Judul: Desain dan Implementasi Sistem Terdistribusi dengan Model Replikasi Multi-master pada Basis Data untuk Optimasi Keandalan Sistem
Abstrak: An important factor in the usability of an information system service is security and reliability guarantee. Computer network reliability is defined as the ability to optimize functions in a particular period. Performance, availability, and security are factors influencing reliability. In term of ensuring the reliability, replication technique is one of the mechanisms that copy and distribute data from one database into another. It synchronizes between one or more databases that guarantee data consistency. Multi-master replication is a process that allows any computer can write and read data in a master database. When there is a change in one database master then other master will be updated automatically, and vice versa. A distributed system is a form of the system architecture in which computers are autonomous can communicate and share resources regardless of where the computer was located, and the platform used. Problems in both data processing in data loss and the backup method are still manual so that existing systems less reliable. Seeing these problems need to be constructed a prototype system that is more reliable both in thems of availability or system performance. The study was conducted at the Insistute of Science and Technology Al-Kamal using sample data and existing architecture. The existing system was engineered in a prototype that utilizes a distributed load balancing technology for the system. Furthermore, the research built a backup database with multi-master replication model. Multi-master replication method can improve the availability of the system model. The research resulted that data changes were not lost as long as the system could guarantee their connections. Performance distributed systems using a load balancer can maintain server availability. The system takes 0.731-second and 63.56 to show login page and student data. The number of connections did not affect tes-duration, however, it affected the reply time. F-value 0.11 form test duration and 0.07 for reply time proved the conclusion. The result of this research and model will be proposed as a new model to replace the existing system model.
Keyword: Distributed system, Multi-master, Reliability, Replication

Judul: Perbandingan Algoritma Lazy Update Pada Distributed Search Structure Dengan Model Simulasi
Abstrak: Index pada distributed database sangat menentukan kinerja sistem database. Setiap operasi pada database sebelum mengakses suatu data harus memiliki informasi ten tang lokasi data terse but. Informasi mengenai lokasi data ini disimpan pada index. Untuk meningkatkan kinclja sistem distributed database, telah banyak dilakukan penelitian tentang struktur index dan algoritmanya, salah satunya adalah algoritma fa:y update. Beberapa aigoritma lazy update antara lain :jlxed-posilion copies !Jynchronolls !Jplit danjlxed-posilion cupies semi jynchronolfs split. Metode synchronous split masih menggunakan jynchronizatiol1 untuk salah satu action sehingga terjadi beberapa block action, sedangkan metode semi synchronous split tidak lagi menggunakan .~ynchronization. Pada penelitian ini dilakukan perbandingan untuk mengetahui perbedaan kinerja antara kedua metode fixed-position copies tersebu!. Perbandingan terse but dilakukan dengan menggunakan simulasi komputer. Hasil simulasi ini memberikan beberapa data antara lain cost communication, throughput, duration, serta banyaknya block actiol1 yang terjadi. HasiJ perbandingan antara kedua metode tersebut menunjukkan bahwa metode semi synchronous split memiJiki lebih ban yak keunggulan, antara lain cosl communication yang lebih rendah, throughput yang lebih besar, duration yang leb;h kecil, serta tidak terjadinya block action. Kata Kunci: algoritma, distributed database, index, distributed search structure, B-tree, distributed B- tree,Full replication, path replication, half split, lazy update,Fixed Position copies, simulasi, jaringan. queue.
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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).
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