Performance comparison between bootstrap and multiscale bootstrap for assessing phylogenetic tree for RNA polymerase

Phylogenetic inference refers to the reconstruction of evolutionary relationships among various species that is usually presented in the form of a tree. This study constructs the phylogenetic tree by using a novel distance-based method known as Modified one step M-estimator (MOM) method. The branches of the phylogenetic tree constructed were then evaluated to see their reliability. The performance of the reliability was then compared between the p-value of multiscale bootstrap (AU value) and bootstrap p-value (BP value). The aim of this study was to compare the performance between the AU value and BP value for assessing phylogenetic tree of RNA polymerase. The results have shown that multiscale bootstrap analysis can detect high sampling errors but not in bootstrap analysis. To overcome this problem, the multiscale bootstrap analysis has reduced the sampling error by increasing the number of replications. The clusters were indicated as significant if AU values or BP values were 95% or higher. From the analysis, the results showed that the BP and AU values differ at 11th and 15th branch of the phylogenetic tree. The BP values at both branches were 72 and 85%, respectively, thereby making the cluster not significant but by looking at the AU values, the two branches were more than 95% and the clusters were significant. This was due to the biasness in calculation of the probability of bootstrap analysis, therefore, the multiscale bootstrap analysis has improved the calculation of the probability value compared to the bootstrap analysis

Pengujian hipotesis berbilang: perbandingan simulasi Monte Carlo berdasarkan Ralat Jenis I

Pengujian hipotesis berbilang merupakan pengujian yang melibatkan ujian serentak lebih daripada satu hipotesis dan digunakan untuk mengawal kadar ralat berkumpulan (FWER) dan kadar penemuan palsu (FDR) dengan meminimumkan Ralat Jenis I. Kajian ini bertujuan untuk membuat perbandingan ujian pengujian hipotesis berbilang bagi ujian-t iaitu pengujian antara dua kumpulan sampel melalui perbandingan antara ujian Bonferroni, ujian Holm, ujian Hochberg, ujian Hommel, ujian Benjamini-Hochberg dan ujian Benjamini-Yekutieli dengan mengikut keadaan yang tertentu iaitu nilai α, bilangan ujian, m dan jenis taburan yang berbeza. Perbandingan pengujian hipotesis berbilang berdasarkan kebarangkalian Ralat Jenis I bagi kes kadar ralat berkumpulan (FWER) dan kadar penemuan palsu (FDR) dijalankan berdasarkan simulasi Monte Carlo. Didapati, bagi kumpulan min yang sama iaitu {0,0} bagi kesemua keadaan, Ralat Jenis I bernilai sifar. Hal ini kerana kesemua ujian gagal menolak hipotesis nol dan terbukti menyatakan kesemua hipotesis nol adalah benar. Selain itu, aras keertian 0.01 tidak sesuai digunakan bagi kesemua keadaan kerana aras keertian ini dikatakan sangat jitu. Bagi kumpulan min yang berbeza iaitu {0,1}, ujian Benjamini-Yekutieli sesuai digunakan bagi mengawal kadar penemuan palsu (FDR) kerana dapat meminimumkan Ralat Jenis I dengan baik berbanding dengan ujian lain. Manakala bagi kadar ralat berkumpulan (FWER), ujian Hommel sesuai digunakan berbanding dengan ujian lain. Hal ini kerana ujian ini dapat mengawal dengan baik dan meminimumkan Ralat Jenis I

Existence of fractal behaviour in ozone time series

Fractal has received a wide attention and has been used in many areas such as meteorology, stock market and also in medical field. It can be viewed as an object which has similar appearance when viewed at different scales which are known as self-similar. Thus, the scale invariance and scaling properties of the time series may be explored using fractal techniques. The aim of this study is to investigate the presence of fractal behaviour in the ozone time series. The presence of fractal behaviour can lead to the possibility of implementing the fractal approach in order to examine the properties of a time series. In this study, the daily average of ozone concentration from six selected air monitoring stations with different types of backgrounds in Peninsular Malaysia are used. From the autocorrelation function (ACF) plot obtained for the six stations, the slow decay in ACF values indicates that self-similarity are present where it shows that the series is having the property of fractal behaviour. In this paper, the existence of fractal behaviour is investigated by using the power spectrum method and the empirical probability distribution function. The result shows that the daily average of ozone concentration exhibits fractal behaviour for all the six monitoring stations considered

