Judul: Pengembangan Sensor Warna Daun untuk Menduga Kebutuhan Pupuk pada Tanaman Padi
Abstrak: Leaf colour is an indicator of plant fertility level which can be used for predicting fertilizer need of the paddy plants. The use of leaf colour chart (LCC) is one of instruments to measure greenness level. This research used image processing technology for analysing leaf colour level according to the IRRI-LCC standard. Taking the image of paddy leaves used a cart which is equiped with a proximity sensor and a CCD camera. Proximity sensor functions sending a signal to the camera to capture an image at every certain travelling distance. The captured images were then saved in the hard disk memory. Furthermore, those images were processed with Visual Basic program for analysing leaves area and greenness level. Then, the results were transformed into an area colour map, where each patch of land contains information about fertilizer need. Beside analysing with image processing, the measurement of leaf colour level was also done manually. The result of the manual measurement was also translated into an area colour map. The results of the manual and image processing measurement were then compared for determining the accuracy level. Accuracy at the colour level 2 was 38%, the colour level 3 was 69%, and the colour level 4 was 75%. The correlation between leaf colour level and nutrient content of soil was observed by comparing the result of soil nutrient content test and leaf colour level. It was found that both averages show a strong correlation
Keyword: 

Judul: Rancang Bangun Alat Elektronik Pengukur Indeks Warna Daun Padi Untuk Rekomendasi Pemupukan Nitrogen
Abstrak: Nondestructive nitrogen monitoring for rice leaf is necessary for applying site specific nitrogen recommendation. Electronic SPAD chlorophyll meter device from Konica Minolta and IRRI-Leaf Color Chart now is the most known tools for measuring rice leaf index which have correlated reading with leaf nitrogen content. Both device is using leaf color properties principles to gave index value for estimating leaf nitrogen content. In this research, a new Prototype of leaf color measurement portable device has been build using TAOS TCS230 RGB Color Sensor. This device is using white LED light source to get reflection from rice leaf. Value read from sensor within range 400-600 nm will be processed in microcontroller to gave color value, leaf index and nitrogen fertilizer amount to be applied in the rice field. Performance test result indicate that the device has worked well on distinguishing colors as calibrated with GretagMacbeth color patch. Using BWD calibration the devices display XYZ and RGB color value as well as the BWD unit and fertilizer recommendation.
Keyword: 

Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
Keyword: