bluuebunny/crossref_metadata_2025 huggingface dataset:
Mekanisme Penyerakan Zarah dalam Pemprosesan Berkoloid Oksida Seramik (Al2O3–ZrO2–MgO) Menggunakan DAXAD 19TM
Authors: Muchtar Andanastuti , Osman Husna , Tasirin Siti Masrinda
Published: January 2013

Dalam kajian ini, kesan agen penyerak komersil Daxad 19TM terhadap sifat reologi dan pemadatan ampaian seramik alumina–zirkonia–magnesia telah dikenalpasti. Komposisi serbuk yang digunakan adalah berasaskan kepada 85% isipadu alumina (ketulenan 99.99%) dan 15% isipadu zirkonia (ketulenan 99.5%). Penambahan serbuk magnesia (ketulenan 99.99%) pula adalah pada kuantiti yang kecil iaitu 0.25% berat daripada jumlah berat alumina dan zirkonia. Untuk mengelakkan masalah pengaglomeratan zarah, teknik pemprosesan berkoloid dipilih dalam pembikinan sampel. Untuk ini, Daxad 19TM dicampurkan ke dalam ampaian dengan tujuan untuk menyerakkan zarah. Kuantiti penyerak Daxad 19TM yang digunakan ialah dalam julat 0 hingga 0.60% berat. Kajian reologi menggunakan alat meter kelikatan dilakukan bagi mengenalpasti kuantiti Daxad 19TM yang optimum bagi penyerakan zarah. Setelah itu, sampel anum dihasilkan melalui proses penuangan buburan. Sampel diprasinter pada suhu 800°C selama 45 minit sebelum disinter pada suhu 1600°C selama 2 jam. Kajian ini secara keseluruhannya telah mendapati julat penggunaan optimum penyerak Daxad 19TM di dalam ampaian seramik yang dihasilkan adalah di antara 0.4875% hingga 0.525% berat daripada berat keseluruhan serbuk seramik yang digunakan. Kertas ini juga membincangkan mekanisme penyerakan zarah dalam ampaian alumina–zirkonia–magnesia melalui penggunaan Daxad 19TM.

Kata kunci: Penyerakan zarah, reologi, ketumpatan, alumina, zirkonia

The effects of a commercially available dispersant, Daxad 19TM, on the rheology and densification characteristics of alumina–zirconia–magnesia suspensions have been investigated. The compositions of powders used are based on 85% volume of alumina (99.99% purity) and 15% volume of zirconia (99.95% purity). The addition of a small amount of magnesia is based on 0.25% weight of the combined weight of both alumina and zirconia powders. In an effort to avoid the agglomeration of particles, colloidal processing technique is used to produce samples. For this, Daxad 19TM is added to the suspensions to disperse the oxide particles. The Daxad 19TM addition is within the range of 0–0.60% weight. Rheological investigation is carried out using a rotational viscometer to determine the optimum quantity of dispersant (Daxad 19TM) that can best disperse the powders. Green samples are then prepared using the slip casting process. The sample are pre–sintered at a constant temperature of 800°C for 45 minutes before being sintered at 1600°C with a holding time of 2 hours. The optimum concentration of Daxad 19TM for a successful dispersion of powders is found to be between 0.4875–0.525% weight of the combined weight of alumina and zirconia powders. This paper also discusses the mechanisms for particle dispersion in alumina–zirconia–magnesia suspensions.

Key words: Particle dispersion, rheology, density, alumina, zirconia
The Effect of Varying Process Parameters on the Microhardness and Microstructure of Cu–Steel and Al–Al2O3 Friction Joints
Authors: Yeoh Cheow Keat , Jamaludin Shamsul Baharin , Ahmad Zainal Ariffin
Published: January 2013

Perbezaan dalam kelajuan putaran serta tekanan tempaan semasa kimpalan geseran mempengaruhi sifat–sifat sambungan yang terhasil. Sambungan geseran tembaga C11000 dan keluli lembut AISI 1030 (Cu–keluli) serta aluminium 6061 dan alumina (Al–Al2O3) disediakan dengan menggunakan mesin kimpalan geseran pacuan terus. Kekerasan mikro merentasi sambungan menunjukkan kekerasan tembaga yang lebih rendah dan kekerasan keluli yang lebih tinggi berbanding kekerasan bahan induk apabila kelajuan putaran 900 rpm digunakan. Pada kelajuan putaran 1800 rpm, keputusan yang sebaliknya diperolehi. Ubahbentuk ira terhad pada kawasan < 0.5 mm daripada garis sambungan. Kekerasan mikro merentasi sambungan untuk sambungan Al–Al2O3 tidak dapat memberi keputusan yang jelas disebabkan kesan liang terhadap kekerasan mikro yang diukur. Keputusan ini menunjukkan ujian kekerasan mikro tidak sesuai untuk pencirian sambungan Al–Al2O3.

Kata kunci: Kimpalan geseran, tembaga, keluli, aluminium, alumina, kekerasan mikro

Varying the rotational speed and forging pressures during friction welding affect the joint properties differently. C11000 copper to AISI 1030 mild steel (Cu–steel), and 6061 aluminum to alumina (Al–Al2O3) friction joints were fabricated on a direct drive friction welding machine. Microhardness traverses across the joint showed lower copper hardness, and higher steel hardness compared to the parent material, when 900 rpm rotational speed as used. This trend is reversed when the rotational speed is increased to 1800 rpm. Grain structure distortation was confined to an area of < 0.5 mm from the joint interface. Microhardness traverses across the Al–Al2O3 joint could not yield much information due to the influence of porosity on the microhardness readings. The results indicate that microhardness test is not appropriate for the characterization of Al–Al2O3 friction joints.

