Analisis sentimen merupakan teknik yang bertujuan menentukan opini dari masyarakat bersifat positif atau negatif. Internet merupakan bagian terpenting dalam kehidupan sehari-hari. Banyak situs yang menyediakan berbagai macam review tentang suatu produk atau jasa yang menggambarkan pendapat pengguna. Salah satu contohnya adalah situs internet Yelp. Yelp adalah sebuah situs yang berisi berbagai macam review, seperti transportasi, media massa, restoran, hotel, makanan, elektronik dan lain sebagainya. Transportasi memiliki peran yang sangat penting dalam menunjang pertumbuhan ekonomi masyarakat dan merupakan urat nadi dalam pembangunan ekonomi suatu negara. Oleh karena itu keberhasilan pembangunan dibidang ekonomi harus ditunjang dengan pengembangan sistim transportasi yang baik, sesuai dengan kebutuhan dan perkembangan zaman. Pengguna transportasi bisa memberikan pendapat mereka mengenai kualitas dari transportasi yang sudah tersedia secara online. Jika membaca review tersebut secara keseluruhan bisa memakan waktu dan sebaliknya jika hanya sedikit review yang dibaca, hasil evaluasi akan bias. Algoritma klasifikasi sentimen review seperti support vector machine (SVM) adalah algoritma yang sering digunakan untuk klasifikasi analisis sentimen review. Namun klasifikasi sentimen review mempunyai kelemahan pada banyaknya fitur atau atribut dataset yang digunakan, metode seleksi fitur chi square dapat digunakan untuk mengurangi fitur atau atribut yang tidak relevan.

Vehicles are very important in transportation that humans widely use in carrying out their activities, including one of them is a passenger car. Safety and security factors in traveling are the most important aspects of traveling. The condition that often occurs in passenger cars is the frequent leakage of carbon monoxide gas in the vehicle cabin. Usually, CO gas leaks occur in the AC hose. So, this research aims to design an Arduino-based carbon monoxide gas leak detector. This research is a research with research and development approach method or Research and Development (R&D). This research aims to produce a carbon monoxide detector design to automatically detect carbon monoxide gas leaks in the vehicle cabin based on Arduino Uno. The design performance of this CO gas leak detector can be obtained from the CO gas content of the MQ7 sensor, then the buzzer will make a sound, while the LCD will display the status "Safe/Alert/Very Dangerous" as a warning to passenger car drivers. DC motor will move the power window if the CO gas content exceeds the threshold of more than 25 ppm.

Visualization of heat flow often uses complex and challenging programs such as Matlab and Ansys Fluent with expensive licenses, and the operation is also difficult. This study aims to demonstrate the phenomenon of convection heat transfer in a simple way. The phenomenon of convection is fairly difficult, and the heat transfer process can cause misconceptions in students. An appropriate and easy-to-use method is needed in preparing for classroom learning. This study was conducted to review the air condition in the car cabin, which is influenced by airflow from the air conditioner, and visualize it. This visualization can be used to explain the phenomenon of heat transfer by convection to students, especially while cooling the car's air conditioner. This research was conducted using a car model with three rows of seats where the air conditioner is only on the front cabin dashboard. On the dashboard, the AC flows are located on the left, right, and center. The calculation is carried out by applying the Black Principle, where other particles around it influence the particle temperature. Microsoft Excel is used to perform mathematical operations and visualize the results in graphs. It successfully delivers a 2D image showing heat distribution in the car cabin space. Visualization of this convection phenomenon can provide an overview of the convection flow phenomenon. So, this method is very easy to operate and apply by teachers in preparing lessons on the phenomenon of temperature convection.