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: 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: Isolasi senyawa golongan flavonoid sebagai antioksidan dari daun dandang gendis (Clinacanthus nutans)
Abstrak: The leaves of dandang gendis (Clinacanthus nutans) exhibit antioxidant activity. The objective of this study is to investigate the highest antioxidant activity from flavonoid extract of the leaves. Antioxidant activities were determined by radical scavenging assay using 1,1-diphenyl-1-pycryl-hydrazyl radical. The result showed that ethyl acetate extract had antioxidant activity with IC50 value of 178.40 mg L-1. The ethyl acetate extract was fractionated further using preparative thin layer chromatography with eluent of n-buthanol:acetic acid: water (4:1:5) and produced 3 fractions. The most active fraction was fraction 2 with IC50 value of 52.93 mg L-1, which was lower than that of butylated hydroxy toluene (IC50 16.71 mg L-1). Flavonoid assay of fraction 2 showed that it contained flavonol and flavon. The ultraviolet-visible spectrum of fraction 2 in methanol solvent showed a maximum absorption at 332 in band 1 and 274 nm in band 2. In MeOH+MeONa and MeOH+AlCl3-HCl solvents there was a bathochromic shift, indicated the presence of 4'-OH and 5-OH. The new peak at 326.5 nm showed the presence of 7-OH substituent.
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