bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of cobalt (Co) in the soil of Antang Landfill, Makassar City, South Sulawesi Province, Indonesia by use of ICP-OES
Authors: Artiningsih A , Zubair H , Imran A M , Widodo S
Published: November 2019

This study analyzed the content of cobalt (Co) heavy metal in the soil conducted around the Final Disposal Sites landfill of Antang Makassar, Indonesia. There were 12 sampling points such as points A1, A2, and A3 (line A); points B1, B2, and B3 (line B); points C1, C2, and C3 (line C); and points D1, D2, and D3 (line D). Every sampling points have a depth of 30 cm vertically, and the soil samples were divided into three layer (upper layer, middle layer, and lower layer) with a depth of 0-10 cm (upper layer), 10-20 cm (middle layer), and 20-30 cm (lower layer). The study used 36 samples all of which were analyzed using ICP-OES to measure the concentrations of heavy metals. The concentration of heavy metals in the soil around landfill of Antang had spread vertically and laterally. The analysis found that cobalt (Co) heavy metal concentrations in Line A, Line B, Line C and Line D for every depth exceeded the normal limit. However, on line B the B1 sampling point at a depth of 10-20 cm and 20-30 cm had a relatively normal concentration, which was 10 ppm. That value was the standard permitted by the General of Drug and Food Control as the level of pollution in the soil. Soil pH varies from 4.82 to 6 and is considered acidic. Soil pH significantly affects the solubility and mobility of metals, because most metals dissolve in acidic soils. Thus, remediation or appropriate precautions were needed to prevent risks to humans and the environment.
Discrete Double-Sided Quaternionic Fourier Transform and Application
Authors: Bahri Mawardi , Azis Moh. Ivan , Firman  , Lande Chrisandi
Published: November 2019

In the present article, we first introduce the definition of the discrete double-sided quaternionic Fourier transform (DQFT) and obtain its inverse. We give examples how to compute the DQFT. We derive a discrete version of the duality property of the DQFT. We finally present an application of the DQFT to study the two-dimensional discrete linear time-varying systems.
Two Uncertainty Principles Related to the Linear Canonical S-Transform
Authors: Bahri Mawardi
Published: November 2019

In this article we derive uncertainty principles for the linear canonical S-transform. This uncertainty principles are obtained by applying the properties and relation between the linear canonical transform and the linear canonical S-transform.
The effect of harvesting with threshold on the dynamics of prey predator model
Authors: Toaha S
Published: November 2019

This article deals with the dynamics of Lotka-Volterra prey predator population. The populations are considered as economically valuable stocks and then exploited. There is no harvesting when the densities of population are still low and the populations are harvested when the threshold value is achieved. The rate of harvesting is assumed to be an increased function and bounded. Phase portrait and linearization approach are used to analyze the behavior of the populations. There exists one equilibrium point for system without harvesting and it is a centre. The trajectories of the population oscillate around the stable equilibrium point. It is possible to find one, two, three, or none equilibrium points for model with harvesting. From the analysis we found that when the populations are not harvested then the equilibrium point becomes a centre. But when the populations are harvested with a smaller value, the equilibrium point becomes unstable spiral. When the value of harvesting rate is increased, the equilibrium point becomes either stable spiral or stable node. When the equilibrium points are unstable, the populations will meet a condition where their sizes are smaller than the threshold value and then the populations must stop being harvested.
Stability analysis of SEISEIR-SEI modelling on the dynamics of spread dengue fever with vaccination and insecticide
Authors: Hartati H , Toaha S , Kasbawati
Published: November 2019

This article focuses on analysing an SEISEIR-SEI model. This model is a development of SEIR-SEI which studies the spread of dengue fever in human and mosquito. This model considers the exposed compartment for vaccinated, non-vaccinated human and also for mosquito. Fogging strategy is also carried out as an effort to inhibit mosquito breeding. Existence and stability of non-endemic and endemic equilibrium points are investigated and analysed using linearization and eigenvalue methods. From the analyses we found a threshold value for stability of non-endemic equilibrium point. Increasing the rate of mosquito bites can reduce the threshold value and even change non-endemic condition becomes endemic. Vaccination strategy does not change the non-endemic condition, it only speeds up the convergence to the non-endemic condition. Fogging strategy only affects position of the endemic and non-endemic equilibrium points. Reducing the rate of mosquito bites can prevent endemic condition. Several numerical simulations were carried out to confirm the analytical results obtained. From simulations we know that reducing the value of threshold may switch stability of non-endemic equilibrium point from unstable to asymptotically stable.
Anti coagulant activities of Brown Seaweed Sargassum cristaefolium Extract
Authors: Manggau M , Hamzah M , Mamada S , Nurdin WB , Zaenuddin EN
Published: November 2019

