Judul: Sentiment Analysis of Twitter Users on Biskita  Transpakuan Bogor Transportation Services Using the Ensemble Method
Abstrak: Bogor merupakan kota terpadat kelima di Indonesia pada tahun 2021. Tingginya jumlah angkutan umum dan kendaraan pribadi membuat pemerintah Kota Bogor berupaya meluncurkan angkutan umum yang lebih ramah pengguna dengan nama Biskita Transpakuan. Umpan balik dari masyarakat diperlukan untuk terus meningkatkan kualitas pelayanan dalam memenuhi kebutuhan pengguna. Umpan balik tersebut dapat berupa dukungan, kritik, dan saran. Analisis sentimen digunakan untuk mengekstrak informasi berharga salah satunya dari media sosial. Metode Ensemble dengan model dasar regresi logistik multinomial, random forest dan multinomial naïve bayes digunakan untuk melakukan klasifikasi. Tujuan penelitian ini untuk mengetahui performa dari model Ensemble dalam melakukan klasifikasi sentimen. Hasil penelitian menunjukkan bahwa model Ensemble dapat memanfaatkan kelebihan masing – masing model dasar dan mendapatkan Akurasi serta skor F1 tertinggi yaitu sebesar 78%., Bogor is the fifth most populous city in Indonesia in 2021. The high number of public transportation and private vehicles has led the Bogor City government to launch a more user-friendly public transportation named Biskita Transpakuan. Feedback from the community is certainly needed to continue to improve service quality in meeting user needs. The feedback can be in the form of support, criticism, and suggestions. Sentiment analysis is used to extract valuable information from social media. Ensemble method with basic models of multinomial logistic regression, random forest and multinomial naïve bayes are used to perform classification. The purpose of this study is to determine the performance of the Ensemble model in performing sentiment classification. The results showed that the Ensemble model can utilize the advantages of each basic model and get the highest Akurasi and F1 score of 78%
Keyword: Biskita, Congestion, Ensemble Method, Sentiment Analysis, Twitter

Judul: Behavioral Economic of Communities on Utilizing Online Transportation and the Impact on CO2 Emissions in Bogor City
Abstrak: In general, the higher the level of economic activities and the number of population, the greater the needs for convenient transportation. The increasing public demand for accessibility, and on time as well as rapid public transportation lead to the development of online transportation services in Indonesia. Online transportation services can be found in almost all regions in Indonesia, including in Bogor City. Beside popular as public transportation for travel, online transportation services are also used by communites to fulfill their daily needs, such as purchasing food and delivering goods. The increasing of online transportation services used will induce to the escalation of online trasportation trips which then can provide negative externalities to the environment. Based on these problems, the objectives of this study are: 1) to analyze the economic behavior of the vehicle owners in Bogor City in the use of transportation, including online transportation; 2) estimate the impact of online transportation use on CO2 emissions in Bogor City. The sampling technique used for this study is accidental sampling. The data obtained is thus analyzed with agglomerative hierarchical clustering (AHC), correspondent analysis, multinomial logistic regression, and Tier-1 method based on IPCC 2006. Based on the results, there are several driving factors that can increase the opportunities of using personal transportation including online transportation on weekdays, i.e. safety reason and the number of private vehicles owned, and the reason for weekends are the convenience of transportation modes, time considering and number of private vehicles owned. Online transportation services are also used by the communities for ordering food. This because people already have private vehicles for mobility, and use of online transportation services for ordering food is considered very easy. Based on the number of online transportations i.e 121,188 units/day, and the use of BBM from online transportation i.e., 2.46 liters/day, then CO2 emissions resulted could reach 242,712.36 tonnes/year., Peningkatan aktivitas perekonomian dan aktivitas masyarakat di Kota Bogor diiringi dengan meningkatnya kebutuhan transportasi untuk kemudahan mobilisasi. Adanya peningkatan permintaan masyarakat untuk transportasi umum yang cepat, mudah diakses, dan tepat waktu menjadi salah satu pendorong berkembangnya jasa transportasi online di berbagai wilayah di Indonesia, termasuk di Kota Bogor. Selain untuk memenuhi kebutuhan perjalanan menuju destinasi tujuan, jasa transportasi online juga dimanfaatkan masyarakat untuk pemenuhan kebutuhan sehari-hari, seperti pembelian makanan dan pengantaran barang. Peningkatan akses penggunaan jasa transportasi online ini tentunya juga akan berdampak pada tingginya jumlah perjalanan kendaraan yang dapat memberikan eksternalitas negatif terhadap lingkungan, seperti pencemaran udara. Berdasarkan permasalahan tersebut, tujuan penelitian ini adalah: 1) menganalisis perilaku ekonomi masyarakat dalam penggunaan transportasi, terutama jasa transportasi online di Kota Bogor; dan 2) mengestimasi dampak penggunaan transportasi online terhadap emisi CO2 di Kota Bogor. Teknik penentuan responden dalam penelitian ini menggunakan metode accidental sampling. Data survei dianalisis dengan metode agglomerative hierarchical clustering (AHC), analisis koresponden, regresi logistik multinomial, dan dengan metode Tier-1 berdasarkan IPCC 2006. Berdasarkan hasil analisis, diketahui faktor pendorong yang dapat meningkatkan peluang masyarakat dalam menggunakan transportasi yang bersifat personal, termasuk transportasi online pada hari kerja yaitu alasan keamanan dalam menggunakan moda transportasi dan jumlah kendaraan pribadi yang dimiliki. Sedangkan faktor pendorong yang dapat
Keyword: Agglomerative Hierarchical Clustering (AHC), Behavioral economic, Multinomial logistic regression, Tier-1

Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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