n. razali, n.a. zainuri, h. othman, z.m. nopiah and n.a.a. bakar.  (2020).  engineering students performance in mathematics through project-based learning.  - universal journal of educational research.  1899-1906. 

ismail khuzainey, mohd nopiah zulkifli, sattar rasul mohamad, pang chau leong.  (2020).  technical competency among vocational teachers in malaysian public skills training institutions: measurement model validation using pls-sem.  - journal of technical education and training.  163-175. 

khuzainey ismail, zulkifli mohd nopiah, mohd sattar rasul.  (2020).  emotional intelligence and work performance among vocational teachers.  - journal of technical education and training.  106-117. 

siti sarah januri, zulkifli mohd nopiah, ahmad kamal ariffin mohd ihsan, nurulkamal masseran, shahrum abdullah.  (2019).  the analysis of fatigue lifetime using markov chain model based on randomization paris law equation.  - international journal of innovative technology and exploring engineering.  282-286. 

khuzainey ismail, zulkifli mohd nopiah, mohamad sattar rasul, pang chau leong.  (2019).  development of competency items for vocational teachers using rasch model analysis.  - journal of engineering science and technology.  51-58. 

rodzidah mohd rodzi, zulkifli mohd nopiah, noor ezlin ahmad basri.  (2019).  waste management risks and opportunities identification in malaysia tvet institution.  - international journal of recent technology and engineering.  1665-1667. 

faridah zulkipli, zulkifli mohd nopiah, noor ezlin ahmad basri, cheng jack kie, khairul irwan khalid.  (2019).  recycle evaluation using system dynamics for solid waste management in malaysia.  - international journal of recent technology and engineering (ijrte).  657-659. 

rodzidah mohd rodzi, zulkifli mohd nopiah, noor ezlin ahmad basri.  (2019).  analysis of solid waste generation and composition in malaysia tvet campus.  - international journal of integrated engineering.  158-170. 

rodzidah mohd rodzi, zulkifli mohd nopiah, noor ezlin ahmad basri.  (2019).  environmental awareness and attitudes towards solid waste management among tvet students in malaysia.  - international journal of innovative technology and exploring engineering.  387-392. 

faridah zulkipli, zulkifli mohd nopiah, noor ezlin ahmad basri, cheng jack kie, muhammad afif zafri khuzairi.  (2018).  prototype pmsp system development for operational level in solid waste management.  - the journal of social sciences research.  . 

m. mahmud, s. s. k. singh, s. abdullah, a. k. ariffin, z. m. nopiah.  (2018).  determining damaging fatigue cycles under influence of random loadings using the root-mean-square level.  - journal of mechanical engineering.  . 

m. f. m. yunoh, s. abdullah, m. h. m. saad, z. m. nopiah, m. z. nuawi, a. ariffin.  (2018).  classification of fatigue damaging segments using artificial neural network.  - journal of mechanical engineering.  . 

faridah zulkipli, zulkifli mohd nopiah, noor ezlin ahmad basri, cheng jack kie.  (2018).  dynamical integrated framework development of solid waste management in malaysia.  - international journal of engineering & technology.  . 

siti sarah januri, zulkifli mohd nopiah, ahmad kamal ariffin mohd ihsan, nurulkamal masseran, shahrum abdullah.  (2018).  the analysis of initial probability distribution in markov chain model for lifetime estimation.  - international journal of integrated engineering.  . 

noraida azura md darom, hawa hishamuddin, rizauddin ramli, zulkifli mat nopiah, ruhul a sarker.  (2018).  an integrated vendor-buyer model subject to supply disruption with transportation cost.  - journal of mechanical engineering.  . 

khuzainey ismail, zulkifli mohd nopiah, & mohamad sattar rasul.  (2018).  challenges faced by vocational teachers in public skills training institutions: a reality in malaysia.  - journal of technical education and training (jtet).  . 

n. lohgheswary, m. h. abdul halim, z. m. nopiah, a. a. aziz, e. zakaria.  (2018).  developing new lab base teaching approach for linear algebra subject in engineering mathematics courses.  - journal of mechanical engineering.  . 

m. f. mod yunoh, s. abdullah, m. h. m. saad, z. m. nopiah, m. z. nuawi, s. s. k. singh.  (2018).  probabilistic-based analysis for damaging features of fatigue strain loadings.  - frattura ed integrita strutturale.  . 

siti sarahjanuri, zulkifli mohd nopiah, ahmad kamal ariffin mohd ihsan, nurulkamal masseran, and shahrum abdullah.  (2018).  initial probability distribution in markov chain model for fatigue crack growth problem.  - international journal of engineering & technology.  . 

faridah zulkipli, zulkifli mohd nopiah, noor ezlin ahamad basri, cheng jack kie, jafri zulkepli and khairul irwan khalid.  (2018).  integrated dynamical model for malaysian solid waste management using system dynamics.  - international journal of engineering & technology.  . 

n. razali, z. m. nopiah and h. othman.  (2018).  comparison of one-step and two-step symmetrization in the variable stepsize setting.  - sains malaysiana.  . 

noraida azura darom, hawa hishamuddin, rizauddin ramli, zulkifli mat nopiah.  (2018).  an inventory model of supply chain disruption recovery with safety stock and carbon emission consideration.  - journal of cleaner production.  . 

m. mahmud, s. abdullah, s. s. k. singh, a. k. ariffin, z. m. nopiah and a. arifin.  (2018).  distribution characterisation of coil spring strain histories using mixed weibull analysis.  - international journal of engineering & technology.  . 

zulkifli m. nopiah, hasan balfaqih and nizaroyani saibani.  (2018).  development of performance measurement framework for supply chain in desalination industry using ahp.  - international journal of engineering & technology.  . 

m. f. m. yunoh, s. abdullah, m. h. m. saad, z. m. nopiah, m. z. nuawi.  (2017).  evaluation of fatigue damage classification based on probabilistic weibull analysis.  - iranian journal of science and technology, transactions of mechanical engineering.  189-195. 

balfaqih, h., nopiah, z.m., al-nory, m.t. and saibani, n.  (2017).  sustainable framework for water desalination supply chain: delphi-ahp technique.  - advanced science letters.  4721-4724. 

hasan balfaqih, malak t. al-nory, zulkifli mohd nopiah , nizaroyani saibani.  (2017).  environmental and economic performance assessment of desalination supply chain.  - desalination.  2-9. 

m. f. m. yunoh, s. abdullah, m. h. m. saad, z. m. nopiah, m. z. nuawi.  (2017).  probability analysis in determining the behaviour of variable amplitude strain signal based on extraction segments.  - latin american journal of solids and structures.  2141-2152. 

m. f. m. yunoh, s. abdullah, m. h. m. saad, z. m. nopiah, m. z. nuawi.  (2017).  k-means clustering analysis and artificial neural network classification of fatigue strain signals.  - journal of the brazilian society of mechanical sciences and engineering.  757-764. 

wan siti adibah wan dahalan, intan nadia ghulam khan & z.m. nopiah.  (2016).  a preliminary study on the legal framework of solid waste management in malaysia.  - the social sciences.  5810-5817. 

normah abdullah, ramin razmi, tan chung chuan, zulkifi mohd nopiah, azah mohamed, mohd zaki nuawi.  (2016).  design and simulation of hierarchical control of two continuous stirred tank heater in series.  - indian journal of science and technology.  1-12. 

kamal, n., rahman, n. n. s. a., husain, h.and nopiah, z. m..  (2016).  the correlation between electrical engineering course performance and mathematics and prerequisite course achievement.  - pertanika journal of social sciences & humanities.  97-110. 

