Displaying publications 1 - 20 of 183 in total

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  1. A Comparison Between Bayesian and Maximum Likelihood Estimations in Estimating Finite Mixture Model for Financial Data
    Seuk-Yen Phoong, Mohd Tahir Ismail
    Sains Malaysiana, 2015;44:1033-1039.
    Over the years, maximum likelihood estimation and Bayesian method became popular statistical tools in which applied to fit finite mixture model. These trends begin with the advent of computer technology during the last decades. Moreover, the asymptotic properties for both statistical methods also act as one of the main reasons that boost the popularity of the methods. The difference between these two approaches is that the parameters for maximum likelihood estimation are fixed, but unknown meanwhile the parameters for Bayesian method act as random variables with known prior distributions. In the present paper, both the maximum likelihood estimation and Bayesian method are applied to investigate the relationship between exchange rate and the rubber price for Malaysia, Thailand, Philippines and Indonesia. In order to identify the most plausible method between Bayesian method and maximum likelihood estimation of time series data, Akaike Information Criterion and Bayesian Information Criterion are adopted in this paper. The result depicts that the Bayesian method performs better than maximum likelihood estimation on financial data.
    Matched MeSH terms: Biometry
  2. A Multivariate Measure of Dispersion and its Limiting Distribution (Ukuran Multivariat bagi Dispersi dan Hal Taburannya)
    Suwanda Idris
    Sains Malaysiana, 2005;34.
    Total Variance (TV) and Generalized Variance (GV) are commonly used as a measure multivariate dispersion. However, these two statistics has some drawbacks. This paper proposes a new measure of multivariate dispersion, named Vectorial Variance (VV) an inner product for set of operators defined on a Hilbert-Smith space. Since, the exact sampling distribution of VV is difficult to find, therefore the asymptotic sampling distribution is obtained.
    [Jumlah Varians dan Varians Teritlak kebiasaannya digunakan sebagai ukuran dispersi multivariate. Namun begitu, kedua-dua statistik ini mempunyai beberapa kelemahan. Dalam tulisan ini akan dicadankgan satu ukuran dispersi multivariate yang baru, dikenali sebagai varians bervektor (VV) yang merupakan suatu hasil darab terkedalam bagi set pengoperasi yang tertakrif ke atas suatu ruang Hilbert-Smith. Oleh kerana taburan pensampilan tepat dari statistik vv tersebut sangat sukar untuk ditentukan, maka taburan pensampilan asimtot telah diperolehi].
    Matched MeSH terms: Biometry
  3. Fulltext A Prospective Randomised Controlled Study Comparing Ultrasonic Dissector with Electrocautery for Axillary Dissection in Patients of Carcinoma Breast
    Deori A, Gupta N, Gupta AK, Yelamanchi R, Agrawal H, Durga CK
    Malays J Med Sci, 2021 Feb;28(1):97-104.
    PMID: 33679225 DOI: 10.21315/mjms2021.28.1.12
    Background: Axillary dissection is one of the important components of modified radical mastectomy (MRM). The present study was conducted to compare surgical outcomes by using monopolar electrocautery and ultrasonic dissector for axillary dissection in MRM.

    Methods: A parallel randomised controlled single blinded study was conducted with a sample size of 70 patients who were randomised into two groups. One group underwent MRM using ultrasonic dissector (Group A) and the other one using electrocautery (Group B). Intra- and post-operative outcomes were compared.

    Results: Group A had an average operating time of 30.86 min, which was statistically less than that of Group B. The mean mop count and the daily drain output in Group A were less as compared to Group B and the differences were statistically significant. Drain was removed early in Group A as compared to Group B. However, post-operative pain scores and seroma formation were not statistically significant among the two groups.

    Conclusion: Ultrasonic dissector group had significantly lesser intra-operative bleeding, operating time and post-operative drain output when compared to electrocautery group. However, the two groups had no significant difference in post-operative pain scores and seroma formation.

