792 research outputs found
An Assessment of Global Factors towards the Financial Performance of a Containership Using a Bayesian Network Method
The movement of containerised goods made 2009 debatably the most dramatic year in the history of the box. A Bayesian network methodology associated with the cause and effect analysis technique is introduced to analyse the global economic conditions, the container market demand and the bunker fuel price in order to measure the financial performance of a containership. This method demonstrates the combination of qualitative and quantitative criteria in order to ensure that the best possible decision can be made by a shipping company. As a consequence, the result provided by the Bayesian Network method can be used as an indicator for helping shipping lines plan a cost-effective business strategy. Keywords: Bayesian Network Method; Uncertainty Treatment; Vessel Speed; Containership; Decision Making Technique.
Optimal energy management for plug-in hybrid electric vehicles
There is a great potential for significant improvement to be made in energy efficiency and reduction in emissions, fuel use, weight and cost of vehicles through implementing innovative technologies. Many automakers have been making great efforts to develop an alternative vehicle that can offer the best solution in reducing the effects of global warming and oil depletion. Such a vehicle will win quick acceptance in the marketplace because of the current high fuel cost. Recently, the plugin hybrid electric vehicle (PHEV) has been identified as one of the most viable technologies to achieve these goals by implementing an optimal energy management system. This paper presents our recent research work on the energy management system for a specific PHEV. The system configuration, analysis, model, control strategy, and simulation results are presented in detail. Recommendations on the directions and areas in which the further research in hybrid vehicle should be aligned are also be included
Influenced factors in the delignification process of red meranti wood sawdust
Lignocellulosic biomass are plants that include forestry residue and agricultural residues that are mainly composed of cellulose, hemicelluloses and lignin. Red Meranti wood sawdust (RMWS) are one of lignocellulosic biomass that rich-cellulose content. To obtain
cellulose, the pretreatments are needed to extract it from outer layer of lignin and hemicellulose by using the acid-chlorite delignification procedure aided with design of experimental from Design Expert 7.1 software. Four factors were selected in design of experiment using two level with half fraction factorial analysis were came out with total of 8 runs. The factors contributed were ratio acetic acid (AC) to RMWS (0.45 and 0.6), ratio sodium chlorite to RMWS (0.6 and 1.64), reaction time (4hr and 6hr) and temperature (55°C and 75°C). The results obtained were showed that the design model was substantial resulting with a coefficient of determination value of 0.9963. Two factors that generated the highest to the process were ratio SC to RMWS (B) and temperature (D). The percentage error between the actual and predicted value for lignin removal at 0.79% and 4.92%, which found to be less than 5%, and thus, the model was successfully validated
Gathering experience in trust-based interactions
As advances in mobile and embedded technologies coupled with progress in adhoc networking fuel the shift towards ubiquitous computing systems it is becoming increasingly clear that security is a major concern. While this is true of all computing paradigms, the characteristics of ubiquitous systems amplify this concern by promoting spontaneous interaction between diverse heterogeneous entities across administrative boundaries [5]. Entities cannot therefore rely on a specific control authority and will have no global view of the state of the system. To facilitate collaboration with unfamiliar counterparts therefore requires that an entity takes a proactive approach to self-protection. We conjecture that trust management is the best way to provide support for such self-protection measures
Kesan penambahan limonena terhadap mikroemulsi asid oleik/Cremophor rh 40/Transcutol/Air
Gambar rajah fasa pseudo-ternari sistem mikroemulsi asid oleik/Cremophor rh 40/Transcutol/Air diperoleh melalui pentitratan air pada nisbah surfaktan:kosurfaktan (Km) yang berbeza. Nisbah optimum bagi surfaktan/kosurfaktan adalah Km=2:1. Kesan penambahan limonena sebagai fasa minyak campuran terhadap sistem mikroemulsi diuji pada nisbah limonena:asid oleik (1:1, 2:1 dan 3:1). Penambahan limonena berupaya menghasilkan rantau mikroemulsi yang lebih besar sehingga 70%-80 % bt. air bagi kesemua nisbah limonena:asid oleik. Nisbah limonena:asid oleik (1:1) memberikan rantau mikroemulsi yang paling luas pada nisbah minyak:surfaktan/kosurfaktan (Minyak:S/KoS=1:9). Sifat isotropik mikroemulsi ditentukan dengan menggunakan mikroskopi cahaya polarasi. Mikroemulsi dibangunkan pada nisbah Km=2:1 dan Minyak:S/KoS (1:9) serta limonena:asid oleik (1:1). Kestabilan dan saiz partikel bagi sistem dikaji dan penambahan limonena didapati tidak merubah sifat serta mikro-struktur sistem mikroemulsi. Kajian konduktiviti elektrik dan kelikatan sistem menunjukkan pembentukan mikroemulsi jenis air-dalam-minyak (10% dan 20 % bt. air) dan dwiselanjar (30%-50 % bt. air). Kesemua sistem mempunyai potensi sebagai sistem penghantar bahan aktif dan menunjukkan kestabilan yang baik pada suhu 4, 25 dan 37°C dalam tempoh lebih daripada 6 bulan
