Judul: Metode Klasifikasi K-Nearest Neighbor untuk Analisis Hoax.
Abstrak: Hoax adalah informasi sesat dan berbahaya yang dapat menyesatkan persepsi manusia dengan menyampaikan informasi palsu sebagai kebenaran. Hoax mampu mempengaruhi banyak orang dengan menodai suatu citra dan kredibilitas. Salah satu cara dalam bidang Information Retrieval yang dapat digunakan untuk membedakan berita hoax dan non-hoax adalah dengan menggunakan metode klasifikasi teks. Metode klasifikasi yang akan digunakan pada penelitin ini adalah metode K-Nearest Neighbor dan dibandingkan dengan Multinomial Naive Bayes. Data pada penelitian ini berupa 300 dokumen hoax dan 300 dokumen non-hoax. Data dibagi menjadi 10 model pengujian menggunakan metode k-fold cross validation. Hasil akurasi tertinggi dari klasifikasi K-Nearest Neighbor sebesar 81.67% sedangkan Multinomial Naive Bayes menghasilkan akurasi tertinggi sebesar 93.33%. Hasil akurasi rata-rata dari klasifikasi K-Nearest Neighbor sebesar 77.50% dan Multinomial Naive Bayes sebesar 85.83%.
Keyword: hoax, klasifikasi, K-Nearest Neighbor, Multinomial Naive Bayes

Judul: Metode Klasifikasi Rocchio untuk Analisis Hoax
Abstrak: Hoax adalah informasi sesat dan berbahaya karena menyesatkan persepsi manusia dengan menyampaikan informasi palsu sebagai kebenaran. Hoax sendiri dapat bertujuan untuk mempengaruhi pembaca dengan informasi palsu sehingga pembaca mengambil tindakan sesuai dengan isi hoax. Untuk mengetahui informasi yang tersebar, maka diperlukan klasifikasi untuk mengetahui apakah informasi tersebut hoax atau bukan. Klasifikasi yang akan digunakan dalam penelitian ini adalah klasifikasi Rocchio, dimana hasil klasifikasi Rocchio akan dibandingkan dengan Multinomial Naive Bayes. Evaluasi pada penelitian ini menggunakan confusion matrix, dimana akurasi Rocchio didapatkan sebesar 83.501% sedangkan Multinomial Naive Bayes sebesar 65.835%.
Keyword: Hoax, Non-Hoax, Klasifikasi, Rocchio, Multinomial Naive Bayes, confusion matrix

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