    Matched MeSH terms: Biometry
  4. A Step-by-Step Process on Sample Size Determination for Medical Research
    Bujang MA
    Malays J Med Sci, 2021 Apr;28(2):15-27.
    PMID: 33958957 DOI: 10.21315/mjms2021.28.2.2
    Determination of a minimum sample size required for a study is a major consideration which all researchers are confronted with at the early stage of developing a research protocol. This is because the researcher will need to have a sound prerequisite knowledge of inferential statistics in order to enable him/her to acquire a thorough understanding of the overall concept of a minimum sample size requirement and its estimation. Besides type I error and power of the study, some estimates for effect sizes will also need to be determined in the process to calculate or estimate the sample size. The appropriateness in calculating or estimating the sample size will enable the researchers to better plan their study especially pertaining to recruitment of subjects. To facilitate a researcher in estimating the appropriate sample size for their study, this article provides some recommendations for researchers on how to determine the appropriate sample size for their studies. In addition, several issues related to sample size determination were also discussed.
    Matched MeSH terms: Biometry
  5. Fulltext A Survey on Medical, Dental, and Pharmacy Students' Knowledge, Attitude, and Practice about Hepatitis B Infection in a Private Medical University of Malaysia
    Upadhyay DK, Manirajan Y, Iqbal MZ, Paliwal N, Pandey S
    J Res Pharm Pract, 2020 10 08;9(3):128-134.
    PMID: 33489980 DOI: 10.4103/jrpp.JRPP_20_8
    Objective: The present study aimed to assess the knowledge, attitude, and practice (KAP) of 3rd- and 4th-year medical, dental, and pharmacy students about hepatitis B (HB) infection at a private medical university, Malaysia.

    Methods: A cross-sectional, questionnaire-based study was conducted among 482 medical, dental, and pharmacy students of 3rd- and 4th-year degree program of Asian Institute of Medicine, Science and Technology University to assess their KAP about HB infection using 34 prevalidated questions by convenient sampling method. A questionnaire was administered to the students, and their responses were measured at "yes" and "no" scale. Students' responses were entered in SPSS version 22, and quantitative analysis was performed using descriptive statistics and nonparametric tests at P < 0.05.

    Findings: The medical, dental, and pharmacy students had good knowledge and practice with positive attitude about HB infection. Mann-Whitney U-test determined a significant difference in knowledge (P < 0.001) and practice (P < 0.001) scores between medical and pharmacy, attitude (P < 0.001) scores between medical and dental, and attitude (P < 0.001) and practice (P < 0.001) scores between pharmacy and dental students. Students' age was correlated with their attitude, practice, and KAP scores and family income with their knowledge, attitude, practice, and KAP scores.

    Conclusion: Although students' knowledge and practice were good with positive attitude, all the students did not participate in health education program, screening, and vaccination of hepatitis B virus (HBV) infection which makes them more vulnerable to occupational HBV infection. Hence, it is recommended to organize a regular health education program for the students on screening and vaccination against HBV to prevent its infection.