mohammad k. younes, z.m. nopiah, n.e. ahmad basri, h. basri, mohammed f.m. abushammala, mohammed y. younes.  (2016).  landfill area estimation based on integrated waste disposal options and solid waste forecasting using modified anfis model.  - waste management.  3-11. 

senin a., nopiah z.m., ihsan a.k.a.m., abdullah s., wahab d.a., jamaludin m.j., zakaria a..  (2016).  johnson cook constitutive modeling for austenite metal in hot forming process.  - jurnal teknologi.  71-75. 

balfaqih h., nopiah z.m., al-nory m.t., saibani n..  (2016).  performance measurement of water desalination supply chain using balanced scorecard model.  - international journal of engineering and technology.  55-63. 

djamaluddin f., abdullah s., ariffin a.k., nopiah z.m..  (2016).  finite element analysis and crashworthiness optimization of foam-filled double circular under oblique loading.  - latin american journal of solids and structures.  2176-2189. 

wan siti adibah wan dahalan , intan nadia ghulam khan dan zulkifli mohd nopiah.  (2016).  household solid waste recycling : a comparison between malaysia and singapore from the legal perspective..  - the social sciences.  5803-5809. 

zain r.m., ab. rahman m.n., ramli a., nopiah z.m., saibani n..  (2016).  using measures of agreement to evaluate a chronic problem of congestion in the empty container depots.  - international review of management and marketing.  843-850. 

balfaqih h., nopiah z.m., saibani n..  (2016).  a conceptual framework for supply chain performance in desalination industry.  - international journal of industrial engineering and management.  95-101. 

hasan balfaqih, zulkifli mohd. nopiah, nizaroyani saibani, malak t. al-nory.  (2016).  review of supply chain performance measurement systems: 1998–2015.  - computers in industry.  135-150. 

n.lohgheswary, z.m.nopiah, e.zakaria.  (2016).  evaluating the reliability of pre-test differential equations questions using rasch measurement model.  - journal of engineering science and technology.  31-39. 

noorhelyna razali, haliza othman, nuryazmin ahmat zainuri, firdaus mohamad hamzah, izamarlina asshaari, fadiah hirza mohammad ariff, zulkifli mohd nopiah.  (2016).  modern or traditional teaching strategy in learning engineering mathematics course.  - journal of engineering science and technology.  13-20. 

nuryazmin ahmat zainuri, izamarlina asshaari, fadiah hirza mohammad ariff, noorhelyna razali, haliza othman, firdaus mohd hamzah, zulkifli mohd nopiah.  (2016).  item analysis for final exam questions of engineering mathematics course (vector calculus) in ukm.  - journal of engineering science and technology.  53-60. 

norbahiah misran, roszilah hamid, badariah bais et al..  (2016).  pertanika journal of social sciences and humanities.  - pertanika journal of social sciences and humanities.  1-282. 

hasan balfaqih, zulkifli mohd nopiah, al-nory, malak t. al-nory, nizaroyani saibani.  (2016).  performance measurement of water desalination supply chain using balanced scorecard model.  - international journal of engineering and technology.  55-63. 

hasan balfaqih, zulkifli mohd nopiah, nizaroyani saibani.  (2016).  a conceptual framework for supply chain performance in desalination industry.  - international journal of industrial engineering and management.  95-101. 

hasan balfaqih, zulkifli mohd. nopiah, nizaroyani saibani, malak t. al-nory.  (2016).  review of supply chain performance measurement systems : 1998 - 2015.  - computers in industry.  135-150. 

mohammad k. younes, z. m. nopiah, n. e. ahmad basri, h. basri , mohammed f. m. abushammala & k. n. a. maulud.  (2015).  prediction of municipal solid waste generation using nonlinear autoregressive network.  - environmental monitoring and assessment.  1-10. 

mohammad k. younes, n. e. ahmad basri, z. m. nopiah, h. basri, & mohammed f. m. abushammala.  (2015).  use of a combination of mrss-anp for making an innovative landfill siting decision model.  - mathematical problems in engineering.  1-13. 

z. m. nopiah, n. f. a. fuaad, n. m. tawil, f. m. hamzah & h. othman..  (2015).  student achievement at pre-university level: does it influence the achievement at the university?.  - journal of engineering science and technology.  68-76. 

n. kamal, n. arsad, h. husain, z.m. nopiah.  (2015).  the relationships between pre-university education and mathematics achievement with performance in engineering subject.  - journal of engineering science and technology (jestec).  10-17. 

mohd nizam ab rahman, rosmaizura mohd zain, afis mohd alias, zulkifli mohd nopiah.  (2015).  statistical process control: best practices in small and medium enterprises.  - maejo international journal of science and technology.  193-208. 

chalang hama rashed mohammed, sallehuddin mohamed haris, zulkifli mohd nopiah.  (2015).  multiple model p+i with anti-windup control of a nonlinear hydro turbine.  - icic express letters.  1841-1846. 

zulkifli mohd nopiah, ahmad kadri junoh and ahmad kamal ariffin.  (2015).  a novel hybrid fuzzy nonlinear weighted goal programming for optimising interior acoustics level in car cabin.  - journal of vibration and control.  1721-1744. 

m.f.m. yunoh, s. abdullah, m.h.m. saad, z.m. nopiah, m.z. nuawi.  (2015).  fatigue feature extraction analysis based on a k-means clustering approach.  - journal of mechanical engineering and sciences.  1275-1282. 

djamaluddin f., abdullah s., ariffin a.k., nopiah z.m..  (2015).  optimization of foam-filled double circular tubes under axial and oblique impact loading conditions.  - thin-walled structures.  1-11. 

f. djamaluddin, s. abdullah, a.k. arrifin and z.m. nopiah.  (2015).  modeling and optimization of aluminum foam cylindrical double tubes under axial impact.  - journal of mechanical engineering and sciences.  1383-1392. 

h. othman, n. a. ismail, i. asshaari, f. m. hamzah, z. m. nopiah.  (2015).  application of rasch measurement model for reliability measurement instrument in vector calculus course.  - journal of engineering science & technology.  84-90. 

mohammad khairi younes, noor ezlin ahmad basri, zulkifli mohammad nopiah, hassan basri, mohammed f.m. abushammala, khairul nizam abdul maulud.  (2015).  integrating approach to size and site at a sanitary landfill in selangor state, malaysia.  - environmental engineering research.  268-276. 

aghil shavalipour, sallehuddin mohamed haris, zulkifli mohd nopiah.  (2015).  symbolic parametric lqr controller design for an active vehicle suspension system.  - journal of applied sciences.  1127-1132. 

aghil shavalipour, sallehuddin mohd haris, zulkifli mohd nopiah.  (2015).  algebraic h2 optimal control design in an active vehicle suspension application.  - international review on modelling and simulations.  377-385. 

mohammad k. younes, z.m. nopiah, n.e. ahmad basri, h. basri, mohammed f.m. abushammala & maulud k.n.a..  (2015).  solid waste forecasting using modified anfis modeling.  - journal of the air & waste management association.  1229-1238. 

nopiah z.m., junoh a.k., ariffin a.k..  (2015).  vehicle interior noise and vibration level assessment through the data clustering and hybrid classification model.  - applied acoustics.  9-22. 

djamaluddin f., abdullah s., ariffin a.k., nopiah z.m..  (2015).  non-linear finite element analysis of bitubal circular tubes for progressive and bending collapses.  - international journal of mechanical sciences.  228-236. 

m. b. ali, s. abdullah, m. z. nuawi, a. k. ariffin, z. m. nopiah.  (2014).  evaluating instrumented charpy impact strain signals using curve fitting equations.  - journal of central south university.  21(2):600-609. 

m. m. padzi, s. abdullah, m. z. nuawi, s. m. beden, z.m. nopiah.  (2014).  evaluating ultrasound signals of carbon steel fatigue testing using signal analysis approaches.  - journal of central south university.  21(1):232-241. 

