cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
-
Contact Email
-
Phone
-
Journal Mail Official
-
Editorial Address
-
Location
Kota surabaya,
Jawa timur
INDONESIA
IPTEK The Journal for Technology and Science
Published by Institut Teknologi Sepuluh Nopember Surabaya
ISSN : 08534098     EISSN : 20882033     DOI : -
Core Subject : Science,
Computer Science & IT
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.
Arjuna Subject : -
Articles 8 Documents
 1 
Search results for , issue "Vol 22, No 2 (2011)" : 8 Documents clear
A New Method for Modeling Bottom Shear Stress under Irregular Waves Taufiqur Rachman; Suntoyo Suntoyo
IPTEK The Journal for Technology and Science Vol 22, No 2 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i2.60

Abstract

The bottom shear stress estimation is the most important step to device an input to all the practical sediment transport models. In this paper, the modeling of bottom shear stress in a rough turbulent bottom boundary layer under irregular waves of experimental result is examined by a new calculation method of bottom shear stress based on incorporating velocity and acceleration terms simultaneously. A new acceleration coefficient is proposed to formulate the bottom shear stress under irregular waves. The new formula is further examined with a basic harmonic wave cycle modified with the phase difference and square of the instantaneous friction velocity incorporating the acceleration effect as proposed by the previous researchers. The new method gave the smallest the RMSE value indicating that the new method has the best agreement with the bottom shear stress of experimental results. Therefore, it can effectively be utilized in a beach evolution model by combining it with the irregular wave transformation model.
Application of Interval Type-2 Fuzzy Logic System in Short Term Load Forecasting on Special Days Agus Dharma; Imam Robandi; Mauridhi Hery Purnomo
IPTEK The Journal for Technology and Science Vol 22, No 2 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i2.65

Abstract

This paper presents the application of Interval Type-2 fuzzy logic systems (Interval Type-2 FLS) in short term load forecasting (STLF) on special days, study case in Bali Indonesia. Type-2 FLS is characterized by a concept called footprint of uncertainty (FOU) that provides the extra mathematical dimension that equips Type-2 FLS with the potential to outperform their Type-1 counterparts. While a Type-2 FLS has the capability to model more complex relationships, the output of a Type-2 fuzzy inference engine needs to be type-reduced. Type reduction is used by applying the Karnik-Mendel (KM) iterative algorithm. This type reduction maps the output of Type-2 FSs into Type-1 FSs then the defuzzification with centroid method converts that Type-1 reduced FSs into a number. The proposed method was tested with the actual load data of special days using 4 days peak load before special days and at the time of special day for the year 2002-2006. There are 20 items of special days in Bali that are used to be forecasted in the year 2005 and 2006 respectively. The test results showed an accurate forecasting with the mean average percentage error of 1.0335% and 1.5683% in the year 2005 and 2006 respectively.
The Performance of by Turns Fermentation- Dryer for Vanilla (Vanilla Planifolia Andrews) Processing Sitti Nur Faridah; Abdul Waris; Haerani Haerani
IPTEK The Journal for Technology and Science Vol 22, No 2 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i2.61

Abstract

The drying and fermentation are the processing steps which influence the quality of vanilla. Thus, an effort to produce instrument which can dry and ferment vanilla by turns automatically was done. Based on the test result on the instrument, it was known that the heater and heat-exchanger can function excellently. It can be seen from the increase of temperature after passing heater and heat-exchanger; and the decrease of air humidity in the drying chamber. The small differences of air flow speed between racks proved the uniformity of air flow speed in the drying chamber. The time and temperature control system showed temperature stability on drying process (i.e. 60°C) and on fermentation process (i.e. 40°C); moreover, temperature response reached 60°C and did not exceed the setting time (maximum 30 minutes). The water percentage depletion from 88% to 55% is relatively slow (in 5 days fermentation-drying process). The depletion is appropriate with the recommendation for fermentation-drying vanilla processing.
Heat Assisted Magnetization Reversal on Perpendicular Magnetized Nano-Dot Nur Aji Wibowo; Cari Cari; Budi Purnama
IPTEK The Journal for Technology and Science Vol 22, No 2 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i2.64

Abstract

Heat assisted magnetization reversal on perpendicular magnetized nano-dots has been studied by solved Landau Lifshift-Gilbert equation for magnetic recording application. The heat assisted magnetization reversal scheme has been proven to be effectively reduces threshold field down to 90 %. Otherwise, this field doesn’t depend on heating time. To understand a read-write information process, cooling time dependence of threshold field has been evaluated. As a result, the threshold field depends on the cooling time and become constant after 300 ps. This result corresponds to data transfer of Hard Disc Drive about 30 Gb/s.
Multi-Objective Two-Dimensional Truss Optimization by using Genetic Algorithm Alrasyid, Harun; Aji, Pujo
IPTEK The Journal for Technology and Science Vol 22, No 2 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i2.62

