Judul: Pemodelan Pendinginan Evaporatif pada Rumah Tanaman Tipe Arch Menggunakan Jaringan Saraf Tiruan
Abstrak: Budidaya tanaman di dalam rumah tanaman di daerah yang beriklim tropika basah menghadapi kendala tingginya suhu udara pada siang hari ketika cuaca cerah. Penggunaan pendingin evaporatif dapat menjaga suhu udara di dalam rumah tanaman agar lebih sesuai bagi pertumbuhan tanaman. Namun di daerah beriklim tropika basah penggunaan pendingin evaporatif menyebabkan kelembaban udara di dalam rumah tanaman sangat tinggi sehingga tanaman mudah terserang jamur. Hubungan suhu dan kelembaban udara di dalam rumah tanaman tipe arch dengan kondisi iklim dan kondisi operasi pendingin evaporatif perlu diketahui untuk menjadi pertimbangan perbaikan rancangan maupun pengelolaan rumah tanaman tersebut. Penelitian ini bertujuan membangun model prediksi suhu dan kelembaban udara di dalam rumah tanaman berdasarkan kondisi iklim dan kondisi operasi pendingin evaporatif. Model dibangun menggunakan algoritma Jaringan Saraf Tiruan (JST) propagasi mundur. Model JST yang dibangun ternyata mampu memprediksi suhu dan kelembaban udara dengan baik yaitu dengan nilai Root Mean Square Error (RMSE) 0,297°C untuk prediksi suhu udara dan 2,862% untuk prediksi kelembaban udara., Crops cultivation inside the greenhouse in humid tropical climatic region faces problem of high air temperature during sunny days. The use of evaporative cooling could keep air temperature inside the greenhouse more growth. However, in humid tropical climates, the use of evaporative cooling causes the humidity of the air in the greenhouse to be very high so that the crops are susceptible to fungi. The relationship between air temperature and humidity inside the arch-type greenhouse with the climatic condition and operating condition of evaporative cooling have to be known for greenhouse design evaluation as well as its management considerations. This research aims to develop a predictive model for air temperature and humidity inside the greenhouse based on climatic condition and operating condition of evaporative cooling. The model was developed by using Artificial Neural Network (ANN) backpropagation algorithm. The developed ANN model evidently could well predicted air temperature and humidity with RMSE values of 0,297°C for temperature model and 2,862% for humidity model.
Keyword: artificial neural networks, evaporative cooling, greenhouse, modeling

Judul: Pengembangan Model Termal dan Evaluasi Performa Pendinginan Evaporatif pada Rumah Tanaman Tipe Arch
Abstrak: ABSTRAK ITSBAT BILLAH. Pengembangan Model Termal dan Evaluasi Performa Pendinginan Evaporatif pada Rumah Tanaman Tipe Arch. Dibimbing oleh HERRY SUHARDIYANTO. Penggunaan rumah tanaman di daerah tropis seperti Indonesia dihadapkan pada masalah kenaikan suhu udara yang terlalu tinggi dari kondisi ideal sehingga menyebabkan stress pada tanaman. Sistem pendinginan evaporatif dapat digunakan untuk mengatasi masalah tersebut, namun penggunaannya di Indonesia perlu dipelajari lebih lanjut. Penelitian ini bertujuan untuk membuat model termal sistem pendinginan evaporatif pada rumah tanaman serta melakukan evaluasi terhadap performa sistem tersebut. Selain itu kebutuhan pendinginan untuk mencapai suhu udara di dalam rumah tanaman pada set point tertentu juga dilakukan dalam penelitian ini. Prediksi suhu udara dan evaluasi performa sistem pendinginan evaporatif dilakukan menggunakan data eksperimental yang diperoleh melalui pengukuran langsung di lapangan. Hasil penelitian menunjukkan efisiensi penjenuhan sistem pendinginan evaporatif dapat mencapai nilai maksimum. Suhu udara di dalam rumah tanaman dapat mencapai rata-rata 1,46 oC lebih tinggi dari pada suhu udara luar pada saat beban panas tertinggi dalam sehari. Hasil validasi model diperoleh R2 = 0,7654–0,907 dan RMSE = 0,60–1,46. Model termal dapat digunakan untuk memprediksi suhu udara dan kebutuhan pendinginan untuk mencapai suhu pada set point tertentu. Kata kunci: rumah tanaman, model termal, pendinginan evaporatif, ABSTRACT ITSBAT BILLAH. Thermal Modelling and Performance Evaluation of Evaporative Cooling System in an Arch Greenhouse. Supervised by HERRY SUHARDIYANTO. The application of greenhouse in tropical region such as Indonesia is facing the problem of inside air temperature rising in mid day that can cause heat stress to the plant. Evaporative cooling system can be the alternative to solve that problem, but the application of evaporative cooling system for greenhouse in Indonesia need to be studied further. The goal of this study is to develop greenhouse thermal model that consider the existing evaporative cooling system and evaluate performance of the system. The result showed that the sturation efficiency could reached maximum value. The greenhouse inside air temperature could be 1,46 oC higher than the outside air temperature when the value of the heat load reached the highest during measurement time. R2 = 0,765–0,907 and RMSE = 0,60–1,46 were obtained from experimental validation of the model . The developed thermal model can be used for predicting the inside air temperature and the cooling requirement to obtain inside air temperature at given set point. Keywords: evaporative cooling, greenhouse, thermal model
Keyword: Greenhouse, evaporative cooling

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
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