(Downloads: 44)
Abstract (Viewed: 2)This is a review of studies on various types of paper-based epoxy composites currently being designed and developed for technological use. The concept of designing composite materials is very significant for small to large industry and it is important where initiation of repairing work is now being considered for engineering applications. This composite material is of interest due to its advantages compared with others, including low environmental effects and low cost for a wide range of works. This review aims to provide an overview of morphological, physical and mechanical properties of various paper sheets-based epoxy composites and details of achievements made. From this approach, this paper also presents the preliminary study of SEM results of paper sheets-based epoxy composites designed for repairing work applications. It has been found that a well-arranged laminated paper sheet layers could help the bond strength with epoxy matrix. Thus, this paper sheet-based epoxy composite can be considered as an easiest way, cheap and biodegradable that can be used for various small repairing works in structural and automotive applications.Composites, mechanical properties, paper sheets, physical properties, SEM-EDX
3
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(Downloads: 36)
Abstract (Viewed: 1)Human platelets are anucleate cells that lack in deoxyribonucleic acid (DNA), thus hampering genomic study on them. However, the presence of their own messenger ribonucleic acid (mRNA) transcript allows functional study via the transcriptome approach. Transcriptome not only allows profiling of platelet but also aids in studying gene regulation in virus infections and other diseases that have an impact on platelets. Some viruses are known to affect the platelet either by causing a reduction or destruction. Dengue virus is one of the most postulated virus having such effect and frequently linked to platelet reduction. The transcriptome approach has a pivotal role in providing a deeper insight to link certain diseases and their effect on platelets. This review critically discusses role of platelet in dengue and other viral diseases of public health relevance, with a specific focus on the methods currently used in platelet transcriptome profiling. Anucleate cells, arbovirus, dengue, platelet transcriptome profiling, viral diseases
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(Downloads: 28)
Abstract (Viewed: 2)Estimation of stature is important in forensic examination. It is difficult to identify the deceased when the body has been mutilated and only fragmented remains are found. Body height estimation from fingers has been useful in establishing stature approximation. The present research attempts to construct a formula from measurements of the whole fingers from proximal to distal ends. The material for the present study comprises fifty (50) Mongoloid Javanese men between the ages of 21 and 25 years. Measurement of fingers and stature are taken on each subject based on internationally recommended standard methods and techniques. This study uses Pearson correlation test, and Regression analyses to determine the body height formula. The results indicate average height of the subject is 1675.96 mm. The results of index, middle, and ring finger measurements are positively correlated (p < 0.001) with stature. There are moderate correlations r=0.4 to 0.5, between the length of fingers and body height. It can be concluded measuring each segment of finger can provide an estimation of stature. However, measuring the intact fingers is easier and more practical and is sometimes appreciated by the victims' families.Finger length, forensics, height estimation, identification, phalanx, stature
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(Downloads: 28)
Abstract (Viewed: 3)Chronic inflammation is associated with processes that contribute to the onset or progression of cancer. This study examined the correlation between dichotomised patients with malignant tumours and inflammatory markers based on the altered glucose metabolism measured by the FDG SUVmax that underpins the degree of tumour aggressiveness. Thirty-one patients underwent 18F-FDG PET/CT for various carcinoma along with blood inflammatory markers such as C-reactive protein (CRP), interleukin-6 (IL6), lipid profile and fasting blood glucose (FBG) levels were obtained in retrospective study. Patients were dichotomised by the cut-off SUVmax value of 6.0 dl/ml derived from curve analysis (P=-0.025). The mean age of the subjects were 53.16 ± 12.06 years and mean SUVmax of 8.80±6.27 g/ml. Significant correlation was noted between the SUVmax and CRP and IL6 (r=0.361; P<0.05) and IL-6 with BMI and FBG with r=0.38; p<0.05 and r=0.34; p<0.05 respectively. The odds ratio (95% confidence intervals) for patients with the SUVmax cut-off 6.0dl/ml was predicted by FBG ( OR:0.385, p<0.05) and the SUVmax > 6.0 dl/ml was inversely related to IL-6 (OR: 0.049, with p<0.005). Serum inflammatory markers and endogenous glucose are associated with a potentially more aggressive malignant cancer. In particular, IL6 may be used as a useful surrogate marker for tumour aggressiveness with an important prognostic value. Inflammation, Computed tomography, positron emission tomography, [18F]-fluorodeoxyglucose, multimodality
6
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(Downloads: 74)
Abstract (Viewed: 1)Contrast enhancement is the focus of this paper namely use of digital for medical imaging. Five types of images were analysed, namely hand, brain, head, ankle and knee. Three techniques have been used such as INT Operator, Fuzzy Type-1 and Fuzzy Type-2 on five different images. The obtained results have been compared based on four quality parameters, namely mean square error (MSE), normalisation coefficient (NC), root mean square error (RMSE) and peak signal to noise ratio (PSNR).Results showed INT Operator provides the best resultant image compared with other techniques. Contrast enhancement, INT operator, Fuzzy Type-1, Fuzzy Type-2
7
Full Article
(Downloads: 14)
Abstract (Viewed: 2)Cellulose acetate (CA) is an interesting material due to its wide spectrum of utilities across different domains ranging from absorbent to membrane filters. In this study, polystyrene (PS) nanofibres, and cellulose acetate/polystyrene (CA/PS) blend nanofibres with various ratios of CA: PS from 20: 80 to 80: 20 were fabricated by using electrospinning technique. The SEM images show that the nanofibres exhibited non-uniform and random orientation with the average fibre diameter in the range of 100 to 800 nm. It was found that the incorporation of PS had a great effect on the morphology of nanofibre. At high proportion of PS, no or less beaded CA/PS nanofibres were formed. Thermal properties of the composite nanofibres were investigated by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. The TGA results showed thermal stability of CA/PS nanofibres were higher than pristine CA. Cellulose acetate, electrospinning, nanofibres, polystyrene