Key words: Friction welding, copper, steel, aluminum, alumina, microhardness
Finite Element Modelling of Structural Clay Brick Masonry Subjected to Axial Compression
Authors: Bakhteri Jahangir , Makhtar Ahmad Mahir , Sambasivam Shamala
Published: January 2013

Kertas kerja ini membentangkan pembuktian berangka hasil dari ujikaji kesan ketebalan sambungan lepa ke atas sifat kekuatan mampatan bagi prisma bata–lepa yang berbeban paksi. Pemodelan mikro tiga dimensi bagi prisma tersebut dibuat dengan dua kaedah: yang pertama, model tersebut dianggap telah dibina dengan bahan sejenis; yang kedua, model dilihat sebagai bahan komposit yang dibina dari lepa dan bata. Kaedah yang kedua membuat anggapan bahawa prisma terdiri daripada bahan komposit dan memberikan ramalan yang lebih tepat bagi pengagihan tegasan dalam prisma dan ramalan kegagalan bahan juga menunjukkan kesesuaian yang baik dengan keputusan ujikaji. Ini menunjukkan bahawa anggapan kaedah pemodelan bahan komposit lebih baik daripada anggapan bahan sejenis. Dalam kajian ini, suatu faktor penggandaan kekuatan telah dicadangkan untuk tujuan reka bentuk yang boleh digunakan untuk menilai keputusan ujikaji kekuatan mampatan batu bata dari keputusan analisis unsur terhingga.

Kata kunci: Pertukangan bata, kesejenisan, komposit, tegasan, keterikan

This paper presents the numerical verifications of the experimental investigation on the effect of mortar joint thickness on compressive strength characteristics of axially loaded brick–mortar prisms. The three dimensional micro modeling of the prisms was based on two approaches: firstly, models were assumed to be made of homogeneous material; the second approach envisaged the models as composite material made of brick and mortar. The later modeling approach, which assumed the prism to be made of composite material, gave more accurate prediction of the stress distribution in the prisms, and also the failure loads predictions were in good agreement with the experimental results, suggesting that this modeling approach with composite material assumption is more appropriate than the homogenous material assumption. In the present work, a strength magnification factor has also been proposed for the design purposes, which can be used to assess the experimental compressive strength of the brick masonry from its finite element analysis results.

Key words: Masonry, homogenization, composite, stress, strain
A Visual Tool for Determining the Maximum Independant Set of a Graph Using the Polynomial Formulation Method
Authors: Fong Wan Heng , Salleh Shaharuddin
Published: January 2013

Set tak bersandar maksimum merupakan satu masalah prototaip dalam teori graf yang meliputi banyak aplikasi dalam sains dan kejuruteraan. Dalam kertas ini, kami mengkaji masalah menentukan set tak bersandar maksimum bagi graf G (V, E) peringkat n menggunakan kaedah huraian polinomial. Kaedah ini menggunakan jiran nod–nod peringkat pertama dan kedua bagi menentukan sama ada nod–nod tersebut suatu set tak bersandar maksimum. Ia meliputi pengmaksimuman polinomial n pembolehubah, di mana n ialah jumlah nod dalam G. Seterusnya, suatu perisian berbentuk penglihatan bagi menyelesai masalah pencarian set tak bersandar maksimum menggunakan Visual C++ dicadangkan dalam kertas ini.

Kata kunci: Set tak bersandar, huraian polinomial, jiran peringkat kedua.

Maximum independent set is a prototype problem in a graph theory that has many applications in engineering and science. In this paper, we study the problem of determining the largest number of maximum independent sets of a graph G (V, E) of order n using polynomial formulations. This method uses the first and second order neighbourhoods of nodes to determine whether a node is in the maximum independent set. This involves the maximization of an n–variable polynomial, where n is the number of nodes in G. Finally, we present a visual tool developed using the Visual C++ programming language for solving the maximum independent set problem.

Key words: Independent set, polynomial formulation, second-order neighbourhood
Ciri–ciri Temporal dalam Sistem Capaian Berita
Authors: Hj. Ali Noraida , Abdul Jalil Masita , Che Mat Noor Azliza
Published: January 2013

Kertas kerja ini memfokus kepada penyelidikan terhadap konsep penggunaan temporal dalam pengarkiban berita. Ia meliputi perwakilan data temporal menggunakan teknik setem masa (timestamp) dan capaian maklumat menggunakan teknik pengindeksan bagi pengurusan data sejarah berita. Temporal mengandungi empat ciri yang utama iaitu tajuk berita, kategori berita, status masa dan tahun (era). Status masa dan tahun (era) melibatkan logik temporal bagi proses capaian berita. Logik temporal membincangkan mod operasi masa seperti sebelum, selepas, antara, semenjak dan sehingga. Oleh itu, gabungan antara data sejarah berita dan enjin temporal akan menjadikan proses capaian berita lebih mudah, cepat dan tepat. Untuk merealisasikan konsep ini, satu model iaitu Sistem Capaian Berita Bertemporal telah dibangunkan. Kertas kerja ini akan membincangkan bagaimana konsep temporal diterapkan ke dalam sistem ini.

Kata kunci: Perwakilan masa, setem masa, hubungan aljabar, perwakilan temporal

This paper focuses on the research on the usage of temporal concept in News Archiving. It covers temporal data representation using “timestamp” technique, and indexed–based information retrieval technique in managing news archive data. Temporal classification contains four main characteristics such as title of news, time status, news category, and the years (era). Time status and year (era) criteria involve temporal logic for news retrieval process. Temporal logic discusses the operation modes between historical data and temporal engine will make retrieving news for references easier, more efficient, and accurate. To realize this research, one model called the Temporal Based Archiving News Retrieve System was developed. This paper will discuss how temporal concept was applied in this system.