Modelling, Simulations, and Optimisation of Electric Vehicles for Analysis of Transmission Ratio Selection
Pure electric vehicles (PEVs) provide a unique problem in powertrain design through the meeting of performance specifications whilst maximising driving range. The consideration of single speed and multispeed transmissions for electric vehicles provides
Exploring the use of social media tools among students for teaching and learning purpose
Social media network is a fairly recent word used to define a form of learning that can be performed via websites online learning. The exploring of the potential use of social media tools and impact of contingent factors on the relationship between three predictors was investigated. A total of 235 valid responses were received from undergraduate students Faculty of Computing, Universiti Teknologi Malaysia (UTM) in the study. Several factors have been found to correlate with social media use, active learning both to affect teaching and learning. The researchers made use of the structural equation modelling (SEM) method with the SmartPLS program to shed a light on the adoption process. The results show that the use of social media positively and significantly relates to active learning, which in turn affect teaching and learning
The influence of surfactant/co-surfactant hydrophilic-lipophilic balance on the formation of limonene-based microemulsion as vitamin C carrier
This research was conducted to produce a limonene-based microemulsion system as vitamin C carrier. The microemulsion was produced using limonene as the oil phase, tween20 and tween80 as surfactants while propylene glycol, polyethylene glycol 400 and glycerol as co-surfactants. Pseudo-ternary phase diagrams were constructed to determine the microemulsion area by using the water titration method at 25°C. The effect of hydrophilic-lipophilic balance (HLB) value of the mixture of S/CoS on the formation of limonene-based microemulsion was studied. The HLB value calculated for the mixture of tween20/propylene glycol in the different ratio was between 10.1 and 13.4. From the experiment, the preparation of limonene-based microemulsion system with tween20/propylene glycol was able to provide large and high stability of microemulsion region on ternary phase diagram (23.6%) while higher HLB value resulted in larger microemulsion area in ternary phase diagrams. The sole formulation with propylene glycol was further selected to carry out the physicochemical characterization of system’s stability, particle size and electrical conductivity. All microemulsion systems showed good stability for four weeks at temperature of 4, 25 and 40°C without any phase change and separation. Particle size characterization results elucidated that all microemulsion systems consisted particle size between 20 and 100 nm. The study of electrical conductivity showed that water-in-oil microemulsion was formed from 5-45% wt. of water whereas bicontinuous microemulsion was formed from 50-90% wt. of water content. Overall, the result showed that microemulsion tween20/propylene glycol/limonene/water was potential as a carrier system of vitamin C
A scalable hybrid decision system (HDS) for Roman word recognition using ANN SVM: Study case on Malay word recognition
An off-line handwriting recognition (OFHR) system is a computerized system that is capable of intelligently converting human handwritten data extracted from scanned paper documents into an equivalent text format. This paper studies a proposed OFHR for Malaysian bank cheques written in the Malay language. The proposed system comprised of three components, namely a character recognition system (CRS), a hybrid decision system and lexical word classification system. Two types of feature extraction techniques have been used in the system, namely statistical and geometrical. Experiments show that the statistical feature is reliable, accessible and offers results that are more accurate. The CRS in this system was implemented using two individual classifiers, namely an adaptive multilayer feed-forward back-propagation neural network and support vector machine. The results of this study are very promising and could generalize to the entire Malay lexical dictionary in future work toward scaled-up applications
- …