Brown algae, Sargassum cristaefolium is grown abundant in Indonesia especially in South Sulawesi Province. In vitro anticoagulant effect of the extract has been shown. Therefore a study of Sargassum cristaefolium, used to inhibit blood coagulation in vivo was done. In this study, effect of flavonoid compounds from Sargassum cristaefoilum to elongate bleeding and blood clotting time and also (Prothrombin Time (PT) and Activated Thromboplastin Time (APTT) tests were carried out. Moreover, histology of mice stomach was also studied. From this study we found, that effect on bleeding time after 14 days treatment of Sargassum extract in vivo prolonged the clotting and bleeding time significantly (p < 0.05). Prothrombin time (PT) and activated partial thromboplastin time (APTT) tests on plasma confirm these research. From this study we conclude, that the flavonoid compound in Sargassum cristaefolium exhibited an anticoagulant activity.
Characterization of antioxidative fraction of plant stem Bouea macrophylla Griff
Authors: Rudiana Tarso , Suryani Nani , Indriatmoko Dimas Danang , Yusransyah  , Amelia Ane , Noviany  , Hadi Sutopo
Published: November 2019

Ethyl acetate extract of gandaria (Bouea macrophylla Griff) has very strong antioxidant activity. The aims of this study are to separate and characterize the active fraction of antioxidants and determine the antioxidant activity quantitatively. Ethyl acetate extract of B. macrophylla was separated by gravity column chromatography. Fraction separating was guided with qualitative testing of antioxidant activity. Active fraction result of separation was characterized by liquid chromatography-mass spectroscopy and quantitatively analyzed antioxidant activity using the 2.2-diphenyl-1-picrylhydrazyl method. Naringenin and luteolin were identified in the D-2 fraction which had very strong antioxidant activity with an IC50 value of 2.13 ppm. The hydroxyl group OH group of naringenin and luteolin compounds was thought to play a role in the reduction of free radicals.
Numerical solution to diffusion convection-reaction equation with trigonometrically variable coefficients of incompressible flow
Authors: Hamzah S , Haddade A , Galsan A , Azis M I , Abdal A M
Published: November 2019

This paper is concerned with finding numerical solutions to boundary value problems (BVPs) governed by a diffusion convection-reaction (DCR) equation of in-spatial-trigonometrically varying coefficients with an anisotropic diffusion coefficient. The variable coefficients equation is firstly transformed into a constant coefficients equation. A boundary integral equation is the derived from the constant coefficients equation. Consequently, a boundary element method (BEM) is developed and utilized to find numerical solutions to the boundary value problems. For the computation of the solutions for some examples of problems, a FORTRAN script is constructed. The numerical solutions obtained verify the validity of the analysis used to derive the BEM. The results also show that the BEM procedure elapses very efficient time in producing very accurate and consistent solutions. Moreover, the results indicate the effect of anisotropy and inhomogeneity of the media on the solutions.
Development of LED-DOAS system for observing aerosol optical properties in the lower troposphere
Authors: Aminuddin J , Okude S , Alimuddin I , Tursilowati L , Manago N , Kuze H
Published: November 2019

Aerosols play an important role in the Earth’s radiation budget through the reflection of incoming solar radiation and formation of cloud droplets working as cloud condensation nuclei. The understanding on aerosol optical properties in troposphere, especially their behavior near the ground level, is still insufficient for precise evaluation of their impact. Although a sunphotometer can provide the aerosol optical thickness, its application is limited to daytime under near cloud free conditions. A visibility meter, on the other hand, can give the value of visibility, but the operation wavelength is limited to a single wavelength, e.g. 875 nm. To attain the multi-wavelength observation of aerosol extinction coefficient near the surface level, here we propose the use of a four-color light emitting diode (LED) source emitting at 455, 530, 590, and 625 nm as a light source for the long-path measurement of aerosol extinction. A near-horizontal light path with a round-trip distance of around 630 m has been established inside the campus of Chiba University. A collimated light beam is produced with a 130 mm diameter telescope, and the reflected beam from a retro-reflector is detected using a 200 mm diameter telescope connected to a photodiode. A sinusoidal wave modulation is applied to the LED source, and the resulting modulated signal amplitude is detected and recorded using a digital oscilloscope (Iwatsu, DS-5614A). The results of the recent observation are discussed in conjunction with the concurrent records of a visibility meter (Vaisala, PWD52) and a nephelometer (TSI3563) that can measure the aerosol scattering coefficient.
The role of radiocarbon analysis in determining the chronology of Erong culture in Tana Toraja
Authors: Duli A , Nur M , Hasanuddin  , Rosmawati  , Chia S , Ramli Z
Published: November 2019

Research on the beginning of the growth of Toraja culture needs to track when this unique culture began to develop. The Toraja cultural remains are generally made of stone such as menhirs and stone, and wood graves such as erong grave containers and various daily living equipment. Erong cemetery made of wood is noted as a cultural heritage that is quite old, and generally stored safely in caves, so it is very representative to know its age through the radiocarbon method (C14). A research through selectively taking samples of 22 erong burial sites in Tana Toraja and North Toraja Regency can be a media of tracking the range of the development period of the culture, which is noted around 780 - 1960 AD. Thus the date of the erong burial culture in Tana Toraja can provide a perspective on the initial period and development of the culture.
Supershear rupture of the 28 September 2018 Palu earthquake inferred from Empirical Green’s Function analysis
Authors: Priyobudi  , Ramdhan M
Published: November 2019