8
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(Downloads: 16)
Abstract (Viewed: 1)A helically coiled tube enhances heat transfer rate due to development of secondary flows. Use of helical tube as heat exchanger will enhance heat transfer coefficient. Correlations available in the literature for calculating condensation heat transfer coefficient for straight tube are used to evaluate the performance of helically coiled tube-in-shell heat exchanger. Experiments were performed on helically coiled tube of 175 mm coil diameter. Measurements were taken in 10 steps at inlet rate of mass flow of steam. Mean value of the coefficient of heat transfer at inside surface of the tube for condensation was evaluated by experimental methods and results were compared with three correlations available in literature and the deviations are reported. A new empirical correlation is proposed which is based on the experimental investigations. Condensation, heat transfer coefficient, helical coil
9
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(Downloads: 17)
Abstract (Viewed: 1)Images are inherently affected by different noises such as, speckle, salt and pepper, Gaussian, poisson, and white noise during its acquisition or transmission, hence, their true intensities cannot be reflected from the pixel values of an image. The main focus of this work is on designing a filtering method that preserves the edges of an image while removing the noise. The modified wiener filter is proposed to denoise satellite images. A detailed study on different noises and the filtering techniques, such as mean, median, wiener, Gaussian filter and the proposed modified wiener filter is done. The performance of these filtering methods is assessed by the image quality metrics, such as mean squared error, peak signal to noise ratio, and correlation coefficient. The results show the choice of a filter for denoising depends on the type of noise present in the image. The proposed modified wiener filter performs relatively well for most of the noise models compared with the existing linear and non-linear filtering methods. This technique can be widely used during the pre-processing of satellite images in remote sensing applications. Image denoising, filtering, remote sensing applications, peak signal to noise ratio, satellite images, Modified wiener filter
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(Downloads: 16)
Abstract (Viewed: 6)Tawaf ritual performed during Hajj and Umrah is one of the most unique, large-scale multi-cultural events in this modern day and age. Pilgrims from all over the world circumambulate around a stone cube structure called Ka'aba. Disasters at these types of events are inevitable due to erratic behaviours of pilgrims. This has prompted researchers to present several solutions to avoid such incidents. Agent-based simulations of a large number of pilgrims performing different the ritual can provide the solution to obviate such disasters that are either caused by mismanagement or because of irregular event plans. However, the problem arises due to limited parallelisation capabilities in existing models for concurrent execution of the agent-based simulation. This limitation decreases the efficiency by producing insufficient frames for simulating a large number of autonomous agents during Tawaf ritual. Therefore, it has become very necessary to provide a parallel simulation model that will improve the performance of pilgrims performing the crucial ritual of Tawaf in large numbers. To fill in this gap between large-scale agent-based simulation and navigational behaviours for pilgrim movement, an optimised parallel simulation software of agent-based crowd movement during the ritual of Tawaf is proposed here. The software comprises parallel behaviours for autonomous agents that utilise the inherent parallelism of Graphics Processing Units (GPU). In order to implement the simulation software, an optimized parallel model is proposed. This model is based on the agent-based architecture which comprises agents having a reactive design that responds to a fixed set of stimuli. An advantage of using agents is to provide artificial anomaly to generate heterogeneous movement of the crowd as opposed to a singular movement which is unrealistic. The purpose is to decrease the execution time of complex behaviour computation for each agent while simulating a large crowd of pilgrims at increased frames per second (fps). The implementation utilises CUDA (Compute Unified Device Architecture) platform for general purpose computing over GPU. It exploits the underlying data parallel capability of an existing library for steering behaviours, called OpenSteer. It has simpler behaviours that when combined together, produces more complex realistic behaviours. The data-independent nature of these agent-based behaviours makes it a very suitable candidate to be parallelised. After an in-depth review of previous studies on the simulation of Tawaf ritual, two key behaviours associated with pilgrim movement are considered for the new model. The parallel simulation is executed on three different high-performance configurations to determine the variation in different performance metrics. The parallel implementation achieved a considerable speedup in comparison to its sequential counterpart running on a single-threaded CPU. With the use of parallel behaviours, 100,000 pilgrims at 10 fps were simulated. Agent-based system, crowd simulation, GPU, Hajj and Umrah, parallelisation
11
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(Downloads: 15)
Abstract (Viewed: 2)This study investigated the use of ultrasound-assisted extraction (UAE) and agitated-bed extraction (ABE) to improve extraction efficiency of dyes from exocarp and mesocarp of Cocos nucifera. The UAE method was carried out at a frequency of 37 kHz and power of 150 W at 30°C for 1 hour and ABE technique was performed at 30°C for 24 hours at the agitation of 150 rpm. The effects of different solvent types (methanol, ethanol and acetone) and the different percentage of solvent (20%-70%) were determined. The results showed although the colourant yield increased with the increase of solvent concentration up to 60%, statistic value indicated no significant difference (p > 0.05) for the value of yield using solvent range from 20% to 70% for both UAE and ABE methods. Therefore, the solvent concentration of 20% was selected as the optimum concentration for each type of solvent used for both ABE and UAE methods. In comparison, higher extraction yields were achieved by UAE method where the optimal yield of the colourant of the mesocarp was 7.6% using acetone as solvent and the exocarp yielded about 6.4% using acetone or methanol. The recovery of natural colourant using ultrasound was found to be highly dependent on the type of solvents (acetone > methanol > ethanol) for both mesocarp and exocarp. The present study suggests that UAE method should be employed for hauling out colouring materials from exocarp and mesocarp due to its effectiveness in terms of time and economical usage of solvent. Agitated-bed extraction (ABE), Cocos nucifera, exocarp, mesocarp, natural dye, ultrasound-assisted extraction (UAE)
