Analisis Data pada Jaringan Sensor Nirkabel Menggunakan Metode Support Vector Machine

The aims of this research are to implement Support Vector Machine for analyze abnormal data on sensor network and evaluate the implementation result. The data collection in the research were done through the searching of related libraries and software evaluate/testing. In this research, temperature, wind speed, and humidity tested using three kernels (linear, Gaussian, and polynomial). Evaluation result show that the implementation of Support Vector Machine can perform the best data validity analysis using Gaussian Kernel with the percentage of average accuracy, temperature 97.83%, humidity 94.5325%, and wind speed 96.93% for weather data 20-28 May and July 28-August 10, 2015. Meanwhile, for weather data June 5-6, 2017 obtained the percentage of average accuracy of temperature 92.855% and humidity 92.43%

Pengaruh Waktu Simpan terhadap Kualitas Soyghurt dengan Penambahan Gula dan Stabiliser

Kedelai merupakan salah satu contoh kacang-kacangan yang dapat diambil sarinya. Sari kedelai atau biasa disebut dengan susu kedelai, kaya akan protein dan rendah lemak, sehingga cocok dikonsumsi oleh penderita lactose intolerance dan vegetarian. Salah satu contoh produk olahan susu dari kacang-kacangan adalah soyghurt. Soyghurt merupakan susu kedelai yang telah difermentasikan dengan bakteri Lactobacillus bulgaricus dan Streptococcus thermophilus. Tujuan penelitian ini adalah untuk mempelajari pengaruh waktu simpan dan jenis stabiliser terhadap kualitas soyghurt. Metode yang digunakan untuk pengolahan susu kedelai adalah metode fermentasi. Susu kedelai disterilkan terlebih dahulu pada suhu 70oC selama 15 menit, lalu didinginkan sampai suhu sekitar 43oC, kemudian difermentasi dengan Lactobacillus bulgaricus dan Streptococcus thermophilus selama 14 jam, dan kemudian disimpan dalam lemari es sampai 288 jam. Setiap selang waktu 24 jam, terhadap soyghurt tersebut dilakukan uji kualitas. Dari penelitian disimpulkan bahwa usia bakteri Lactobacillus bulgaricus dan Streptococcus thermophilus adalah 18 jam, dengan waktu fermentasi soyghurt selama 14 jam. Soyghurt dengan penambahan gelatin diperoleh bahwa waktu simpan terbaik 7 hari, sedangkan soyghurt dengan penambahan CMC diperoleh bahwa waktu simpan terbaik 9 hari. Dengan semakin bertambahnya waktu penyimpanan, maka jumlah koloni bakteri akan semakin banyak, harga pH akan semakin rendah, titratable acidity (TA) akan semakin tinggi

Ferromagnetic resonance study of Permalloy/Cu/Co/NiO spin valve system

International audienc

Effect of thickness on the physical properties of ITO thin films

We have studied the effect of thickness on the structural, optical and electrical properties of In2O3:Sn (ITO) thin films. Two series of ITO thin films have been deposited onto glass substrates by DC sputtering at two partial pressures of oxygen (ppo): 4 × 10−4 and 4.75 × 10−4 mbar. Each series consists of samples with thickness ranging from 306 nm to 1440 nm. We observed a change of texture with thickness; the thinner films grow with a 〈111〉 preferred orientation; however as the thickness increased, the preferred orientation becomes in the 〈100〉 direction. The lattice constant and the grain size have also been obtained from the X-ray spectra. The energy gap, Eg, has been obtained from the transmission curve; Eg is found to decrease with increasing thickness for both series. The electrical resistivity ρ has been studied as a function of thickness, ppo and temperature (T). The temperature was varied from room temperature (RT) to 450 °C and back to RT; a hysteresis effect was observed in the ρ vs. T curve. Also, a minimum in ρ was observed, in all these samples, in the temperature range 260 to 280 °C. For these temperatures, we have studied the effect of annealing time on the electrical resistivity for samples having both textures. We noted that ρ increased with annealing time and reaches a saturation value equal to the RT temperature value. Hall effect experiments were done on all these samples. The concentration n and the mobility μH were obtained. These parameters are found to be sensitive to the thickness and the texture of these films. All these results will be correlated and discussed

Ferromagnetic resonance study of Permalloy/Cu/Co/NiO spin valve system

International audienc

Structural, electrical and magnetic properties of evaporated permalloy thin films: effect of substrate and thickness

