Judul: Soil Temperature and Moisture Monitoring System Using LoRa Communication: Case Study on the Impact of Plastic Mulching
Abstrak: Budidaya pertanian memerlukan pemantauan intensif dari penanaman hingga panen. Dalam penelitian ini, sistem monitoring suhu dan kelembaban tanah menggunakan teknologi LoRa (Long Range) dikembangkan untuk memberikan informasi real-time tentang kondisi lingkungan pertanian. Sensor suhu DS18B20 menunjukkan bahwa penggunaan mulsa menurunkan suhu rata-rata tanah dari 31,25 ? (tanpa mulsa 35,77 ?) pada hari pertama menjadi 30,71 ? (tanpa mulsa 33,15 ?) pada hari kedua. Sensor kelembaban tanah FC-28 menunjukkan penggunaan mulsa mengurangi kelembaban rata-rata dari 342 (tanpa mulsa 402) pada hari pertama menjadi 276 (tanpa mulsa 302) pada hari kedua. Pengujian LoRa selama dua hari dengan jarak 400 Meter menunjukkan bahwa sistem ini efektif dalam memantau dan mengontrol kondisi tanah untuk mendukung pertumbuhan tanaman., Agricultural cultivation requires intensive monitoring from planting to harvest. In this study, a soil temperature and moisture monitoring system using LoRa technology was developed to provide real-time information on agricultural environmental conditions. The DS18B20 temperature sensor indicated that mulching reduced average soil temperatures from 31.25 ? (without mulch 35.77 ?) on the first day to 30.71 ? (without mulch 33.15 ?) on the second day. The FC-28 soil moisture sensor showed that mulching decreased average moisture levels from 342 (without mulch 402) on the first day to 276 (without mulch 302) on the second day. LoRa testing over two days with a distance of 400 meters demonstrated that the system is effective in monitoring and controlling soil conditions to support plant growth.
Keyword: kelembaban tanah, LoRa, sensor kelembaban tanah FC-28, sensor suhu DS18B20, suhu tanah

Judul: Development of Microclimate Monitoring System for Multi-Greenhouse using Internet of Things
Abstrak: Suhu udara, kelembapan udara, dan intensitas cahaya merupakan parameter lingkungan mikro di dalam rumah tanaman yang berpengaruh terhadap pertumbuhan tanaman dan perlu dilakukan pemantauan. Saat ini, Internet of Things (IoT) merupakan teknologi yang mumpuni dan dapat digunakan untuk melakukan pemantauan lingkungan mikro rumah tanaman di berbagai lokasi secara langsung. Tujuan penelitian ini yaitu rancang bangun sistem pemantauan suhu nutrisi, suhu udara, kelembapan udara, dan intensitas cahaya pada berbagai rumah tanaman berbasis IoT. Penelitian ini menggunakan metode System Development Life Cycle (SDLC) yang terdiri dari: (1) analisis kebutuhan sistem, (2) desain sistem, (3) implementasi sistem, dan (4) pengujian sistem. Perangkat elektronika yang digunakan yaitu sensor DHT21, BH1750, DS18B20, dan mikrokontroler ESP32. Hasil perhitungan Root Mean Square Error (RMSE) dan Mean Absolute Percentage Error (MAPE) pada kalibrasi sensor yang rendah menunjukkan nilai eror data dari pembacaan sensor yang kecil. Desain sistem dibuat menggunakan rancangan database dan entity relationship diagram. Sistem diimplementasikan pada berbagai rumah tanaman yaitu dua greenhouse tipe standard peak dan satu plant factory. Berdasarkan hasil uji System Usability Scale (SUS), didapatkan nilai SUS 75,67 yang artinya sistem dapat diterima oleh pengguna dan termasuk kategori sistem yang baik pada kelas B. Kesimpulan dari penelitian ini yaitu sistem pemantauan lingkungan mikro pada berbagai rumah tanaman berhasil dilakukan menggunakan perangkat elektronika berbasis IoT yang dapat diakses oleh pengguna pada web server., Air temperature, air humidity, and light intensity are microclimate parameters in greenhouse that affect plant growth and must be monitored. Currently, the Internet of Things (IoT) is powerful and can be used to monitor microclimate parameters in multi-greenhouse at various locations directly. The purpose of this research is to design and develop a system for monitoring nutrient temperature, air temperature, air humidity, and light intensity in multi-greenhouse based on IoT. This research used the System Development Life Cycle (SDLC) method, which consists of: (1) system requirement analysis, (2) system design, (3) system implementation, and (4) system testing. The electronic devices used were DHT21, BH1750, DS18B20 sensors, and ESP32 microcontroller. The low values of Root Mean Square Error (RMSE) dan Mean Absolute Percentage Error (MAPE) obtained in sensor calibration indicate small data errors from sensors. The system design was made with a database design and entity relationship diagram. The system was successfully implemented in multi-greenhouse which two greenhouse standard peak type and a plant factory. Based on the results of System Usability Scale (SUS) test, the system received SUS score of 75.67, which means that system was acceptable to users and included good category in class B. The conclusion of this research was microclimate monitoring system in multi-greenhouse has been successfully implemented using electronic devices based on IoT that can be accessed by users on a web server.
Keyword: ESP32, Internet of Things, rumah tanaman, sensor lingkungan, sistem informasi

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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