Judul: Serial Graph-Validation Queue (SG-VQ) Scheme in Client-Server System
Abstrak: Di era saat ini, real-time collaboration semakin berkembang dan memungkinkan pengguna untuk terhubung dari lokasi berbeda melalui aplikasi yang didukung arsitektur klien-server. Misalnya, fitur seperti desktop sharing untuk berbagi layar dan berbagi dokumen yang memungkinkan pengguna mengakses dokumen yang sama secara bersamaan. Namun, akses database secara simultan oleh klien dan modifikasi data dapat menyebabkan data tidak konsisten. Oleh karena itu, kontrol konkurensi sangat penting. Pemrosesan secara bersamaan dapat mempersulit proses penerapan dan menurunkan kinerja server. Object caching menyajikan alternatif untuk mengatur lalu lintas transaksi. Penelitian ini memodifikasi skema kontrol konkurensi optimis yang memanfaatkan object caching, yaitu skema Validation Queue (VQ) menjadi skema Serial Graph-Validation Queue (SG-VQ). Seperti skema VQ, SG-VQ menggunakan arsitektur klien-server dan object caching. Sebagai bagian dari algoritma validasi, sisi cache menerapkan algoritma validasi berbasis queue, sedangkan sisi server menggunakan algoritma validasi berbasis graph. Penelitian ini memvalidasi SG-VQ melalui transaksi hipotetik yang dibagi dalam tiga kasus dan menggambarkan pemanfaatan serial graph, kasus konflik, serta kasus pola siklik., In the current era, real-time collaboration is growing and enabling users to connect from different locations through applications supported by client-server architecture. For instance, features like desktop sharing for screen sharing and document sharing that allows users to simultaneously access the same document. However, simultaneous database access by clients and data modifications can lead to inconsistent data. Therefore, concurrency control is essential. Concurrent processing can complicate the commit process and degrade server performance. Object caching presents an alternative for managing transaction traffic. This study modifies an optimistic concurrency control scheme utilizing object caching, namely the Validation Queue (VQ) scheme, into the Serial Graph-Validation Queue (SG-VQ) scheme. Like the VQ scheme, the SG-VQ employs the client-server architecture and object caching. As part of the validation algorithm, the cache side adopts a queue-based validation algorithm, while the server side utilizes a graph-based validation algorithm. The research validates the SG-VQ with hypothetical transactions in three cases, illustrating the utilization of serial graphs, conflict case, and cyclic case.
Keyword: Klien-server, Kontrol konkurensi, Serial Graph

Judul: Simulasi Virtual Server
Abstrak: Kebutuhan akan tingkat ketersediaan dan skalabilitas yang tinggi dari suatu situs di internet semakin meningkat. Virtual Server (VS) merupakan salah satu solusi untuk meningkatkan tlngkat ketersediaan dan skalabilitas suatu situs internet. Dibangun olcb sekumpulan server yang tertw.bung dalam suatu jaringan. VS memberikan pelayanan seperti halnya single server dalam hal interaksi dengan pengguna. Secara skematis VS terdiri dari dua bagian, yaitu kelompok server yang meiayani permintaan dari pengguna, disebut Real Server (RS) dan server yang rnenet'Uskan pennintaan (request) dari pengguna. disebut Director atau Load Balancer (DIRJ Implementasi VS terdiri dati tiga metodc penerusan paket, Network Address Translation (NAT), Direct Routing (DR) - keduanya diimplementasikan di dalam Local Area Network (LAN), dan IP Tunneling (TUN) yang diimplementasikan di dalam Wide Area Network (WAN), Terdapat delapan algoritma pemilihan RS oteh DIR. tetapi dalam penelitian ini dibatasi menjadi dua yang menganggap semua RS memiliki spesifikasi yang sarna, yaitu Round Robin (RR) dan Least Connection (LC).
Keyword: 

Judul: Insecticidal Activity of Essential Oils Leaves of Cinnamomum spp. (Lauraceae) against Crocidolomia pavonana and Their Phytotoxicity on Broccoli Seedlings
Abstrak: Essential oils from leaves of 13 species of Cinnamomum were tested for their insecticidal activity on the cabbage head caterpillar Crocidolomia pavonana with leaf immerse method. The results showed that the treatment with 1% (w/v) essential oils leaves of C. celebicum, C. multiflorum, C. sintoc, and C. verum caused 21.45, 93.65, 60.30, and 76.10% mortality, respectively. Based on the results of phytotoxicity and insecticidal activity tests, C. multiflorum oil was further tested at 6 concentration levels. In all treatments, larval mortality has occurred at 24 hours after treatment (HAT) and increased at 48 HAT. LC50 of C. multiflorum oil at 24 and 48 HAT was 0.504 and 0.396%, respectively. The treatment with C. multiflorum oil at ≤0.31% did not inhibit the development of C. pavonana larvae. Determination of the chemical constituents of Cinnamomum oils were carried out by gas chromatography-mass spectrometry (GCMS). Totally, 345 compounds were identified. Methyleugenol constituted the main component (49.4%) of leaf essential oil of C. multiflorum and was assumed to be responsible for the insecticidal activity of the oil against C. pavonana larvae. LC50 of pure methyleugenol obtained at 0.365% (48 HAT) and 0.363% (72 HAT). The results showed that C. multiflorum was more effective with LC50 value equivalent to methyleugenol content of 0.32% (24 HAT) and 0.24% (48 HAT).
Keyword: