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Studi Koefisien N Pada Prediksi Roll Kapal Sarat Rendah Dalam IMO A.749(18) Ali, Baharuddin; Pitoyo, Pitoyo
Wave: Jurnal Ilmiah Teknologi Maritim Vol 6, No 1 (2012)
Publisher : Wave: Jurnal Ilmiah Teknologi Maritim

Perkembangan penggunaan kapal dengan sarat rendah atau rasio B/T besar (deck cargo) di Indonesia menjadi suatu pilihan dalam rangka efektifitas dan efisiensi dibandingkan membangun kapal tipe hatch cargo. Perairan Indonesia yang sangat bervariasi kedalaman lautnya serta terhubung ke jalur sungai-sungai besar yang masuk hingga pedalaman merupakan suatu pertimbangan pemilihan tipe kapal sarat rendah. Seiring dengan itu peraturan keselamatan kapal semakin ketat merupakan tantangan dalam perancangan dan sistim operasional kapal. Karakteristik lengan stabilitas pada kapal sarat rendah yang berbeda pada kapal umumnya seperti yang disyaratkan dalam kriteria kestabilan minimum yang dikeluarkan oleh International Maritime Organization (IMO) Resolusi A.749(18) menjadikan kapal sarat rendah perlu kajian tersendiri. Dari hasil kajian dan uji model didapatkan bahwa untuk kapal sarat rendah (B/T ³ 4) pada prediksi roll dalam weather criterion direkomendasikan untuk adanya koreksi nilai N dari sebelumnya yang dipakai yaitu 0.02 menjadi 0.035, dengan nilai tersebut menunjukkan hasil prediksi maksimum roll yang realistik bagi kapal sarat rendah. Hal ini merupakan masukkan dalam penyusunan aturan keselamatan kapal sarat rendah.

Analisa Hidrodinamika Kapal Container Sarat Rendah Ali, Baharuddin; Firdaus, Nurman; Nurhadi, N
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 14, No 3 (2017): Oktober
Publisher : Department of Naval Architecture - Diponegoro University

Kapal container sebagai sarana angkutan barang berpengaruh vital terhadap laju percepatan perekonomian nasional. Kondisi perairan Indonesia yang kedalaman dan fasilitas pendukung pelabuhan bervariasi serta efisiensi operasional kapal menjadi pertimbangan dalam mendesain kapal. Penggunaan kapal sarat rendah tipe barge bermesin sebagai pengangkut container, Self Propelled Container Barge (SPCB) saat ini banyak menjadi pilihan operator kapal dalam melayani pengiriman barang dengan container. Penelitian ini menyajikan analisis hidrodinamika kapal SPCB 100 TEUs dengan metode pengujian model meliputi seakeeping, turning dan zig-zag manuvering serta resistance test. Dari hasil uji seakeeping diketahui bahwa respon gerak kapal pada kondisi gelombang sea-state 4 masih dalam batas toleransi dengan memperhatikan kombinasi kecepatan dan arah heading kapal. KinerjaÂ manuvering turning dan zig-zag kapal dalam batas aman yang ditetapkan IMO. Dari hasil uji resistance didapatkan kecepatan maksimal yang optimum kapal adalah 12 knot. Selain besaran terukur, uji hidrodinamika dengan model memberikan gambaran fenomena saat kapal beroperasi di laut, sehingga menjadi informasi yang penting dalam desain dan operasional kapal.

PENGARUH BENTUK LAMBUNG KAPAL TERHADAP POLA ALIRAN DAN POWERING PADA KAPAL PERAIRAN SUNGAI DAN LAUT Sahlan, Sahlan; Ali, Baharuddin; H.N, Wibowo; Bisri, A.; Adietya, Berlian Arswendo
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 13, No 1 (2016): Februari
Publisher : Department of Naval Architecture - Diponegoro University

Bentuk lambung haluan kapal yang tepat sangat berpengaruh pada perbaikan pola aliran air maupun penurunan tahanan gelombang yang ditimbulkan badan kapal saat beroperasi. Pada tulisan ini dilakukan kajian tentang pengaruh bentuk lambung haluan kapal yang diwakili oleh Model-A dan Model-B terhadap pola aliran, tahanan dan daya poros pada kapal yang merupakan salah satu jenis kapal perairan sungai-laut. Pada Model-B dilakukan modifikasi bentuk haluan dari Model-A. Dari hasil simulasi didapatkan bahwa peningkatan daya poros sebesar 12% saat kecepatan 14.5 knot pada Model-B atau keuntungan 3% dari penambahan displaceament 15% pada Model-B dari bentuk asli Model-A dengan operasional optimum kapal adalah pada kecepatan antara 12 dan 15 knots.

