Judul: Pengenalan Iris Mata Menggunakan Algoritme K-Nearest Neighbor Berbasis Histogram
Abstrak: Biometrics is the study of automated method to recognize or identify people based on one or more parts of the human body or the behavior of man himself. Iris image recognition is the process of matching between the characteristics of the image query image with the characteristics of the training image stored in database (image library). The system uses an automattic segmentation based on canny edge detection to localized the iris collarete. The features are extracted using histogram. The data are then splitted into three subsets and then alternately used for training and testing using k-Nearest Neighbor. The best recognition of testing data are obtained from combining from left and right eyes rather than using single eye sides.
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Judul: Pengenalan Iris Mata Menggunakan Probabilistic Neural Network dengan Ekstraksi Ciri Log-Gabor Filter
Abstrak: One of the objects of research that is currently prevalent in the developed world is the individual identification technology based on biometrics. Iris biometric is promising for identification, because it has a consistent pattern compared with other types of biometrics. This study established a system of identification using iris images from CASIA eye using 1D log- Gabor filter for feature extraction and PNN as classifier. This system uses automatic segmentation based on the threshold to localize the iris collarette region and normalize the results to the constant dimension using Daugman’s dimensional rubber sheet model by mapping each point in the iris region to a pair of polar coordinates. Data were divided into three subsets. Tests were conducted on the left eye dataset, right eye dataset and a combined dataset of left eye and right eye. The average accuracy produced for the left eye dataset is 98%, for the right eye dataset is 97%, and for the combination of left and right eye is 100%.
Keyword: probabilistic neural network (PNN)., log-Gabor filter, iris recognition

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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