1,521 research outputs found
Dynamic weighted idle time heuristic for flowshop scheduling
The constructive heuristic of Nawaz, Enscore and Ham (NEH) has been introduced in 1983 to solve flowshop scheduling. Many researchers have continued to improve the NEH by adding new steps and procedures to the existing algorithm. Thus, this study has developed a new heuristic known as Dynamic Weighted Idle Time (DWIT) method by adding dynamic weight factors for solving the partial solution with purpose to obtain optimal makespan and improve the NEH heuristic. The objective of this study are to develop a DWIT heuristic to solve flowshop scheduling problem and to assess the performance of the new DWIT heuristic against the current best scheduling heuristic, ie the NEH. This research developed a computer programming in Microsoft Excel to measure the flowshop scheduling performance for every change of weight factors. The performance measure is done by using n jobs (n=6,10 and 20) and 4 machines. The weight factors were applied with numerical method within the range of zero to one. Different weight factors and machines idle time were used at different problem sizes. For 6 jobs and 4 machines, only idle time before and in between two jobs were used while for 10 jobs and 20 jobs the consideration of idle time was idle time before, in between two jobs and after completion of the last job. In 6 jobs problem, the result was compared between DWIT against Optimum and NEH against Optimum. While in 10 jobs and 20 jobs problem the result was compared between DWIT against the NEH. Overall result shows that the result on 6 and 10 jobs problem the DWIT heuristic obtained better results than NEH heuristic. However, in 20 jobs problem, the result shows that the NEH was better than DWIT. The result of this study can be used for further research in modifying the weight factors and idle time selections in order to improve the NEH heuristic
Measurement of body temperature and heart rate for the development of healthcare system using IOT platform
Health can be define as a state of complete mental, physical and social well-being and not merely the absence of disease or infirmity according to the World Health Organization (WHO) [1]. Having a healthy body is the greatest blessing of life, hence healthcare is required to maintain or improve the health since the healthcare is the maintenance or improvement of health through the diagnosis, prevention, and treatment of injury, disease, illness, and other mental and physical impairments in human beings. The novel paradigm of Internet of Things (IoT) has the potential to transform modern healthcare and improve the well-being of entire society [2].
IoT is a concept aims to connec
Maximum Likelihood Performance of Mean Time to Failure for Right-Censored Data
In this paper failure times following Weibull,
exponential and log-normal distribution are considered.
The parameters of these distributions are estimated
by the maximum likelihood method and these values
are used to estimate other quantity of interest such as
Mean Time to Failure (MTTF), an important function
in a reliability analysis. This study is to look at the
performance of maximum likelihood estimate (MLE)
under various conditions by considering varying sample
size and percentage of censored data. The performance
is quantified from the study
Pricing down-and-out power options with exponentially curved barrier
Power barrier options are options where the payoff depends on an underlying asset raised to a constant number. The barrier determines whether the option is knocked in or knocked out of existence when the underlying asset hits the prescribed barrier level, or not. This paper derives the analytical solution of the power options with an exponentially curved barrier by utilizing the reflection principle and the change of measure. Numerical results show that prices of power options with exponentially curved barrier are cheaper than those of power barrier options and power options
Factors influencing behavioral intention to use m-learning and the mediation role of user satisfaction
The rapid development of mobile technologies has resulted in a phenomenal growth in the number of youth using the mobile devices for their learning in Malaysia. An understanding on the influence of mobile technologies and its intention to use for learning are crucial. However, there is still a lacking of attention being given by researchers related to this area. Thus, the aim of this study is to investigate the factors influencing intention to use m-learning among students at Malaysian technical universities. The research model has been adopted by combining two related theoretical models, the unified theory of acceptance and use of technology (UTAUT), and the IS success model. A total of 400 sets of data were collected from four Malaysia technical universities using purposeful structured random sampling and self-administrated survey questionnaire. The SPSS AMOS software has been used to test the model of its goodness of fit and the relationships between the variables. The results revealed that the performance expectancy, perceived playfulness, and self-management of learning have a positive significant influence to predict behavioral intention to use m-learning, while social influence and effort expectancy show a negative impact on the behavioral intention. The performance expectancy, self-management of learning and effort expectancy are positively significantly related to user satisfaction while the social influence, and perceived playfulness are negatively significantly related to user satisfaction. It was also found that user satisfaction partially mediates the relationship between performance expectancy and behavioral intention to use m-learning, and the relationship between factors influencing learning and behavioral intention to use m-learning. However, user satisfaction fully mediates the relationship between effort expectancy and behavioral intention to use m-learning
Pricing holder-extendable options in a stochastic volatility model with an ornstein-uhlenbeck process