12
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(Downloads: 14)
Abstract (Viewed: 3)Many colorimetric biosensors utilise citrate-capped gold nanoparticles (AuNPcit) in combination with functional macromolecules. Proper function of the utilised macromolecules is strongly dependent on the buffer systems. However, it is well known that solvents and buffers might cause aggregation of nanoparticles. A comprehensive and systematic investigation on the effect of buffer composition, concentration and pH on the aggregation of AuNPcit is reported in this study. Distinct aggregation behaviours were observed in acidic and basic pH. In acidic pH, the increase in pH, caused stabilisation of AuNPcit, while in basic pH, the stability was dependent on the ionisation degree of the applied buffer. Theoretical analyses revealed that ionic buffer species act as citrate competitors and control aggregation of AuNPcit. Understanding the fundamental principles of competition between citrate and buffer components allows scientists to choose orthogonal conditions for development of gold nanoparticle-based biosensors which guarantee stability of gold nanoparticles and proper folding of macromolecules simultaneously. Aggregation, citrate buffer, gold nanoparticles, Good's buffers, Henderson-Hasselbach equation
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(Downloads: 12)
Abstract (Viewed: 1)Simultaneous reduction of soot and oxides of nitrogen (NOx) is a prime requirement for modern day diesel engine to meet the increasingly stringent emission standards. Exhaust gas recirculation (EGR) is one of the most effective techniques for reducing oxides of nitrogen emissions in diesel engine. This study is an attempt to analyse experimentally the performance and emission characteristics of methyl esters of jatropha oil methyl ester (JOME) and fish oil methyl ester (FOME) blends with diesel with and without exhaust gas recirculation on a stationary single cylinder diesel engine. Compared with the diesel fuel, the performance of 20% methyl ester blends and 20% EGR shows a considerable reduction of oxides of nitrogen 6.1 g/kWh for JOME blends and 6.3 g/kWh for FOME blends compared with 7.3 g/kWh for Diesel. Adverse effects are a reduction of brake thermal efficiency 25.6% for FOME blends and 26% for JOME blends compared with 28.4% for diesel, an increase of unburnt hydrocarbons 0.8 g/kWh for JOME and 0.9 g/kWh for FOME compared to 0.7 g/kWh for diesel and carbon moNOxide 23.0 g/kWh for JOME and 25.5 g/kWh for FOME compared to 16.8 g/kWh for diesel. Considering both NOx and soot emissions, 20% EGR is observed to be optimum for both 20% JOME and 20% FOME. Combustion analysis, Emission control, Exhaust gas recirculation, FOME, JOME
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(Downloads: 11)
Abstract (Viewed: 1)This paper proposes the Benders Decomposition approach for modelling distribution networks with cross-docking centres. The cross-docking centre eliminates the requirement for inventory stores. The mathematical formulation of the proposed model is also presented, and the latter consists of plants, cross-docking centres and distribution centres. The Bender Decomposition approach is utilised to solve the proposed model which is tested on 15 different characteristics of test instances. The effect of plants, and cross-docking centres are also investigated. The experimental results reveal the proposed formulation provides promising solutions with reasonable computation time. Benders Decomposition, Cross-docking, Dual Sub-Problem, Master Problem, Mixed Integer Programming
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(Downloads: 28)
Abstract (Viewed: 12)The hash function is used as a one-way cryptography method for digital signature and message authentication. Hash values are provided using a mathematical and logical process, so they are different from the generators of random numbers. The position analysis of bits in plaintext and its hash is very suitable to show their relationship. The focus of this paper is to point to the best relations between the plaintext and hash bits, in which the difference between hash methods will be proven. In this work, we use distance correlation (dCorr) as a measurement function of precision statistical dependency between two vectors. The genetic algorithm (GA) is used to find a set of optimal positions between plaintext and its hash data with maximum dCorr. The results of the experiment regarding dCorr indicate that MD5 as a message digest method is different from the random function. Also, the proposed method compared with Tabu search (TS) and Simulated Annealing (SA) algorithms has a lower average execution time for 1000 pairs of plaintext and hash data. Distance correlation, genetic algorithm, hash, message digest
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(Downloads: 14)
Abstract (Viewed: 1)This study focuses on the simulation of ethylene glycol (C2H6O2) - glycerol (C3H8O3) and ethylene glycol (C2H6O2) - calcium chloride (CaCl2) as separating agents in bioethanol production from fermentation effluent. The entire process was simulated using Aspen HYSYS V7.3 software, but the main focus is the extractive distillation where the mixture compounds were utilised. Response Surface Methodology (RSM) was used to optimise the process variables in extractive distillation column with the separating agent ethylene glycol, temperature, solvent to feed molar ratio and reflux ratio. Non-random two-liquid (NRTL) model was used for activity coefficients of mixture from Aspen properties databank. Results show that both mixture compounds values on solvent to feed molar ratio, reflux ratio and reboiler energy consumption were slightly different as separating agent temperature maintained at 80 °C and ethanol composition in distillate was 99.89 mole%. The separating agents show that better ethanol-water separation with lower energy consumption compared with a well-known single compound such as ethylene glycol. Thus, this study is important to improve extractive distillation column operating conditions by studying the effect of mixture compounds as separating agents in bioethanol production. Calcium chloride, extractive distillation, ethylene glycol, glycerol, simulation
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(Downloads: 13)
Abstract (Viewed: 2)In this paper, a mathematical model is proposed for analytical study of plant growth subjected to the effect of toxic metal. The associated state variables are plant biomass, concentration of nutrients and concentration of toxic metal in the soil. The assumption is that the toxic metals present in the soil interferes with nutrient availability and hence, adversely affect the plant's growth. This effect is studied by introducing the time-lag (delay) in consumption and utilisation coefficient due to less availability of nutrients in the presence of toxic metal. The inclusion of delay disturbed the stability of the interior equilibrium of the system and Hopf bifurcation occurred at the critical value of delay parameter. Further, the direction, stability and period of these bifurcating periodic solutions are also studied as well as sensitivity analysis of state variables with respect to model parameters. Numerical simulation support analytical results using MATLAB. Concentration of nutrients, delay, Hopf bifurcation, plant biomass, toxic metal, simulation