We deconvolved 22 teleseismic waveforms of Mw6.1 earthquake with Mw7.5 Palu earthquake to obtain Apparent Source Time Functions (ASTFs). Analysis of those ASTFs resulted rupture directivity, rupture length and rupture velocity of the earthquake. The main earthquake ruptured to N 2270E direction along 80 km away from the epicenter at an average speed of 4.5 km/s. The rupture velocity which is greater than local shear-wave velocity of 3.5 km/s indicated supershear characteristic of the earthquake. An ASTF of SNZO station was used to infer 1-D slip distribution of this earthquake. Based on this ASTF we calculated earthquake moment of 1.45 x 1020 Nm that released in 30 seconds. The largest seismic moment released between 0-15 seconds and decreased before it stopped at 30 seconds. A Maximum slip of 8 meters occurred at a distance of 20 km to the south of the epicentre and decreased to around 4 meter near Palu City.
Numerical solutions for anisotropic-diffusion convection problems of incompressible flow in exponentially graded media
Authors: Haddade A , Syamsuddin E , Massinai M F I , Azis M I , Latunra A I
Published: November 2019

A boundary element method is utilized to find numerical solutions to boundary value problems of exponentially graded media governed by a spatially varying coefficients anisotropic-diffusion convection equation. The variable coefficients equation is firstly transformed into a constant coefficients equation for which a boundary integral equation can be formulated. A boundary element method (BEM) is then derived from the boundary integral equation. Some problems are considered. The numerical solutions justify the validity of the analysis used to derive the boundary element method with accurate and consistent solutions. A FORTRAN script is developed for the computation of the solutions. The computation shows that the BEM procedure elapses very efficient time in producing the solutions. In addition, results obtained from the considered examples show the effect of the anisotropy of the media on the solutions. An example of a layered material is presented as an illustration of the application.
Numerical simulation for steady anisotropic-diffusion convection problems of compressible flow in exponentially graded media
Authors: Assagaf M A H , Massinai A , Ribal A , Toaha S , Azis M I
Published: November 2019

A boundary element method is utilized to find numerical solutions to boundary value problems of exponentially graded media governed by a spatially varying coefficients anisotropic-diffusion convection equation. The variable coefficients equation is firstly transformed into a constant coefficients equation for which a boundary integral equation can be formulated. A boundary element method (BEM) is then derived from the boundary integral equation. Some problems are considered. The numerical solutions justify the validity of the analysis used to derive the boundary element method with accurate and consistent solutions. A FORTRAN script is developed for the computation of the solutions. The computation shows that the BEM procedure elapses very efficient time in producing the solutions. In addition, results obtained from the considered examples show the effect of anisotropy of the media on the solutions. An example of a layered material is presented as an illustration of the application.
Properties of ZnO/TiO2 hetero-structures thin films grown by sol-gel with various zinc acetate dehydrated concentration
Authors: Gareso P L , Aeni N , Musfitasari  , Rauf N , Juarlin E
Published: November 2019

We have investigated the structural and optical properties of ZnO/TiO2 hetero-structures thin film with various zinc acetate dehydrates concentration (0.5 M, 1.0 M, 1.5 M, and 2.0 M) grown by sol-gel method. Zinc oxide sol-gel were prepared by dissolving zinc acetate dehydrates as precursor into an ethanol. The solutions were added with triethanolamine as a stabilizer. For preparing the TiO2 sol-gel, titanium tetraisoproxide (TTIP) was used as precursor and it was dissolved into the ethanol and added with an acetic acid as stabilizer. A glass substrates were cleaned with acetone prior to the thin films was coated on it. The first layer was ZnO thin film and then followed by TiO2 were deposited into the glass substrates. The ZnO/TiO2 hetero-structures thin films were inserted into furnace for undertaking the heat thermal at the temperatures of 5000C for 60 minutes. X-ray diffraction was used to characterize the structural properties of ZnO/TiO2. The optical properties ZnO/TiO2 were characterized using the optical UV-Vis spectrophotometer measurement. Based on the X-RD results, the peak is clearly observed for ZnO thin films in the plane of (100), (002), and (101), indicating that ZnO in the crystalline phase, while TiO2 is in the amorphous phase. The optical band gap of the ZnO/TiO2 hetero-structures thin films for 1.0 M and 1.5 M is 3.150 eV, and 3.153 eV, respectively.
Optical properties of wood by laser spectroscopy
Authors: Muhammad N A , Isnaeni  , Tahir D
Published: November 2019

Optical properties of three Indonesian woods (Red Jabon, Kapur and Red Meranti) has been analyzed based on its photoluminescence (325 nm and 405 nm), reflectance and absorbance spectra. The sample thickness affected to the emission spectra. We found that lignin and cellulose were emitted around the UV (400 nm-500 nm) and visible (500 nm-600 nm) wavelength respectively. The amount of lignin exist in the wood are 25.68% for Red Jabon, 14.57% for Kapur and 27.93% for Red Meranti. This method shows high potentials for determining lignin for any kind of woods.
Chlorine signal investigation in organic product as a pesticide residues by Laser Induced Breakdown Spectroscopy (LIBS)
Authors: Irwan M , Siddiq M , Tahir D
Published: November 2019