Holder-extendable options are characterized by two maturity dates, which means the option can be exercised at either the expiration date or the extended maturity date. This paper develops a pricing framework for holder-extendable options which deals with the extended version of a stochastic volatility model with an Ornstein-Uhlenbeck (OU) process. The extended model allows correlation between volatility and asset returns. The method uses Fourier inversion techniques that does not require an initial guess of the characteristic functions. A closed-form pricing formula for holder-extendable options is derived for logarithmic asset price dynamics
Process parameters influencing tannase production by Aspergillus niger using mangrove (Rhizophora apiculata) bark in solid substrate fermentation
Rhizophora apiculata bark is a tannin-rich waste material obtained from charcoal industry. This industrial waste was used as solid substrate in the study for the production of tannase and at the same time, help in minimizing the country’s industrial wastes. This study was carried out to optimize the physical parameters for the maximal tannase production by Aspergillus niger via solid substrate fermentation using a shake flask system. The optimized physical parameters obtained were combination of 0.75 and 2.00 mm of substrate particles at the ratio of 1: 1, Czapek- Dox medium as moisturizing agent at pH 7, initial moisture content of 1: 1.5 (w/v), incubation temperature at 30°C, mixing at every 24 h and the size of inoculum at 1 × 106 spores/ml which finally, produced a maximum tannase of 4.97 U/g of fermented substrate on the 6th day of cultivation.Key words: Solid substrate fermentation, tannase, Aspergillus niger, Rhizophora apiculata barks
Dense Deposit Disease: A 29-Years Electron Microscopy Experience
Introduction: Dense Deposit Disease (DDD) is a devastating renal disease that leads to renal failure within 10 years of diagnosis in about half of affected patients. In this study, we evaluated the relative prevalence and pathological features of DDD diagnosed at our center over a 29 years period.Methods: We reviewed the clinical and pathological features of all cases of DDD diagnosed at the Electron Microscopy Unit of Ain Shams University (ASUSH) between January 1983 and December 2011.Results: From a total of 3283 renal biopsies, 33 (1%) were diagnosed with DDD (10 children and 23 adults). Nephrotic syndrome was the predominant clinical presentation of DDD (51.5%), and was commoner in children than adults (80% vs. 43%, p=0.03). Capillary wall thickening was seen in all cases (100%). Crescents were more commonly seen in children than adults (70% vs. 21.7%, p=0.008) while interstitial fibrosis was more commonly seen in adults (78.3% vs. 40%, p=0.03). The commonest histological pattern seen under light microscopy was membranoproliferative (27.3%), followed by crescentic (21.2%), membranous (21.2%), diffuse proliferative (18.2%), lobular (6.1%) and mesangial proliferative (6.1%) patterns. Immunohistochemistry was available for 25 cases and showed intense linear staining for C3 along capillary walls. Electron microscopic examination revealed glomerular basement membrane (GBM) thickening and intra-membranous and tubular basement membrane deposits in all cases (100%).Conclusion: DDD is a rare disease in Egypt, found in only 1% of renal biopsies. Pathological features of the disease differ between adults and children; children have predominantly glomerular damage whereas tubule-interstitial lesions are more often encountered in adults.Key words: Dense Deposit Disease; Electron Microscopy; Membranoproliferative Glomerulonephritis; Nephrotic Syndrom
Entrepreneurial motivation and entrepreneurship career intention : case at a Malaysian Public University
Entrepreneurship intention for graduate student like many other job and work career options depends on other
considerations. Literature reviews revealed that more research works are needed in examining the determinants of
entrepreneurship intentions of students. This study is to determine the relationship between student’s entrepreneurial
motivation and entrepreneurship intention. A total of 450 self-administered questionnaires were distributed to the
students of the various faculties, races and student seniority at a Public University using the convenient and
structured sampling method. Finally, 413 duly completed questionnaires were returned and used in the analyses.
Correlation analysis and regression analysis showed that strength of motivation in choosing entrepreneurship as a
career option among the students is related with entrepreneurship intention. The entrepreneurial motivation factors
affecting career intention to be an entrepreneur are made up of behavioral control, subjective norm, and attitude
towards entrepreneurship. Subjective norm (tolerance for risk) and attitude (desirability) of self-employment are
significantly related to both student immediate and future intentions to be an entrepreneur. However, behavioral
control entrepreneurial motivation is found to be significantly related to student immediate career intention but not
significantly related to student future entrepreneurship career intention. Creating of opportunity for practice of key
entrepreneurial behaviors is seen as crucial in cultivating entrepreneurial behaviors. Theory of Planned Behavior
Model can be used as a tool to identify would be entrepreneur and target them for entrepreneurship career
development. This study argued and supported the call that those youths who are really serious to start and own a
business as would be entrepreneurs can be identified and targeted to develop through entrepreneurship interventions
initiative
Di-n-butylbis(N-cyclohexyl-N-ethyldithiocarbamato-κ2 S,S′)tin(IV)
The SnIV atom in the title compound, [Sn(C4H9)2(C9H16NS2)2], is chelated by the two dithiocarbamate ions in a six-coordinate skew-trapezoidal-bipyramidal geometry. The two butyl groups are disordered over two positions in a 1:1 ratio
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