Judul: The Influence of Telepresence, Social Presence, and Social Value on Repurchase Intention of Online Virtual Game Items in Generation Z
Abstrak: Di era digital yang semakin berkembang pesat, manusia dimudahkan dengan berbagai macam hal kebutuhan. Salah satunya dengan hadirnya internet yang memudahkan berbagai macam jenis kegiatan manusia. Kehadiran internet diikuti dengan perkembangan permainan yang kian diminati dan dikenal dengan sebutan game online. Penelitian ini bertujuan untuk menganalisis pengaruh konsumen, telepresence, social presence, dan social value terhadap repurchase intention item virtual game online. Adapun desain penelitian menggunakan cross sectional study secara voluntary sampling yang melibatkan sebanyak 239 konsumen berusia 12-28 tahun dengan kriteria pernah bermain game online dalam 6 bulan terakhir dan pernah membeli item virtual game online. Data dikumpulkan melalui pengisian kuesioner secara online. Analisis data deskriptif dan uji korelasi dilakukan dengan menggunakan SPSS, sedangkan uji pengaruh dilakukan dengan menggunakan LISREL. Telepresence, social presence, dan social value berada pada kategori cukup baik, sedangkan repurchase intention pada kategori cukup rendah. Pada uji hubungan, karakteristik konsumen tidak mempunyai hubungan dengan telepresence, social presence, social value dan repurchase intention. Berdasarkan uji pengaruh, telepresence dan social value berpengaruh signifikan terhadap repurchase intention, sementara social presence tidak memiliki pengaruh yang signifikan terhadap repurchase intention.
Keyword: generasi z, repurchase intention, social presence, social value, telepresence

Judul: The Influence of Self-Confidence and Perceived Product Quality on Consumptive Behavior at E-commerce in Generation Z
Abstrak: Kemajuan teknologi saat ini memengaruhi segala aspek kehidupan manusia khususnya dalam hal berbelanja. Penelitian ini bertujuan untuk melihat pengaruh kepercayaan diri dan persepsi kualitas produk terhadap perilaku konsumtif generasi Z yang berbelanja melalui e-commerce. Desain penelitian ini adalah cross-sectional study dan teknik purposive sampling menggunakan kuesioner online dengan jumlah responden 192 orang. Data diolah dan dianalisis menggunakan program Microsoft Excel 2019, Statistical Program for Social Sciences (SPSS) 25, dan SMART-PLS. Hasil menunjukkan tidak terdapat hubungan antara karakteristik responden dengan kepercayaan diri, persepsi kualitas produk, dan perilaku konsumtif. Hasil uji pengaruh menunjukkan bahwa kepercayaan diri berpengaruh positif terhadap persepsi kualitas produk dan berpengaruh negatif terhadap perilaku konsumtif, serta persepsi kualitas produk juga berpengaruh negatif terhadap perilaku konsumtif., Advances in technology today affect all aspects of human life, especially in terms of shopping. This study aims to see the influence of self-confidence and perceived product quality on the consumptive behavior of Generation Z who shop through e-commerce. The design of this study was a cross-sectional study and a purposive sampling technique using an online questionnaire with 192 respondents. Data was processed and analyzed using the Microsoft Excel 2019 program, Statistical Program for Social Sciences (SPSS) 25, and SMART-PLS. The results show that there is no relationship between the characteristics of respondents with self-confidence, perceived product quality, and consumptive behavior. The results of the influence test show that self-confidence has a positive effect on perceived product quality and a negative effect on consumptive behavior, and perceived product quality also has a negative effect on consumptive behavior.
Keyword: consumptive behavior, e-commerce, generation z, perceived product quality, self-confidence, generasi z, kepercayaan diri, persepsi kualitas produk, perilaku konsumtif

Judul: Penentuan pH dan suhu optimum aktivitas kitinase Bacillus cereus I.5 dan pengujian kitinase dalam mendegradasi eksoskeleton kutu bertepung putih (Ferrisia virgata Cockerell)
Abstrak: Bacillus cereus I.5 is one of chitinolytic bacteria isolated from chilli rhizosphere. The chitinase could be apply as a biocontrol of plant pest. One method to precipitate enzyme by using ammonium sulphate. It could increase specific activity enzyme. This research was conducted to determine optimum pH and temperature of chitinase activity of Bacillus cereus I.5 and tested its ability to degrade chitin exoskeleton of Ferrisia virgata Cockerell, one of Jatropha’s pest. Enzyme activity was obtained at the 10% ammonium sulphate saturation level, which is 20 times higher compared to crude enzyme. Specific enzyme activity increased from 0,039 U/mg of crude extract to 0,778 U/mg after ammonium sulphate precipitation. Chitinase of B. cereus i.5 showed highest activity at pH 7,0 and 55 °C although the enzyme also showed its activity at pH 5,0-9,0 and temperature 26-≤55 oC. Application of crude chitinase and the enzyme after ammonium sulphate precipitation on degrading of chitin Ferrisia virgata showed it worked better if incubated firstly at its optimum temperature.
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