Key words: Time representation, timestamp, algebra relationship, temporal representation
Fingerprint Recognition in Wavelet Domain
Authors: Wan Adnan Wan Azizun , Lim Tze Siang , Hitam Salasiah
Published: January 2013

Teknik cetak ibujari merupakan satu daripada teknologi biometrik yang paling boleh diharapkan. Beberapa pendekatan terhadap pemadanan ibujari secara automatik telah dicadangkan dalam saranan. Dalam pengecaman ibujari, pra–prosesan seperti pelicin, binarization dan thinning diperlukan. Kemudian, ciri–ciri cetak ibujari yang terperinci diambil berdasarkan algoritma pengecaman cetak ibujari (seperti dengan menggunakan Fast Fourier Transform (FFT)) mungkin memerlukan teknik–teknik pengkomputeran yang banyak sehingga menjadikannya tidak praktikal. Algoritma berdasarkan wavelet mungkin merupakan kunci untuk membina sistem pengecaman cetak ibujari kos rendah yang boleh dioperasi dalam sistem komputer bermodul kecil. Di sini, satu sistem pengecaman cetak ibujari yang boleh menjalankan pemadanan cetak ibujari berdasarkan kepada ciri–ciri yang diperolehi daripada domain jelmaan wavelet diperkenalkan. Kajian ini adalah berdasarkan kepada perisian MATLAB dan aplikasinya dalam toolbox seperti Wavelet and Image Processing Toolbox.

Kata kunci: Biometrik, wavelet, cetaksekuriti, pengecaman cetak ibujari

Fingerprint technique is one of the most reliable biometric technologies. In the fingerprint recognition, pre-processing such as smoothing, binarization, and thinning are needed. Then, fingerprint minutia feature is extracted. Some fingerprint identification algorithm (such as using Fast Fourier Transform, (FFT)) may require so much computation as to be impractical. Wavelet based algorithm may be the key to making a low cost fingerprint identification system that would operate on a small computer. We present a fingerprint recognition system that can match the fingerprint images based on features extracted in the wavelet transform domain. This study is implemented based on MATLAB Software and their toolbox applications, such as Wavelet and Image Processing Toolbox.

Key words: Biometrics, wavelet, security, fingerprint recognition
Electrostatic Sensor for Real–Time Mass Flow Rate Measurement of Particle Conveying in Pneumatic Pipeline
Authors: Rahmat Mohd. Fua’ad , Yaw Wee Lee
Published: January 2013

This paper discussed the electrostatic sensors that have been constructed for real–time mass flow rate measurement of particle conveying in a Pneumatic pipeline. Many industrial processes require continuous, smooth, and consistent delivery of solids materials with a high accuracy of controlled flow rate. This requirement can only be achieved by installing a proper measurement system. Electrostatic sensor offers the most inexpensive and simplest means of measuring solids flows in pipes.

Key words: Electrostatic sensor, cross-correlation, peripheral velocity
Membrane Ultrafiltration of Treated Palm Oil Mill Effluent (POME)
Authors: Nik Sulaiman Nik Meriam , Chea Kin Ling
Published: January 2013

Industri minyak sawit mempunyai impak yang besar ke atas alam sekitar. Efluen kilang minyak sawit (dikenali juga sebagai palm oil mill effluent, POME) merupakan buangan cecair yang terdiri daripada sebatian organik yang berasal daripada bahan bolehurai dan sedia direput oleh miroorganisma aerobik dan juga anarobik. Teknologi rawatan POME masa kini banyak bertumpu kepada kaedah biologis. Proses–proses ini memerlukan keluasan tanah yang besar dan tidak menjamin pencapaian had discas yang dibenarkan[1]. Kertas ini menghuraikan satu kajian mengenai potensi kegunaan teknologi membran untuk merawat POME dari kolam discas terakhir. Bahagian pertama kajian ini meneliti ciri–ciri beberapa kolam yang terdapat di loji rawatan air sisa POME yang sedia ada. Kajian membran pula melibatkan penggunaan membran gentian kosong dengan MWCO berjulat 30K hingga 100K. Data yang diperolehi menunjukkan bahawa membran yang mempunyai MWCO 100K menghasilkan fluks yang lebih tinggi daripada membran MWCO 30K, tetapi membran MWCO 30K memberi permeat yang kualitinya lebih baik. Kualiti permeat hasil daripada membran di atas berjaya menurunkan COD, SS, TKN dan nitrogen–amonia masing–masing sebanyak 97.66%, 98%, 53.85% dan 61.91%. Tetapi pemindahan warna memerlukan rawatan tambahan.

Kata kunci: Membran, penurasan-ultra, POME, rawatan sisa

The palm oil industry has a significant impact on the environment. Palm oil mill effluent (POME), which is the liquid discharge, comprises of mainly organic compounds originating from biodegradable materials and is readily decomposed by anaerobic, and aerobic microorganisms. The current treatment technology of POME is largely biological in nature. These processes require large acreage of land and do not always achieve the discharge limits [1]. This paper describes a study on the potential use of membrane technology to treat POME from the final discharge pond. The first part of the study investigated the establishment of characteristics of the various ponds within the current POME wastewater treatment plant. The membrane study essentially used hollow fiber membrane of MWCO ranging from 30 to 100K. The results showed that the hollow fiber membrane with MWCO 100K gave higher fluxes compared to the MWCO 30K, however, the latter membrane gave better quality permeate. The quality of permeate achieved from the membrane with MWCO 30K gave reductions in COD, SS, TKN and ammoniacal–N of 97.66 %, 98 %, 53.85 % and 61.91 % respectively. However, color removal may require further treatment.

Key words: Membrane, ultrfiltration, POME, waste treatment
Persepsi Guru Terhadap Kepimpinan Pengetua: Implikasi dalam Pengurusan Sekolah Bestari
Authors: Teng Lung Kiu , Lope Pihie Zaidatol Akmaliah
Published: January 2013

Tinjauan yang dilakukan adalah untuk menentukan persepsi guru terhadap kepemimpinan pengetua dalam teknologi pengajaran. Tinjauan ini melibatkan 129 orang guru sekolah menengah: 66 orang daripada sekolah bestari dan 63 orang daripada sekolah biasa. Kajian ini mengukur tahap kepemimpinan moral pengetua sekolah menengah dan perbezaan persepsi guru terhadap tahap kepemimpinan moral pengetua di antara sekolah bestari dan sekolah biasa. Kesan kepemimpinan moral pengetua dalam teknologi pengajaran terhadap tahap disiplin pelajar, motivasi pelajar dan komitmen guru juga diselidik. Fokus perbincangan dan implikasi kajian adalah tertumpu kepada peningkatan keberkesanan pengurusan dan kepemimpinan pengetua sekolah menengah, terutama sekali dalam teknologi pengajaran.

Kata kunci: Kepemimpinan moral, pengetua, sekolah bestari, teknologi pengajaran

A survey was conducted to determine the perceptions of teachers regarding principals’ leadership in instructional technology. The survey involved 129 secondary school teachers: 66 teachers from smart schools and 63 teachers from ordinary schools. This study examined the level of moral leadership practiced by principals in secondary schools and the differences regarding perceptions of moral leadership between smart school and ordinary school teachers. The effects of moral leadership in leadership in instructional technology on students’ discipline, motivation and teachers’ commitment were also explored. Discussions and implications of the study focus on enhancing the effectiveness of management and leadership for secondary school principals, especially in instructional technology.

Key words: Moral leadership, principal, smart school, instructional technology
Faktor–faktor Gaya Pembuatan Keputusan dalam Pembelian Barangan di Kalangan Pengguna
Authors: Panatik @ Abdul Rahman Siti Aisyah
Published: January 2013

Kajian ini bertujuan untuk melihat faktor–faktor yang mempengaruhi gaya pembuatan keputusan serta perbezaan gaya pembuatan keputusan pengguna dalam membeli sesuatu barangan berdasarkan jantina dan etnik. Terdapat lapan faktor utama yang dikaji iaitu faktor kekeliruan terhadap pilihan yang banyak, tabiat setia kepada jenama, gerak hati, kesedaran kepada fesyen terkini, kesempurnaan kualiti, kesedaran kepada harga, rekreasi, dan kesedaran kepada jenama. Kajian deskriptif ini berdasarkan kaedah tinjauan dengan menggunakan 480 orang pengguna yang membeli–belah di tiga pasaraya terbesar di Johor Bahru (Pasaraya Giant di Plentong dan Tampoi serta Carefour). Dapatan kajian menunjukkan bahawa faktor kesempurnaan merupakan faktor yang paling tinggi mempengaruhi gaya pembuatan keputusan pembelian barangan di kalangan pengguna. Manakala tidak terdapat perbezaan yang signifikan dalam gaya pembuatan keputusan pengguna berdasarkan jantina. Kajian ini juga menunjukkan terdapat perbezaan signifikan gaya pembuatan keputusan dalam pembelian barangan berdasarkan etnik Melayu, Cina dan India.

Kata kunci: Gaya pembuatan keputusan, tingkah laku pengguna, pengguna

The purpose of this study is to determine the factors that influence decision–making style among consumers as well as to identify consumers’ decision–making style differences based on gender and ethnics. Eight factors which influence decision making style among consumers were investigated such as confusion caused by too many choices, loyalty to brand, impulsiveness, novelty fashion consciousness, perfect quality, price conscious, recreational and brand conciousness. This descriptive study used a survey method which involved 480 consumers of three supermarkets in Johor Bahru (Giant at Plentong and Tampoi, and Carrefour). Results indicated that the perfect quality factor was the dominant influence on decision–making styles among respondents and that there is no difference of decision–making style based on gender. However, there is a significant difference of decision–making styles based on Malay, Chinese, and Indian ethnicity.

Key words: Decision-making style, consumer behavior, consumer
Estimating a Logistic Weibull Mixture Models with Long–Term Survivors
Authors: Abu Bakar Mohd. Rizam , Daud Isa , Ibrahim Noor Akma , Rahmatina Desi
Published: January 2013

Model gabungan mempostulatkan sebuah populasi yang terdiri daripada dua jenis individu iaitu peka dan kebal. Individu yang peka merupakan individu yang berisiko mengalami peristiwa terhadap kajian yang dibuat. Manakala individu yang kebal adalah individu yang tidak berisiko mengalami peristiwa tersebut. Kertas kerja ini memfokuskan kepada kovariat pada individu seperti umur, pembedahan dan pemindahan yang dihubungkan dengan kebarangkalian wujudnya kebal dalam sebuah model logistik Weibull dan menghuraikan kesan pemindahan jantung terhadap masa hayat seterusnya.

Kata kunci: Model gabungan, model logistik Weibull mudah, model Weibull belahan, model logistik Weibull belahan

The mixture model postulates a mixed population with two types of individuals, the susceptible and long–term survivors. The susceptibles are at the risk of developing the event under consideration. However, the long–term survivors or immune individuals will never experience the event. This paper focuses on the covariates associated with individuals such as age, surgery and transplant related to the probability of being immune in a logistic Weibull model and to evaluate the effect of heart transplantation on subsequent survival.