We have been determined chlorine (Cl) spectra line as one of the most hazardous pesticide by using laser induced breakdown spectroscopy (LIBS) with various concentration of sodium chloride in cacao (1%, 3%, 5%, 7% and 10%). The experiment is carried out with a Nd-YAG laser system operating at a wavelength of 1064 nm, pulse energy is 150 μJ and various integration time are 10 ms, 50 ms and 80 ms. Based on the result, chlorine (Cl) line is detected at a wavelength of λ = 837,56 nm is enhancement slightly increasing with sodium chloride concentration in organic product. So, LIBS method is high potential for investigating of chlorine (Cl) residues in organic products
Quantifying entrance skin dose for early diagnose of lung cancer
Authors: Latif A , Suryani S , Abdullah B
Published: November 2019

Lung cancer is disease that can cause death in a short time, but it is almost never detected at an early stage, because its symptons are not specific, such as coughing and lack of appetite. In some patients who have a smoking habit, it is easier to be suspected of having a tumor or lung cancer. In order to detect a tumor or lung cancer, a chest X-ray examination is generally done as an early diagnosis. As we have already known, exposure of X-ray radiation to the body can have a negative impact, therefore the dose of X-ray radiation exposure must be minimized. In this study a measurement of entrance skin dose (ESD) was performed on chest X-ray examination in patients suspected of having a tumor or lung cancer. The results showed that patients who had symptoms similar to those of tumor or lung cancer had higher ESD than those who did not. Although the radiation dose is higher than dose on routine chest X-ray examination, it only shows abnormality of radiological photogaraph but do not accurately indicate the presence of tumor or cancer.
Effect of SSD and absorbing filter in calibration process of Thermo Luminescence Dosimeter TLD-700
Authors: Nurdin W B , Aswad  , Bariah K
Published: November 2019

It had been carried out the study about effect of the skin source distance (SSD) and absorbing filter in the callibration process of Thermo Luminescence Dosimeter TDL-700. This effect used the analysis of dose radiation from output using Cs-137 in the calibration process of TLD-700. The calibration process used different measurement at an SSD of 100, 150, 200, and 250 cms and different scales of 0.1, 0.5, 1.0, 3.0 and 5.0 mSvs, respectively. We found that the larger the radiation source used, the greater exposure dose were accepted. Dose radiation output from source Cs-137 source values obtained optimal dose in distance 200 cm absorbed by using filters. The results of the measurement of the output dose using variation of SSD and the variation of absorbed filter on TLD-700 calibration showed that the value of dose that have deviation with the predicted dose less than 6.0%. The measurement of radiation output dose with Cs-137 source on TLD-700 calibration process shows that the larger required dose at the time of irradiation, the greater the radiation time should be given. Radiation measurement of Cs-137 source without absorbed filter is very high so that the irradiation time is relatively short. This is because the radiation emitted by the Cs-137 source is directly absorbed by the TLD-700 during irradiation
Analytical Approach of Long Waves Dynamics in an Estuary (Case Study in Karang Mumus River Estuary)
Authors: Raming I , Suriamihardja D A , Kusuma J
Published: November 2019

A mathematical model is developed for describing a propagating long wave in an estuary. Wave dynamics in an estuary will employ the Saint Venant equation in the form of a nonlinear partial differential equation (PDE), which consists of equations of mass conservation and momentum conservation. Waves propagate in an estuary usually generated by tides entering a gentle slope channel. The analytical approach is used to solve this non-linear PDE approach using a perturbation method. This paper considers only a zero order. A cross-differentiation between conservation of mass and conservation of momentum equations result in the Bessel differential equation. The solution of zero order gives decreasing amplitude of the long wave to the end of the estuary.
Study of Macro Earthquake Attenuation Using Q-Factor Coda Waves Around Matano Fault
Authors: Karnaen M , Suriamihardja D A , Maulana A , Jaya A
Published: November 2019

All Several macro earthquakes have occurred at the Matano fault so it is interesting to study how the energy attenuation in the coda wave. Coda wave is a signal that follows a secondary wave on a seismogram recording. Some macro earthquakes can be monitored well by BMKG through LUWI Station at a distance of 200-300 km from the epicenter. The coda Q-factor is analysed using coda waves at range 2-4 Hz and 4-8 Hz frequencies of lapse times at 20 seconds in vertical component. Variation of coda Q-factor is influenced by the rock medium in the Matano Fault. This Matano Fault is very unique because it is a collision of continental and oceanic rocks that extend from western to eastern part. The study area is divided into three zones, namely the western, central, and eastern zones. The objective of this study is to identify vulnerabilities at low or high level in each zones by the Coda Q-factor that will classify hazardous earthquakes. The value of coda Q-factor is obtained 126.27 in the west, 162.80 in the middle, and 181.96 in the eastern part of the fault. The western part is the most vulnerable area because low coda Q-factor is associated with sediments layer. It is formed by metamorphic rocks close to the active Fault of Palu Koro. The highest coda Q-factor is located at the eastern part of the fault which hazardous zone and has the potential to cause a large earthquake. The eastern zone has a composition of ultrabasic rocks with high rock stress. In general, the average value of Q-factor in the Matano Fault is 157.01, where the value indicates that the characteristics of the Matano Fault are seismic active zones.
Protein Content Sensor based on Plastic Optical Fiber
Authors: Anisfaizurrahmah  , Arifin A , Abdullah B
Published: November 2019