We have studied the effects of the substrate and the thickness on the structural, electrical and magnetic properties of permalloy thin films Ni81Fe19 (Py). Series of Py thin films were evaporated on four various substrates: glass, kapton, Si(1 0 0) and Si(1 1 1). The thickness ranges from 13 nm to 190 nm. We show that evaporated permalloy on kapton and Si(1 1 1) present a strong ⟨1 1 1⟩ preferred orientation for samples thicker than 85 nm; however, the films grown on glass and Si(1 0 0) present a weak (1 1 1) texture for most of these samples. Generally, the lattice constant for Py/glass, Py/Si(1 0 0) and Py/Si(1 1 1) samples is found to be smaller than the bulk value (abulk), while for the Py/kapton, it is larger than abulk. There is an overall increase of the grain sizes (100 Å–480 Å) with thickness for Py/Si(1 1 1), Py/Si(1 0 0) and Py/glass. For the Py/kapton samples, the grain sizes (about 130 Å) seem to be independent of the thickness. The resistivity, ρ, decreases with increasing thickness for all samples. The highest values of ρ were observed in the Py/kapton thin films, diffusion at the grain boundaries might be in part responsible for these high values. The magnetization easy axis is found to be in the film plane for all samples. For all series, the two thinner films seem to exhibit a perpendicular magnetocrystalline anisotropy. The coercive field, HC//, values range from 1 Oe to 67 Oe. A peak in the HC// vs. t curve is observed for Py/Si while for Py on glass and Py/kapton, HC// seems to be constant. We also observed that for the thicker Py/Si(1 1 1) samples, the coercivity decreases as the grain sizes increase

Effect of the substrate on the structural and electrical properties of dc sputtered Ni thin films

We have studied the effect of the substrate on the structural and electrical properties of Ni thin films. Series of Ni thin films have been prepared by dc diode sputtering on four different substrates, glass, Si(111), Si(100) and mica; the Ni thickness ranges from about 47 nm to 317 nm. We observed that Ni grown on glass has no texture. On the other hand Ni deposited on Si gets the 〈111〉 preferred orientation for all samples, even the thinner ones. Grain sizes were found to increase with increasing thickness for Ni/glass and Ni/Si(100), with the grains in Ni/Si(100) much larger than the corresponding ones for Ni on glass. The lattice constant of Ni on glass is smaller than that of the bulk. For the Ni on Si, however, the lattice constant is practically equal to the bulk value. We noted that the resistivity ρ decreases with increasing thickness and with increasing grain size for practically all samples. Also the Ni thin films deposited on a semiconductor substrate (Si(100) and Si(111)) get a higher resistivity than Ni on an insulator (Ni/glass for example) for the same Ni thickness. No magnetoresistance was observed in these Ni thin films at ambient temperature and for about a half kOe perpendicular magnetic field. These experimental results will be interpreted and discussed

Frequency- and time-domain investigation of the dynamic properties of interlayer-exchange-coupled Ni81Fe19/Ru/Ni81Fe19 thin films

Pulsed inductive microwave magnetometer (PIMM), conventional ferromagnetic resonance (FMR), and vector network analyzer FMR (VNA-FMR) have been used for complementary studies of the various excited modes in exchange-coupled NiFe(30 nm)/Ru(d(Ru))/NiFe(30 nm) films with variable Ru thicknesses d(Ru). For antiferromagnetically coupled layers, two modes, which vary in their relative intensity as a function of the bias field, are detected. These two modes, which are observable simultaneously over a limited range of the bias field with PIMM, are identified as optic and acoustic modes. The mode frequencies and the interlayer exchange coupling are found to oscillate as a function of the Ru layer thickness with a period of 8.5 A. The frequency oscillations of the optic mode are coupling dependent, while those of the acoustic mode are indirectly related to coupling via the canting angle of the layer magnetizations below the saturation. Comparison between PIMM and VNA-FMR in terms of frequency of modes shows good agreement, but the optic mode is observed over a wider field range with VNA-FMR. Furthermore, we clearly observed different behaviors of the FMR linewidths as a function of the spacer thickness for the optic and acoustic modes. In addition, perpendicular standing spin waves have been studied as a function of coupling. The FMR linewidth of the different modes increases with the microwave frequency and typical damping constants of alpha=0.0073 have been measured. The effect of the pulse field amplitudes on the properties of the various excited modes has been simulated and studied experimentally

Structural and electrical properties of as-deposited and annealed DC sputtered ITO thin films

We have studied the effect of annealing on the structural and electrical properties of tin-doped indium oxyde, $\rm In _2O_3{:}Sn$ (ITO), thin films prepared by DC sputtering at different partial pressure of oxygen (ppo). Annealing experiments have been done in vacuum and in Ar atmosphere up to a temperature of 450 °C. A change of texture from $\langle 100\rangle$ to $\langle 111\rangle$ as the ppo was increased was noted in the as-deposited films. Annealing induced cristallinity and improved the texture of these films. The lattice constant decreased after annealing. The (222) grain size increased after vacuum annealing but was unaffected by annealing in Ar atmosphere; while the (400) grain size decreased for samples having the $\langle 100\rangle$ texture. The electrical resistivity decreases sharply after annealing to a minimum value of 87 × 10-4 Ω cm