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(Downloads: 12)
Abstract (Viewed: 1)The multi reservoir water resource system has various purposes and therefore, operation planning is becoming complex and involves a number of decision variables. This paper presents an efficient and reliable teaching-learning based approach, namely teaching-learning based optimisation (TLBO) algorithm for optimisation of multireservoir operation policy. It is based on the teaching-learning process of the education system. TLBO algorithm does not require any algorithm-specific parameters for obtaining optimal results; instead it requires only the population size and number of iterations. The time required for obtaining the specific optimised algorithm parameter is reduced and results are also near the global-optimal solution. Furthermore, the number of function evaluations required is less. This TLBO algorithm is implemented at the five-reservoir model of the upper Godavari river project in the city of Nashik in Maharashtra, India. The efficiency of the results of the TLBO algorithm is compared with the genetic algorithm (GA). The results show that TLBO algorithm is considered to be a viable alternative to the operating policy of multireservoir system and it avoids the local optimal solution. Multireservoir operation, optimisation, TLBO algorithm
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(Downloads: 16)
Abstract (Viewed: 2)Precision agriculture with regard to crop science was introduced to apply only the required and optimal amount of fertiliser, which inspired the present study of nutrient prediction for oil palm using spectroradiometer with wavelengths ranging from 350 to 2500 nm. Partial least square (PLS) method was used to develop a statistical model to interpret spectral data for nutrient deficiency of nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), calcium (Ca) and boron (B) of oil palm. Prior to the development of the PLS model, pre-processing was conducted to ensure only the smooth and best signals were studied, which includes the multiplicative scatter correction (MSC), first and second derivatives and standard normal variate (SNV), Gaussian filter and Savitzky-Golay smoothing. The MSC technique was the optimal overall pre-treatment method for nutrients in this study, with highest prediction R2 of 0.91 for N and lowest RMSEP value of 0.00 for P. Nutrients, oil palm, pre-processing, partial least square, spectroradiometer
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(Downloads: 18)
Abstract (Viewed: 2)Hidden Markov model (HMM) can be categorised as an ergodic model or a left-to-right model. The categorization is subject to its state transition. An ergodic Hidden Markov model has full state transitions but a left-to-right hidden Markov model has partial state transitions. A Bakis Hidden Markov model (BHMM) is a special type of the left-to-right Hidden Markov model. State sequence for a BHMM is invisible but this research is able to track the most likelihood state sequence using Viterbi algorithm. However, while tracking the optimal state sequence for BHMM, the conventional algorithm does not provide a measure of uncertainty which is present in the solution. This issue can be overcome by the proposed novel algorithm, namely, BHMM entropy-based forward algorithm (BHMM-EFA) for computing state entropy of a BHMM. This algorithm is based on a decreasing-ladder trellis structure which provides a clear picture on how the entropy associated with the optimal state sequence is determined. Therefore, the novel algorithm requires calculations for tracking the optimal state sequence of a first-order BHMM where T is the length of the observational sequence and N is the number of hidden states. Bakis Hidden Markov model, entropy, forward probability, state transition, uncertainty, Viterbi Algorithm
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(Downloads: 19)
Abstract (Viewed: 6)Water is an important natural resource for all living organisms. Due to increase in population, industrial magnification and urbanisation, water gets contaminated these days. The aim of present study is to design a low cost and reliable system for the monitoring of real time water quality. This study includes monitoring of physiochemical parameters such as pH, Temperature, Turbidity and Total Dissolved Solids (TDS). Microcontroller based multi sensor system can measure the said parameters for detecting water contamination and incorporates communication technology for further processing and alerts. Data communication module can transmit the data received from system to intended user for making alerts regarding water quality. User can check the water quality information perpetually even from far away and he or she can take several safety measures to prevent health hazards. Facile design and low cost make this system captivating enough for large scale deployment.Automation, contamination detection, multi sensor system, turbidity sensor, water quality monitoring
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(Downloads: 10)
Abstract (Viewed: 2)The primary goal of a MANET routing protocol is to provide a stable and efficient route to exchange messages between source and destination in a timely manner. This paper proposes an adaptive mechanism, namely Optimised Border node based Most Forward within Radius (OBMFR) mechanism to improve the method of choosing forwarding nodes towards the destination. The routing constraints such as region, mobility speed, residual energy and queue length are utilised by fuzzy logic controller to elect the potential forwarding node to improve the stability of routing paths. The performance metrics such as delay, routing overhead and energy consumption are significantly reduced as inferred from NS2 simulation. Fuzzy logic, MANET, NS2, overhead, routing protocol
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(Downloads: 14)
Abstract (Viewed: 1)The assumption when constructing a control chart is that the process parameters, i.e. mean and standard deviation, are known. Nevertheless, this assumption is not realistic in practical situations. In most of the application of a control chart, the mean and standard deviation are unknown and are estimated from an in-control Phase-I samples. When the process parameters are estimated, the control chart performs differently compared with the corresponding chart with known process parameters because of the variability of estimators. The usual practice to evaluate the performance of a control chart is to use the average run length (ARL). The ARL is the average number of samples plotted on a control chart before an out-of-control signal is detected. In addition, the expected ARL (EARL) is used as a performance measure for the random process mean shift. In this article, the performance of the side sensitive group runs (SSGR) chart with known and estimated process parameters are studied and examined in terms of ARL and EARL. Estimated parameters, expected average run length, side sensitive group runs