Key words: Mixture model, simple logistic Weibull model, split Weibull model, split logistic Weibull model
Estimation of p–Adic Sizes of Common Zeroes of Partial Derivative Polynomials Associated with a Quintic Form
Authors: Sapar S.H. , Mohd. Atan K. A.
Published: January 2013

Katakan x = {xi, x2,...,xn} vektor dalam ruang Zn dengan Z menandakan gelanggang integer dan q integer positif, f polinomial dalam x dengan pekali dalam Z. Hasil tambah eksponen yang disekutukan dengan f ditakrifkan sebagai S (f;q) = exp (2πif (x)/ q) yang dinilaikan bagi semua nilai x di dalam reja lengkap modulo q. Nilai S(f;q) adalah bersandar kepada penganggaran bilangan unsur |V|, yang terdapat dalam set V = {x mod q | fx = 0 mod q} dengan fx menandakan polinomial-polinomial terbitan separa f terhadap x. Untuk menentukan kekardinalan bagi V, maklumat mengenai saiz p-adic pensifar sepunya perlu diperolehi. Makalah ini membincangkan suatu kaedah penentuan saiz p-adic bagi komponen (ξ,η) pensifar sepunya pembezaan separa f(x,y) dalam Zp[x, y] berdarjah lima berasaskan teknik polihedron Newton yang disekutukan dengan polinomial terbabit. Polinomial berdarjah lima yang dipertimbangkan berbentuk f(x,y) = ax5 + bx4y + cx3y2 + dx2y3 + exy4 + my5 + nx + ty + k.

Kata kunci: Hasil tambah eksponen, kekardinalan, saiz p–adic, polihedron Newton

Let x = {xi, x2,...,xn} be a vector in a space Zn with Z ring of integers and let q be a positive integer, f a polynomial in x with coefficients in Z. The exponential sum associated with f is defined as S (f;q) = exp (2πif (x)/ q) where the sum is taken over a complete set of residues modulo q. The value of S (f;q) has been shown to depend on the estimate of the cardinality | V |, the number of elements contained in the set V = {x mod q | fx = 0 mod q} where fx is the partial derivatives of f with respect to x. To determine the cardinality of V, the information on the p-adic sizes of common zeros of the partial derivatives polynomials need to be obtained. This paper discusses a method of determining the p-adic sizes of the components of (ξ,η) a common root of partial derivative polynomials of f(x, y) in Zp[x, y] of degree five based on the p-adic Newton polyhedron technique associated with the polynomial. The quintic polynomial is of the form f(x,y) = ax5 + bx4y + cx3y2 + dx2y3 + exy4 + my5 + nx + ty + k.

Key words: Exponential sums, cardinality, p–adic sizes, Newton polyhedron
Fire–Flame Imaging Using Electrical Capacitance Tomography
Authors: Abdul Rahim Ruzairi , Chan Kok Seong , Ibrahim Sallehudin , Sulaiman Shaharum , Abdul Manaf Mohamad Shukri
Published: January 2013

Ciri–ciri sifat pengukuran tomografik yang khusus telah terbukti dengan keupayaannya untuk memisit keadaan dinamik suatu proses dalam satu unit pengoperasian seperti dalam kebuk atau alat pengangkut tanpa memberi sebarang gangguan kepada proses tersebut. Proses Tomografi Kapasitan (Electrical Capacitance Tomography–ECT) merupakan teknik tidak intrusif untuk mengetahui taburan kandungan dalam paip dengan mengkaji perubahan ketelusan dielektrik bagi bahan yang terkandung dalam paip. Satu pengesan ECT 8 elektrod dengan pengaturcaraannya dalam Microsoft Visual Basic 6.0 telah dibinakan untuk menunjukkan paparan pengguna. Sistem ini berupaya mengetahui pembahagian api yang terbakar dalam sesuatu perkakas. Data daripada sistem perkakas akan diperolehi melalui satu unit pengawal dan dimasukkan dalam komputer untuk mendapatkan gambaran keratan rentas pembakaran api. Algoritma pembinaan semula imej (Image Reconstruction Algorithm) yang digunakan dalam projek ini adalah Unjuran Belakang Linear (Linear Back Projection LBP) yang konvensional tetapi efektif.

Kata kunci: Proses Tomografi Kapasitan, pembahagian api yang terbakar, Unjuran Belakang Linear, tidak intrusif, Visual Basic

The specific characteristic of tomographic measurement is its proven ability to interrogate the dynamic state of a process condition within a unit operation such as a mixing vessel or conveyor without interfering with the process itself. This is achieved using noninvasive sensors along a cross–sectional boundary of the process equipment. Electrical Capacitance Tomography (ECT) is a non–intrusive technique for obtaining information about the distribution of the contents of closed pipes by measuring variations in the dielectric permittivity of the material within the electrodes sensing region. An 8 electrode ECT sensor system with a graphical user interfacing (GUI) software programming has been developed by using Microsoft Visual Basic 6.0. This system can be used to investigate the distribution of fire flame inside the vessel. Data from the hardware system can be acquired directly to computer through a microcontroller control unit to provide the cross sectional image of the fire flame. Image reconstruction algorithm used in this project is the conventional, but effective Linear Back Projection (LBP).

Key words: Electrical Capacitance Tomography, fire flame, Linear Back Projection, nonintrusive, Visual Basic
The Development of Measures of Self–Regulative Knowledge and its Relationship to Self–Regulated Learning: A Preliminary Study
Authors: Abdullah Melissa Ng Lee Yen , Abu Bakar Kamariah , Roslan Samsilah , Wong Su Luan , Abd. Rahman Puteri Zabariah
Published: January 2013

Kajian ini menghasilkan sebuah instrumen untuk mengukur pengetahuan tentang strategi pembelajaran aturan kendiri. Ia juga mengkaji hubungan antara pengetahuan tersebut dengan pembelajaran aturan kendiri. Sampel kajian terdiri daripada 322 pelajar dari dua buah sekolah menengah. Pengetahuan pelajar tentang strategi pembelajaran diukur dengan Self–Regulative Knowledge Scale yang dihasilkan dalam kajian ini. Pembelajaran aturan kendiri pula diukur dengan Learning Strategies Subscale (Pintrich, et al., 1991). Skala yang dihasilkan didapati sahih dan boleh dipercayai. Selain itu, dapatan kajian menunjukkan bahawa pengetahuan pelajar tentang strategi pembelajaran aturan kendiri mempunyai hubungan yang positif dan signifikan dengan pembelajaran aturan kendiri mereka.