yunoh m.f.m., abdullah s., nopiah z.m., nuawi m.z..  (2014).  fatigue time history analysis for determining the strain signal behaviour.  - international journal of vehicle systems modelling and testing.  363-371. 

k. a zakaria, s. abdullah, m. j. ghazali, m. z. nuawi, s.m. beden & z. m. nopiah.  (2014).  fatigue strain signal behaviour and damage assessment of an engine mount bracket.  - journal of scientific & industrial research.  73(2014):112-116. 

nopiah z.m., junoh a.k., ariffin a.k..  (2014).  computational method for predicting the effects of vibrations to acoustical comfort in vehicle cabin.  - international journal of vehicle noise and vibration.  150 - 170. 

m.f.m. yunoh, s. abdullah, m.h.m. saad, z.m. nopiah and m.z. nuawi.  (2014).  fatigue data extraction analysis using daubechies wavelet transform.  - australian journal of basic & applied sciences.  38-40. 

nopiah, z. m., osman, m. h., abdullah, s., baharin, m. n..  (2014).  application of a multi-objective approach and sequential covering algorithm to the fatigue segment classification problem.  - arabian journal for science and engineering.  39(3): 2165-2177. 

zulkifli mohd nopiah, ahmad kadri junoh, ahmad kamal ariffin.  (2013).  formulation of weighted goal programming using the data analysis approach for optimising vehicle acoustics levels.  - international journal of acoustics and vibration.  18(3):124-133. 

mohammad k.younes, z.m.nopiah, b. nadi, n.e.ahmad basri, hassan basri, mohammed f.m. abushammala and khaldoun shatanawi.  (2013).  investigation of solid waste characterization, composition and generation using management of environmental systems in zarqa, jordan.  - asian journal of chemistry.  25(17):9523-9526. 

zulkifli mohd nopiah, ahmad kadri junoh, ahmad kamal ariffin.  (2013).  optimisation of acoustical comfort in vehicle cabin using goal programming.  - international journal of vehicle noise and vibration.  9(3):194-215. 

chalang hama rashed mohammed, sallehuddin mohamed haris, zulkifli mohd nopiah.  (2013).  multiple model adaptive control of a hydro turbine plant - performance of h-infinity, lqg and pi controllers.  - international journal of advanced mechatronic systems.  5(1):47-58. 

zulkifli mohd nopiah, ahmad kadri junoh and ahmad kamal ariffin.  (2013).  noise annoyance fuzzy index in passenger car cabin.  - international journal vehicle noise and vibration.  216-233. 

m.f.m. yunoh, s. abdullah, z.m. nopiah & m.z. nuawi.  (2013).  a review of localised time-frequency features classification associated to fatigue data analysis.  - international review of mechanical engineering.  960-976. 

s. abdullah, c.k.e. nizwan, m. f. m. yunoh, m. z. nuawi and z. m. nopiah.  (2013).  fatigue features extraction of road load time data using the s-transform.  - international journal of automotive technology.  14(5):805-815. 

m. h. osman, z. m. nopiah, s. abdullah, a. lennie.  (2013).  self-tuning varri method in preparing fatigue segment.  - jurnal teknologi (sciences and engineering).  63(2):45-50. 

ahmad mohd yusof, maznah banu mohamed habiboo raman, zulkifli mohd nopiah.  (2013).  modeling of the malaysian crude oil system.  - jurnal ekonomi malaysia.  47(1):125-130. 

n.m. tawil , a. zaharim , i. shaari , n.a. ismail , z.m. nopiah and h. othman.  (2013).  e-learnig as an alternative mode for learning vector calculus for ukm engineering students.  - international journal of soft computing.  8(1):1-7. 

mohammad, m., abdullah, s., jamaludin, n., innayatullah, o., nopiah, z.m..  (2013).  fatigue failure assessment of metallic specimens using the acoustic emission technique.  - materials testing.  55(4):310-318. 