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(Downloads: 16)
Abstract (Viewed: 1)High reliability, high speed and low cost are the prime factors account for the complexity of electronic systems. Reliability and failure prediction are the major constraints to estimate the residual life of the component to anticipate the costly failures or system unavailability. Reliability prediction of passive components, especially PN junction diode, is of great concern as it is a critical element of bipolar junction transistors and other semiconductor devices, so the chances of failure as well as damage are increased as every component has its own characteristics and operating conditions. In this paper, artificial Intelligence techniques are employed on PN junction diode which embrace knowledge of failure mechanism of a component and predict the residual life of the component and a preventive action to be taken before serious breakdown occurs. The residual life calculated from experimental method is compared with artificial intelligence techniques, namely. ANN, fuzzy logic and ANFIS. The ANFIS has been proved as the most accurate system to predict remaining useful lifetime with an accuracy of 99.03%. A Graphical user interface is also designed based on fuzzy inference system, which indicates the remaining useful lifetime of PN junction diode. Accelerated life testing, ANFIS, artificial intelligence (AI), GUI, residual life
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(Downloads: 13)
Abstract (Viewed: 1)The improvement of the composite material against fatigue loading is of a great interest. In this study, the classical lamination theory of laminated composite was developed in order to include the effect of fibre prestressing on the composite's fatigue life when it was subjected to tension-tension fatigue loading. The biaxial fabric prestress term of the plain-weave composite (E-glass/polyester) was included in the theory and simplified. The overall tensile stress within the composite lamina was reduced by inducing compressive residual stress imparted from releasing the fibre pretension load. The fatigue life of the prestressed E-glass/polyester composite lamina was prolonged 36 times compared to the non-prestressed counterparts when the fabric was biaxially prestressed with 100 MPa. Biaxial fabric prestress, development of classical lamination theory, plain-weave fabric, residual stresses, tension-tension fatigue
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(Downloads: 12)
Abstract (Viewed: 1)Curcuma longa (turmeric) is a rhizomatous herbaceous perennial plant which is widely cultivated in tropical regions, such as Indonesia. It has been intensively used for medical purposes as an ingredient of traditional medicine for a long time. In order to extend its shelf-life, turmeric is generally dried under the sun prior to use. This method generally takes a longer time and is less controlled, thus yielding less qualified products. This experiment was carried out using a manually designed solar dryer for improving the drying process of turmeric. The drying process using solar dryer is shorter and also protects the samples from dirt, insects, as well as direct contact with UV radiation which may deteriorate its bio-active compounds. The drying was done until moisture of about 10% content was achieved. In general, it took about 450 minutes in the solar dyer in comparison to that of 480 minutes using sun drying to reach the equilibrium moisture content. This was caused by a higher temperature profile distributed inside the solar dryer accelerating the drying process. The use of solar dryer has the potential to be further developed to replace the conventional sun drying method of herbs. Curcuma longa, drying process, solar dryer, sun drying, turmeric
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(Downloads: 33)
Abstract (Viewed: 10)Tritrophic interaction among plants, herbivores and natural enemies of the herbivores is mediated by volatiles. Tritrophic interaction model using rice plant, brown planthopper (BPH), and egg parasitoid of BPH were used to study the volatiles involved in the interaction. Extraction of chemicals in rice plants, determination of the extracted volatiles using GC-MS, and bioassays of the volatiles to analyse the orientation behavior of the egg parasitoid were methods used to study the involvement of the volatiles in the interaction. The knowledge of chemistry involved in such complicated natural interaction is beneficial for enhancing conservation biological control (CBC) of BPH using natural population of its egg parasitoid. Implementation of the positive volatile compounds attract the egg parasitoid as a component of CBC, materials involved that adsorb and release the volatiles efficiently. A material made of integrated bio-silica-cellulose was proven to be an effective adsorbent. Analytical chemistry was important in supporting these findings. Furthermore, in order to increase the efficiency of the volatiles that are positively involved in the tritrophic interaction, developing an attractant formula using synthetic-similar compounds and bio-silica-cellulose adsorbent is valuable in enhancing CBC. Biosilica-cellulose adsorbent, chemical cues, tritrophic interaction
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(Downloads: 13)
Abstract (Viewed: 1)Cloud computing has set a trend on a worldwide stage along with the rapid growth to enhance global technology standard and market scale in recent years. For the cloud users, load balancing in data center networks initiates the necessity of reducing the downtime for migrating overloaded virtual machines. To achieve better during-task deployment, optimal physical host must be selected efficiently. Nowadays, cloud customers are facing security risks in the context of load balancing of Virtual Machines (VM) which is infrequently addressed. This research addresses this pertinent issue and provides a different perspective of studying ways to develop VM deployment strategy by reducing the probability of VM co-tenancy with their targets. This will in turn make it difficult for attackers to evaluate the strategy. A model called Optimal Physical Host for Load Balancing (OPH-LB) is proposed to find the probability with probabilistic estimation in the form of its computing capability and performance in secure multi-tenant cloud. The proposed solution is evaluated via Cloudsim 3.0.3 and compared with two existing well-known algorithms. The reported results indicate that OPH-LB outperforms in improving the makespan, throughput, performance and reduces the failure number of task deployment. The results show that OPH-LB can effectively reduce the risks and security score and upgrades the utilisation of resources, with an improvement of 42.13% in all types of analyses for the experimental data. Cloud computing, deployment, optimality, performance, probability, security