Plastic optical fiber (POF) content protein sensor has been developed. This sensor is made with a gamma and spiral configuration, with a cladding peel length of 5 cm. POF sensor is dipped into the container containing Bovine Serum Albumin (BSA) solution with different concentrations of 0.1-1 mg/ml. Both ends of the sensor are connected by Light Emiting Diode (LED) and Phototransistor. The LED light will propagate through the POF and it is received by the phototransistor. Light that propagates will be interfenced due to increasing of protein concentration around the sensor, so that the output voltage will be affected. The output voltage will be forwarded to Arduino Uno and read by the computer. The best results were obtained in a spiral configuration with 3 bending with a sensitivity of 0.007 Vml/mg and a resolution of 0.142 mg/ml. This method has advantages that are easy fabrication, simple measurement process, and low cost.
Nanostructure and Optical Properties of Fe3O4: Effect of Calcination Temperature and Dwelling Time
Authors: Indrayana I P T , Tjuana L A , Tuny M T , Kurnia
Published: November 2019

In this work, we reported the nanostructure and optical properties of the Fe3O4 nanoparticles. The Fe3O4 have been synthesized from local iron sand Halmahera Utara by using the coprecipitation method at a temperature of 80°C and NaOH concentration of 3M. The nanoparticles were calcined at 150°C and 250°C for 4 hours consecutively, while the calcination dwelling time was 2 hours and 4 hours at a temperature of 250°C. The results show that a formation of Fe3O4 nanoparticles with a spinel crystal structure. The lattice parameter of nanoparticles decreases with an increase of calcination temperature and dwelling time due to higher thermal energy driving the atom to move closer to each other. Hence, the crystallite size of the nanoparticles increases due to the expansion process to the grain of the nanoparticles. The optical gap energy of the nanoparticles decreases due to the formation of a larger particle. It also confirms that the existence of Fe3+-O and Fe2+-O bonds in the nanoparticles which are characteristic functional group bond of Fe3O4 in the tetrahedral and octahedral sublattice. This result can prove that a higher calcination temperature and longer dwelling time can improve the nanostructure and optical properties of Fe3O4.
Orthogonal iteration process of determining K value on estimator of Jackknife ridge regression parameter
Authors: Tinungki G M
Published: November 2019

Jackknife is re-sampling bias estimation method, in predict standard deviations. The principle of the Jackknife method in regression parameters estimation is to eliminate one data and repeat it as much as the number of existing data samples. The step in estimating regression parameter of Jackknife Ridge (JR) was the first to transform data through cantering and scaling process and orthogonalization on independent variables. The second determines initial value k0 and perform the iteration process. The third by transform initial estimator JR and finally by testing the feasibility of the resulting model of Jackknife ridge regression. Results obtained, iteration process is conducted until obtained a value of

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The use of multivariate page test in dealing the violations of principal assumptions in completely randomized block design
Authors: Tinungki G M , Sirajang N
Published: November 2019

There are various variance analysis tests, one of which is the Friedman test, it is used as an alternative to two way variance analysis technique. If there are unmet assumptions in the Friedman test, that is, they are not normally distributed and do not have a homogeneous variant, then the multivariate Page test can be used to determine whether there is a median difference between k (k ⩾ 3), a median population. The Page test will be applied in the case of the growth rate of soybean plants that obtain 5 types of treatment that are conditioned, namely seedling, watering, giving 100% KL, 75%, and 50% KL Based on statistical test using multivariate page indicated that there is influence on 5 types treatment of seed conditioning i.e dry seed (control), distilled water, 100 g PEG L-1 of water, 200 g PEG L-1 of water, and 300 g PEG L-1 of water against 3 response measurements i.e germination, growth rate and growing Randomness Of Soybean.
Detection of Outliers in Multivariate Data using Minimum Vector Variance Method
Authors: Herdiani E T , Sari P P , Sunusi N
Published: November 2019

Outliers are observations that do not follow the distribution of data patterns and can cause deviations from data analysis, so a method for identifying outliers is needed One method in scanning detection is Minimum Vector Variance which is a robust estimator that uses the minimum Vector Variance (VV) criteria. In this study, the MVV method was used to detect outliers in criminality data in Indonesia in 2013 and data that had been entered out by 5% and 10%. The results showed that the MVV method was more effective than the Mahalanobis distance when detecting outliers in data that had been entered out by 5% and 10%.
Power behavior of test based on the moving sums (MOSUM) of spatial least squares residuals
Authors: Somayasa W
Published: November 2019

The optimality of a test can be studied by investigating the behavior of the corresponding power function under alternatives. In this paper we study the rate of decay of power functions obtained from asymptotic model validity tests in linear regression analysis based on the moving sums (MOSUM) process of ordinary least squares (OLS) residuals of univariate spatial observations. The powers under study appear as the evaluation of the probability of events generated by the Kolmogorov-Smirnov (KS) and Cramer-von Mises functionals of the Slepian field plus a deterministic trend. It is shown under mild conditions that the rate of the power to the size of test is bounded by a constant which is proportional to the length of the trend. It is also shown that the rate of decays of the powers of the KS and CvM MOSUM tests coincide with the Neyman-Pearson test which is most powerful (MP) test for simple hypotheses. The performance of the power functions are also discussed by simulation.
Asymptotic modelling of corn plant data using moving sums (MOSUM) technique
Authors: Somayasa W
Published: November 2019

Empirical model building using linear regression has been widely used in agricultural study. The validity of an assumed model is usually check using either F of likelihood ratio test under normally distributed observations. In this paper an asymptotic method based on the moving sums (MOSUM) of triangular array of ordinary least squares (OLS) residuals is proposed. Reasonable tests statistics for detecting valid model are defined as the Kolmogorov-Smirnov (KS) and Cramér-von Mises (MvM) functionals of the residual MOSUM process. The limit process is obtained for the condition under H
0 and under H
1 by applying the continuous mapping theorem to the existing limit theorem for partial sums of the residuals. The quantiles of the KS and CvM statistics under H
0 are approximated by simulation. The application of the method in obtaining a valid model for the speed of growth of corn plants results in the conclusion that a first-order polynomial regression model is shown to be plausible.
Comparison of C4.5 algorithm with naive Bayesian method in classification of Diabetes Mellitus (A case study at Hasanuddin University hospital Makassar)
Authors: Ente D R , Arifin S , Andreza  , Thamrin S A
Published: November 2019

Diabetes mellitus (DM) is one of the chronic and deadly diseases that are widely observed in various countries today. This disease continues and is increasing to a very alarming stage. Indonesia ranks fourth in the world with the highest DM after the United States, India and China. The method used in this study is data collection, variable selection, classification methods, validation and evaluation and decision making. The algorithm used in this study is C4.5 Algorithm and Naive Bayesian Method using a dataset obtained from the results of Hasanuddin University hospital medical records. The results of calculations that have been done obtained accuracy on the C4.5 algorithm of 100% and on the Bayesian naive method obtained at 90%. From these results it can be concluded that to diagnose DM disease it is recommended to use the C4.5 Algorithm .
The analysis of factors that affecting household food security of tuberculosis patients in Surabaya
Authors: Susilaningrum D , Ulama B S S , Wulandari S P , Salamah M
Published: November 2019

Tuberculosis (TB) cases and household food security are fundamental problem which can be concerned with each other. Household food insecurity can affect the ability of a family member in counteracting an infectious disease such as TB. This research is aimed to study the factors that affecting household food security of tuberculosis patients in Surabaya. By Binary logistic regression model, there are four significant variables; Head of Household’s Occupation, Expenditure per Month, The Household Density and Type of Roof, with the correct classification 65.6%.
The Role of Firm’s Unique Resource in Developing Sustainable Competitive Advantage from Strategy Inimitability and its Effect on Firm Performance of Mining Companies in Indonesia
Authors: Rauf Abdul , Kadir Abd. Rahman , Kamariah Najmi
Published: November 2019

The positive relationship between unique resources and sustainable competitiveness of the company has been well understood and applies to almost all businesses. However, little is known about the specific effects of the uniqueness of resources and business strategies in this relationship. Using resource-based view (RBV), Porter's five-factor theory, and game theory, as well as imitation theory between companies, this study explains how the influence of company-specific resources and the uniqueness of the company's strategy as a sustainable competitive advantage affect performance. Analysis of data collected from surveys on 101 mining companies in Indonesia shows companies with distinctive resources are able to produce unique business strategies and insofar as they cannot be replicated, companies can enjoy sustainable competitive advantage. This implies that mining companies need to avoid their resources and business strategies to be imitated by their competitors if the company still wants to maintain competitive advantage and performance.
Substitution Box Design Based from Symmetric Group Composition
Authors: Bin Roslan Muhammad Fahim , Seman Kamaruzzaman , Ab Halim Azni Haslizan , Syam Mohd Sayuti M Nor Azizi
Published: November 2019

This work shows a new design of substitution box (S-Box) construction for the implementation in the block cipher. The S-Box is the only component in block cipher such as advanced encryption standard (AES) that possess the nonlinearity characteristics. Hence, it is crucial to properly design so that it able resist the cipher against known attack such as linear and differential attacks. Thee construction is based on composition of permutation within the symmetric group. This paper focus on the AES S-Box class which received 8-bit input and produced 8-bit output. This bijective S-Box consist of 256 elements which later involve in the process of composition. Initially, a set of 30 S-Box with high nonlinearity is generated using 30 irreducible polynomials under the finite field GF(28). These S-Box is then undergoing two rounds of composition which finally yield about 1.62 million S-Box. More than half of the generated S-Box achieve the nonlinearity of at least 100 with the maximum recorded nonlinearity of 110. This method also guarantee that the generated S-Box is bijective. To show the security level of our construction method, a comparison to other constriction methods is conducted. The methods introduced in this paper have slightly higher nonlinearity compared to several construction with the value of differential uniformity not on the par as AES however comparable to other similar heuristic construction.
Stagnation-Point Flow and Heat Transfer Over an Exponentially Stretching/Shrinking Sheet in Hybrid Nanofluid with Slip Velocity Effect: Stability Analysis
Authors: Anuar N S , Bachok N , Arifin N M , Rosali H , Pop I
Published: November 2019