Analisa Perubahan Panjang Model FPU Barge Terhadap Koefisien Linier dan Kuadratik Roll Damping Ali, Baharuddin; Indiaryanto, Mahendra; Permana, Chandra; Widodo, W
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 15, No 3 (2018): Oktober
Publisher : Department of Naval Architecture - Diponegoro University

Roll damping sangat berperan penting pada maksimum roll terutama pada daerah resonansi disekitar roll natural period. Dalam prediksi gerak roll, prediksi roll damping dilakukan dengan metode difraksi radiasi yang Â menambahkan viscous roll damping dari formulasi semi empiris maupun dari uji roll decay. Pada uji roll decay akan didapatkan koefisien komponen roll damping linier dan quadratik yang selanjutnya diperlukan dalam perhitungan nilai roll damping. Nilai koefisien roll damping ini bisa diperoleh dengan melakukan fitting hasil uji roll decay dengan metode Froude maupun Bertin. Pada studi ini dilakukan analisa terhadap perubahan roll damping dan akibatnya terhadap gerak roll pada dua buah model FPU barge yang identik namun berbeda dimensi. Perubahan dimensi model benda apung akan menimbulkan perubahan pula pada karakteristik koefisien linier maupun quadtatik roll dampingnya. Dari hasil pengujian model diketahui bahwa pengurangan dimensi panjang model dengan posisi relatif titik berat dan jari-jari girasi roll tetap akan menaikan nilai koefisien roll damping 21% dari desain induknya. Kenaikan nilai koefisien roll damping didominasi oleh komponen linier. Dengan adanya kenaikan koefisien roll damping pada model yang lebih pendek menyebabkan turunnya nilai respon gerak roll melalui uji seakeeping.

STUDI KOEFISIEN N PADA PREDIKSI ROLL KAPAL SARAT RENDAH DALAM IMO A.749(18) Ali, Baharuddin; Pitoyo, Pitoyo
Wave: Jurnal Ilmiah Teknologi Maritim Vol 6, No 1 (2012)
Publisher : Badan Pengkajian dan Penerapan Teknologi

Perkembangan penggunaan kapal dengan sarat rendah atau rasio B/T besar (deck cargo) di Indonesia menjadi suatu pilihan dalam rangka efektifitas dan efisiensi dibandingkan membangun kapal tipe hatch cargo. Perairan Indonesia yang sangat bervariasi kedalaman lautnya serta terhubung ke jalur sungai-sungai besar yang masuk hingga pedalaman merupakan suatu pertimbangan pemilihan tipe kapal sarat rendah. Seiring dengan itu peraturan keselamatan kapal semakin ketat merupakan tantangan dalam perancangan dan sistim operasional kapal. Karakteristik lengan stabilitas pada kapal sarat rendah yang berbeda pada kapal umumnya seperti yang disyaratkan dalam kriteria kestabilan minimum yang dikeluarkan oleh International Maritime Organization (IMO) Resolusi A.749(18) menjadikan kapal sarat rendah perlu kajian tersendiri. Dari hasil kajian dan uji model didapatkan bahwa untuk kapal sarat rendah (B/T ³ 4) pada prediksi roll dalam weather criterion direkomendasikan untuk adanya koreksi nilai N dari sebelumnya yang dipakai yaitu 0.02 menjadi 0.035, dengan nilai tersebut menunjukkan hasil prediksi maksimum roll yang realistik bagi kapal sarat rendah. Hal ini merupakan masukkan dalam penyusunan aturan keselamatan kapal sarat rendah.

The Wave Heights Distribution of Random Wave Based on Ocean Basin Firdaus, Nurman; Ali, Baharuddin; Nasir, Mochammad; Muryadin, M
Kapal: Jurnal Ilmu Pengetahuan dan Teknologi Kelautan Vol 17, No 3 (2020): October
Publisher : Department of Naval Architecture - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/kapal.v17i3.31021

The wave height parameter in ocean waves is one of the important information for a marine structure design. The present paper investigates the results of wave heights distribution from laboratory-generated for single sea state. Data of the random wave time series collected at the ocean basin are analyzed using the wave spectrum and compared with the theoretical spectrum in this study. The random wave data is varied with four sea states consisting of sea states 3, 4, 5 and 6 obtained from laboratory measurements. The parameter conditions of generated sea waves are represented by a value of significant wave height and wave peak period in the range of sea states. The individual wave heights data in each sea state are presented in the form of exceedance probability distribution and the predictions using a linear model. This study aims to estimate the wave heights distribution using the Rayleigh and Weibull distribution model. Furthermore, the accuracy of the wave heights distribution data's prediction results in each sea state has been compared and examined for both models. The applied linear models indicate similar and reasonable estimations on the observed data trends.

Hydrodynamic Analysis of Patrol Vessel Based On Seakeeping and Resistance Performance Firdaus, Nurman; Ali, Baharuddin
Journal of Ocean, Mechanical and Aerospace -science and engineering- Vol 60 No 1 (2018): Journal of Ocean, Mechanical and Aerospace -science and engineering- (JOMAse)
Publisher : International Society of Ocean, Mechanical and Aerospace -scientists and engineers- (ISOMAse)

The patrol vessel must have a good performance criteria for a sea worthiness.The hydrodynamic aspects analysis of a ship design is a main step conduct by designer. This study describes an analysis of motions and ship resistance. The seakeeping test conducted two variations of a ship loading condition. The ship's motion response to sea-state 4 waves with the heading of 180 and 135 deg. The ship resistance test with two draft conditions is calculated by model test and numerical simulation. The ship motion response is expressed in terms of the probability distribution. The values of ship resistance are presented as a non-dimensional graph with a Froude number. The ship loading conditions on a vertical center of gravity is higher resulting in a larger ship motion response than lower vertical center of gravity, as well as the heading of wave is very influential. The results of resistance test above Froude number 0.3, a resistance of ship increase and began to appear hump resistance around a hull.

