We discuss the dynamics of new COVID-19 epidemic model by considering asymptomatic infections and the policies such as quarantine, protection (adherence to health protocols), and vaccination. The proposed model contains nine subpopulations: susceptible (S), exposed (E), symptomatic infected (I), asymptomatic infected (A), recovered (R), death (D), protected (P), quarantined (Q), and vaccinated (V ). We first show the non-negativity and boundedness of solutions. The equilibrium points, basic reproduction number, and stability of equilibrium points, both locally and globally, are also investigated analytically. The proposed model has disease-free equilibrium point and endemic equilibrium point. The disease-free equilibrium point always exists and is globally asymptotically stable if basic reproduction number is less than one. The endemic equilibrium point exists uniquely and is globally asymptotically stable if the basic reproduction number is greater than one. These properties have been confirmed by numerical simulations using the fourth order Runge-Kutta method. Numerical simulations show that the disease transmission rate of asymptomatic infection, quarantine rates, protection rate, and vaccination rates affect the basic reproduction number and hence also influence the stability of equilibrium points.

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Background: The government established a vaccination program to deal with highly reactive COVID-19 cases in Indonesia. In obtaining accurate predictions of the dynamics of the compartment model of COVID-19 spread, a good parameter estimation technique was required.. Purpose: This research aims to apply Particle Swarm Optimization as a parameter estimation method to obtain parameters value from the Susceptible-Vaccinated-Infected-Recovered compartment model of COVID-19 cases. Methods: This research was conducted in April-May 2020 in Indonesia with exploratory design research.  The researchers used the data on COVID-19 cases in Indonesia, which was accessed at covid19.go.id. The data set contained the number of reactive cases, vaccinated cases, and recovered cases. The data set was used to estimate the parameters of the COVID-19 compartment model. The results were shown by numerical simulations that apply to the Matlab program. Results: Research shows that the parameters estimated using Particle Swarm Optimization have a fairly good value because the mean square error is relatively small compared to the data size used. Reactive cases of COVID-19 have decreased until August 21, 2021. Next, reactive cases of COVID-19 will increase until the end of 2021. It is because the virus infection rate of the vaccinated population is positive . If  occurs before the stationary point, then the reactive cases of COVID-19 will decrease mathematically. Conclusion: Particle Swarm Optimization methods can estimate parameters well based on mean square error and the graphs that can describe the behavior of COVID-19 cases in the future.

Tujuan dilaksanakan program English Breakfast (EB) untuk membantu siswa meningkatkan kemampuan berbahasa Inggris melalui pemberian kosa kata bahasa Inggris secara rutin yang nantinya berdampak terhadap hasil belajar siswa khususnya siswa Suntisart Wittaya School, Kabang District, Yala Province, Thailand. Program ini dilaksanakan sebanyak 3-4 kali setiap minggu dengan alokasi waktu 8-9 menit di pagi hari. Tahap-tahap yang dilakukan pada program ini yaitu: perencanaan, persiapan, pelaksanaan, pengamatan, dan refleksi. Adapun metode yang dilakukan dalam pelaksanaan EB yakni tanya jawab antara guru dengan siswa menggunakan berbagai media visual. Program English Breakfast menghasilkan data banyaknya kosa kata yang diberikan pada setiap pertemuan.  Selain itu, pengaruh program English Breakfast terhadap pembelajaran juga menghasilkan data rata-rata nilai harian siswa pada mata pelajaran English Conversation setelah pelaksanaan program English Breakfast. Program ini berjalan dengan lancar dan berdampak positif terhadap hasil belajar siswa pada mata pelajaran English Conversation. Jika program ini terus dilaksanakan secara rutin, maka kemampuan bahasa Inggris siswa semakin meningkat. Akibatnya, hasil belajar siswa pada mata pelajaran English Conversation juga menjadi optimal.