Reliability Analysis of Covid-19 Risk Management System in Malaysia Higher Learning Institution

Reliability concerns the extent to which a measurement of a phenomenon provides a stable and consistent result. Reliability is also concerned with repeatability. For example, a test will be reliable if measurement is repeated and conducted under constant conditions, hence will give the same result. This article attempts to present the result of a reliability study in the development of the Covid-19 risk management system in a Malaysia Institution of Higher Learning. The system is called C19-HIRAO. Two types of reliability study were explored for this purpose namely interrater reliability study and test-retest method. Interrater reliability study consists of Cohen’s Kappa statistic and percent agreement (conventional method). Interrater Cohen’s Kappa and Test-retest method were performed by the raters from Universiti Malaysia Pahang (UMP). The result proved that the developed C19-HIRAO has achieved an almost perfect agreement (0.92), moderate agreement (0.75), and very high relationship (1.00) for Interrater percentage agreement, Interrater Cohen’s Kappa, and test-retest method respectively. In conclusion, although this system is still newly developed, the risk rating value obtained is consistent among different raters. The value of this risk rating is also stable and reliable over the time when test-retest reliability is conducted within the stipulated time frame by the same rater

Digital aerial imagery of unmanned aerial vehicle for various applications

Digital aerial imagery (DAI) can be acquired using digital mapping camera attached to light aircraft. The DAI is used for the production of topographic and thematic map. The cost of acquiring DAI is very expensive and suitable for large area coverage. The acquisition of DAI is not economical and suitable for small area coverage. Therefore an alternative method should be used to fulfill this need. There are two alternative methods that can be used for acquisition of DAI which include using a small format digital camera attached to light aircraft and using a small format attached to an unmanned aerial vehicle (UAV). UAV system has been reported used in various and diversified applications such as mapping applications (eg. map revision, landslide, coastal erosion, archaeology, forestry), industrial application (eg. engineering, crash accident), Geographic Information System (GIS) applications and others. In this study, micro unmanned aerial vehicle (UAV) systems which comprise of fixed wing UAV flying and rotary UAV are attached with small format high resolution digital camera to acquire DAI for the purpose of mapping at the flying height of 300m at 100m respectively. The micro UAVs were flown autonomously (i.e automatically) and a series of DAIs of a slope using fixed wing UAV and a stream using rotary UAV were acquired rapidly within short period. Ground control point (GCP) and check point (CP) were established using the Global Positioning System and conventional Total Station techniques around the study area for the slope and stream respectively for the purpose of digital image processing and accuracy assessment. The DAIs were processed to produce photogrammetric output such as digital elevation model (DEM) and orthophoto. All these photogrammetric products were successfully produced and assessed. The achievable accuracy is less than ±1m for slope mapping and ±0.280m for stream mapping. In this study, it is proven that the micro UAV system can be used for mapping which cover small area. As conclusion, micro UAV is suitable for mapping small area, rapid data acquisition, accurate, low cost and can be employed for various applications

Accuracy assessment of calibrating high resolution digital camera

Today many photogrammetric works involved the use of digital cameras due to it's in low cost. Digital camera has been used in many photogrammetric applications such as archaeology, architecture, accident investigation, cultural heritage and etc. Theoretically, most digital camera is known as non-metric camera where the interior geometrical of digital camera is not stable, however, the optical quality is not acceptable. The need for camera calibration has been fundamental requirement for obtaining accurate measurement since the inception of photogrammetry. This study deals with the acquisition and processing of different configuration of digital camera (convergent and generic network) which are position at different height versus different digital camera setup. The accuracy assessment was performed for two high resolution digital cameras which are Nikon D90 and Rollei D30metric5 digital cameras. The height of digital camera is setup at approximately 80cm and 100cm. Finally, this study evaluates the accuracy of the camera calibration based on standard deviation of interior camera calibration parameters. This study shows that high resolution Nikon D90 digital camera which is categorized as low cost could be used in photogrammetric application with good accuracy achievable