EPI International Journal of Engineering
EPI International Journal of Engineering (EPI-IJE) is published and managed by Center of Technology, Faculty of Engineering, University of Hasanuddin (CoT, FoE, UNHAS), Indonesia. The main objective of this international journal is to create publishing opportunities and to disseminate knowledge in engineering-related topics collected from all over the world. A wide range of topics may be accepted, including from both conventional engineering and newly developed fields. Multi-disciplinary and Inter-disciplinary fields are encouraged to submit, and the topic on engineering education is also welcome. Manuscripts should be in English only. This journal system is open free-access to public in electric form, and the paper-form journal is also available. No fee is charged to accepted papers. On acceptance of submitted paper, authors are asked to submit a short copy-right form, but the authors have rights to reuse their work. The submitted manuscripts are under peer review at least by two reviewers, and publication is made biannually.
Articles
139 Documents
<![CDATA[History of Mitigating Rolling Contact Fatigue and Corrugation of Railway Rails in Japan - Review ]]>
<![CDATA[Makoto Ishida]]>
<![CDATA[ EPI International Journal of Engineering Vol 1 No 2 (2018): Volume 1 Number 2, August 2018 with Special Issue on Railway Engineering ]]>
Publisher : <![CDATA[Center of Techonolgy (COT), Engineering Faculty, Hasanuddin University ]]>
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DOI: 10.25042/epi-ije.082018.02
<![CDATA[Rail is the one of the most important materials to support and guide railway vehicles safely and smoothly. Since rail suffers from variousinteracting forces and environmental atmosphere, wear and fatigue pose large problems with wheel and rail. Hence, wear and fatigue ofwheel and rail have been studied so far to keep running safety and some level of riding comfort of vehicle taking into account trackmaintenance cost in the world. In this review, the history of theory and practice of rail maintenance in Japanese railways is describedfocusing on rolling contact fatigue (RCF) corrugation of rails caused by dynamic rolling friction at wheel/rail interface. In particular, “squat”mainly callled in UK or “rail surface shelling” called in Japan which is one of typical fatigue phenomenon for steel wheel-on-rail system andrail corrugations caused by dynamic lateral friction and vertical loading at sharp curves and/or long wavelength of rail corrugation causedby longitudinal roll-slip or stick-slip excited by the resonance of unsprung mass of bogie vertical vibration supported by track stiffness. Inaddition, the practice of countermeasure for RCF defect of squat, preventive grinding, and countermeasure for top of low rail corrugation,top of low rail lubrication “Friction Moderating System” are described. Also, the possibility of preventing long wavelength of rail corrugationformed in tangential track in undersea tunnel (salty water) enviornment is described.]]>
<![CDATA[Effect of Moment of Inertia of Attached Mass on Natural Frequencies of Cantilevered Symmetrically Laminated Plates ]]>
<![CDATA[Kenji Hosokawa]]>
<![CDATA[ EPI International Journal of Engineering Vol 1 No 2 (2018): Volume 1 Number 2, August 2018 with Special Issue on Railway Engineering ]]>
Publisher : <![CDATA[Center of Techonolgy (COT), Engineering Faculty, Hasanuddin University ]]>
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DOI: 10.25042/epi-ije.082018.05
<![CDATA[Since composite materials such as laminated composite plates have high specific strength and high structural efficiency, they have been usedin many structural applications. It is therefore very important to make clear the vibration characteristics of the laminated plates for the designand the structural analysis. Especially, the vibration characteristics of the laminated plates with attached mass are essential. However, wecannot find the theoretical or experimental approaches for the free vibration of laminated plates with attached mass. In the present study, theexperimental and numerical approaches are applied to the free vibration of cantilevered symmetrically laminated plates with attached mass.First, by applying the experimental modal analysis technique to the cantilevered symmetrically laminated plates with attached mass, thenatural frequencies and mode shapes of the plates are obtained. Next, the natural frequencies and mode shapes of the cantileveredsymmetrically laminated plates with attached mass are calculated by Finite Element Method (FEM). Finally, from the experimental andnumerical results, the effect of the moment of inertia of the attached mass to the natural frequencies and mode shapes of the cantileveredsymmetrically laminated plates are clarified.]]>
