Forecasting electricity consumption using the second-order fuzzy time series

There is a great development of Universiti Tun Hussein Onn Malaysia (UTHM) infrastructure since its formation in 1993. The development will be accompanied by the increasing demand for electricity. Hence, there is a need to forecast UTHM electricity consumption accurately so that UTHM can plan for future energy demand and utility saving decisions. Previous studies on UTHM electricity consumption prediction have been carried out using time series models, multiple linear regression and first-order fuzzy time series (FTS). The first-order FTS yield the best accuracy among these three methods. Previous forecasting problem showed higher order FTS can yield better accuracy. Therefore, in this study, the second-order FTS with trapezoidal membership function was implemented on the UTHM monthly electricity consumption from January 2009 to December 2018 to forecast January to December 2019 monthly electricity consumption. The procedure of the FTS and trapezoidal membership function was described together with January data. The second-order FTS forecast UTHM electricity consumption better than the first-order FTS

Two-pump parametric amplification in the presence of fiber dispersion fluctuations: a comparative study

Fiber optical parametric amplifiers (FOPAs) operating based on four-wave mixing (FWM) are versatile devices with increasing applications in optical communication systems. In this paper, the effects of dispersion fluctu�ations on the performance of bandwidth, ripple, parametric gain, and saturation power of a two-pump FOPA based on four-wave and six-wave models are studied and compared. Coupled-amplitude equations representing the non-degenerate FWM process in optical fiber are solved numerically to compute the parametric gain over the communication wavelengths. The behaviors of the performance parameters are critically analyzed and compared with different types of fluctuation strengths (or amplitudes) specified by the combinations of correlation length (Lc) and fluctuation amplitude (σ). Based on the results, it was found that the flat gain bandwidth for the four-wave model remains unchanged and is insensitive to the strengths of fluctuations. The gain ripples, however, get higher as the fluctuation strengths increase. On the other hand, the flat gain bandwidths of the six-wave model are hardly identified due to the tremendous and continuous ripples within the pump wavelengths. In addition, the minimum parametric gain values for both four-wave and six-wave models reduce as the fluctuation strengths increase. Also, the lowest value of parametric gain leads to the highest saturation power and vice versa. The dispersion fluctuations affect the FWM process’s efficiency and deteriorate the overall amplifier performance, particularly for the six-wave model. The numerical analysis obtained via the six-wave model is especially useful since this model closely matches with practical circumstances

Simulation of Internal Undular Bores Propagating over a Slowly Varying Region

Internal undular bores have been observed in many parts of the world. Studies have shown that many marine structures face danger and risk of destruction caused by internal undular bores due to the amount of energy it carries. This paper looks at the transformation of internal undular bore in two-layer fluid flow under the influence of variable topography. Thus, the surface of the bottom is considered to be slowly varying. The appropriate mathematical model is the variable-coefficient extended Korteweg-de Vries equation. We are particularly interested in looking at the transformation of KdV-type and table-top undular bore over the variable topography region. The governing equation is solved numerically using the method of lines, where the spatial derivatives are first discretised using finite difference approximation so that the partial differential equation becomes a system of ordinary differential equations which is then solved by 4th order Runge-Kutta method. Our numerical results show that the evolution of internal undular bore over different types of varying depths regions leads to a number of adiabatic and non-adiabatic effects. When the depth decreases slowly, a solitary wavetrain is observed at the front of the transformed internal undular bore. On the other hand, when the depth increases slowly, we observe the generation of step-like wave and weakly nonlinear trailing wavetrain, the occurrence of multi-phase behaviour, the generation of transformed undular bore of negative polarity and diminishing transformed undular bore depending on the nature of the topography after the variable topography

Health risk assessment and source identification of Polycyclic Aromatic Hydrocarbons (PAHs) in commercially available singed cowhide within the Greater Accra Region, Ghana

