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Makara Journal of Technology
Published by Universitas Indonesia
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Core Subject : Science,
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Articles 5 Documents
Search results for , issue " Vol 8, No 1 (2004)" : 5 Documents clear
PID Fuzzy Logic Controller System for DC Motor Speed Control Bachri, H Samsul
Makara Journal of Technology Vol 8, No 1 (2004)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.7454/mst.v8i1.76

Abstract

A good controller system must have resilience to disturbance and must be able to response quickly and accurately. Problem usually appears when PID controller system was built sensitively hence the systems respon to the disturbance will yield big overshot/undershot then the possibility of  oscillation to be happened is excelsior. When the controller system was built insensitively, the overshot/undershot will be  small but the recovery time will be longer. Hybrid controller system could overcome those problems by combining PID control system with fuzzy logic. The main control of this system is PID controller while the fuzzy logic acts to reduce an overshot/undershot and a recovery time. The fuzzy logic controller is designed with two input error and delta error and one output of the motor speed. The output of fuzzy logic controller should be only half of the PID controller for limiting entirely fuzzy output. This hybrid system design has a better respon time controller system than PID controller without fuzzy logic.
Construction of Depth-Structure Shelf-edge Map for Case Study of Kujung Formation, East Java Sea Rusli, Saifatur; Suparto, Suparto
Makara Journal of Technology Vol 8, No 1 (2004)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.7454/mst.v8i1.77

Abstract

In general, reflection seismic method has capability to represent sub-surface in time domain. Seismic cross-section that depicts the formation of sub-surface usually use time domain in the format of TWT (Two Way Times). This due to in the process of seismic data acquisition, seismic wave propagates in down-going and up-going manner so that the obtained results from data processing are in the format of TWT seismic vs. shot points. This paper will describe the construction of depth-structure map for case study of Kujung Formation, East Java Sea, as exploration activities of oil companies in Indonesia. Manual data is peaked from seismic cross section and crossed with Vrms data of 3 wells in exploration location. TWT Shelf-edge map of Kujung Formation is divided into 2 parts and the results is crossed with velocitystructure map using Geoframe software CPS-3 so that depth-structure of shelf-edge of Kujung Formation, East Java Sea, is obtained. One of the objectives of this map construction is to get more real visualization of sub surface by using depth domain approach and as sustainable exploration activities of oil companies in Indonesia
Graded Channel MOSFET simulation with S-Pisces 2B Siswono, Hartono
Makara Journal of Technology Vol 8, No 1 (2004)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.7454/mst.v8i1.78

Abstract

Graded-Channel Metal-Oxide-Semiconductor Field-effect-Transistor or GCMOSFET is being discussed in this paper. GCMOSFET technology has been developed to meet the growing demand for low power and high performance application. In this paper, it will be shown that, compared to ungraded MOSFET, the GCMOSFET device offers the advantage of significantly higher drive current. The higher drive current is achieved because the effecctive channel length of GCMOSFET is shorter than the ungraded MOSFETs. From the simulation result with S-PISCES 2B and MATLAB, it can been shown that the ID from GCMOSFET is higher than the ID from ungraded MOSFET. As an example, with VG = 4 V and VD = 4 V, ID from MOSFET is equal with 9.78 e-06 A and ID from GCMOSFET is equal with 16.56 e-06 A. Beside that, as an example, to get ID = 1.13 e-05 A with MOSFET will need VG = 4 V and VD = 4.7 V, and with GCMOSFET VG = 4 V and VD = 1.2 V will be needed. This result has shown that GCMOSFET needs lower supply voltage than the ungraded MOSFET which means that GCMOSFET needs lower power consumption than ungraded MOSFET. From the simulation results, it can be proved that GCMOSFETwith shorter LGC (graded channel region length) will give larger ID than ID from GCMOSFET with longer LGC. As we can see that for VGS = 4 V and VDS = 2 V, GCMOSFET with LGC = 4 μm will give ID = 16,56E-06 A, GCMOSFET with LGC = 3,5 μm will give ID = 17,51E-06 A, and GCMOSFET with LGC = 3 μm will give ID =18,49E-06
Quarternair CuGaSeTe and CuGa0.5In 0.5Te2 Thin Films Fabrication Using Flash Evaporation Soepardjo, A Harsono
Makara Journal of Technology Vol 8, No 1 (2004)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.7454/mst.v8i1.79

Abstract

Quarternair materials CuGaSeTe and CuGa0.5In 0.5Te2 are the basic materials to solar cell fabrication. These materials have high absorption coefficients around 103 - 105 cm-1 and band gap energy in the range of 1-5 eV. In this research, the films were made by flash evaporation method using quarternair powder materials of CuGaSeTe and CuGa0.5In 0.5Te2 to adhere in a glass substrate. After the films were obtained, the properties of these films will be characterized optically and electrically. The lattice parameter of the films and the crystalline film structure were obtained using X-Ray Diffraction (XRD) spectroscopy. The XRD results show that the quarternair CuGaSeTe and CuGa0.5In 0.5Te2 films have a chalcopyrite structure. The absorption coefficient and the  band gap energy of the films were calculated using transmittance and reflectance patterns that measured using UV-VIS Difractometer. The films composition can be detected by using the Energy Dispersive Spectroscopy (EDS), while the films resistivity, mobility and the majority carrier of the films were obtained from Hall Effect experiments.
Analysis of Kancils Car Knuckle Prototype Soemardi, Tresna; Mahmudah, Aida
Makara Journal of Technology Vol 8, No 1 (2004)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.7454/mst.v8i1.80

Abstract

The objective of this work is to execute strength analysis of knuckle, which is made from FCD 50, by using static analysis on maximum loading. This maximum loading is obtained from front axle loading calculation on particular operating condition. That is, vehicle is braking while cornering in down hill. From previous vehicle loading calculation, we get a number of loading values on different speed and deceleration. At the end, we get a value of speed and deceleration that guarantee the vehicle safety if it is braking while cornering in down hill. As comparison, loading calculation is executed too for same operating condition on level ground. This is because of different deceleration for each operating condition, 0,5g for operating condition on downhill and 0,2g on level ground. The result shows that maximum loading occurred when vehicle is operated on down hill is larger than on level ground. Study of static focused on quantitative description of loads that act on technical structure in equilibrium.

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