    Matched MeSH terms: Biometry
  6. A comparison of bivariate, multivariate random-effects, and Poisson correlated gamma-frailty models to meta-analyze individual patient data of ordinal scale diagnostic tests
    Simoneau G, Levis B, Cuijpers P, Ioannidis JPA, Patten SB, Shrier I, et al.
    Biom J, 2017 Nov;59(6):1317-1338.
    PMID: 28692782 DOI: 10.1002/bimj.201600184
    Individual patient data (IPD) meta-analyses are increasingly common in the literature. In the context of estimating the diagnostic accuracy of ordinal or semi-continuous scale tests, sensitivity and specificity are often reported for a given threshold or a small set of thresholds, and a meta-analysis is conducted via a bivariate approach to account for their correlation. When IPD are available, sensitivity and specificity can be pooled for every possible threshold. Our objective was to compare the bivariate approach, which can be applied separately at every threshold, to two multivariate methods: the ordinal multivariate random-effects model and the Poisson correlated gamma-frailty model. Our comparison was empirical, using IPD from 13 studies that evaluated the diagnostic accuracy of the 9-item Patient Health Questionnaire depression screening tool, and included simulations. The empirical comparison showed that the implementation of the two multivariate methods is more laborious in terms of computational time and sensitivity to user-supplied values compared to the bivariate approach. Simulations showed that ignoring the within-study correlation of sensitivity and specificity across thresholds did not worsen inferences with the bivariate approach compared to the Poisson model. The ordinal approach was not suitable for simulations because the model was highly sensitive to user-supplied starting values. We tentatively recommend the bivariate approach rather than more complex multivariate methods for IPD diagnostic accuracy meta-analyses of ordinal scale tests, although the limited type of diagnostic data considered in the simulation study restricts the generalization of our findings.
    Matched MeSH terms: Biometry/methods*
  7. Fulltext A new Multi Sine-Cosine algorithm for unconstrained optimization problems
    Rehman MZ, Khan A, Ghazali R, Aamir M, Nawi NM
    PLoS One, 2021;16(8):e0255269.
    PMID: 34358237 DOI: 10.1371/journal.pone.0255269
    The Sine-Cosine algorithm (SCA) is a population-based metaheuristic algorithm utilizing sine and cosine functions to perform search. To enable the search process, SCA incorporates several search parameters. But sometimes, these parameters make the search in SCA vulnerable to local minima/maxima. To overcome this problem, a new Multi Sine-Cosine algorithm (MSCA) is proposed in this paper. MSCA utilizes multiple swarm clusters to diversify & intensify the search in-order to avoid the local minima/maxima problem. Secondly, during update MSCA also checks for better search clusters that offer convergence to global minima effectively. To assess its performance, we tested the MSCA on unimodal, multimodal and composite benchmark functions taken from the literature. Experimental results reveal that the MSCA is statistically superior with regards to convergence as compared to recent state-of-the-art metaheuristic algorithms, including the original SCA.
    Matched MeSH terms: Biometry*
  8. Fulltext A new strategy of handling general insurance modelling using applied linear method
    Wan Muhamad Amir W. Ahmad, Mohamad Arif Awang Nawi, Mustafa Mamat
    Malaysian Journal of Applied Sciences, 2018;1(1):45-54.
    MyJurnal
    This paper proposes the use of bootstrap, robust and fuzzy multiple linear regressions method in
    handling general insurance in order to get improved results. The main objective of bootstrapping is to
    estimate the distribution of an estimator or test statistic by resampling one's data or a model estimated
    from the data under conditions that hold in a wide variety of econometric applications. In addition,
    bootstrap also provides approximations to distributions of statistics, coverage probabilities of confidence
    intervals, and rejection probabilities of hypothesis tests that produce accurate results. In this paper, we
    emphasize the combining and modelling using bootstrapping, robust and fuzzy regression methodology.
    The results show that alternative methods produce better results than multiple linear regressions (MLR)
    model.
    Matched MeSH terms: Biometry
  9. A new thermographic NDT for condition monitoring of electrical components using ANN with confidence level analysis
    Huda AS, Taib S, Ghazali KH, Jadin MS
    ISA Trans, 2014 May;53(3):717-24.
    PMID: 24593986 DOI: 10.1016/j.isatra.2014.02.003
    Infrared thermography technology is one of the most effective non-destructive testing techniques for predictive faults diagnosis of electrical components. Faults in electrical system show overheating of components which is a common indicator of poor connection, overloading, load imbalance or any defect. Thermographic inspection is employed for finding such heat related problems before eventual failure of the system. However, an automatic diagnostic system based on artificial neural network reduces operating time, human efforts and also increases the reliability of system. In the present study, statistical features and artificial neural network (ANN) with confidence level analysis are utilized for inspection of electrical components and their thermal conditions are classified into two classes namely normal and overheated. All the features extracted from images do not produce good performance. Features having low performance reduce the diagnostic performance. The study reveals the performance of each feature individually for selecting the suitable feature set. In order to find the individual feature performance, each feature of thermal image was used as input for neural network and the classification of condition types were used as output target. The multilayered perceptron network using Levenberg-Marquardt training algorithm was used as classifier. The performances were determined in terms of percentage of accuracy, specificity, sensitivity, false positive and false negative. After selecting the suitable features, the study introduces the intelligent diagnosis system using suitable features as inputs of neural network. Finally, confidence percentage and confidence level were used to find out the strength of the network outputs for condition monitoring. The experimental result shows that multilayered perceptron network produced 79.4% of testing accuracy with 43.60%, 12.60%, 21.40, 9.20% and 13.40% highest, high, moderate, low and lowest confidence level respectively.
    Matched MeSH terms: Biometry
  10. A simplified clustering method for novice narcotic chemists
    Chan KW, Tan GH, Wong RC
    Sci Justice, 2012 Sep;52(3):136-41.
    PMID: 22841136 DOI: 10.1016/j.scijus.2012.04.006
    Statistical classification remains the most useful statistical tool for forensic chemists to assess the relationships between samples. Many clustering techniques such as principal component analysis and hierarchical cluster analysis have been employed to analyze chemical data for pattern recognition. Due to the feeble foundation of this statistics knowledge among novice drug chemists, a tetrahedron method was designed to simulate how advanced chemometrics operates. In this paper, the development of the graphical tetrahedron and computational matrices derived from the possible tetrahedrons are discussed. The tetrahedron method was applied to four selected parameters obtained from nine illicit heroin samples. Pattern analysis and mathematical computation of the differences in areas for assessing the dissimilarity between the nine tetrahedrons were found to be user-convenient and straightforward for novice cluster analysts.
    Matched MeSH terms: Biometry
  11. Fulltext Academic procrastination and self-efficacy among a group of dental undergraduate students in Malaysia
    Uma E, Lee CH, Shapiai SNHBM, Binti Mat Nor AN, Soe HHK, Varghese E
    J Educ Health Promot, 2020;9:326.
    PMID: 33426130 DOI: 10.4103/jehp.jehp_195_20
    BACKGROUND: Undergraduate dental students have to do multiple tasks as part of their extensive curriculum in order to achieve the proficiencies expected of them. During the course of their study, a tendency to procrastinate and question their self-efficacy is detrimental for the students. The aim of this study was to evaluate the level of procrastination and self-efficacy and its related factors among dental undergraduate students.