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(Downloads: 75)
Abstract (Viewed: 12)In this era of digital revolution, voluminous amount of data are generated from different networks on a daily basis. Security of this data is of utmost importance. Intrusion detection systems have been found to be one of the best solutions in detecting intrusions. Network intrusion detection systems are employed as a defence system to secure networks. Various techniques for the effective development of these defence systems are found in the literature. However, research on the development of datasets used for training and testing purposes of such defence systems is of equal concern. Better datasets improve the online and offline intrusion detection capabilities of detection models. Benchmark datasets like KDD 99 and NSL-KDD cup 99 are obsolete and do not contain network traces of modern attacks like Denial of Service, hence are unsuitable for the purpose of evaluation. In this study, a detailed analysis of CIDDS-001 dataset was conducted and the findings are presented. A wide range of well-known machine learning techniques were used to analyse the complexity of the dataset. Evaluation metrics including detection rate, accuracy, false positive rate, kappa statistics, and root mean squared error were utilised to assess the performance of employed machine learning techniques. Anomaly, decision tree, k-means clustering, k-nearest neighbour, labelled flow, metrics, random forests, signature
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(Downloads: 13)
Abstract (Viewed: 2)Medical emergencies are life-threatening situations which need immediate interventions. Response to such emergency situation will depend upon the resources available at that instant. A response time of any healthcare system will make a difference between life and death of a victim. In this work, the authors investigated the performance of various routing protocols for Ad Hoc network application in healthcare services for emergency situations where the data from the patients were collected via wearable devices. The comparison study is done to test the suitability of the Medium Access Control (MAC) protocols for such m-health applications established through an ad hoc network. The established network, however, diagnoses the patient's parameters on real-time basis and sends the data to the doctors and to a database within the hospital, which is constantly monitored, creating a virtual Intensive Care Unit (ICU) for a victim so as to address any abnormal behaviour during remote process. The proposed architecture was designed with the aim to manage emergency situations by reducing delays and increase the effectiveness of the patient monitoring mechanism in situations where the delay in providing medical aid to the patient maked a difference to his / her survival. To demonstrate the effectiveness of the study, an Electrocardiogram (ECG) pattern of a patient was monitored on real-time basis. A custom packet frame was designed for data transmission having a special field to store ECG data along with other general information as per the packet standards. Ad hoc network, ECG, healthcare system, MAC protocols, performance evaluation, telemedicine, WLAN
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Abstract (Viewed: 4)Spamming is a major issue in the area of web search. There are many features (Link & Content based) which are used for spam and non-spam classification. This paper recommends CFS+PSO, which takes the advantages of swarm behaviour (uses randomness and global communication between particles) and Correlation Based Feature Selection Technique (CFS). The objective of feature selection is to build logical model with improved performance in time and accuracy. The performance of CFS+PSO is evaluated on WEBSPAM-UK2006 with Multilayer Perceptron (MLP), Naïve Bayes, Support Vector Machine (SVM), J48 & AdaBoost. Experimental results show great decline in existing features and computational time while increases in the accuracy measures (F1 Score and AUC). Content and link based features, correlation based feature selection, data mining, filter and wrapper model, particle swarm optimization, spam
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Abstract (Viewed: 1)The purpose of this study is to evaluate the ball-milling process for the production of carbon particles from rice straw waste. In the experimental method, carbon particles are prepared by adding heat treatment to the rice straw waste at the temperature of 250°C. The heated rice straw waste is grinded using a conventional grinding method and put into the ball-milling process. Physicochemical properties of carbon particles are evaluated before and after the ball-milling process. The results indicate that sizes of carbon particles decrease significantly from micro (after the conventional grinding process) to submicron range (after additional ball milling process). Almost no changes in the chemical properties of carbon particles are observed. This result implies that the ball-milling process is effective to decrease the size of the prepared carbon particles. The collision phenomenon combined with shear stress among the stainless steel balls is the main reason for breaking carbon particles, making the particle sizes smaller. Activated carbon particles, ball-milling process, rice straw waste
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Abstract (Viewed: 1)Indonesia has a variety of culture, tribes, customs, religion, and arts. One of the most popular cultural heritages in Indonesia is Batik. Each print or pattern has different meanings reflecting the culture of the area where the batik originates from. There are many ways to preserve batik; one of which is by giving information and understanding about the culture of batik through a technology called Augmented Reality (AR). In this study, the philosophy of batik patterns is visualised through AR application. Markerless's AR method is used so that the AR used to detect batik without using any markers. The application is implemented on android-based devices, either smartphones or tables, as they are very popular. Results of the visualisation are the image, name and philosophy of the batik detected. The application can detect at most around 50 cm and 30°C. Batik pattern, android, Markerless augmented reality method, philosophy