Abstract

During last three decade, many mathematical programming methods have been develop for solving optimization problems. However, no single method has been found to be entirely efficient and robust for the wide range of engineering optimization problems. Most design application in civil engineering involve selecting values for a set of design variables that best describe the behavior and performance of the particular problem while satisfying the requirements and specifications imposed by codes of practice. The introduction of Genetic Algorithm (GA) into the field of structural optimization has opened new avenues for research because they have been successful applied while traditional methods have failed. GAs is efficient and broadly applicable global search procedure based on stochastic approach which relies on “survival of the fittest” strategy. GAs are search algorithms that are based on the concepts of natural selection and natural genetics. On this research Multi-objective sizing and configuration optimization of the two-dimensional truss has been conducted using a genetic algorithm. Some preliminary runs of the GA were conducted to determine the best combinations of GA parameters such as population size and probability of mutation so as to get better scaling for rest of the runs. Comparing the results from sizing and sizing– configuration optimization, can obtained a significant reduction in the weight and deflection. Sizing–configuration optimization produces lighter weight and small displacement than sizing optimization. The results were obtained by using a GA with relative ease (computationally) and these results are very competitive compared to those obtained from other methods of truss optimization.
Vanadium Contribution to the Surface Modification of Titanium Silicalite for Conversion of Benzene to Phenol Mulyatun, Mulyatun; Prasetyoko, Didik
IPTEK The Journal for Technology and Science Vol 22, No 2 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i2.58

Abstract

Vanadium oxide supported on the surface of titanium silicalite was investigated in benzene hydroxylation to determine its activity as heterogeneous catalyst. Effect of vanadium loading on structure and activity of titanium silicalite was investigated. On the basis of X-ray diffraction and infrared spectroscopy techniques, it was found that the titanium structure was remained on the modified catalyst. The catalytic activity of the modified catalyst was observed to be higher than that of parent catalyst.
Impact of Stakeholder Psychological Empowerment on Project Success Chandra, Herry Pintardi; Indarto, Indarto; Wiguna, I Putu Artama; Kaming, Peter F
IPTEK The Journal for Technology and Science Vol 22, No 2 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i2.63

Abstract

The relationship between psychological empowerment of stakeholders and project success is an important thing that must be known by project manager. This research developed and tested the model to predict how well the impact of stakeholder psychological empowerment on project success. Stakeholder psychological empowerment was defined to have five indicator variables covering intrinsic motivation, opportunity to perform, ability to perform, task behaviors, and contextual behaviors. Meanwhile, project success can be measured by cost performance, time performance, quality performance, profitability, and customer satisfaction. In this study, it was hypothesized that stakeholder psychological empowerment influenced project success. Based on the data obtained from a questionnaire survey carried out to 204 respondents, structural equation modeling (SEM) was used for predicting the performance of project success. It was found that stakeholder psychological empowerment influenced project success, especially on the ability to perform of stakeholders.
Thermal Analysis on Radial Flux Permanent Magnet Generator (PMG) using Finite Element Method Irasari, Pudji; Syaeful A, Hilman Syaeful A; Kasim, Muhammad
IPTEK The Journal for Technology and Science Vol 22, No 2 (2011)
Publisher : IPTEK, LPPM, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v22i2.59

Abstract

The main source of heat in the permanent magnet generator (PMG) is the total losses which f come from winding losses, core losses and rotational losses. Total heat arising from such these losses must be properly distributed and maintained so as not to exceed the maximum allowable temperature to prevent damage to insulation on the winding and demagnetization on the permanent magnet machines. In this research, we consider thermal analysis which is occurred on the radial flux PMG by using finite element method to determine the extent to which the heat generated can be properly distributed. The simulation results show that there are no points of heat concentration or hot spot. The simulation maximum temperatures of the permanent magnet and the winding are 39.1oC and 72.5oC respectively while the experimental maximum temperature of the winding is 62oC.

Page 1 of 1 | Total Record : 8

 1 

Filter by Year

2011 2011


Reset
Filter By Issues
All Issue Vol 36, No 1 (2025) Vol 35, No 3 (2024) Vol 35, No 2 (2024) Vol 35, No 1 (2024) Vol 34, No 3 (2023) Vol 34, No 2 (2023) Vol 34, No 1 (2023) Vol 33, No 3 (2022) Vol 33, No 2 (2022) Vol 33, No 1 (2022) Vol 32, No 3 (2021) Vol 32, No 2 (2021) Vol 32, No 1 (2021) Vol 31, No 3 (2020) Vol 31, No 3 (2020): In-Press Vol 31, No 2 (2020) Vol 31, No 1 (2020) Vol 30, No 3 (2019) Vol 30, No 2 (2019) Vol 30, No 1 (2019) Vol 29, No 3 (2018) Vol 29, No 2 (2018) Vol 29, No 1 (2018) Vol 28, No 3 (2017) Vol 28, No 2 (2017) Vol 28, No 1 (2017) Vol 27, No 3 (2016) Vol 27, No 2 (2016) Vol 27, No 1 (2016) Vol 26, No 2 (2015) Vol 26, No 1 (2015) Vol 25, No 3 (2014) Vol 25, No 2 (2014) Vol 25, No 1 (2014) Vol 24, No 3 (2013) Vol 24, No 2 (2013) Vol 24, No 1 (2013) Vol 23, No 4 (2012) Vol 23, No 3 (2012) Vol 23, No 2 (2012) Vol 23, No 1 (2012) Vol 22, No 4 (2011) Vol 22, No 3 (2011) Vol 22, No 2 (2011) Vol 22, No 1 (2011) Vol 21, No 4 (2010) Vol 21, No 3 (2010) Vol 21, No 2 (2010) Vol 21, No 1 (2010) Vol 20, No 4 (2009) Vol 20, No 3 (2009) Vol 20, No 2 (2009) Vol 20, No 1 (2009) Vol 19, No 4 (2008) Vol 19, No 3 (2008) Vol 19, No 2 (2008) Vol 19, No 1 (2008) Vol 18, No 4 (2007) Vol 18, No 3 (2007) Vol 18, No 2 (2007) Vol 18, No 1 (2007) More Issue