An overview on audio steganography techniques

Steganography is a form of security technique through obscurity; the science and art of hiding the existence of a message between sender and intended recipient. Steganography has been used to hide secret messages in various types of files, including digital images, audio and video. The three most important parameters for audio steganography are imperceptibility, payload (bit rate or capacity), and robustness. Any technique which tries to improve the payload or robustness should preserve imperceptibility. The noise which is introduced due to bit modification would limit payload. This paper presents a categorization of information hiding techniques and overviews those techniques that intend to improve payload and imperceptibility

Preparation and characterisation of 3D printed polyamide 6 composites for craniofacial reconstruction

Craniofacial defect is typically unique and depend on the anatomical condition of the patient for which patient specific implant (PSI) is desirable. The FDM based 3D printer could be utilised to cater the needs. However, the commercially available feedstock is bio-incompatible and lack of mechanical integrity which hinder the application. This study aimed to develop a new polyamide 6 based filament feedstock aiming for craniofacial reconstruction. Polyamide 6 was compounded with carbon fibre and zinc oxide prior to filament feedstock fabrication and 3D printing processes. The effect of carbon fibre as well as hybrid carbon fibre/zinc oxide incorporation on the physicochemical properties of the compounds as well mechanical and biological properties of the 3D printed parts were assessed. The melting temperature of the composites were not affected by the filler incorporation, however, the melt flow rate, tensile, compressive and surface roughness properties of the PA 6 composites increased appreciably. The composites also exhibited better toughness properties than unfilled PA 6 after 60 days of immersion in simulated body fluid despite of high moisture absorption. The viability of osteoblast cells were more than 70% following treatment with extracted composites at concentrations of 50, 25, 12.5 and 6.25 mg/ml. The composites also demonstrated appreciable antibacterial effect against Grampositive and negative bacteria of Staphylococcus aureus and Pseudomonas aeruginosa. However, the effect was selective and more pronounced in S. aureus. The newly developed polyamide 6 based filament feedstock is compatible to be used with FDM based 3D printer. With enhanced mechanical and biological properties, the developed composites are potential to be used for craniofacial reconstruction

Preparation and characterization of polyamide 12 composites for craniofacial reconstruction utilizing additive manufacturing

This study was carried out to prepare and characterize polyamide 12 composites as potential biomaterial for craniofacial reconstruction utilizing additive manufacturing. Polyamide 12 was compounded with ceramic fillers of β-TCP (ranged from 5 to 25 wt%) and zirconia (fixed at 15 wt%) via twin screw extruder. Obtained pellets were used to characterize the thermal properties, melt flow rate and chemical bonding of the composites. The remaining pellets were used to prepare tensile, flexural and impact specimens via injection molding and 3D printing. The mechanical and topological properties of prepared specimens were evaluated and analyzed using statistical analysis of One-Way ANOVA with significant level of p=0.05. The melt flow rate of the polyamide 12 composites were significantly difference as compared to pure polyamide (p<0.01). Mechanical and topological properties of injection molded polyamide 12 composites showed a mix of significant and insignificant differences as compared to pure polyamide. However, no significant differences were detected in the mechanical and topological properties of 3D printed composites. The mechanical properties of 3D printed polyamide 12 composites was influenced by inter layer bonding which could be boosted further via optimization of bed temperature. Overall, with mechanical and topological properties that could be enhanced, polyamide 12composites are potential biomaterial for craniofacial reconstruction

The Mediating Effect of Consumers’ Purchase Intention: A Perspective of Online Shopping Behavior among Generation Y

Young consumers spend most of their time online in comparison to the working adults due to their great potential of buying power as well finding that online shopping is more convenient. The objective of this study is to investigate factors determining online purchase intention among the university students whereby variables such as attitude, subjective norm, trust, purchase intention and behavior were tested. Total of 800 questionnaires were distributed and 662 questionnaires were usable. A quantitative research was undertaken through the distribution of survey questionnaires and the data were analyzed using Structural Equation Modelling (SEM) to test the relations among variables. The analyses have proven that purchase intention has functioned effectively as a mediator between the independent variables (attitude, subjective norm and trust) and dependent variables (online shopping behavior).The results of this study offer some new frontiers in supporting as well as enriching more studies in the scope of online shopping behaviors. This study contributes to the dynamics of the causative relations between examined variables and highlights the significance of attitude, subjective norm, trust and consumer behavior in ascertaining the purchase intention in the context of Malaysian online purchases. Keywords: Purchase intention, Attitude, Subjective norm, Trust, Consumer behavio

Reflectance characteristics of silicon surface fabricated with the arrays of uniform inverted pyramid microstructures in UV-visible range