<![CDATA[Characteristic of Current Diffusion on Double-Plate Conductor for Smaller Resistive Load ]]>
<![CDATA[A. M. Shiddiq Yunus]]>;
<![CDATA[Apollo Apollo]]>;
<![CDATA[Muhammad Ruswandi Djalal]]>;
<![CDATA[Ahmed Abu-Siada]]>
<![CDATA[ EPI International Journal of Engineering Vol 2 No 1 (2019): Volume 2 Number 1, February 2019 with Special Issue on Composite Materials & Stru ]]>
Publisher : <![CDATA[Center of Techonolgy (COT), Engineering Faculty, Hasanuddin University ]]>
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DOI: 10.25042/epi-ije.022019.10
<![CDATA[Power transmission line is one of the pivotal parts of a power system. It connects power generation house with the consumer even in the long distances. Research on current diffusion on the conductor is inevitable to maximize the power dispatch on transmission line. The main purpose of this study is to recognize the behaviors and characteristics of current diffusion in double-plates conductor for further development in the future. The research outcomes would be very useful, particularly in the transmission line study. In this paper, study will be focused on the characteristic of current diffusion in conductor due to its variation impedance value of load particularly when resistive load is smaller than the conductor impedance (Zo). This research is conducted by experimental test and carried out through extensive simulation using MATLAB and Visual Basic Program in MS. Excel. Poynting theory is employed as a validation approach. The simulation and experiment results show that if RL is smaller than the line impedance Zo, deficiency current establish will occur where the electromagnetic energy is not sufficient for the load.]]>
<![CDATA[The Influences of Lengthening Dimension of Ro-Ro Ferry Toward the Considerations of Hydrodynamics Characteristic and Loading Capacity Aspect ]]>
<![CDATA[Andi Rachmianty]]>;
<![CDATA[Suandar Baso]]>;
<![CDATA[Syamsul Asri]]>
<![CDATA[ EPI International Journal of Engineering Vol 2 No 1 (2019): Volume 2 Number 1, February 2019 with Special Issue on Composite Materials & Stru ]]>
Publisher : <![CDATA[Center of Techonolgy (COT), Engineering Faculty, Hasanuddin University ]]>
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DOI: 10.25042/epi-ije.022019.08
<![CDATA[The ferry business has become an important business segment for ship designers, builders and operators. Therefore, many ways have been done in order to increase ferry business through the proper design or converting ships by lengthening. This research is focused on the influences of lengthening a Ro-Ro ferry to hydrodynamics characteristic and loading capacity aspects. Moreover, the ships also are fixed in the same width and draft dimensions. The difference of the Ro-Ro ferries length is indicated by the addition of one column of car space where one column car space is given by car size including distance between car columns spaces which is an increment of every 5.88 meter. The total resistances of Ro-Ro ferries are obtained by ship model experiment in towing tank. There are 4 ship models that are made. The lengthening a Ro-Ro ferry is described into non-dimensional parameter by the ratio of ship length and displacement volume (L/V1/3). The hydrodynamics and the loading capacity of carried car aspects could be described into the ratio of resistance and loading capacity of carried car (RT/SUK) with ship speed. The research result shows that the lengthening of a Ro-Ro ferry affects on total resistance, speed, and loading capacity of carried car. The increase of total resistance is caused by higher residual resistance at high speeds and this is experienced by small length size. Therefore by lengthening the Ro-Ro ferry it could reduce total resistance in the same speed especially the residuary resistance but eventhough lengthening Ro-Ro ferry the effective speed should be considered. In additions, the effective speed for actual ships dimension in the same Rt/SUK 0.05 i.e. B5L10 is about 13.85 knot, B5L11 14.33 knot, B5L12 14.94 knot, and B5L13 15.45 knot respectively.]]>
<![CDATA[Multi-Objective Optimization of Variable-Stiffness Composites Fabricated by Tailored Fiber Placement Machine ]]>
<![CDATA[Shinya Honda]]>
<![CDATA[ EPI International Journal of Engineering Vol 2 No 1 (2019): Volume 2 Number 1, February 2019 with Special Issue on Composite Materials & Stru ]]>
Publisher : <![CDATA[Center of Techonolgy (COT), Engineering Faculty, Hasanuddin University ]]>