norngainy mohd. tawil, nur arzilah ismail, izamarlina asshaari, haliza osman, zulkifli mohd nopiah, azami zaharim.  (2012).  learning process in mathematics and statistics courses towards engineering students: e-learning or traditional method?.  - asian social science.  8(16):128-133. 

zulkifli mohd nopiah, suaidah rosli, mohd nor baharin, haliza othman, arzilah ismail.  (2012).  evaluation of pre-assessment method on improving students performance in complex analysis course.  - asian social science.  134-139. 

n.k. khamis, m.z. nuawi, s. abdullah, z.m. nopiah, l. abdullah.  (2012).  signal analysis software as an educational tool for engine diagnostic system.  - international review of mechanical engineering.  6(3):666-670. 

z. m. nopiah, a. lennie, s. abdullah, m. z. nuawi, a. z. nuryazmin, m. n. baharin.  (2012).  effect of fatigue strain data behaviour using cycle counting method.  - international review of mechanical engineering.  6(3):644-648. 

mohd amin at-tasneem, sallehuddin mohamed haris, zulkifli mohd nopiah.  (2012).  a computing capability test for a switched system control design using the haris-rogers method.  - journal of zhejiang university - science c.  13(10):781-792. 

nopiah, z.m., osman, m.h., abdullah, s., kamarudin, m.n.b.c., asshari, i..  (2012).  satisfying statistical constraints in preparing edited variable amplitude loading history using genetic algorithm.  - modern applied science.  6(9):68-75. 

nopiah z.m., jamalluddin m.h., haliza othman n.a.i., asshaari i., osman m.h..  (2012).  reliability analisis of examination questions in a mathematics course using rasch measurement model.  - sains malaysiana.  41(9):1171-1176. 

m marsdek, a mohamed, z m norpiah.  (2011).  risk of static security assessment of a power system using non-sequential monte carlo simulation.  - journal of applied sciences.  11(2):300-307. 

s. abdullah, t. e. putra, m. z. nuawi and z. m. nopiah.  (2011).  the use of morlet wavelet coefficients for identifying fatigue damage features.  - pertanika journal of science & technology.  19(5):107-114. 

putra t.e., abdullah s., nuawi m.z., nopiah z.m., abdullah l., arifin a..  (2011).  extracted fatigue damaging events using the morlet wavelet-based algorithm.  - transactions hong kong institution of engineers.  18(1):22-29. 

marayati marsadek, azah mohamed and zulkifli mohd. nopiah.  (2011).  assessment of the risk of voltage collapse in a power system using intelligent techniques.  - australian journal of basic and applied sciences.  5(6):1167-1179. 

ahmad mohd yusof, zulkifli mohd nopiah , maznah banu habiboo raman.  (2011).  pemodelan sistem tenaga fosil malaysia: satu pendekatan pemprograman linear.  - jurnal ekonomi malaysia.  45(2011):3-9. 

z. m. nopiah, m. n. baharin, s. abdullah, m. i. khairir and a. ariffin.  (2010).  running damage extraction technique for identifying fatigue damaging events.  - wseas transactions on mathematics.  9(5):324-333. 

a. lennie, s. abdullah, z.m. nopiah and m.n. baharin.  (2010).  behavioural investigation of fatigue time series using the statistical approach.  - journal of applied sciences.  10 (16):1714-1722. 

marayati marsadek, azah mohamed, zulkifli mohd nopiah.  (2010).  assessment and classification of line overload risk in power systems considering different types of severity functions.  - wseas transactions on power systems.  5(3):182-191. 

t. e. putra, s. abdullah, m. z. nuawi and z. m. nopiah.  (2010).  wavelet coefficient extraction algorithm for extracting fatigue features in variable amplitude fatigue loading.  - journal of applied sciences.  10(4):277-283. 

