19672 research outputs found
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Preventing Shoulder-Surfing Attacks using Digraph Substitution Rules and Pass-Image Output Feedback
No full textIn this paper, we focus on methods to prevent shoulder-surfing attacks. We initially adopted digraph substitution rules from PlayFair cipher as our proposed method. PlayFair cipher is a modern cryptography method, which exists at the intersection of the disciplines of mathematics and computer science. However, according to our preliminary study it was insufficient to prevent shoulder-surfing attacks. Thus, a new method had to be proposed. In this new proposed method, we improvised the digraph substitution rules and used these rules together with an output feedback method to determine a pass-image. Our proposed method was evaluated with a user study. The results showed our proposed method was robust against both direct observation and video-recorded shoulder-surfing attacks. © 2019 by the authors
Critical Dynamics of Transverse-field Quantum Ising Model using Finite-Size Scaling and Matrix Product States
No full textThe study of phase transition is usually done by numerical simulation of finite system. Conventional methods such as Monte Carlo simulations and phenomenological renormalization group methods obtain the critical exponents without obtaining the quantum wavefunction of the system. The Matrix Product States formalism allows one to obtain accurate numerical wavefunctions of short ranged interacting quantum many-body systems. In this study we combine the Finite Size Scaling theory and Matrix Product States formalism to study the critical dynamics of one-dimensional quantum Ising model. Finite size simulations of 20, 40, 60, 80, 100 and 120 spins are done using the Density Matrix Renormalization Group to obtain the ground state wavefunction of the system. The thermodynamic quantities such as the magnetization, susceptibility and correlation function are calculated. The critical exponents independently calculated are respectively β/ν = 0.1235(1), γ/ν = 1.7351(2), and η = 0.249(1). They conform with the theoretical values from analytical solution and fulfil the hyperscaling relation. We showed that both methods combined can reliably study the critical dynamics of one-dimensional Ising-like quantum lattice systems. Application of the study on water-ice phase transition of single-file water in nanopores is proposed. © 2019, Springer Science+Business Media, LLC, part of Springer Nature
Molecular Bose–Einstein condensates: effects of molecular rotations on transition temperature and heat capacity
No full textWe study the effects of molecular rotations on the transition temperature of molecular Bose-Einstein condensates (BEC). A semi-analytical method that includes the translation and rotational degrees of freedom is introduced to compute the temperature dependence of the mean condensate number and the heat capacity. Rotating molecules show a lower transition temperature and smaller heat capacity compared to an atomic BEC. The transition temperature increases with increased rotational frequency. These findings are explained and verified by analytical expressions that we derive. The results for three-, two- and one-dimensional harmonic traps are compared, showing a higher transition temperature for molecules in a lower dimensional trap. We discuss the possibility of realizing the trapping and rotational parameters. © 2019 IOP Publishing Ltd
Design of a compact and effective greywater treatment system in Malaysia
No full textWater shortage has been one of the major concerns faced by about 2.7 billion people around the world due to several factors, including water pollution, climatic change, etc. Several nations have been seeking practical alternatives to address this issue and one of the most pragmatic approaches is the development and implementation of greywater treatment systems. To date, a great assortment of greywater treatment systems have been developed. The current study presents a different water treatment system to treat residential, commercial and industrial greywater in Malaysia. Unlike most existing systems which involve separate steps of treatment, the proposed method integrates aeration, disinfection and membrane filtration in a compact reactor, which could potentially reduce the operational cost, space and equipment. Aeration is required to promote pollutant degradation by aerobic microorganisms, while disinfection (UV) is needed to eliminate pathogenic bacteria. Subsequently, membrane filtration is used to remove suspended and dissolved pollutants of which are relatively smaller in size. The results have proven that the proposed system is effective in improving the quality of greywater, in which, the parameters (BOD, turbidity, total suspended solids, TDS, pH, DO) are reported to be in good agreement with the standards. While this study is conducted in a laboratory environment, its excellent results suggest that the proposed system is potentially practical for commercial use in future. © 2019 Desalination Publications. All rights reserved
