Judul: Analisis Model Antrian Mx/M/1 dengan Kedatangan Pelanggan Massal.
Abstrak: Model antrian Mx/M/1 dengan kedatangan pelanggan massal adalah model antrian server tunggal dimana proses kedatangan mengikuti proses Poisson, waktu pelayanan menyebar secara eksponensial serta kedatangan pelanggan dalam bentuk sekumpulan (batch). Pada karya ilmiah ini model antrian tersebut dikaji dalam dua kasus. Kasus pertama, ukuran batch diasumsikan sebagai peubah acak sembarang yang memiliki fungsi massa peluang. Kasus kedua, ukuran batch diasumsikan konstan sepanjang waktu. Nilai harapan dari banyaknya pelanggan di sistem dan ukuran kinerja dari sistem ketika ukuran batch konstan diperoleh dengan metode fungsi pembangkit peluang. Ilustrasi numerik dari ukuran kinerja tersebut juga disajikan dengan bantuan software Mathematica 12.0. Hasil simulasi numerik menunjukkan bahwa ketika nilai traffic intensity meningkat, rata-rata banyaknya pelanggan dan waktu tunggu di sistem antrian meningkat. Selanjutnya, ketika ukuran batch meningkat, maka rata-rata banyaknya pelanggan dan waktu tunggu meningkat.
Keyword: Kedatangan massal, Poisson, eksponensial, fungsi pembangkit, peluang.

Judul: Analisis Model Antrean Berulang M/G/1 dengan Prioritas Preemptive Resume dan Collisions pada Kerusakan Server dan Penundaan Perbaikan
Abstrak: Sistem antrean M/G/1 adalah sistem antrean dengan proses kedatangan pelanggan berdistribusi Poisson, waktu layanan pelanggan berdistribusi umum, dan server tunggal. Pada karya ilmiah ini, terdapat dua jenis pelanggan yaitu pelanggan positif dan negatif. Pelanggan positif akan dilayani seperti biasa oleh server dan diambil dari antrean sesuai dengan disiplin yang ditentukan, sedangkan pelanggan negatif yang tidak mendapat pelayanan mengakibatkan kerusakan pada server dan dapat menghapus pelanggan yang ada dalam layanan pada sistem. Disiplin antrean yang digunakan dalam model ini adalah disiplin prioritas preemptive. Dengan menyelesaikan persamaan diferensial untuk fungsi pembangkit peluang dalam kondisi steady-state, diperoleh peluang lama server sedang menganggur, sibuk melayani pelanggan, menunggu perbaikan, dan sedang dalam perbaikan, serta ukuran kinerja lainnya. Kemudian, diperoleh juga nilai harapan periode sibuk., The M/G/1 queue system is a queue system with arrival process of customers follows Poisson process, customer service time has a general distribution, and has single server. In this manuscript, there are two types of customers, namely positive and negative customers. The positive customers are treated in the normal way by a server and are taken from a queue according to the specified queueing system, while the negative customer, which does not receive service, causes the server breakdown and removes the customer being in service from the system. The queue discipline used in this model is preemptive resume priority. By solving the differential equation for the probability generating function in steady-state condition, the probability that the server is idle, busy serving a customer, waiting for repair and under repair, and other performance measure was obtained. Finally, the expected value of busy period was obtained as well.
Keyword: expected value, Poisson, probability, retrial queue

Judul: Durability of Specific Immunoglobulin (Ig) Y Againts Influenza and Covid-19 in Sunscreen
Abstrak: The benefit of specific immunoglobulin Y (Ig Y) as an active ingredient in personal care products such as sunscreen has not been properly studied. Our study aims to evaluate the reliability of specific IgY against influenza and the COVID-19 virus in a sample sunscreen product. Specific IgY influenza and COVID-19 viruses were inserted in the sample sunscreen at two concentrations of 0.1% and 0.25%. Three treatments were observed: control (C) sunscreen without IgY, treatment 1 (T1) sunscreen with 0.1% IgY, and treatment 2 (T2) sunscreen with 0.25% IgY. Organoleptic observations were carried out to monitor changes in aroma, color, and texture, and sunscreen sampling was done every week for 6 weeks. The durability of IgY was evaluated using an enzyme-linked immunosorbent assay (ELISA) and a neutralization assay. Organoleptic observation from weeks 1 to 6 showed consistency in its aroma, color, and texture. Enzyme-linked immunosorbent assay and neutralization assay (NA) results of the T1 and T2 groups showed negative results except for sample T1 at week 5, which showed a positive result in the Influenza A ELISA. Based on the results, it seems that IgY concentrations of 0.1% or 0.25% were not optimal. However, this negative result might be due to low concentration of the IgY and the presence of beeswax, which inhibits IgY and causes it to dissolve in distilled water, thus preventing it from being detected in the assay.
Keyword: Immunoglobulin Y, Sunscreen, Influenza, COVID-19, Biological Activity