Experimental Study of the Probability Distributions on the Seakeeping Performance of Monohull and Catamaran Design Ali, Baharuddin; Firdaus, Nurman
Journal of Ocean, Mechanical and Aerospace -science and engineering- Vol 47 No 1 (2017): Journal of Ocean, Mechanical and Aerospace -science and engineering- (JOMAse)
Publisher : International Society of Ocean, Mechanical and Aerospace -scientists and engineers- (ISOMAse)

A safety and a comfort criteria of ship, one of them which can be known from ability of the ship motion on sea wave. The development of maritime technology in particular shipbuilding, catamaran ship design is one of the considerations in modern ship design, in addition to monohull ship design. This research describes the analysis of seakeeping model test of monohull and catamaran ship. The seakeeping model test is performed on sea- state 4 with a heading of 45 deg, 90 deg, 135 deg and 180 deg. Ship motion responses in the form of heave, pitch and roll motion, are presented in the form of the probability distribution curves. From the results of seakeeping test, it can be seen that the catamaran ship provides motion response relatively smaller than the monohull ship.

Multivariate Time Series Forecasting using Hybrid Vector Autoregressive and Neural Network for Coupled Roll-Sway-Yaw Motions Prediction Suhermi, Novri; Suhartono, -; Rahayu, Santi Puteri; Ali, Baharuddin; Dahlila, Dea; Aisy, Rahida Rihhadatul
JOIV : International Journal on Informatics Visualization Vol 9, No 4 (2025)
Publisher : Society of Visual Informatics

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.62527/joiv.9.4.3077

There are six types of motion referred to as the six degrees of freedom, which define the motion of a ship. For a ship to remain stable, it must be in a symmetrical position. Therefore, a ship's stability can be determined based on its motion. Ship motions can be analyzed either in an uncoupled system or a coupled system. One of the coupled motion systems that is often studied is the roll-sway-yaw motion. In this study, we apply the Hybrid Vector Autoregressive–Neural Network (VAR-NN) model to build a multivariate time series model for predicting the roll-sway-yaw motions of a prototype ship. The Hybrid VAR-NN is a data analysis technique that integrates the linear capabilities of the VAR model with the nonlinear capabilities of the NN model to capture both linear and nonlinear trends simultaneously. The dataset for this study was generated from waves in a prototype ship experiment and divided into in-sample and out-of-sample data. The model was trained using the in-sample data, and predictions were made on the out-of-sample data using the trained model. The forecast results of the VAR-NN model were compared with those from the pure VAR and pure NN models. Model selection was based on out-of-sample performance criteria, with the Root Mean Square Error (RMSE) employed as the prediction performance metric. According to the experimental results, the Hybrid VAR-NN model outperformed the other models, demonstrating its ability to improve the prediction performance of the pure models through its hybrid approach.

Cultural Da'wah in the Sambas Malay Community through Tepung Tawar Tradition Lamazi, Lamazi; Amin, Muliaty; Ali, Baharuddin; Yaumi, Muhammad; Masduki, Anwar
MUHARRIK: Jurnal Dakwah dan Sosial Vol. 6 No. 1 (2023): Muharrik: Jurnal Dakwah dan Sosial
Publisher : Fakultas Dakwah Institut Agama Islam Sunan Giri Ponorogo

Show Abstract | Download Original | Original Source | Check in Google Scholar

Sambas Malay community is included in an area with a tradition of spreading da'wah, one of which is the tradition of tepung tawar (fresh flour). The spread of da'wah through this tradition is a contact of customs and culture and is not in line with Islamic teachings. Hence, the tradition of fresh flour is one part of the cultural da'wah in the Sambas Malay community. This study aims to examine the value of da'wah contained in the tradition of tepung tawar (fresh flour) in the life of the Sambas Malay community. This research is descriptive field research using qualitative analysis. Data collection was done through observation, interview and documentation. The results of this study found that the form of cultural da'wah contained in the tradition of tepung tawar (fresh flour) in the Sambas Malay community consists of three stages: preparation, implementation, and post-implementation. There are several values contained in this tradition of fresh flour such as having an open attitude, having high Islamic values, ethical and moral values, togetherness values, shared ideals, deliberation values, and socio-cultural values and religiosity values. As well as the relationship between the tradition of tepung tawar (fresh flour) with aqiqah, which is in contact with Hinduism, Buddhism and Islam, this becomes a style of tradition that exists in the life of the Sambas Malay community, which is seen in the tradition of tepung tawar (fresh flour)

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