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Abstract (Viewed: 1)Optimisation, which is a method to obtain optimal or near-optimal values of objective functions, has been widely used to make a decision in many problem domains, such as engineering, chemical, business, etc. This research is aimed to build an R package that implements 11 methods based on meta-heuristics methods that are inspired by natural phenomena and animal behaviours. Here, R programming language is considered since it is a popular programming language for data science. In this version of the package, 11 meta-heuristic algorithms are implemented, namely particle swarm optimisation (PSO), ant lion optimizer (ALO), grey wolf optimizer (GWO), dragonfly algorithm (DA), firefly algorithm (FFA), genetic algorithm (GA), grasshopper optimisation algorithm (GOA), moth flame optimizer (MFO), sine cosine algorithm (SCA), whale optimisation algorithm (WOA), and harmony search (HS). The methods have proven to be reliable and stable. To validate the package, the study presents 13 benchmarking functions in our experiments such as sphere model, Schwefel's Problem 2.22, Generalised Rosenbrock's Function and Step Function. Based on the experiments, package metaheuristicOpt produces optimal solutions as indicated by references proposing respective algorithms. Meta-heuristics algorithm, optimisation, R programming language, software library, Swarm intelligence
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Abstract (Viewed: 5)This paper is an outome of a study on the development of the conceptual design of advanced fast reactors that have passive and inherent abilities. Safety performance indicators are evidenced by the ability of the reactor to remain under control and can operate on a new equilibrium shortly after an accident. Simulations are performed when an accident due to unprotected loss of flow (ULOF) and unprotected loss of heat sink (ULOHS) occurs at the reactor. The passive safety system is realised by the reactor vessel auxiliary cooling systems (RVACS), before its performance is evaluated. The simulation results show that the current power reactors can survive the ULOF and ULOHS accident. The optimisation of the reactor and the RVACS results in higher natural circulation level, indicating the reactors satisfy the inherent or passive safety standards. The results from the 'accident' show there is a large safety margin to the maximum temperature within the fuel, cladding, and coolant. Accident analysis, advance reactor, heat sink system, NPP, RVACS, ULOF, ULOHS
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Abstract (Viewed: 1)The surface of a liquid at rest behaves in an interesting way, almost as if it was a stretched membrane under tension. A steel needle can be made to float on the surface of water even though it is denser than water. The surface of a liquid acts like it is under tension, and this tension, acting along the surface, is a product of attractive forces between the molecules. This effect is called surface tension. There are various methods to determine the surface tension coefficient of a liquid. This research focused on determination of pure water surface coefficient using Jolly's Spring Balance. The parameter measured is the height of the liquid bubbles at critical condition that in the right condition will break. Repeated measurement methods that are statistically processed are used to measure uncertainty. The magnitude of pure water surface value using Jolly Balance Spring Apparture's obtained γ (water) = (3,620 ± 0.0028) × 10-2 N / m at temperature (27 ± 0.25)°C and pressure (68.8 ± 0.005) cmHg. Liquid used in this research is pure water at temperature 27°C. Altitude, jolly's balance spring, surface tension
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Abstract (Viewed: 2)Implementation of Information and Communication Technology (ICT) to assist document management in the mail distribution will be useful in improving document management performance effectively and efficiently. Securing information in mail disposition using electronic media should be made in such an order to prevent unwanted things. Cryprography or digital signature are some of the techniques that ensures security. The purpose of this study is to see the effect of digital signatures to maintain data security using Rivest-Shamir-Adleman (RSA) and Advanced Encryption Standard (AES) algorithms to the disposition system of letter based on cryptographic purposes, namely Secrecy, Data Integrity, Authentication and Non-repudiation. Several tests of various attacks to the system were conducted. The study concluded the additions of AES algorithm can maintain secrecy and integrity of the letters, while RSA algorithm can maintain authentication and non-repudation of the letters. AES and RSA algorithms, cryptography attacks, digital signature, mail disposition
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Abstract (Viewed: 3)This study aims to analyse the technical efficiency of Chemical Industry in Indonesia using Stochastic Frontier Analysis (SFA) approach. A survey explanatory method is adopted with panel type data at 4240 inputs and output level of companies during six years of observation (2010-2015). Determinant technical efficiency is estimated by using multiple regression. Both technical efficiency calculations and regression determinants are done using the TE effect approach in Frontier 4.1 software. The result of research indicates that market share variable significantly and negatively affects technical efficiency. Other variables, such as company age, business ownership, ratio concentration, and capacity utilisation affect the technical efficiency are not significant. This finding implies that to improve the efficiency of the chemical industry, market share needs to be increased through various activities such as promotion. Chemical industry, Stochastic frontier analysis, technical efficiency
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Abstract (Viewed: 2)Verification and validation of system models at design level has a huge impact on the quality of the system software engineering process. In general, system modeling and designing Unified Modelling Language (UML) is a standard for the design models of the systems. However, verification and validation of UML models at early design level is not available, but somehow Object Constraint Language (OCL) constraints are defined at the class level to ensure that the model is correctly designed. As for the static–dynamic structure, there is no such mechanism defined in UML/OCL that has a huge impact on the development of the software. Our research is focused on providing verifiable UML/OCL models. Our approach using UML-based Specification Environment (USE) for UML class model is integrated with the OCL constraints to check if the model is correctly designed as well as constraints for verification and validation. In USE, the output is shown as the verifiable UML/OCL models by visual graphical models. OCL constraints, static and dynamic, Unified Modelling Language (UML) and Object Constraints Language (OCL), verification and validation