Kata kunci: Pengetahuan aturan kendiri; alat ukur; pembelajaran aturan kendiri; strategi–strategi pembelajaran; aturan kendiri

This study produced an instrument to gauge self–regulative knowledge. It also looked into the relationships between such knowledge and self–regulated learning. The sample consisted of 322 students from two secondary schools. Self–regulative knowledge was measured by the Self–Regulative Knowledge Scale, developed in this study. Self–regulated learning, on the other hand, was measured by the Learning Strategies Subscale (Pintrich, et al., 1991). The newly developed instrument was found to be valid and reliable. In addition, the results showed that students’ self–regulative knowledge was positively and significantly related to their self–regulated learning.

Key words: Self–regulative knowledge; scale; self–regulated learning; learning strategies; self–regulation.
A Study On The Effects Of Noise On Industrial Workers In Malaysia
Authors: Mokhtar Mohzani , Kamaruddin Sahrul , A. Khan Zahid , Mallick Zulquernain
Published: January 2013

Kertas kerja ini mempersembahkan keputusan satu kajian ergonomik berkaitan kesan kebisingan terhadap pekerja industri di Malaysia. Tiga industri berbeza yang telah dipilih untuk kajian ialah pengeluar produk berasaskan getah, syarikat hentakan logam dan syarikat percetakan penerbitan. Satu soal selidik yang mengandungi 37 soalan yang merangkumi semua aduan berkaitan kesan kebisingan terhadap manusia telah disedia dan diberikan kepada 120 pekerja industri yang dipilih. Maklum balas daripada pekerja dikumpulkan sebagai data untuk analisis selanjutnya. Satu pengujian Chi–Square telah digunakan untuk menentukan sama ada kesan kebisingan adalah signifikan atau tidak signifikan. Didapati bahawa pada tahap signifikan, α = 0.05, fisiologi, kehilangan pendengaran, audiotori dan gangguan tidur adalah kesan kebisingan yang secara statistiknya signifikan. Bagaimanapun, kesan kebisingan terhadap psikologi telah didapati tidak signifikan.

Kata kunci: Ergonomik, kesan kebisingan, kesan fisiologi, kesan kehilangan pendengaran, kesan audiotori, kesan psikologi

This paper presents results of an ergonomic study pertaining to the effect of noise on industrial workers in Malaysia. Three different industries selected for the study were rubber product manufacturing, metal stamping, publication and printing. A questionnaire consisting of 37 questions, covering all possible reported effects of noise on humans, was prepared and served to a total of 120 workers at the above mentioned industries. Responses from the workers were collected for analysis. A Chi–Square test was used to determine whether the effects of noise were statistically significant or not. It is found from the results of the survey, at a level of significance, α = 0.05, physiological, hearing loss, auditory, and sleep disturbances effects of noise are statistically significant. However, psychological effect of noise is found to be non-significant.

Key words: Ergonomics, noise effects, physiological effects, hearing loss effects, auditory effects, psychological effects
Optimal Buffer Allocation For Unpaced Balanced And Unbalanced Mean Processing Time
Authors: Othman Zalinda , Kamaruddin Shahrul , Ismail Mohd. Shihabudin
Published: January 2013

Artikel ini membincangkan peruntukan penampan optimum untuk talian pengeluaran unpaced yang pendek dan boleh diharap (tiada mesin rosak). Parameter utama yang mempengaruhi talian dalam kajian ini adalah min masa pemprosesan (μ) dan pekali variasinya (Cv). Lapan taburan min masa pemprosesan telah dikaji. Setiap taburan dipadankan dengan 15 konfigurasi peruntukan penampan. Kaedah simulasi digunakan bagi menganggar kadar keluaran talian untuk setiap kes. Keputusan kajian menunjukkan peruntukan penampan tertentu mempengaruhi kadar keluaran talian. Bagi talian yang boleh diharap dan min seimbang, peruntukan penampan yang optima adalah dengan mengagihkan bilangan penampan secara sama rata ke setiap slot penampan. Jika penampan tambahan diperlukan selepas agihan dilakukan, letakkan penampan tambahan tersebut pada slot penampan yang di tengah. Manakala bentuk peruntukan penampan yang baik bagi talian yang mempunyai min tidak seimbang (dengan anggapan setiap stesen mempunyai Cv tetap dan boleh diharap) ialah mengikut bentuk taburan min masa pemprosesan talian tersebut.

Kata kunci: Talian pengeluaran unpaced, min tidak seimbang, peruntukan penampan optima, talian seimbang, talian pengeluaran unpaced boleh diharap

This article discusses an optimal buffer allocation for short unpaced production line and it is assumed reliable (no machines breakdown). The main parameters that affect the line are mean processing time (μ) and its coefficient of variation (Cv). Eight different mean processing time distributions were studied. Each distribution was matched with 15 different buffer allocations. Simulation method was used to estimate the line throughput rate. The results showed that the allocation of buffers affect the throughput rate. For a reliable and balanced line, the optimum buffer allocation is by equally distributing the number of buffers to each buffer slot. In the case of an extra buffer is needed after equally distribution, it is placed at the center buffer slot. Meanwhile, the best buffer allocation shape for a line with unbalanced mean (with the assumption that each station is having fixed Cv and is reliable) follows the shape of the mean processing times of that line.