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DOI: 10.25042/epi-ije.022019.04
<![CDATA[A multi-objective optimization method for the laminated composite fabricated by a tailored fiber placement machine that is an application of embroidering machine is presented. The mechanical properties of composite with curvilinear fibers including stiffness, volume fraction, and density are variable depending on curvatures of fibers. The present study first measures the relation between curvatures and mechanical properties. The measured results indicate that the stiffness of composite decreases linearly as the curvature increases. Then, the obtained relation is applied to the multi-objective optimization where the maximum principal strain and magnitude of curvature are employed as objective functions. Obtained Pareto optimum solutions are widely distributed ranging from the solutions with curvilinear fibers to those with straight fibers, and the curvilinear fiber has still advantages over straight fiber even its weakened stiffness.]]>
<![CDATA[Autonomy Stemmer Algorithm for Legal and Illegal Affix Detection use Finite-State Automata Method ]]>
<![CDATA[Ana Tsalitsatun Ni'mah]]>;
<![CDATA[Dwi Ari Suryaningrum]]>;
<![CDATA[Agus Zainal Arifin]]>
<![CDATA[ EPI International Journal of Engineering Vol 2 No 1 (2019): Volume 2 Number 1, February 2019 with Special Issue on Composite Materials & Stru ]]>
Publisher : <![CDATA[Center of Techonolgy (COT), Engineering Faculty, Hasanuddin University ]]>
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DOI: 10.25042/epi-ije.022019.09
<![CDATA[Stemming is the process of separating words from their affixes to get a basic word. Stemming is generally used when preprocessing in text-based applications. Indonesian Stemming has developed research which is divided into two types, namely, stemming without dictionaries and stemming using dictionaries. Stemming without dictionaries has a disadvantage in the results of removal of affixes which are sometimes inappropriate so that it results in over stemming or under stemming, while stemming using dictionaries has a disadvantage during the stemming process which is relatively long and cannot eliminate affixes to compound words. This study proposes a new stemming algorithm without a dictionary that is able to detect legal and illegal affixes in Indonesian using the Finite-State Automata method. The technique used is rule-based Stemmer based on Indonesian language morphology with Regular Expression. Test results were carried out using 118 news documents with 15792 words. The first test results on the autonomy stemmer algorithm obtain the correct word which amounts to 10449 of the total number of words processed, which means getting an average accuracy of 66%. The second test results on the autonomy stemmer algorithm get the results of the average speed of 0.0051 seconds. The third test result is being able to do the elimination of affixes to compound words.]]>
<![CDATA[Free Vibration Analysis of L-Shaped Folded Thin Plates ]]>
<![CDATA[Koji Sekine]]>
<![CDATA[ EPI International Journal of Engineering Vol 2 No 1 (2019): Volume 2 Number 1, February 2019 with Special Issue on Composite Materials & Stru ]]>
Publisher : <![CDATA[Center of Techonolgy (COT), Engineering Faculty, Hasanuddin University ]]>
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DOI: 10.25042/epi-ije.022019.12
<![CDATA[Free vibration analysis of L-shaped folded thin plates having various boundary conditions is presented. Vibration properties of the folded plates are analyzed by means of the Ritz method. Displacement functions satisfying the geometric boundary conditions are assumed in the form of double power series. The interconnection of plate elements of the folded plates is defined by translational and rotational coupling springs. The generalized eigenvalue problem, which is derived by means of minimizing the energy functional, is solved to determine the natural frequencies and mode shapes. The accuracy and validity of the present solutions are demonstrated through convergence studies and comparisons with the results from the literature and FEM (finite element method) analysis solutions. Numerical results are presented for different conditions, such as width ratio, length ratio and the four types of boundary condition.]]>
<![CDATA[Renewable Energy Developments in Indonesia ]]>
<![CDATA[Muhammad Zulkifli]]>;
<![CDATA[Ryuji Tohyama]]>;
<![CDATA[Tomohiro Tohyama]]>;
<![CDATA[Kazuyuki Maeda]]>
<![CDATA[ EPI International Journal of Engineering Vol 2 No 1 (2019): Volume 2 Number 1, February 2019 with Special Issue on Composite Materials & Stru ]]>
Publisher : <![CDATA[Center of Techonolgy (COT), Engineering Faculty, Hasanuddin University ]]>
