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IPTEK The Journal for Technology and Science
ISSN : 08534098     EISSN : 20882033     DOI : -
Core Subject : Science,
IPTEK The Journal for Technology and Science (eISSN: 2088-2033; Print ISSN:0853-4098), is an academic journal on the issued related to natural science and technology. The journal initially published four issues every year, i.e. February, May, August, and November. From 2014, IPTEK the Journal for Technology and Science publish three times a year, they are in April, August and December in online version.
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Articles 6 Documents
Search results for , issue "Vol 23, No 1 (2012)" : 6 Documents clear
PEMFC Optimization Strategy with Auxiliary Power Source in Fuel Cell Hybrid Vehicle Tinton Dwi Atmaja; Amin Amin
IPTEK The Journal for Technology and Science Vol 23, No 1 (2012)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v23i1.17

Abstract

one of the present-day implementation of fuel cell is acting as main power source in Fuel Cell Hybrid Vehicle (FCHV). This paper proposes some strategies to optimize the performance of Polymer Electrolyte Membrane Fuel Cell (PEMFC) implanted with auxiliary power source to construct a proper FCHV hybridization. The strategies consist of the most updated optimization method determined from three point of view i.e. Energy Storage System (ESS), hybridization topology and control system analysis. The goal of these strategies is to achieve an optimum hybridization with long lifetime, low cost, high efficiency, and hydrogen consumption rate improvement. The energy storage system strategy considers battery, supercapacitor, and high-speed flywheel as the most promising alternative auxiliary power source. The hybridization topology strategy analyzes the using of multiple storage devices injected with electronic components to bear a higher fuel economy and cost saving. The control system strategy employs nonlinear control system to optimize the ripple factor of the voltage and the current and using the AOC-EMS system to improve the hydrogen consumption rate. ECMS and BERS strategy based on Time-Triggered Controller Area Network (TTCAN) also promoted to optimize hydrogen consumption rate from recovered kinetic energy while in braking regeneration mode.
Empirical Bayesian Method for the Estimation of Literacy Rate at Sub-district Level Case Study: Sumenep District of East Java Province A.Tuti Rumiati; Khairil Anwar Notodiputro; Kusman Sadik; I Wayan Mangku
IPTEK The Journal for Technology and Science Vol 23, No 1 (2012)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v23i1.13

Abstract

This paper discusses Bayesian Method of Small Area Estimation (SAE) based on Binomial response variable. SAE method being developed to estimate parameter in small area due to insufficiency of sample. The case study is literacy rate estimation at sub-district level in Sumenep district, East Java Province. Literacy rate is measured by proportion of people who are able to read and write, from the population of 10 year-old or more. In the case study we used Social Economic Survey (Susenas)data collected by BPS. The SAE approach was applied since the Susenas data is not representative enough to estimate the parameters at sub-district level because it’s designed to estimate parameters in regional area (in scope of a district/city at minimum). In this research, the response variable being used was logit function trasformation of pi (the parameter of Binomial distribution). We applied direct and indirect approach for parameter estimation, both using Empirical Bayes approach. For direct estimation we used prior distribution of Beta distribution and Normal prior distribution for logit function (pi) and to estimate parameter by using numerical method, i.e integration Monte Carlo. For indirect approach, we used auxiliary variables which are combinations of sex and age (which is divided into five categories). Penalized Quasi Likelihood (PQL) was used to get parameter estimation of SAE model and Restricted Maximum Likelihood method (REML) for MSE estimation. Instead of Bayesian approach, we are also conducting direct estimation using classical approach in order to evaluate the quality of the estimators. This research gives some findings, those are: Bayesian approach for SAE model gives the best estimation because having the lowest MSE value compares to the other methods. For the direct estimation, Bayesian approach using Beta and logit Normal prior distribution give a very similar result to the direct estimation with classical approach since the weight of is too large, which is about 0.905. It is also found that direct estimation using Bayesian approach with the Beta prior distribution gives better MSE than using logit normal prior distribution.
Fractal Based on Noise for Batik Coloring using Normal Gaussian Method Rusmono Yulianto; Mochammad Hariadi; Mauridhi Hery Purnomo
IPTEK The Journal for Technology and Science Vol 23, No 1 (2012)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v23i1.18

