No abstract

Installation and decommissioning activities of offshore structures often applied a floating crane barge for a lifting operation. The excessive movement response of lifted module affected by the motion of floating crane barge in waves can increase a large amplitude. However, the coupled motions of a floating crane barge and lifted module are not easy to predict accurately due to the dynamic movement of a lifted module and the complex coupling system. The coupled motion responses of a floating crane barge and a lifted module during lifting operation were investigated based on time domain by experimental method in this study. The model tests are carried out at Manoeuvring and Ocean Basin of Indonesian Hydrodynamic Laboratory, BRIN. The experimental conditions include the load cases of without and with a load of lifted module in crane tip, and the lifting operation was evaluated under irregular wave conditions. The experimental results show in that the phenomena of shift resonant frequency for the dynamic responses are clearly observed on the coupled motion of multibody system. The dynamic oscillations of the lifted module have a significant effect on the motion response of the floating crane barge. And the hoisting of lifted module has an obstructed effect on the rolling motion of crane barge.

Inovasi teknologi untuk pendidikan mutlak dibutuhkan di era Revolusi Industri 4.0, karena teknologi digital dapat memberikan solusi terhadap permasalahan masyarakat di sektor pendidikan. Fleksibilitas, efektifitas dan efisiensi penggunaan teknologi yang tepat dapat menembus ruang dan waktu dalam menjembatani komunikasi antar para pemangku kepentingan dalam proses pendidikan. Penerapan sistem monitoring pembelajaran online sebagai kegiatan pengabdian kepada masyarakat oleh Departemen Teknik Kelautan FTK-ITS dengan mitra sekolah Al Uswah Surabaya, menjadi solusi terhadap sistem yang masih konvensional yang kurang efektif dan efisien serta rentan terhadap ketidakakuratan akibat kesalahan manusia. Pada akhirnya, dengan sistem ini dapat memperbaiki pelayanan dan kinerja, sehingga efektivitas dan efisiensi proses tersebut meningkat. Parameter penting yang direkam menjadi database oleh sistem monitoring pembelajaran terkait kehadiran siswa, kehadiran guru dan durasi waktu proses belajar mengajar dapat dianalisis secara statistik deskriptif. Fitur sistem yang mampu diakses orang tua siswa, bahkan dapat menjadi media promosi untuk meningkatkan reputasi sekolah serta peran serta orang tua/wali siswa dalam mendukung kesuksesan kegiatan pendidikan. Sistem elektronik ini tidak akan memberikan hasil optimum jika tidak diiringi dengan perubahan pemahaman dan perbaikan budaya belajar mengajar guru, siswa, serta manajemen sekolah. Atau sebaliknya, dengan kehadiran sistem ini secara tidak langsung dapat memaksa untuk terjadinya perubahan budaya belajar-mengajar ke arah yang lebih baik secara bertahap. Dalam penelitian ini parameter penting terkait kegiatan proses belajar mengajar selanjutnya dianalisis untuk menemukan hubungan yang mendukung hipotesis terkait peningkatan budaya belajar mengajar dan reputasi sekolah melalui penggunaan sistem berbasis teknologi komunikasi dan informasi ini.

No abstract

A marginal field defines as an oil and/or gas field that has a short production period, low proven reservoir, and could not be exploited using existing technology. As the demand for oil and gas keeps increasing, one of the solutions to tackle the issues is to build the modified platform which came to be more minimalist to conduct the oil and gas production in the marginal field. Naturally, the minimum offshore structures are cost less but low in redundancy, therefore, pose more risks. Although the study on the minimum structures is still uncommon, there are opportunities to find innovative systems that need to have a further analysis toward such invention. Therefore, this study took the modified jacket platform as a minimum structure, and local stresses analysis by using finite element method is applied for the most critical tubular joint with multiplanarity of the joint is taking into account. The analysis was carried out using the finite element program of Salome Meca with three-dimensional solid elements are used to model the multiplanar joint. Various loading types of axial force, in-plane bending moment, and out-of-plane bending moment are applied respectively to investigate the stress distribution along the brace-chord intersection line of the tubular joint. The results show that the hotspot stress occurred at a different point along each brace-chord intersection line for each loading type. Finally, as compared to the in-plane bending moment or out-of-plane bending moment loading types, the axial force loading state is thought to generate greater hotspot stress.