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DOI: 10.25042/epi-ije.022019.15
<![CDATA[Replacing consumption of fossil fuel with renewable energy is an important way in reducing carbon emission and one of effective solution facing issues of electricity in Indonesia. In light of the perspective of promoting the renewable energy, we plan to use palm oil as biofuels for power generation activities that will help to supply electricity for local community in Indonesia. This paper is a preliminary study that aims to overview the current progress of renewable energy development in Indonesia, also to introducing background of our planning as one of solution in dealing with Indonesia`s current renewable energy usage. Based on expected outputs of our planning, this study attempts to discuss our concept which is to promote of Local Production Energy for Local Consumption and its application which will lead to development of one Smart Energy Community, as one of the key points to developing Smart City.]]>
<![CDATA[Heave and Pitch Motions of a Towed Ship in Waves Incorporated with an Asymmetrical Bridle Towline Model ]]>
<![CDATA[Ahmad Fitriadhy]]>;
<![CDATA[Nurul Aqilah Mansor]]>;
<![CDATA[Nur Adlina Aldin]]>
<![CDATA[ EPI International Journal of Engineering Vol 2 No 1 (2019): Volume 2 Number 1, February 2019 with Special Issue on Composite Materials & Stru ]]>
Publisher : <![CDATA[Center of Techonolgy (COT), Engineering Faculty, Hasanuddin University ]]>
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DOI: 10.25042/epi-ije.022019.07
<![CDATA[Investigation of a ship towing system performance in waves incorporated with an asymmetrical towline configuration is necessarily to be studied to ensure a towing safety of navigation. To achieve the objective, this paper presents the ship towing motion performance in waves using Computational Fluid Dynamic (CFD) approach. Here, the heave and pitch motions of the towed ship so-called barge has been analysed, where several effects of the towing angle and towing speeds have been taken into account. In the calm water condition, the results revealed that the increase of tow angle was proportional with the sufficient reduction of the sway amplitude motion and inversely proportional to her yaw motion. The increase of the asymmetrical tow angle, however, has led to increase her sway motion amplitude in wave condition and conversely reduced the tow speed increased. In addition to the pitch motion characteristic, it subsequently increased by 12.1% as the tow angle raised from 25° to 35°; meanwhile the pitch motion of barge has by 10.2% as the tow speed increased from 0.655 m/s to 0.728 m/s. This CFD simulation is very useful as the preliminary prediction on the heave and pitch motion characteristics ensure a safety navigation of a towed ship in waves.]]>
<![CDATA[Heave and Pitch Motion Performances of a Ship Towing System Incorporated with Symmetrical Bridle Towline Model ]]>
<![CDATA[Ahmad Fitriadhy]]>;
<![CDATA[Nur Adlina Aldin]]>;
<![CDATA[Nurul Aqilah Mansor]]>;
<![CDATA[Nur Aqilah Hanis Zalizan]]>
<![CDATA[ EPI International Journal of Engineering Vol 2 No 1 (2019): Volume 2 Number 1, February 2019 with Special Issue on Composite Materials & Stru ]]>
Publisher : <![CDATA[Center of Techonolgy (COT), Engineering Faculty, Hasanuddin University ]]>
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DOI: 10.25042/epi-ije.022019.06
<![CDATA[An investigation on vertical motion characteristics of a ship towing system incorporated with symmetrical bridle towline configuration set a real challenge for the naval architect engineer. This paper presents a Computational Fluid Dynamic (CFD) approach to analyse heave and pitch motion performances in waves. Several towing parameters such as various towline length and towing’s velocity have been taken into account. Here, 1B (barge) is employed in the simulation; and designated as a towed ship. The results revealed that the subsequent increase of the towline lengths has been basically proportional with the increase of her heave motion; while inversely decrease in pitch motions. In addition, the effect of the extending towline length = 1.0 to 3.0 resulted in insignificant effect to the towline tension. However, the increase of the towing’s velocity from 0.509 m/s to 0.728 m/s has led to significantly increase her heave motion and the towline tension by 40.46% and 24%, respectively; meanwhile, the pitch motion barge has sufficiently decreased by 35.94%. This simulation has been beneficial for the towing operator to ensure a higher level of the safety navigation of ship towing system.]]>
