Rekayasa
Journal Information

ISSN / EISSN :
0216-9495 / 2502-5325
Current Publisher: University of Trunojoyo Madura (10.21107)
Total articles ≅ 97
Current Coverage
DOAJ
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Latest articles in this journal
Rekayasa, Volume 13, pp 307-316; doi:10.21107/rekayasa.v13i3.9858
Abstract:
Pemilihan lokasi merupakan langkah awal untuk penentuan kegiatan perikanan budidaya laut yang berkelanjutan. Dokumen Rencana Zonasi Wilayah Pesisir dan Pulau-Pulau Kecil (RZWP3K) Provinsi Jawa Timur menyebutkan bahwa kawasan pesisir dan laut yang berada di perairan Selat Madura dan Selat Bali, terutama pesisir Kabupaten Situbondo dan Banyuwangi dialokasikan sebagai wilayah pengembangan budidaya laut. Penelitian ini bertujuan untuk menganalisa karakteristik kondisi perairan Kabupaten Situbondo dan Banyuwangi, khususnya mengenai kelayakan sebagai lokasi budidaya laut. Penelitian ini dilaksanakan pada bulan Juni sampai dengan Juli tahun 2020. Pengambilan data sample air laut dilakukan di titik pengamatan yang tersebar di 15 kecamatan pesisir di Kabupaten Situbondo (Selat Madura) dan Banyuwangi (Selat Bali dan Samudera Hindia). Metode yang digunakan adalah dengan menganalisis parameter kualitas perairan dan menghitung nilai indeks kesesuaian. Selain itu dilakukan pula pendugaan besarnya beban limbah dan analisis komponen utama. Hasil penelitian dapat disimpulkan bahwa lokasi yang sesuai untuk pengembangan budidaya laut di Kabupaten Situbondo terletak di Kecamatan Suboh, Kendit, Arjasa dan Jangkar dengan nilai indeks kesesuaian berkisar antara 63,5-67,5. Sementara untuk Kabupaten Banyuwangi, kawasan yang sesuai untuk pengembangan budidaya laut terletak di Kecamatan Wongsorejo dan Muncar dengan nilai indeks antara 64 – 68.5. Estimasi beban limbah menunjukkan bahwa potensi limbah yang terjadi akibat budidaya laut dengan KJA adalah sekitar 0,24 ton N/10 unit karamba. Hasil perhitungan analisis komponen utama menunjukkan stasiun pengamatan memiliki karakteristik nilai parameter kualitas air yang beragam.
Rekayasa, Volume 13, pp 277-283; doi:10.21107/rekayasa.v13i3.8926
Rekayasa, Volume 13, pp 234-239; doi:10.21107/rekayasa.v13i3.8545
Abstract:
A multi-criteria collaborative filtering recommendation system allows its users to rate items based on several criteria. Users instinctively have different tendencies in rating items that some of them are quite generous while others tend to be pretty stingy. Given the diverse rating patterns, implementing a normalization technique in the system is beneficial to reveal the latent relationship within the multi-criteria rating data. This paper analyses and compares the performances of two methods that implement the normalization based multi-criteria collaborative filtering approach. The framework of the method development consists of three main processes, i.e.: multi-criteria rating representation, multi-criteria rating normalization, and rating prediction using a multi-criteria collaborative filtering approach. The developed methods are labelled based on the implemented normalization technique and multi-criteria collaborative filtering approaches, i.e., Decoupling normalization and Multi-Criteria User-based approach (DMCUser) and Decoupling normalization and Multi-Criteria User-based approach (DMCItem). Experiment results using the real-world Yelp Dataset show that DMCItem outperforms DMCUser at most in terms of Precision and Normalized Discounted Cumulative Gain (NDCG). Though DMCUser can perform better than DMCItem at large , it is still more practical to implement DMCItem rather than DMCUser in a multi-criteria recommendation system since users tend to show more interest to items at the top list.
Rekayasa, Volume 13, pp 291-298; doi:10.21107/rekayasa.v13i3.7606
Rekayasa, Volume 13, pp 225-233; doi:10.21107/rekayasa.v13i3.9130
Rekayasa, Volume 13, pp 284-290; doi:10.21107/rekayasa.v13i3.9011
Rekayasa, Volume 13, pp 236-269; doi:10.21107/rekayasa.v13i3.9146
Rekayasa, Volume 13, pp 240-245; doi:10.21107/rekayasa.v13i3.7869
Rekayasa, Volume 13, pp 219-224; doi:10.21107/rekayasa.v13i3.8703
Abstract:
The use of steel in building or construction manufacture continues to decrease, owing in part to the sustainability and mechanical properties of fibers which have higher strength in minimum weight than steel. This preliminary study was defined to evaluate the mechanical properties of high-performance fibers, especially ultrahigh molecular weight polyethylene (UHMWPE), in terms of the composite to be the main material of windmill turbines. It was UHMWPE as reinforcement and high-density polyethylene (HDPE) as a matrix in this composite system. The composites were processed in a variety of pressure and duration (50 to 165 bar and 10 minutes to 48 hours). The mechanical strength was tested by 3-point bending tests to measure the interlaminar shear strength, shear modulus, and bending strength. The result showed a significant difference in properties of the composite which is higher pressure and longer duration obtained a higher value of mechanical strength.
Rekayasa, Volume 13, pp 212-218; doi:10.21107/rekayasa.v13i3.9013