The Seismic Refraction Survey to Determine the Depth of Bedrock at the Damansara Area for Horizontal Directional Drilling Method Application

The seismic reflection survey conducted along the road at Damansara to determine the depth of bedrock in order to justify whether HDD method can be utilize to store the fiber optic cable. 10 line seismic survey performed along 1.2 km roadside. The result show that the subsurface profile represent by two layer of earth materials that is topsoil and bedrock granite. Determination between topsoil and granite based on the values of seismic velocity. The boundary between granite and soil interpreted by a velocity value 1,200 m/s. If the velocity values is less than 1,200 m/s, it interpreted as soil or highly weathered rock. Meanwhile the velocity value more than 1,200 m/s is refer as rock and hard to excavate especially using HDD method. The study shows that the general thickness of topsoil along the road in Damansara is around 2.0 to 4.0 m. The minimum thickness of topsoil is 1.0 m and maximum found around 6.0 m. The bedrock observed very shallow and not suitable for HDD method to implement

An overview of homogeneity of variance tests on various conditions based on type 1 error rate and power of a test

In most statistical analyses, the data variance used is assumed to be homogeneous, but not all cases follow the assumption. Therefore, the homogeneity of variance assumption testing should be carried out prior to performing the main analysis. There are various statistical tests of variance homogeneity that exist and to obtain the best statistical test in the testing of variance equality, this study makes a comparison of statistical tests against assumptions met, assumptions violated and the existence of outlier. The comparison is based on the Type 1 Error rate and the power of the statistical test. For normal distribution, the comparison is between parametric statistical tests such as the Fisher test, the Bartlett test, the Levene test, the Brown-Forsythe test, and the Cochran C test. While for chi-squared distribution and outlier data, the comparison is between parametric and nonparametric statistical tests. The nonparametric statistical tests used are the Mood test, the Ansari-Bradley test, and the Fligner-Killeen test. The data used is the result of a normal and Chi-squared Monte Carlo simulation. The results showed that almost all the parametric statistical tests can control Type 1 Errors well in almost all situations. For the Chi-squared distribution only the Brown-Forsythe parametric statistical test was found to be robust. But most of the robust tests on non-normal data are nonparametric statistical tests. While for normal data with heterogeneous variance, the power of the test of all parametric statistical tests is seen to increase and exceed 0.80 as the size effect increases. On non-normal distributions, the power of the test is smaller than normal, but the value will increase as the size effect increases. The case was different for the Fisher test, the Bartlett test, and the Cochran C test, which was tested against data with 10% outlier in one group. The power of the test for the 1:2 variance ratio is seen as large, but the value is decreasing as the size effect increases. Thus, it can be concluded that none of the statistical tests were found to be robust and suitable for use in all the conditions set

Pemodelan dan peramalan permintaan pelancong asing ke Malaysia berdasarkan model ADLM

Corak permintaan pelancong asing ke Malaysia dianalisis dan diramal dengan menggunakan kaedah ekonometrik. Kaedah ini digunakan bagi menentukan faktor-faktor ekonomi yang mempunyai kesan terhadap permintaan pelancong asing ke Malaysia. Walaupun terdapat banyak kajian lepas telah dijalankan bagi mendapatkan model siri masa dan model ramalan kedatangan pelancong asing ke Malaysia, tetapi model-model tersebut tidak mengambil kira faktor makroekonomi pelancong dalam membuat peramalan. Dalam kajian ini, sembilan buah negara dipilih, iaitu negara yang banyak menyumbang kepada ketibaan pelancong ke Malaysia, iaitu Australia, Brunei, China, Indonesia, India, Jepun, Filipina, Korea Selatan dan United Kingdom. Beberapa pemboleh ubah makroekonomi dipilih, iaitu bilangan ketibaan pelancong di Malaysia, pendapatan pelancong, harga relatif, harga pengganti dan pemboleh ubah patung untuk meneliti permintaan pelancong asing ke Malaysia dalam jangka pendek dan panjang. Terdapat krisis ekonomi pada tahun 1997 dan serangan SARS pada tahun 2003 memberi kesan ketara yang menjejaskan permintaan pelancongan asing di Malaysia dalam jangka masa pendek. Manakala pemboleh ubah pendapatan pelancong pula memberi kesan kepada permintaan pelancongan di Malaysia dalam jangka panjang. Model Taburan Lat Autoregresi (ADLM) digunakan dalam kajian ini dan dimodelkan menggunakan data dari tahun 1990 hingga 2014. Seterusnya peramalan permintaan pelancongan dibandingkan dengan data sebenar pada tahun 2015 bagi pengesahan kecekapan model

