Pixel Value Graphical Password Scheme: Analysis on Time Complexity performance of Clustering Algorithm for Passpix Segmentation

Passpix is a key element in pixel value access control, containing a pixel value extracted from a digital image that users input to authenticate their username. However, it is unclear whether cloud storage settings apply compression to prevent deficiencies that would alter the file's 8-bit attribution and pixel value, causing user authentication failure. This study aims to determine the fastest clustering algorithm for faulty Passpix similarity classification, using a dataset of 1,000 objects. The source code for the K-Means, ISODATA, and K-Harmonic Mean scripts was loaded into a clustering experiment prototype compiled as Clustering.exe. The results demonstrate that the number of clusters affects the time taken to complete the clustering process, with the 20-cluster setting taking longer than the 10-cluster setting. The K-Harmonic Mean algorithm was the fastest, while K-Means performed moderately and ISODATA was the slowest of the three clustering algorithms. The results also indicate that the number of iterations did not affect the time taken to complete the clustering process. These findings provide a basis for future studies to increase the number of clusters for better accuracy

Design and fabrication of Surface Acoustic Wave resonators on Lithium Niobate

Surface Acoustic Wave (SAW) resonators are essential components in communication devices and are used mainly as oscillators, frequency synthesizers and transceivers. Common piezoelectric substrates are quartz, Lithium Tantalate (LiTaO3) and Lithium Niobate (LiNbO3). In this paper we describe the design and fabrication of SAW resonators on LiNbO3. The design of the SAW resonators was simulated using COMSOL MultiphysicsTM. Two SAW resonators with resonance frequency of 218 MHz with varying number of reflectors were fabricated and measured. Measurements conducted using an RF Probe station and network analyzer yielded losses of -48.3 dB and -49.32 dB for Resonator 1 and Resonator 2 respectively

Challenges of implementing occupational health services (OHS) in Malaysia -perspective of occupational health doctors

Mortality estimation due to work-related illness has reached up to 2.4 million each year. The current coverage of occupational health services (OHS) in Malaysia is still low. Occupational health doctors (OHDs) are one of the essential personnel to ensure proper execution of OHS. This study was conducted to explore the experiences and views of OHDs on the challenges in implementing OHS in Malaysia. Four focus group discussions were conducted with OHDs (N = 23) from four different states in Malaysia in 2016. Another five OHDs participated in in-depth interviews to implement the identified codes or themes. The discussions were recorded and transcribed verbatim. NVivo version 11.0 was used to facilitate data analysis. The data were analysed following the thematic analysis guidelines. Three themes were identified from the discussions: difficulties in diagnosing occupational diseases and poisoning; poor practices, attitudes, and commitment by both workers and employers; and non-compliance with laws and regulations related to the industries. The common challenges discussed by the participants were the lack of knowledge and skills among OHDs, and the shortage of standard procedures, leading to difficulties to screen occupational diseases. The poor cooperation and behaviour from the industries also hindered OHDs when performing their services. This study suggests better training and provision of standard tools or guideline to assist OHDs in making occupational disease diagnoses, increasing OHS awareness among the industries, and enacting OHS as part of the laws and regulations with adequate enforcement