Cryptography and network security is a broad field that deals with numerous strategies and approaches to achieve this level of security, and the methodologies are evolving. Cryptography provides the ability to meet critical network security goals. This study has been done to identify PERMATA Insan College students' awareness of cryptography. This study has been conducted through a survey at PERMATA Insan College that involved 13 to 17 years old students. Based on the survey that has been held, the result showed that most students slightly know about cryptography. It can be concluded that a small number of students know about cryptography but the rest need clarification on what cryptography is exactly.

In the globalization era of Education 4.0, developing global awareness about the importance of learning a foreign language in secondary school is essential. The Japanese language has become a more widely recognized language that has been taught in secondary schools. Therefore, this study has been done to determine whether students at PERMATA Insan College have learned the Japanese language. This study was conducted through a survey of PERMATA Insan College from the age of 13 until 17 years old. As a result, most students are familiar to the Japanese language. It can be concluded that students at PERMATA Insan College have learned the Japanese language throughout their schooling.

This research presents a deep insight to address the notion of stability of an epidemical model of the HIV infection of CD4+ T-Cells. Initially, the stability of an ordinary differential equation (ODE) model is studied. This is followed by studying a delay differential equation (DDE) model the HIV infection of CD4+ T-Cells. The available literature on the stability analysis of the ODE model and the DDE model of the CD4+ T-Cells shows that the stability of the models depends on the basic reproduction number “R0”. Accordingly, for the basic reproduction number R0 <1, the model is asymptotically stable, whereas, for R0 >1, the models are globally stable. This research further studies the stability of the models and address the lower possible stability limits for the infection rate of CD4+ T-Cells with virus and the reproduction rate of infectious CD4+ T-Cells, respectively. Accordingly, the results shows that the lower possible limits for the infection rate of CD4+ T-Cells with virus are 0.0000027 mm-3 and 0.000066 mm-3 for the ODE and DDE models, respectively. Again, the lower stability limits for the reproduction rate of infectious CD4+ T-Cells with virus are 12 mm3 day-1 and 273.4 mm3 day-1 for the ODE and DDE models, respectively. The research minutely studies the stability of the models and gives a deep insight of the stability of the ODE and DDE models of the HIV infection of CD4+ T-Cells with virus.