    SUBJECTS AND METHODS: This cross-sectional study was conducted among all (n = 361) consented dental undergraduate students of our dental school. A twenty-item Lay's Procrastination Scale for student population and a ten-item General Self-Efficacy Scale were used for the study after getting institutional ethical approval. The quantitative data were explained using descriptive statistics. Independent sample t-test and ANOVA were used to determine the association between self-efficacy, academic procrastination, and genders and academic years. Pearson correlation coefficient was used to determine the association between self-efficacy and procrastination. Multiple linear regression analysis was performed to determine the related factors to academic procrastination.

    RESULTS: High procrastination (score ≥62) was seen among 28.5% of students. The mean self-efficacy score was 29.5. There was no significant difference between genders for procrastination scores (P = 0.835) and between academic years (P = 0.226). Males showed significantly more self-efficacy (P < 0.001), and self-efficacy did not show any significant difference (P = 0.204) between academic years though a tendency for year 5 students to have lower self-efficacy scores was observed. Academic procrastination was negatively correlated with self-efficacy (r = -0.238 and P < 0.001).

    CONCLUSIONS: For dental undergraduates who have cognitive load as well as work associated with patients, procrastination and self-efficacy are negatively correlated.

    Matched MeSH terms: Biometry
  12. Fulltext Adaptation of Demirjian’s method for age estimation via third molar development among adolescents and young adults of Malay ethnicity: a preliminary assessment
    Eva Tan Lee Yin, Kuck Peng Sim, Mohd Yusmiaidil Putera Mohd Yusof
    Malaysian Journal of Medicine and Health Sciences, 2020;16(101):14-18.
    MyJurnal
    Introduction: Identification of remains recovered at advanced stages of decomposition can be problematic due to the lack of physical evidence. Nonetheless, human dentition is least susceptible to decomposition and as such carry a significant value in personal identification of decomposed remains. Demirjian’s method of age estimation was developed specifically for children with developing dentition. In this article, a method on adapting the Demirjian’s method for Malay ethnic-specific age estimation using the third molar development is presented. Methods: Orthop- antomograms of Malay subjects aged 18 to 25 were obtained from UiTM Sungai Buloh. Total of 318 samples were taken, comprising of 123 and 195 images from male and female subjects. Development of right and left mandibular third molar was classified according to the eight stages of development as illustrated in Demirjian’s method. Data obtained were subjected to statistical analysis such as descriptive statistics and analysis of variance. The intra- and inter-gender variation between left and right mandibular third molar was evaluated using independent student t-test and analysis of variance, respectively. Results: Intra-gender comparison analysis revealed a significant difference in the female and male with a p-value of 0.000 and 0.003, respectively. Regression equation to estimate age based on third molar development were formulated according to dental age and maturity score. Conclusion: The Demirjian’s method was successfully adapted for age estimation of individuals of Malay ethnicity. These findings can help with victim identification in cases of poor skeletal framework recovery and highly decomposed remains.
    Matched MeSH terms: Biometry
  13. Fulltext Agreement analysis of LENSTAR with other techniques of biometry
    Jasvinder S, Khang TF, Sarinder KK, Loo VP, Subrayan V
    Eye (Lond), 2011 Jun;25(6):717-24.
    PMID: 21394115 DOI: 10.1038/eye.2011.28
    To assess the agreement of the optical low-coherence reflectometry (OLCR) device LENSTAR LS900 with partial coherence interferometry (PCI) device IOLMaster and applanation and immersion ultrasound biometry.
    Matched MeSH terms: Biometry
  14. Fulltext Agreement analysis of Pentacam and Lenstar in measurement of keratometry, anterior chamber depth and lens thickness
    Azlindarita A. Mohd Abdullah, Norasyikin Mustafa, Pei LV, Subrayan V
    Journal of Clinical and Health Sciences, 2016;1:10-15.
    To assess the agreement of the Scheimpflug camera system Pentacam with the optical low-coherence reflectometry (OLCR) device LENSTAR LS900 in measuring anterior segment biometry.
    Matched MeSH terms: Biometry
  15. An empirical assessment of the closeness of hidden truncation and additive component based skewed distributions
    Hazarika PJ, Chakraborty S
    Sains Malaysiana, 2014;43:1801-1809.
    Hidden truncation (HT) and additive component (AC) are two well known paradigms of generating skewed distributions from known symmetric distribution. In case of normal distribution it has been known that both the above paradigms lead to Azzalini's (1985) skew normal distribution. While the HT directly gives the Azzalini's ( 1985) skew normal distribution, the one generated by AC also leads to the same distribution under a re parameterization proposed by Arnold and Gomez (2009). But no such re parameterization which leads to exactly the same distribution by these two paradigms has so far been suggested for the skewed distributions generated from symmetric logistic and Laplace distributions. In this article, an attempt has been made to investigate numerically as well as statistically the closeness of skew distributions generated by HT and AC methods under the same re parameterization of Arnold and Gomez (2009) in the case of logistic and Laplace distributions.