Students Perspective on Lecturer Characteristic for Effective Teaching

AbstractThis study was conducted to explore students’ evaluation on the lecturers’ characteristics that influence effective teaching at the Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi. The evaluations were on the lecturers’ preparation, teaching styles and responsibilities. The Analytical Hierarchy Process (AHP) as a ranking method was used in this study to ensure that the main factors can be identified based on the weights. From the analysis, the main factors in AHP are arranged in decreasing order; preparation, followed by the style of teaching, and finally responsibilities. This result will help to provide guidelines to the lecturers for effective teaching

Testing personal orientations - organizational climate fit using polynomial regressions, response surface, and bootstrapping

Personal orientations-organizational climate fit as a predictor of organizational commitment was examined using a sample of 350 Malaysian medical doctors from public and private hospitals in the northern states of Malaysia. The fit hypothesis was tested using polynomial regression and response surface methodology, followed by bootstrapping to estimate confidence intervals and for significance testing of response surface features. The results generally indicated that the personal orientations-organizational climate fit has a positive impact on the affective and normative organizational commitment of doctors. The need for achievement and the need for power were found to be significant dimensions that predicted the affective-normative commitment

Approximation of the sum of independent lognormal variates using lognormal distribution by maximum likelihood estimation approached

Three methods of approximating the sum of lognormal variates to a lognormal distribution were studied. They were the Wilkinson approximation, the Monte Carlo version of the Wilkinson approximation and the approximation using estimated maximum likelihood lognormal parameters. The lognormal variates were generated empirically using Monte Carlo simulation based on several conditions such as number of lognormal variates in the sum, number of sample points in the variates, the variates are independent and identically distributed (IID) and also not identically distributed (NIID) with lognormal parameters. Evaluation of all three lognormal approximation methods was performed using the Anderson Darling test. Results show that the approximation using estimated maximum likelihood lognormal parameters produced Type I errors close to the 0.05 target and is considered the best approximation

INCEPTION OF 3Es IN PROMOTING DISASTER RESILIENT COMMUNITIES LIVING NEAR HYDROPOWER DAMS OF PENINSULAR MALAYSIA

Excessive rain pattern has been the major cause contributing to flooding of low land due to excess water release from affected dams. This deliberate measure has to be taken to prevent the catastrophic effect of a dam break scenario. Therefore, this kind of disaster is considered as a local phenomenon. The local communities are the vulnerable population to face the immediate impact of such disaster. Needless to mention that they are also first emergency responders which is crucial for saving lives. It is therefore imperative for the involved stakeholders to improve local communities’ resilience to dam related disasters. This resonates well with the Hyogo Framework for Action, which identify local communities as integral cornerstone for saving lives and livelihoods. In the case of communities living near main hydropower dams owned by Tenaga Nasional Berhad, an initiative known as Integrated Community Based Disaster Management (ICBDM) has been launched in May 2015. This initiative adopts the concept of 3Es; embrace, educate and empower. The priority is to ensure the vulnerable communities embrace the reality, being educated to face any upcoming situation as well as being empowered to take charge of immediate live saving efforts in the future. The initiative involves five key scopes encompassing technical and non-technical areas and promotes the strategic partnerships between dam owner, authority and the community. It is anticipated that this initiative will build the resilience of communities to dam related disaster