This study ascertains the sources and potential carcinogenic threats of polycyclic aromatic hydrocarbons (PAHs) in singed cowhide. The objective was to assess the sources of PAHs and the health threats singed cowhide possess to the consuming public. A total of fifty-four (54) cowhide samples from selected markets within the Greater-Accra Region of Ghana were analyzed using Agilent GC 6890N, MS5975B Series gas chromatography in a splitless mode. The study shows that, singed cowhide within the Greater Accra Region is dominated by positive genotoxicity PAHs classified as carcinogens (1) and possible carcinogens (2B) as well as positive and questionable genotoxic PAHs that are not classifiable (3). The [B(a)P]eq and PEC results suggest that consumption of singed cowhide at the rate of 25.2 g/day poses potential adverse health effects such as cancer, mutations and birth defects in terms of B(a)P to humans. Results further show that, the HQ/HI < 1, thus, there is no concern for potential human health risks caused by exposure to non-carcinogenic PAHs in singed cowhide. However, the carcinogenic toxic equivalent (TEQs) values for both adults and children were greater than the screening values and therefore, there is concern for potential human health risks caused by exposure to carcinogenic PAHs in singed cowhide. Source assessment of PAHs in singed cowhide shows that, PAH sources in singed cowhide is predominantly from pyrolitic rather than petrogenic origins. Thus, the PAHs in singed cowhide within the Greater Accra Region originate primarily from incomplete combustion and of petroleum origin due to singeing.&nbsp

Lessons from contemporary trials of cardiovascular prevention and rehabilitation: A systematic review and meta-analysis

Background: Meta-analyses of cardiac rehabilitation trials up to 2010 showed a significant reduction in all-cause mortality but many of these trials were conducted before the modern management of acute coronary syndromes. Methods: We undertook a meta-analysis of contemporary randomised controlled trials published in the period 2010 to 2015, including patients with other forms of atherosclerotic cardiovascular disease, to investigate the impact of cardiovascular prevention and rehabilitation on hard outcomes including survival. Results: 18 trials randomising 7691 patients to cardiovascular prevention and rehabilitation or usual care were selected. All-cause mortality was not reduced (RR 1.00, 95% CI 0.88 to 1.14), but cardiovascular mortality was by 58% (95% CI 0.21, 0.88). Myocardial infarction was also reduced by 30% (95% CI 0.54, 0.91) and cerebrovascular events by 60% (95% CI 0.22, 0.74). Comprehensive programmes managing six or more risk factors reduced all-cause mortality in a subgroup analysis (RR 0.63, 95% CI 0.43, 0.93) but those managing less did not. In the three programmes that prescribed and monitored cardioprotective medications for blood pressure and lipids all-cause mortality was also reduced (RR 0.35, 95% CI 0.18, 0.70). Conclusions: Comprehensive prevention and rehabilitation programmes managing six or more risk factors, and those prescribing and monitoring medications within programmes to lower blood pressure and lipids, continue to reduce all-cause mortality. In addition, these comprehensive programmes not only reduced cardiovascular mortality and myocardial infarction but also, for the first time, cerebrovascular events, and all these outcomes across a broader spectrum of patients with atherosclerotic disease

Insecticidal Effects of Organotin(IV) Compounds on Plutella Xylostella (L.) Larvae. II. Inhibitory Potencies Against Acetylcholinesterase and Evidence for Synergism in Tests With Bacillus Thuringiensis(BER.) and Malathion

Features of pesticide synergism and acetylcholinesterase (AChE) inhibition (in vitro) were studied using a selected range of organotin compounds against the early 4th instar larvae of a highly resistant strain of the diamondback moth (DBM), Plutella xylostella, a major universal pest of cruciferous vegetables

The role of tank-treading motions in the transverse migration of a spheroidal vesicle in a shear flow

The behavior of a spheroidal vesicle, in a plane shear flow bounded from one side by a wall, is analysed when the distance from the wall is much larger than the spheroid radius. It is found that tank treading motions produce a transverse drift away from the wall, proportional to the spheroid eccentricity and the inverse square of the distance from the wall. This drift is independent of inertia, and is completely determined by the characteristics of the vesicle membrane. The relative strength of the contribution to drift from tank-treading motions and from the presence of inertial corrections, is discussed.Comment: 16 pages, 1 figure, Latex. To appear on J. Phys. A (Math. Gen.

Numerical Simulation of undular bore evolution with chezy friction, 2015

This paper studies and simulates numerically the evolution of undular bore under the effect of damping in the framework of the perturbed extended Korteweg-de Vries equation. Here, we consider Chezy frictional term to be the damping term in the perturbed extended Korteweg-de Vries equation. Numerical simulations show that under the influence of the friction, the undular bore with thick leading wave will transform into KdV-like solitary wave as the leading wave of the undular bore. The amplitude of the "thick" leading wave will remain the same for some time even though there is dissipation effect