    Matched MeSH terms: Biometry
  16. Fulltext An image encryption scheme based on public key cryptosystem and quantum logistic map
    Ye G, Jiao K, Huang X, Goi BM, Yap WS
    Sci Rep, 2020 Dec 03;10(1):21044.
    PMID: 33273539 DOI: 10.1038/s41598-020-78127-2
    Most of existing image encryption schemes are proposed in the spatial domain which easily destroys the correlation between pixels. This paper proposes an image encryption scheme by employing discrete cosine transform (DCT), quantum logistic map and substitution-permutation network (SPN). The DCT is used to transform the images in the frequency domain. Meanwhile, the SPN is used to provide the security properties of confusion and diffusion. The SPN provides fast encryption as compared to the asymmetric based image encryption since operations with low computational complexity are used (e.g., exclusive-or and permutation). Different statistical experiments and security analysis are performed against six grayscale and color images to justify the effectiveness and security of the proposed image encryption scheme.
    Matched MeSH terms: Biometry
  17. Fulltext An overview of meta-analysis in health science
    Samia Amin, Sayed Mahmud Saiful Amin
    Malaysian Journal of Medical Research, 2017;1(2):28-37.
    MyJurnal
    Meta-analysis is a subset of systematic review; a technique for systematically combining pertinent qualitative
    and quantitative study data from numerous selected studies to broaden a single conclusion that has more
    statistical power. This inference is statistically stronger than the analysis of any single study, due to increase
    numbers of topics, greater variety amongst subjects, or collected effects and outcomes. The aim of this review
    article is to highlight the definition, history, purpose, characteristics, use, advantage, disadvantage, validity,
    and steps in conducting meta-analysis.
    Matched MeSH terms: Biometry
  18. Fulltext Anthropometric characteristics of Malay nose- a pilot study
    Tengku Fazrina Tengku Mohd Arif, Farah Farhana Muhamad Hanafi, Nur Wardah Hanis Abdul Razak, Narissaporn Chaiprakit, Hazmyr Abdul Wahab
    ESTEEM Academic Journal, 2020;16(2):11-20.
    MyJurnal
    Anthropometric analysis provides the most reliable comparison of the body forms by using specific landmarks determined in respect of anatomical prominences. The knowledge of unique shape, anatomy and dimensions of the nose is very useful for surgeon undertaking its repair and reconstruction. Prosthetic rehabilitation also requires the ability to imagine the position and dimension of the nose within the facial proximity. Therefore, the access to nasal data for each
    population are advantageous. The aims were to measure parameters of external nose of a Malay population and to determine the significant difference in nose value parameters between gender and age group. The direct anthropometric measurements were carried out in 86 Malay subjects within the age range of 18 to 55 years old who attended UiTM dental clinic. Nasal landmarks were
    identified, and the nose parameters were measured using digital calliper. The values were expressed as mean, standard deviation and range. Nasal height, width and length of the nasal bridge were higher in male. The intercanthal width and philtrum length were statistically not significant for both genders. There were significant differences in nasal width, philtrum length, intercanthal width and outer intercommisural mouth width between the three age groups. However, the height of the nose, length of the nasal bridge and nasal index between age group were statistically not significant. The male population and the 41-55 years age group have higher nose value parameters. The most common type of nose was platyrrhine: broad. This study also suggested that Malay population have medium broad nose as the nasal index for both genders was ≤ 84.90.
    Matched MeSH terms: Biometry
  19. Fulltext Are Malaysian Type 2 Diabetes patients willing to be trained to speak to their offspring about risk of diabetes and preventive measures?
    Badlishah-Sham SF, Ramli AS, Isa MR, Mohd-Zaki N, Whitford DL
    BMC Fam Pract, 2020 03 11;21(1):50.
    PMID: 32160862 DOI: 10.1186/s12875-020-01121-0
    BACKGROUND: Offspring of type 2 diabetes patients have an absolute risk of 20-40% of developing the condition. Type 2 diabetes patients should be encouraged to speak to their offspring regarding diabetes risk and prevention strategies. The Health Belief Model conceptualises that the higher the perceived risk, the more likely an individual will modify their behaviour. The objectives of this study were to i) determine the distribution of type 2 diabetes patients regarding their willingness to accept training to speak to their offspring, ii) determine the distribution of type 2 diabetes patients regarding their willingness to accept training based on the HBM and iii) to determine the factors associated with their willingness to accept training.

    METHODS: This was a cross-sectional study amongst type 2 diabetes patients attending two primary care clinics in Malaysia. Sociodemographic data and knowledge of diabetes risk factors were collected. The adapted, translated and validated Diabetes Mellitus in the Offspring Questionnaire-Malay version (DMOQ-Malay) was self-administered. Statistical analysis included descriptive statistics, univariate and multiple logistic regression (MLogR).

    RESULTS: A total of 425 participants were recruited. Of these, 61.6% were willing to accept training. In MLogR, six variables were found to be significantly associated with willingness to accept training. These were i) positive family history [Adj. OR 2.06 (95% CI: 1.27, 3.35)], ii) having the correct knowledge that being overweight is a risk factor [Adj. OR 1.49 (95%CI: 1.01, 2.29)], iii) correctly identifying age ≥ 40 years old as a risk factor [Adj. OR 1.88 (95%CI: 1.22, 2.90)], iv) agreeing that speaking to their offspring would help them to prevent type 2 diabetes [Adj. OR 4.34 (95%: 1.07, 17.73)], v) being neutral with the statement 'I do not have much contact with my offspring' [Adj. OR: 0.31 (95% CI: 0.12, 0.810] and vi) being neutral with the statement 'my offspring are not open to advice from me' [Adj. OR: 0.63 (95% CI: 0.31, 0.84].

    CONCLUSION: The majority of type 2 diabetes patients were willing to accept training to speak to their offspring to prevent diabetes. A training module should be designed to enhance their knowledge, attitude and skills to become family health educators.
    Matched MeSH terms: Biometry
  20. Fulltext Assessment of DSM Based on Radiometric Transformation of UAV Data
    Chaudhry MH, Ahmad A, Gulzar Q, Farid MS, Shahabi H, Al-Ansari N
    Sensors (Basel), 2021 Feb 27;21(5).
    PMID: 33673425 DOI: 10.3390/s21051649
    Unmanned Aerial Vehicle (UAV) is one of the latest technologies for high spatial resolution 3D modeling of the Earth. The objectives of this study are to assess low-cost UAV data using image radiometric transformation techniques and investigate its effects on global and local accuracy of the Digital Surface Model (DSM). This research uses UAV Light Detection and Ranging (LIDAR) data from 80 meters and UAV Drone data from 300 and 500 meters flying height. RAW UAV images acquired from 500 meters flying height are radiometrically transformed in Matrix Laboratory (MATLAB). UAV images from 300 meters flying height are processed for the generation of 3D point cloud and DSM in Pix4D Mapper. UAV LIDAR data are used for the acquisition of Ground Control Points (GCP) and accuracy assessment of UAV Image data products. Accuracy of enhanced DSM with DSM generated from 300 meters flight height were analyzed for point cloud number, density and distribution. Root Mean Square Error (RMSE) value of Z is enhanced from ±2.15 meters to 0.11 meters. For local accuracy assessment of DSM, four different types of land covers are statistically compared with UAV LIDAR resulting in compatibility of enhancement technique with UAV LIDAR accuracy.
    Matched MeSH terms: Biometry
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