In this paper, inverted pyramidal microstructures are designed and fabricated on silicon (Si) surface. The characteristics of surface reflectance are simulated using two-dimensional (2D) finite-difference time-domain (FDTD) method by varying the spacing (S) and width (W) of the pyramidal microstructures. The results showed that the effect of S is more significant compared to W where the reflectance of the irradiated light has been increased gradually with the increase of S from 0 to 3 µm, and the difference is around 9.6%. Due to the etching constraint, S= 3 µm is chosen for the fabrication. Textured structure is fabricated by the anisotropic etching of tetramethyl-ammonium hydroxide (TMAH) with additional of isopropyl alcohol (IPA). Long etching time of 120 min is required to form uniform arrays of pyramidal microstructures with smooth and well-terminated four sidewalls at (111) plane. Due to the undercut etching under SiO2 mask, it results to the formation of slightly larger W and smaller S in the fabricated structures. The measured average reflectance in UV-visible range for the Si with inverted pyramidal microstructures is very low down to 10.4%. The discrepancy between the measured and simulated values is speculated to be due to the use of 2D FDTD instead of three-dimensional (3D) FDTD

Predictors for inadequate knowledge and negative attitude towards childhood immunization among parents in Hulu Langat, Selangor, Malaysia

Vaccine hesitancy among parents has led to re-emergence of vaccine preventable diseases. In Malaysia, measles cases had increased by three times in 2015 compared to previous year. Immunization coverage has always been above 95% since 2009. However, in 2014, Mumps-Measles-Rubella (MMR) coverage has a significant drop to 93.4%. The aim of the study was to identify predictors for inadequate knowledge and negative attitude towards childhood immunization among parents in Hulu Langat, Selangor. A cross sectional study design was conducted from January to July 2016 with760 respondents. Respondents were selected by cluster random sampling and a validated self-administered questionnaire was used. The majority of respondents were female (70%), Malay (87%), employed (92%) and parents with tertiary education (99.7%). In this study, 12.8% parents have an inadequate knowledge on childhood immunization and 47.6% parents have a negative attitude towards childhood immunization. The predictors for inadequate knowledge on childhood immunizations were last child’s age of 2 years old or more (AOR=1.413 95% CI 0.28-0.69); parents without tertiary education (AOR=2.02 95% CI 1.15-3.54); parents withouteducational exposure on childhood immunization (AOR=2.87 95% CI 1.59-5.18) and parents who obtained information on childhood immunization from non-healthcare provider (AOR=2.66 95% CI 1.50-4.70). Predictors for negative attitude on childhood immunizations were being male (AOR=1.44 95% CI 1.04-2.01); parents without tertiary education (AOR=1.67 95% CI 1.04-2.68); household income of less than RM5000 (AOR=1.85 95% CI 1.28-2.67) and unsatisfactory religious belief (AOR=2.76 95% CI 2.03-3.75). Therefore, these predictors should be considered in any health intervention on childhood immunizations for parents in Malaysia

Guru cemerlang Pendidikan Moral: keperluan menguasai aspek kandungan dalam pengajaran dan pembelajaran Pendidikan Moral dan implikasinya

Guru memainkan peranan yang penting dalam melaksanakan mata pelajaran Pendidikan Moral di sekolah di samping meningkatkan kualiti pencapaian murid. Memandangkan Pendidikan Moral itu sendiri adalah kompleks, maka guru perlu mempunyai pemahaman yang kukuh dan menguasai konsep-konsep asas moral, konsep utama Pendidikan Moral dan isi kandungan Pendidikan Moral itu sendiri sebelum mengajar muridnya. Penguasaan aspek kandungan oleh guru cemerlang Pendidikan Moral adalah sangat penting kerana ia merupakan aspek asas dalam pengajaran dan pembelajaran. Walaupun secara umumnya diketahui guru cemerlang adalah pakar dalam mata pelajaran yang diajar, namun bagi Pendidikan Moral kelonggaran berlaku apabila majoriti guru cemerlang Pendidikan Moral tidak mempunyai pengkhususan dalam mata pelajaran ini. Kertas konsep ini akan menjelaskan tentang kepentingan guru menguasai pengetahuan kandungan dan konsep utama yang wajar difahami oleh guru cemerlang Pendidikan Moral di Malaysia. Perbincangan kertas ini adalah berdasarkan konsep Pendidikan Moral di Malaysia oleh Aroff, teori pengetahuan guru oleh Shulman dan teori sekolah dan perkembangan moral oleh Sugarman yang menyentuh tentang aspek penting bagi seorang guru Pendidikan Moral

Mazdak technique for PSNR estimation in audio steganography

A novel method to estimate PSNR of the resu lt of audio steganography before embedding is presented. Estimated PSNR by proposed linear interpolation formula was tested and the result was almost the same with the obtained PSNR in practical way