Abstract

Noise is an un-expected signal which exists naturally at any system. In the study of fractal batik coloring, noise as a spot is generated as the basis of batik motive coloring. Even distribution of noise spots will produce art-works which involve elements of culture and technology. The development of batik motives and colors could be harmonized with the development of technology, such as the use of fractal method in order to create the new motives of batik. Fractal is a geometric form which can be separated into pieces, where each part is the repeated small version. The coloring of batik was based on the generating noise using Gaussian method. Noise on fractal batik was spots which were generated randomly on the surface of fractal batik, meanwhile Gaussian method was a noise model which followed normal distribution standard with zero average and standard deviation 1.The generating noise as coloring basis of fractal batik patterns, which was formed in the previous study, showed the distant error of noise between 9.1 pixels and 13.7 pixels. This was because the distribution of noise on the fractal batik patterns was carried out randomly using Gaussian method for every process of fractal rewriting system.
Sensitive Magnetic Field Sensor Based on Compensated Double Pick Up Coil Purnama, Budi; Suharyana, Suharyana; Sutomo, Artono Dwijo
IPTEK The Journal for Technology and Science Vol 23, No 1 (2012)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v23i1.16

Abstract

Sensitive magnetic field sensor based on compensated double pick up coil has been developed. In order to confirm sensitifity of modified design, experiment carried out in two steps. Firstly, sensitify of conventional design is clarified. Here pick up coil as an active sensor and solenoid as an exitation coil is separately made. Secondly, modified sensor of integrated configuration is developed. Here for both active flux gate sensor and the exitation coil is made in same one core magnetic. Ferrite and standar foil soft magnetic is utilized in this experiment. In attention, frequency of 50 Hz is used for the whole experimens. A result showed that sensitvity of the integrated configuration sensor is much larger than conventional one. Then, power consume of the integrated flux gate sensor is much lower than conventional. Finally, a range measurement of the integrated configuration sensor can be realized less than 20 T which potential may perhaps sense a change of natural local magnetic field.
Analysis of Energy Spectrum and Wave Function of Modified Poschl Teller Potential Using Hypergeometry and Supersymmetry Method Solikhah, Fuzi Marati; Suparmi, Suparmi; Variani, Viska Inda
IPTEK The Journal for Technology and Science Vol 23, No 1 (2012)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v23i1.15

Abstract

Modified Poschl Teller potential is a potential model used to describe behavior of inter moleculer forces. The spectrum energy and wave function of the particle affection in modified Poschl Teller potential are obtained by solving the Schrodinger equation, using hypergeometric equation and supersymmetric method. The energy spectrum and wave function are obtained from hypergeometric equation, which is constructed from Schrodinger equation through variable substitution. The energy spectrum and wave function are obtained using raising and lowering supersymmetric operator and applying shape invariance property. The solution of those equation of the energy spectrum and wave function obtained using these two methods are exact solution. Further, the wave function and density probability are visualized using computer simulation.
Application of Laminated Veneer Lumber (LVL) on the Wooden Boat Construction Ahmad Basuki Widodo
IPTEK The Journal for Technology and Science Vol 23, No 1 (2012)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v23i1.14

Abstract

LVL (Laminated-Veneer Lumber) has many advantages and economic values, which is important for wooden boat construction. The recovery of veneer, the main material of LVL, are higher than sawn-timber and their drying process are faster. LVL produced with a continuous press has been approved as an engineered material with reliable strength and stiffness. In a wooden boat processing, the easy forming into a curve shape and strength are main factor, because of the streamline shape of boats. LVL material is able to meet those requirements. As an endless-length LVL is made from a log limited-length hence LVL always contain joints. Butt joint have numerous drawbacks, but they are inherently simple and less time to manufacture than other joints types. The purposes of this experiment are to investigate the basic characteristics of LVL which are important for deck and hull planking in the wooden boat constructions. Yellow meranti and red meranti were peeled by a veneer lathe and phenol formaldehyde adhesive were used. Result of experiment indicated that at the position 0o (β), the flexibility and strength of LVL up to proportional limit increased with increasing number of layer and spacing of butt-joint (d/t). LVL at the position 45o and 90o (β), all types of LVL had lower flexibility and strength than the standard value for deck and hull planking. In bending experiment test speciment at position 45° with direction of grain, maximum width of LVL equal to the spacing of frame and at position 90° equal to the width of hull planking in wooden boat. Based on the interpretations of the above results, it can be concluded that (1). LVL of 9, 6 and 4 plies with upside (inside) veneer butt-joint is appropriate for deck and hull planking in wooden boat manufacturing, (2). LVL of 9, 6 and 4 plies with spacing of butt-joint (d/t) more than 20 is appropriate for deck and hull planking in manufacturing wooden boat.

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