Effects of different heat treatments on the antioxidant activity and ascorbic acid content of bitter melon, Momordica charantia
No full textThis study investigated the effects of different heat treatments, namely boiling, microwaving and pressure cooking, on the reduced ascorbic acid content and antioxidant activity in Momordica charantia extracts. The total antioxidant activity of M. charantia extracts was determined by ferric reducing-antioxidant power and 2,2-diphenyl-1-picrylhydrazyl radical scavenging assays. The reduced ascorbic acid content was estimated by ferric reducing-antioxidant power-ascorbic acid assay and confirmed by high performance liquid chromatography. Regardless of the cooking method, all cooked M. charantia extracts had significantly (p boiled > pressure-cooked > uncooked. The reduced ascorbic acid in M. charantia strongly correlated with the total antioxidant activity (r = 0.958, p < 0.05) and radical scavenging potency (r= 0.951, p < 0.05). The principle component analysis showed that 87% of the variation in the antioxidant values of M. charantia extracts was attributed to the different cooking methods. Heat treatment either by boiling or microwaving for a short period of time (10 minutes) improved the reduced ascorbic acid content in the M. charantia extract. This study showed that the reduced ascorbic acid could be retained under high temperature and pressure in M. charantia extracts. © 2019 Instituto de Tecnologia de Alimentos - ITAL. All rights reserved
Nucleation and growth controlled reduced graphene oxide–supported palladium electrocatalysts for methanol oxidation reaction
No full textIn spite of advantages of direct methanol fuel cells, low methanol oxidation reaction and fuel crossover from anode to cathode, there remains a challenge that inhibits it from being commercialized. Active electrocatalysts are in high demand to promote the methanol oxidation reaction. The methanol reached at the anode can be immediately reacted, and thus, less methanol to cross to the cathode. The performance of electrocatalysts can be significantly influenced by varying the concentration of precursor solution. Theoretically, concentrated precursor solution facilitates rapid nucleation and growth; diluted precursor solution causes slow nucleation and growth. Rapid nucleation and slow growth have positive effect on the size of electrocatalysts which plays a significant role in the catalytic performance. Upon the addition of appropriate concentration of graphene oxide, the graphene oxide was reported to have stabilizing effect towards the catalyst nanoparticles. This work synthesized reduced graphene oxide–supported palladium electrocatalysts at different concentrations (0.5, 1.0, 2.0, 3.0 and 4.0 mg mL −1 ) with fixed volume and mass ratio of reduced graphene oxide to palladium by microwave-assisted reduction method. Results showed that reduced graphene oxide–supported palladium synthesized at a concentration of 1.0 mg mL −1 gave the best methanol oxidation reactivity (405.37 mA mg −1 ) and largest electrochemical active surface area (83.57 m 2 g −1 ). © The Author(s) 2019
Dietary intake, physical activity and muscle strength among adolescents: the Malaysian Health and Adolescents Longitudinal Research Team (MyHeART) study
No full textObjective To examine the role of dietary intake and physical activity in muscle strength among adolescents. Design Cross-sectional analysis. Setting The Malaysian Health and Adolescents Longitudinal Research Team (MyHeART) study. Participants Fifteen-year-old secondary school children who have given consent and who participated in the MyHeART study in 2014. Primary outcome measure Muscle strength was measured in relation to dietary intake (energy and macronutrients) and physical activity by using a hand grip dynamometer. Results Among the 1012 participants (395 male; 617 female), the hand grip strength of the males was higher than that of the females (27.08 kg vs 18.63 kg; p<0.001). Also, males were more active (2.43vs2.12; p<0.001) and consumed a higher amount of energy (2047 kcal vs 1738 kcal; p<0.001), carbohydrate (280.71 g vs 229.31 g; p<0.001) and protein (1.46 g/kg body weight (BW) vs 1.35 g/kg BW; p<0.168). After controlling for ethnicity, place of residency and body mass index, there was a positive relationship between hand grip strength and the intake of energy (r=0.14; p=0.006), carbohydrate (r=0.153; p=0.002) and fat (r=0.124; p=0.014) and the physical activity score (r=0.170; p=0.001) and a negative relationship between hand grip strength and the intake of protein (r=-0.134; p=0.008), for males. However, this was not observed among females. Conclusions Energy, carbohydrate and fat intakes and physical activity score were positively correlated with hand grip strength while protein intake was negatively correlated with hand grip strength in males but not in females. © Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ