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Abstract (Viewed: 1)Two-dimensional photonic crystals with nano-rod configuration integrated in a silicon-on insulator are analysed in this study. A photonic crystal waveguide suspended over a silicon substrate then weight can be applied on that substrate to change the displacement of substance and to measure sensitivity for pressure in terms of micro units. The overall objective of this work is to detect displacement, which indicates the force applied on the slab with photonic crystals that have line defects. Stress and displacement of the slab reveal the pressure applied. Stress is calculated by the power distribution/excitation in the slab. The displacement of the slab is due to the force, while pressure is determined by the photonic crystal sensor. The quality and sensitivity of the sensor are 1496 and 1200 RIU, respectively. The transmission spectrum is 0.1 micron to 0.5 microns shift, respectively, which are found to be distinct.Photonic crystal (PhC), silicon-on insulator (SOI), micro pressure, stress, optical membrane, nano rods
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Abstract (Viewed: 1)The Micro Opto Electro Mechanical System (MOEMS) is a most promising cutting-edge technology development that uses recent trends and has huge potential for use in sensing applications. This simulation study describes the Photonic Crystal- (PhC) based micro pressure sensor, which is highly position-sensitive and free from external electromagnetic interference. Functionality of MOEMS in the photonic crystal-based micro pressure sensor is achieved through the movement of the two piston-shaped slab structures analysed in Rods in Air (RIA) and Holes in Slab (HIS) that belong to photonic crystal configurations. Displacement of the micro cavity due to applied pressure gives rise to shifts in wavelength. It is found that for each submicron displacement starting from 0 to 0.25 mm of the piston-shaped slab that is embedded, an approximate range of wavelength shift of 0.0001 for rods in air and for holes in slab configurations occurs. The simulation design shows a remarkable response in terms of intensity shift for desirable range of wavelengths 1.36 µm to 1.44 µm for RIA and 1.377 to 1.382 for HIS, thus confirming that wavelength is adaptable. The performance parameters such as Q factor and deflection range for wavelength and intensity are observed for both RIA and HIS configurations and it is found that the sensor with the HIS configuration shows better performance with Q factor of 15897 compared with the sensor with RIA configuration, which remained at a Q factor of 2482. Deformation of structure for applied pressure exhibits a linear relationship with a resonant wavelength shift. Structural variation in relation to wavelength shift exhibits a pressure sensitivity of 58.4 µm/Pa and 0.98 µm/µPa for each configuration. Photonic crystal, rod in air, holes in micro cavity, Perfectly Matching layer (PML), pressure, total direct strain, Finite Difference Time Domain (FDTD)
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Abstract (Viewed: 1)The paper describes a unique approach for a label-free biosensor designed for early-stage detection of malignant and invasive melanoma. Refractive Index variation analysis plays a vital role in the photonic crystal-based sensor design. The photonic crystal-based micro interferometer biosensor has been designed in rods in air configuration. The design comprises a hexagonal ring structure between two bus waveguides forming sensing and reference arms. The early-stage diagnosis of melanoma is dependent on the comparison of normal cells against affected cells. The diagnosis is conducted using the arms of the interferometer. The sensitivity of the biosensor is determined by the phase shift/wavelength difference between the arms of the interferometer sensor. The sensitivity of the designed sensor is 4000nm/RIU. The simulations are done using the FDTD technique. The relative shifts in frequency and wavelength are due to the refractive index deviation in the sensing arm. Quality factor is obtained at 10654.3 for the wavelength 1550 nm. Bus waveguides, early stage diagnosis, FDTD, interferometer, melanoma, photonic crystal, quality factor, refractive index deviation
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Abstract (Viewed: 7)The mobile ad hoc network (MANET) is a wireless network based on a group of mobile nodes without any centralised infrastructure. In civilian data communication, all nodes cannot be homogeneous-type and not do a specific data communication. Therefore, node co-operation and cheat-proof are essential characteristics for successfully running MANETs in civilian data communication. Denial of service and malicious behaviour of the node are the main concerns in securing successful communication in MANETs. This scheme proposed a generic solution to preventing malicious behaviour of the node by the cluster head through the single hop node clustering strategy. Ad hoc network, black-hole attack, cheat-proof, malicious node, MANET
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Abstract (Viewed: 1)The problem of routing and wavelength assignment is apparent in the dynamic all-optical network that plays an important role in the optical transport layer network. It is solved by minimising the connection blocking since the grooming adaptive shortest path algorithm shows comparably better results in terms of the calculation to find blocking probability. The shortest path algorithm used in this paper contains the present network state information, and each node creates a shortest path tree towards all the other nodes, which form node pairs by connecting each branch in the tree. The adaptive shortest path algorithm will find the shortest path throughout the network path and it chooses the best path from the available source-destination. Considering the number of nodes as 14 and comparing for different topology, it has been observed that the wavelength usage in each node varies with respect to different topology. Additionally, a comparative study of wavelength usage has been achieved for topologies like random, ring and tree. Adaptive shortest path algorithm, blocking probability, topology, wavelength assignment
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Abstract (Viewed: 7)Literature has established the effectiveness of self-regulatory techniques using Heart Rate Variability (HRV)-Biofeedback Technology in improving individual's heart coherence. The current study aims to evaluate the effectiveness of Quick Coherence Technique, a self-regulatory technique, through the application of HRV-biofeedback technology on the level of heart coherence among university students. A total of 20 students of a technical public university participated in the study. The Quick Coherence Technique (QCT) and the emWave device and software of the HeartMath Institute were used to collect the data. According to the HRV power spectrum, the HRV data is divided under very low frequency (VLF), low frequency (LF), and high frequency (HF) frequency ranges. Based on the results, the use of HRV-biofeedback technology and the QCT had helped to increase the levels of HRV scores and heart coherence of the participants. Biofeedback, coherent heart, heart coherence, Heart Rate Variability, Quick Coherence Technique

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