Key words: Unpaced production line, unbalanced mean, optimal buffer allocation, balanced line, reliable unpaced production line
Attribute Based Feature Recognition For Machining Features
Authors: Abu Risal , Md. Tap Masine
Published: January 2013

Automasi pengecaman ciri adalah satu komponen yang kritikal dalam mengintegrasikan CAD/CAPP/CAM. Aturcara pengecaman ciri perlu dilaksanakan dalam perancangan proses supaya keputusan berkaitan dengan aktiviti perancangan proses boleh dibuat. Berbagai kaedah telah dibangunkan untuk mengautomasikan pengecaman ciri. Kertas kerja ini membentangkan satu pendekatan kepada pengecaman ciri menggunakan rule based yang berdasarkan sifat-sifat tertentu sesuatu ciri seperti jumlah permukaan, jumlah bucu, jenis muka, dan sifat-sifat lain ciri seperti lekuk/cembung. Kaedah yang dicadangkan dilaksanakan menggunakan Graphics Interactive Programming (GRIP), dan permodelan padu Unigraphics. Hasil ujian menunjukkan bahawa pendekatan yang dikemukakan dapat mengecam ciri yang mempunyai satu set sifat-sifat yang unik. Pendekatan ini juga ringkas, mudah difahami dan digunakan.

Kata kunci: CAD, CAPP, CAM, model padu, ciri, pengecaman ciri

Automated feature recognition is considered a critical component for integration of CAD/CAPP/CAM. The automation of process planning requires the implementation of a feature recognition procedure, so that decisions relating to steps of process planning activities can be made. Various methodologies have been developed to automate feature recognition. This paper presents an approach to feature recognition using rule based on different characteristics specific to each feature such as the total number of faces, the total number of edges, the type of faces, and the attribute of feature i.e. protrusion/depression. The proposed method is implemented using Graphics Interactive Programming (GRIP) and Unigraphics solid modeler. The results show that the proposed technique is capable of recognizing features with a unique set of attributes. The rule is also simple, easy to understand and implement.

Key words: CAD, CAPP, CAM, solid models, features, feature recognition
Pendekatan Ontologi Dalam Capaian Dan Perwakilan Semantik Dokumen Web
Authors: Che Alhadi Arifah , Noah Shahrul Azman , Zakaria Lailatul Qadri
Published: January 2013

Visi web semantik membolehkan capaian maklumat dilakukan secara semantik, yang mana model semantik kueri dipadankan dengan maklumat semantik dokumen web. Namun demikian kebanyakan dokumen web adalah tidak berstruktur dan tidak mempunyai maklumat semantik dokumen menyebabkan kesukaran proses pengkuerian. Oleh itu, capaian dan pengekstrakan maklumat semantik daripada dokumen web adalah amat penting dalam merealisasikan visi web semantik dan meningkatkan kualiti capaian maklumat. Kertas kerja ini membincangkan pengaplikasian pendekatan ontologi spesifik dan pemprosesan bahasa tabii dalam menyokong capaian dan pengekstrakan maklumat semantik dokumen web. Dengan menggunakan kedua-dua teknik ini, setiap kali capaian maklumat dilakukan, sistem akan menjana model integrasi semantik dokumen iaitu dokumen yang dicapai oleh enjin gelintar komersial yang ditetapkan. Model intergrasi semantik dokumen ini membolehkan pengguna mencapai dan melayarinya secara semantik. Hasil pengujian capaian dan padanan konsep yang dijalankan memperlihatkan kedua-dua teknik yang digunakan mampu mengenal pasti dan mengekstrak maklumat semantik daripada kueri dan kandungan dokumen web.

Kata kunci: Capaian dokumen semantik, web semantik, ontologi, analisis bahasa tabii, perwakilan semantik dokumen, perwakilan semantik kueri

The Semantic Web vision offers the potential to express queries in a more semantically way whereby semantic query model will be matched with semantic information of the document. However, the unstructured natures of existing web documents, which lack of semantic prove to be a difficult task for such a query. Therefore, semantic information retrieval and semantic information extraction of web documents content are important to realize semantic web vision and enhance the quality of information access. To support this, the semantic information content of web documents need to be specified in order to make the tangled information more structured and accessible. In this paper, we propose an approach meant to semantically query web documents using natural language analysis technique and a domain specific ontology. Using both techniques, the tool gradually constructs the semantic document integration model of the documents retrieved from an existing search engine for each search session. The semantic model can then be semantically refined and browsed by the user. The result of concept matching and accessing shows that both techniques that have been used could identify and extract semantic information from query and web document content.

Key words: Semantic document retrieval, semantic web, ontology, natural language analysis, semantic document representation, semantic query representation
The Impact Of Information Technology On Performance: The Mediating Role Of Management Accounting Systems
Authors: Ismail Noor Azizi
Published: January 2013

Kertas kerja ini melaporkan hasil kajian yang menerangkan hubungan antara kecanggihan Teknologi Maklumat (IT) dan prestasi firma yang bersaiz kecil dan sederhana (SMEs), dengan memasukkan ke dalam model kajian, keupayaan sistem perakaunan pengurusan untuk menghasilkan maklumat perakaunan pengurusan (kapasiti MAS). Bagi menguji hubungan tersebut, data telah dikumpul daripada 310 firma menggunakan kaedah soal selidik. Hasil ujian menunjukkan bahawa kecanggihan IT merupakan penentu kepada kapasiti MAS, sementara kapasiti MAS pula akan menentukan prestasi firma. Dalam kata lain, kapasiti MAS memainkan peranan sebagai penghubung antara kecanggihan IT dengan prestasi firma. Interpretasi hasil ujian ini ialah firma yang menggunakan IT yang lebih canggih akan dapat menghasilkan maklumat perakaunan pengurusan yang mencukupi dan seterusnya dapat meningkatkan prestasi firma.