Prioritising factors influencing consumers' reversing intention of e-waste using analytic hierarchy process
No full textImproper management of electronic waste (e-waste) is becoming a threat globally and emerges as the most recent and dangerous environmental issue that is abruptly affecting ecological and human health. In such scenario, manufacturers need to play their role in accepting responsibility to take care of the waste when they reach their end of life. For said purpose, the present study identified factors by which manufacturer can encourage end-consumers to reverse the products, at their discretion, when it reach end of life. Factors identified from literature were prioritised by using analytic hierarchy process (AHP). Results of the present study will help the manufacturers in devising their strategies for marketing and customer relationship management in a way that they can encourage consumers to reverse the products when it reach end of life. © 2019 Inderscience Enterprises Ltd
Mode in Arabic-English Translation: with Reference to the Quran
No full textA rhetorical question has the form of a question but does not perform its function, i.e. does not seek any information but rather, is used to give a specific or rhetoric function such as denial, assertion, testing, equalization and negation. The present study investigates the two English translations that were used in the translation of the Quranic rhetorical questions. In a nutshell, this is a comparative study that aims to discover if the grammatical shifts that had occurred in the two English translations would have an effect on the denial, assertion, testing, and equalization and negation modes of the Quranic rhetorical questions. For this purpose, we had adopted the register theory of Halliday and Hassan (1985) as well as the translation shifts of Catford (1965) in the comparison of the two English translations, namely the Koran Interpreted that was authored by Arberry (1955) and the Noble Quran: English translation of the meanings and commentary as transcribed by al-Hilali and Khan (1996). According to the analyses, the occurrence of grammatical shifts between the two translations had in fact affected the mode of the ST rhetorical questions, their rhetorical meanings and consequently, issues on mode sustenance. Therefore, it can be said that the register theory of Halliday and Hassan (1985) had been a beneficial tool used in the analysis of the translation process. © 2019 Peoples' Friendship University of Russia. All rights reserved
Multiplicity in entrepreneurship economic development of Malaysian smallholder farmers
No full textLand can be considered as economics generated space by farming communities, mostly located in rural areas. Modern agriculture has largely been accompanied with the development of new techniques in producing agriculture products. Current world agriculture demands for more agronomics at a higher level of economic development. Most agricultural activities are labour intensive and may or may not employ new technologies. Agriculture that lacks innovation has high tendencies to fail in modern farming practices leading to clogged economic growth in this sector. Use of modern technologies and machineries can overcome poverty problems among smallholder farmers by increasing farm production and supply into the market. Understanding the production of agriculture requires the knowledge of the distribution market till the ground level of the farm land. Nevertheless, poverty among smallholder farmers is always linked to lost opportunities of resources. This occurs due to the practice of conventional agricultural methods in farming, distance from market, and employment of outdated production equipment. Therefore, there is a high need for innovation, support of network and latest information on new equipment and technologies in the market be disseminated to increase farm production. To counter this, entrepreneurship mechanisms have been introduced by many developed countries in addressing poverty in this community. In current times, agropreneurship alone in farming is deficient in various angles, but multiple entrepreneurship has begun to emerge to support the smallholder farmers' talent, skills and ability to shape their economic growth and release them from the poverty trap. This paper intends to evaluate whether the multiple entrepreneurship implemented by Malaysian smallholder farmers is effective in raising income and their quality of well-being and poverty eradication in rural area. The discussion emphasizes on the serious need for modernization in agriculture through such entrepreneurship that are guided by government policies. © 2019 Academy of Entrepreneurship Journal