The effect of slip on stagnation point flow and heat transfer over an exponentially stretching/shrinking sheet filled with Copper-Alumina/water nanofluids is investigated numerically in this paper. The governing boundary layer equations are transformed into a set of ordinary differential equations using a similarity transformation and then solved numerically using the bvp4c function in Matlab. The effects of nanoparticle volume fraction, slip parameter and stretching/shrinking parameter on the flow pattern and heat transfer have been studied. It is found that dual solutions exist for hybrid nanofluid in the case of shrinking sheet. Furthermore, slip parameter and Copper nanoparticle acts in widening the range of solution. Hybrid nanofluids have the higher heat transfer rate compared to nanofluid and viscous fluid. A stability analysis showed that the first solution is linearly stable and physically realizable.
Malaysia’s 14th General Election via Twitter: An analysis using the epidemiological model
Authors: Noor N S M , Akil K A K , Shafie L A
Published: November 2019

Twitter has been prominently used during the electoral campaigns. Twitter helps the politicians to spread and share their political agenda. Through Twitter, every information is accessible to anyone and anybody around the world in keeping up with the latest information like a manifesto and others that relate to political issues. However, the popularity of political parties and leaders that could raise the winning opportunities in the election is not fully understood. This study aims to analyse the spreading of information during Malaysia’s 14th General Election via Twitter. This study employed an epidemiological model which is a system of differential equations known as Susceptible-Infected-Recovered (SIR). The model involves three state variables, which are active Twitter users (S), the transmission node (I) and immune Twitter users (R). The Twitter accounts owned by two political parties and two political leaders have been followed before and after the election. The influence of contact rate between active Twitter users and the transmission node of Twitter users on Malaysia’s 14th General Election was analysed. The results showed that the contact rate between active Twitter users and the transmission node of the Twitter users has a significant influence on Malaysia’s 14th General Election.
Natural convection flow of Sodium Alginate based Casson nanofluid about a solid sphere in the presence of a magnetic field with constant surface heat flux
Authors: Alwawi Firas A , Alkasasbeh Hamzeh T , Rashad Ahmad M , Idris Ruwaidiah
Published: November 2019

In this paper, we examined a free convection flow of Sodium Alginate (SA) as a host Casson fluid with three different types of nanoparticles specifically, Silicon Dioxide (SiO2), Copper oxide (CuO), and Copper (Cu) on a solid sphere in the presence of magnetic field along with prescribed surface heat flux. The Keller-box method was carried out for solving the transformed governing partial differential equations. Numerical results for the local skin friction coefficient are obtained and compared with literature. Also, the influences of Casson parameter, magnetic parameter, nanoparticles volume fraction, on local skin friction coefficient, local Nusselt number, temperature, and velocity are analyzed graphically. Our study revealed that the local Nusselt number, local skin friction coefficient and velocity profiles of SiO2 - SA based Casson nanofluid are higher than the other nanoparticles - SA based Casson nanofluid, as well as it has the lowest temperature profiles.
Pseudospecteral method with linear damping effect and de-aliasing technique in solving nonlinear PDEs
Authors: Alias Azwani , Nik Ismail Nik Nur Amiza , Harun Fatimah Noor
Published: November 2019

Pseudospectral method is an alternative of finite differences and finite elements method to solve nonlinear partial differential equations (PDEs), especially in nonlinear waves. The Pseudospectal method is very efficient because it use the fast fourier transform to calculate discrete Fourier transform in the algorithm. In this paper, the Pseudospectral scheme is modified by adding the linear damping effect and de-aliasing technique, and has been tested in Ostrovsky equation, where Ostrovsky equation is a modified of Korteweg-de Vries equation with an addition of background Earth’s rotation. The addition of the linear damping is to prevent the possibility of radiated waves re-entering from the boundaries and disturbing the main wave structure. Most of the numerical simulations occur with the aliasing errors due to pollution of numerically calculated Fourier transform by higher frequencies component because of the truncation of the series. To prevent this, the de-aliasing technique is implemented on the nonlinear term and linear damping region by setting of the amplitudes to be zero at the end of both boundaries. Therefore, the simulation results of Pseudospectral method will be smooth without any high frequency errors even for the high amplitude of the waves from initial condition.
MHD stagnation point flow towards a quadratically stretching/shrinking surface
Authors: Nasir N.A.A.M. , Ishak A. , Pop I. , Zainuddin N.
Published: November 2019