Kata kunci: Teknologi Maklumat, sistem maklumat, sistem perakaunan pengurusan, sistem maklumat perakaunan, industri kecil dan sederhana

This paper reports the results of a study which offers an explanation for the relationship between Information Technology (IT) sophistication and performance of small and medium sized enterprises (SMEs), by incorporating into the model of the capability of management accounting systems to generate management accounting information (MAS capacity). To assess the relationship, data were collected from 310 (25% response rate) SMEs by way of questionnaire surveys. The results indicate that IT sophistication is a determinant of MAS capacity, which, in turn, is a determinant of firm performance. In other words, MAS capacity plays a mediating role in the relationship between IT sophistication and firm performance. An interpretation of the results is that those firms that employed sophisticated IT can generate sufficient management accounting information and thereby improve performance.

Key words: Information Technology, information systems, management accounting system, accounting information systems, small and medium enterprises
Mengukur Paras Kesahsahihan Spesifikasi Z Dalam Penilaian Spesifikasi Keperluan Pelajar Melalui Pendekatan Pelaksanaan Bersimbol
Authors: Shukur Zarina , Mohd. Yusof Ahmad Rizal
Published: January 2013

Kertas ini mengesyorkan kaedah pengukuran paras kesahsahihan spesifikasi formal perisian. Pengesahsahihan dilakukan untuk memastikan spesifikasi menyatakan kelakuan program dengan tepat dan memenuhi keperluan pengguna. Paras kesahsahihan ini ingin diukur khususnya untuk kegunaan guru dalam menilai spesifikasi keperluan yang disediakan oleh pelajar. Pengesahsahihan dilakukan dengan menggunakan teknik pengujian, iaitu spesifikasi yang dihasilkan (oleh pelajar) dilaksanakan secara bersimbol terhadap sejumlah kes ujian yang disediakan secara bermakna dengan bantuan pelanggan (diwakili oleh guru). Seterusnya output ujian dalam bentuk predikat matematik antara pelanggan (guru) dan penspesifikasi (pelajar) dibandingkan. Hasil daripada perbandingan ini adalah suatu nilai numerik yang mencerminkan paras kesahsahihan spesifikasi berkaitan.

Kata kunci: Spesifikasi formal, pengesahsahihan spesifikasi, perlaksanaan bersimbol, paras kesahsahihan, ukuran kesahsahihan spesifikasi

This paper proposes a method to measure the level of formal software specification validity. The validation of a specification is done in order to ensure that the specification correctly specify the program behaviour and fulfill the user requirements. We wish to measure the level of validity for teacher purposes in evaluating requirement specification which is written by students. The validation is done by using testing technique that is; the specification (which is prepared by the student) will be symbolically executed against several test cases which have been prepared earlier (by the teacher). Then, the output from the test, which is in the form of mathematical predicates will be compared against the expected answer. The result from the comparison is a numeric value which represents the level of the specification validity.

Key words: Formal specification, specification validation, symbolic execution, validity level, specification validation measure
Effects of Ultrasonic Waves on Enhancement of Relative Volatilities in Methanol–Water Mixtures
Authors: Ripin Adnan , Abdul Mudalip Siti Kholijah , Mohd. Yunus Rosli
Published: January 2013

Penggunaan gelombang ultrabunyi dalam pelbagai bidang termasuk proses pemisahan telah meningkat sejak akhir-akhir ini. Kajian ini melaporkan keberkesanan penggunaan gelombang ultrabunyi dalam meningkatkan pemisahan campuran binari dalam turus penyulingan. Campuran binari yang digunakan adalah metanol-air. Kesan keamatan gelombang bunyi yang berbeza iaitu 50, 100, 200 and 250 W/A.cm2 pada frekuensi 40 kHz terhadap keseimbangan wap-cecair (KWC) dikaji bagi mendapatkan nilai keamatan yang sesuai. Eksperimen juga dijalankan bagi mengkaji kesan frekuensi (25 and 68 kHz) terhadap data KWC. Didapati, penggunaan gelombang ultrabunyi berjaya meningkatkan proses pemisahan dengan meningkatkan nilai kemeruapan relatif. Purata kemeruapan relatif yang tertinggi bagi metanol-air iaitu 29.413 diperoleh daripada uji kaji yang menggunakan keamatan 200 W/A.cm2 dan frekuensi 25 kHz. Proses peronggaan dan kesan vakum yang wujud semasa perambatan gelombang ultrabunyi dalam cecair membawa kepada perubahan nilai kemeruapan relatif dan data KWC. Keputusan yang diperoleh menunjukkan keberkesanan penggunaan gelombang ultrabunyi bagi meningkatkan pemisahan campuran binari dalam turus penyulingan.

Kata kunci: Keseimbangan wap–cecair, metanol–air, gelombang ultrabunyi, kemeruapan relatif

The application of ultrasonic wave in various fields including separation process has increased predominantly. This paper reports the practicability of using ultrasonic wave to enhance separation of binary mixtures by distillation. The binary mixture utilized was methanol-water. The effect of different ultrasonic intensity at 50, 100, 200 and 250 W/A.cm2 with frequency of 40 kHz to vapor-liquid equilibrium (VLE) of methanol-water was investigated to obtain the most suitable operating intensity. Experimental studies were also carried out to investigate the frequency effect (25 and 68 kHz) to VLE data. It was found that the use of ultrasonic wave enhanced the separation process by increasing the relative volatility of components. The highest average relative volatility of methanol-water at 29.413 was obtained from experimental study using intensity 200 W/A.cm2 and frequency of 25 kHz. The changes in relative volatility and VLE were caused by cavitational activities and vacuum effect that occur during transmission of ultrasonic wave in liquid medium. The results from this study proved the practical feasibility of using ultrasonic wave to enhance separation of binary mixtures in distillation column.

Key words: Vapor–liquid equilibrium, methanol–water, ultrasonic waves, relative volatility