Judul: Perkiraan Biaya Perangkat Lunak Menggunakan Logika Fuzzy
Abstrak: Perkiraan biaya perangkat lunak merupakan salah satu bagian terpenting dari pengembangan perangkat lunak. Perkiraan biaya yang terlalu kecil akan mengakibatkan perangkat lunak yang dihasilkan berkualitas rendah. Sebaliknya, perkiraan biaya yang terlalu besar akan mengakibatkan pemborosan sumber daya yang digunakan. Pada penelitian ini, dikembangkan suatu model perkiraan biaya perangkat lunak menggunakan logika fuzzy. Penelitian ini membandingkan dua metode perkiraan biaya perangkat lunak, yaitu Intermediate COCOMO dan Fuzzy Intermediate COCOMO. Data yang digunakan adalah data proyek NASA yang telah dilakukan pada tahun 1980 sampai 1990. Model yang dihasilkan dievaluasi menggunakan MRE (Magnitude of Relative Error), Mean MRE (MMRE), Median MRE (MdMRE), Min MRE, Max MRE, dan Standar Deviasi MRE (SdMRE). Kinerja model secara umum direpresentasikan dalam nilai MMRE.
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Judul: Perkiraan Biaya Perangkat Lunak dengan Jaringan Saraf Tiruan Propagasi Balik
Abstrak: In line with the advance of technology, human needs for software are also growing. Software is used to help people to lighten their work. This has caused the software becomes increasingly complex and the production cost also become increasingly expensive. No wonder if the software developers need a method of cost estimation that estimates accurately for the efficiency and effectiveness of the company. With this, the company can be protected from loss due to incorrect cost estimates. This study uses data from the COCOMO 81 derived from the Boehm journals in 1981, entitled Software engineering economics. This data group consists of 63 projects each have 17 main attributes, namely, a numerical type of 15 Cost Driver (CD), the size of the project in Kilo Lines of Code (KLOC), and the actual cost of the project in the Person of the Month (PM). Data are grouped into two parts, namely training data and test data in the form of 15 types of Cost Drivers and the size of the project (KLOC), this data is transformed into the range [0.1, 0.9] according to the sigmoid function of range. In this research, the neural network is used to do the software cost estimation. The network architecture used was the multilayer perceptron with a back propagation learning algorithm. The number of neuron in the hidden layer is determined from the optimal architecture which provides a best estimation value. Once found the best architecture which is has the optimal number of neuron, conducted the evaluation. The evaluation method used is the Mean Magnitude Error (MRE) and Pred (l). MRE is the error between the actual and estimated value while Pred (l) is prediction at the level L. Results of research indicate that there are relation between the types of project with the MRE. There is a tendency for this technique provides a high accuracy if the actual value of the test data is big. Poor accuracy obtained at the small value of actual test data. This research resulted in the value of Mean MRE (MMRE) of 76%, Median MRE (MRE Med) of 23% and Pred (0.25) of 52%. On this research, normalization of the target data has not been conducted so that the error generated in the process of evaluation is big.
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Judul: Application of phycocyanin from microalgae Spirulina platensis as light harvesting in anatase TiO2 nanoparticle solar cell.
Abstrak: The dye sensitized solar cell (DSSC) has been assemblied used hybrid titanium oxide (TiO2) film/phycocyanin. The TiO2 film was synthesized by sol gel method with titanium chlorida (TiCl4) as precursor by hydrolysis used sulfuric acid (H2SO4). Furthermore, it calcinated for 2,5 hours in variation of annealing temperature (400oC, 600oC, 800oC, dan 1000oC). In XRD patterns exhibited which annealing temperature at 400oC to 800oC were anatase phase all. When annealed at temperature 1000oC, it caused phase transformation from anatase to rutile. The crystals size according to XRD patterns were 13,75 nm, 20,79 nm, 25,25 nm, 48,88 nm and particle size from SEM images were 43,06 nm, 44,91 nm dan 64,99 nm, 80,40 nm, respectively. The crystals and particle size increased with annealing temperature. The film thickness influenced material absorption. The optical measurement of TiO2 film and TiO2/phycocyanin hybrid film used UV-Vis spectrophotometer. Additional phycocyanin caused peak width of absorbed region from ultraviolet to visible region. The band gap energy of TiO2 can be calculated using the cut off wavelength obtained from the absorbance spectrum of a nanoparticles TiO2 films. Based on intersection between linear and energy (hv) axis. In this study just limited for anatase phase. It was caused anatase band gap is wider than rutile phase. That’s meaningful for solar cell application such as dye sensitized solar cell (DSSC). The absorption coefficient average at difference annealing temperature such as at 400oC, 600oC, 800oC were 8,1600x102, 1,7535x103 and 4,0154x102, where α < 104 include to direct transition. Band gap energy 400oC, 600oC, 800oC were 3,79 eV, 3,59 eV, and 3,35 eV, respectively. Based on this result, exhibition that band gap energy of TiO2 semiconductor film decreased with increasing annealing temperature. Spirulina platensis was cultivated in technical modification (Hastuti) with aeration under light intensity about 3000 lux. The cell density (stationer phase) for eighth day which OD value was more than 0,5. It means, the culture can be harvested. In 80 liters Spirulina platensis culture have been produced biomass dry about 10,46 gram and extracted phycocyanin in dry powders was 5,50 gram. The phycocyanin absorption spectrum at the wavelength of 619,36 nm (visible region) which had relaxation energy was 2,945 eV. The emission peak at the wavelength of 708,55 nm with relaxation energy about 2,793 eV. The Stokes shift based on difference energy absorption and emission calculated about 0,152 eV. Both of this showed phycocyanin can absorbed and radiated the sun light which received. This choice characteristic pigment was a good one related to sensitizer in solar cell application. Integration between light harvesting protein and TiO2 semiconductor surface had important role in improving of output as solar cell materials. The presence of carboxylate group (-COOH) made pigment be more efficient was due to anchored to the surface of TiO2 ampoter. The phycocyanin pigment had carboxylate group which reacted with TiO2 surface formed ester. The carboxylate group increased of dye electronics couple from excited state (p anti bonding orbital) to semiconductor acceptor state (TiO2 conduction band). The samples which made based on annealing temperature variation formed be solar cell respectively. Furthermore, cells be assembled for
Keyword: anatase, dye sensitized solar cell, efficiency, gap energy, phycocyanin