nopiah z.m., baharin m.n., abdullah s., khairir m.i..  (2010).  the detection of abrupt changes for variable amplitude fatigue loading by using running damage extraction method.  - journal of applied sciences.  10(7):544-550. 

s. abdullah, t. e. putra, m. z. nuawi, z. m. nopiah, a. arifin and l. abdullah.  (2010).  extracting fatigue damage features using stft and cwt.  - wseas transactions on signal processing.  6(3):91-100. 

s. abdullah, n. ismail, m. z. nuawi, m. z. nopiah & a. ariffin.  (2010).  using the hybrid kurtosis-based method to correlate strain and vibration signals.  - wseas transactions on signal processing.  6(3):79-90. 

s. abdullah, t. e. putra, m. z. nuawi, z. m. nopiah, a. arifin and l. abdullah.  (2010).  the morlet wavelet analysis for fatigue feature clustering.  - wseas transactions on mathematics.  9(5):345-354. 

z. m. nopiah, m. i. khairir, s. abdullah, m. n. baharin, and a. arifin.  (2010).  time complexity estimation and optimisation of the genetic algorithm clustering method.  - wseas transactions on mathematics.  9(5):334-344. 

nopiah z.m., zainuri n.a., asshaari i., othman h., abdullah s..  (2009).  improving generic skills among engineering students through problem based learning in statistics engineering course.  - european journal of scientific research.  33(2):270-278. 

zainuri n.a., nopiah z.m., asshaari i., yaacob n.r..  (2009).  the level of mathematical knowledge of first year engineering students at the faculty of engineering and build environment, universiti kebangsaan malaysia.  - european journal of scientific research.  32(2):201-207. 

mohammad reza faraji zonooz, z.m. nopiah, ahmad mohd.yusof, kamaruzzaman sopian.  (2009).  a review of markal energy modeling.  - european journal of scientific research.  26(3):352-361. 

h. abdullah, j. jurait, a. lennie, z.m. nopiah, i. ahmad.  (2009).  simulation of fabrication process vdmosfet transistor using silvaco software.  - european journal of scientific research.  29(4):461-470. 

ab rahman m.n., zain r.m., ghani j.a., nopiah z.m., ismail a.r., rahman s.a..  (2009).  barriers to implementing an online spc system in malaysian automotive manufacturing companies.  - european journal of scientific research.  30(2):315-325. 

azami zaharim, shahrum abdullah, mohammad darahim ibrahim, zulkifli mohd nopiah.  (2009).  genetic algorithm in time series fatigue analysis.  - european journal of scientific research.  28(1):68-75. 

mohd nizam ab rahman, rosmaizura mohd zain, zulkifli mohd nopiah, jaharah a ghani, baba md deros, nurhamidi mohamad, ahmad rasdan ismail.  (2009).  the implementation of spc in malaysian manufacturing companies.  - european journal of scientific research.  26(3):453-464. 

zulkifli mohd nopiah, muhammad ihsan khairir, shahrum abdullah, che ku eddy nizwan, mohd noor baharin.  (2009).  peak-valley segmentation algorithm for kurtosis analysis and classification of fatigue time series data.  - european journal of scientific research.  29(1):113-125. 

s. abdullah, m. d. ibrahim, a. zaharim and z. mohd nopiah.  (2008).  statistical analysis of a nonstationary fatigue data using the arima approach..  - wseas transactions on mathematics.  7(2):59-66. 

kamaruzzaman sopian, azami zaharim, yusoff ali, zulkifli mohd nopiah, juhari ab. razak, nor salim muhammad.  (2008).  optimal operational strategy for hybrid renewable energy system using genetic algorithms.  - wseas transactions on mathematics.  7(4):130-140. 

s. abdullah, m.d. ibrahim, z. mohd nopiah and a. zaharim.  (2008).  analysis of a variable amplitude fatigue loading based on the quality statistical approach.  - journal of applied sciences.  8(8):1590-1593.