A quadratically stretching/shrinking surface of two dimensional magnetohydrodynamics stagnation point flow is investigated numerically. The velocity of the surface is assumed in quadratic form and subject to a linear mass flux. The influences of the governing parameters namely stretching/shrinking parameter ⋋, suction/injection parameter S, fluid temperature index m, and magnetic parameter M on the flow and thermal fields are studied. The model of nonlinear ordinary differential equations is obtained by reducing the partial differential equations of the boundary layer using an suitable similarity transformation. The equations are then solved numerically by boundary value problem solver, bvp4c built in MATLAB software. The numerical results are verified by comparing them with previously reported results. The characteristics of the flow and heat transfer characteristics are shown graphically and analyzed for distinct values of the governing parameters. It is found that both magnetic and temperature index parameters reduce the velocity flow while the magnetic parameter enhances the heat transfer rate. There exist dual solutions for certain range of ⋋. A stability analysis is performed to determine which of these solutions are stable and which are not.
MHD Stagnation Point Flow of Micropolar Nanofluid with Soret and Dufour Effects
Authors: Binti Zulkifli Siti Norfatihah , Sarif Norhafizah Md , Salleh Mohd Zuki , Azmi Ezzatul Farhain
Published: November 2019

The effect of Soret and Dufour on magnetohydrodynamic (MHD) stagnation point flow of a micropolar nanofluid over a horizontal stretching sheet is considered. A boundary condition that assumed nanoparticle flux at the plate to be zero is applied in this study. The governing equations are in partial differential equations therefore a similarity transformation variable is employed to reduce the governing non-linear partial differential equations into non-dimensional ordinary differential equations. The ordinary differential equations are computed numerically using Runge-Kutta-Fehlberg (RKF45). Validation of the result is made by comparing the present results with the previous studies. Numerical results are presented in the graphical form for temperature and concentration profile to provide a better insight of this study. It is found that, temperature profile and nanoparticle volume fraction profile increase with an increasing values of Soret and Dufour effects.
The Lefkovitch Matrix of Aedes Aegypti with Rainfall Dependent Model for Eggs Hatching
Authors: Tokachil M N , Yahya A
Published: November 2019

Dengue is known as borne disease that was spread by a species of mosquito which is Aedes aegypti. This disease is considered as a dangerous disease since it can threat human life. Shah Alam city has the high reported dengue cases in Malaysia. Based on this situation, this research was done in order to simulate the population of the mosquito in the city which involved in dengue transmission. A stage-structured of the mosquito life cycle was interpreted into Lefkovitch matrix model which consist of possible rate relating to the mosquito life cycle. The egg hatching rate was set as the main factor which influence the number of mosquito population and it depends on water availability due to rainfall. In this research, the temperature was set as constant because the temperature in Malaysia does not show any significant different compared to the rainfall distribution. The validation of the result was made by doing comparison between the simulations of eggs number with the amount of rainfall in order to see the relationship of the trends for both variables. As a result, the dynamic of dengue cases might be possible related to the trend of rainfall which provide breeding site for the female mosquito to lay eggs which contribute to the increase in the number of mosquito population. However, for the further studies, the researcher should consider other factor such as humidity since it might influence the mosquito life cycle and thus can give more accurate results.
Hybrid nanofluid flow and heat transfer past a permeable stretching/shrinking surface with a convective boundary condition
Authors: Waini I , Ishak A , Pop I
Published: November 2019

The steady flow and heat transfer past a permeable stretching/shrinking surface in a hybrid nanofluid with a convective boundary condition is studied. The governing equations of the problem are transformed to the similarity equations by using similarity transformation technique. The problem is solved numerically using the boundary value problem solver (bvp4c) in Matlab software. The plots of the skin friction coefficient and the local Nusselt number as well as the velocity and temperature profiles for selected parameters are presented. Results show that dual solutions exist for a certain range of the stretching/shrinking and suction parameters. The critical values of these parameters decrease with the increasing of the copper (Cu) nanoparticle volume fractions. It is found that the heat transfer rate for hybrid nanofluid is higher than that for nanofluid for the impermeable stretching surface. It is also found that the increasing of the copper (Cu) nanoparticle volume fractions enhances the skin friction coefficient and reduces the local Nusselt number for the shrinking surface. The rise in Biot number leads to the increment of the temperature at the surface and widen the thermal boundary layer for both branches. A temporal stability analysis is performed to determine the stability of the dual solutions in a long run, and it is revealed that only one of them is stable while the other is unstable.
Rayleigh–Bénard convection in rotating nanofluids layer with feedback control subjected to magnetic field
Authors: Khalid Izzati Khalidah , Mohd Mokhtar Nor Fadzillah , Ibrahim Zarina Bibi
Published: November 2019

Magnetic field on Rayleigh–Bénard convective instability in rotating feedback–controlled nanofluids layer heated from below has been examined for the boundaries of free–free, rigid–free and rigid–rigid. Model applied to nanofluids associated with the Brownic movement and thermophoresis mechanism. A normal–mode linear stability assessment has been performed, the eigenvalue solution has been extracted by using single term Galerkin technique and computed by employing Maple software. It is found that the influences of magnetic field, feedback control, rotation are to slow down the thermal instability.