Judul: Rancang bangun data logger berbasis sensor Dht22 untuk mengukur suhu dan kelembaban habitat satwa herpetofauna Secara real-time
Abstrak: Pada penelitian ini dilakukan perancangan data logger suhu dan kelembaban berbasis sensor DHT22 untuk pemantauan habitat satwa herpetofauna. Satwa herpetofauna sangat sensitif dengan perubahan suhu dan kelembaban habitatnya. Data dari sensor diteruskan melewati rangkaian buffer menuju mikrokontroler dan berakhir pada Data logger yang dibangun dari 3 komponen utama yaitu RTC peripheral (pewaktu), EMS SDcard (perekam), dan SDcard (media penyimpanan). Kemampuan minimal selang pengukuran alat adalah 5 detik setiap data. Hasil pengukuran dianalisis dengan metode ploting curve pada program Microsoft Excel 2007. Secara umum sebaran data menunjukan nilai suhu yang berbanding terbalik dengan kelembaban pada pengukuran di dalam lubang, dalam ruangan, dan luar ruangan. Komparasi alat ukur mendekati nilai komparator (termometer raksa) dibandingkan dengan alat Thermometer-Hygrometer TFA. Nilai ketepatan alat terhadap komparator sebesar 98%.
Keyword: data logger, habitat, herpetofauna, kelembaban, suhu

Judul: Rancang Bangun dan Uji Kinerja Water Temperature Data Logger
Abstrak: Water temperature data logger is an instrument to record the water temperature automatically and to show a comprehensive monitoring of temperature condition of the medium or environment. This research aims to design and construct water temperature data logger and to perform field test. There were five stages conducted: the casing design, electronic system design, software design, test labs, and field test. Casing was designed using cylindric aluminum material with a diameter of 3.2 cm and a length of 16.5 cm. The electronic systems are built from the microcontroller ATmega328P as main controller, DS18B20 as temperature sensor, mini DC motor as vibration indicator, DS3231 as time marker sensor, and micro SD card as data storage. The result of performance test of water temperature data logger showed that casing was waterproof and did not need an addition of ballast. The battery life time is 10 days 8 hours for 30 minutes sampling intervals. The range error value of sensor calibration is between (-0.37) – 0.41°C and RMSE value 0.23 °C. The result of measurement in Bogor Agricultural University lake on October 10th – 20th 2013 ranged from 27.69 - 31.63 °C with the lowest daily temperature at 5.30 – 8.30 WIB and the highest at 12.00 - 16.00 WIB. T-test comparison of data between the water temperature data logger and a thermometer in MSP Department FPIK IPB pond for two days showed that the data were not significantly different
Keyword: temperature, performance test, instrument, design, data logger

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
Keyword: