Scientific Journal of Informatics
Scientific Journal of Informatics published by the Department of Computer Science, Semarang State University, a scientific journal of Information Systems and Information Technology which includes scholarly writings on pure research and applied research in the field of information systems and information technology as well as a review-general review of the development of the theory, methods, and related applied sciences.
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564 Documents
<![CDATA[Improve the Accuracy of Support Vector Machine Using Chi Square Statistic and Term Frequency Inverse Document Frequency on Movie Review Sentiment Analysis ]]>
<![CDATA[Larasati, Ukhti Ikhsani]]>;
<![CDATA[Muslim, Much Aziz]]>;
<![CDATA[Arifudin, Riza]]>;
<![CDATA[Alamsyah, Alamsyah]]>
<![CDATA[ Scientific Journal of Informatics Vol 6, No 1 (2019): May 2019 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
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DOI: 10.15294/sji.v6i1.14244
<![CDATA[Data processing can be done with text mining techniques. To process large text data is required a machine to explore opinions, including positive or negative opinions. Sentiment analysis is a process that applies text mining methods. Sentiment analysis is a process that aims to determine the content of the dataset in the form of text is positive or negative. Support vector machine is one of the classification algorithms that can be used for sentiment analysis. However, support vector machine works less well on the large-sized data. In addition, in the text mining process there are constraints one is number of attributes used. With many attributes it will reduce the performance of the classifier so as to provide a low level of accuracy. The purpose of this research is to increase the support vector machine accuracy with implementation of feature selection and feature weighting. Feature selection will reduce a large number of irrelevant attributes. In this study the feature is selected based on the top value of K = 500. Once selected the relevant attributes are then performed feature weighting to calculate the weight of each attribute selected. The feature selection method used is chi square statistic and feature weighting using Term Frequency Inverse Document Frequency (TFIDF). Result of experiment using Matlab R2017b is integration of support vector machine with chi square statistic and TFIDF that uses 10 fold cross validation gives an increase of accuracy of 11.5% with the following explanation, the accuracy of the support vector machine without applying chi square statistic and TFIDF resulted in an accuracy of 68.7% and the accuracy of the support vector machine by applying chi square statistic and TFIDF resulted in an accuracy of 80.2%.]]>
<![CDATA[Penggunaan Metode Depth First Search (DFS) dan Breadth First Search (BFS) pada Strategi Game Kamen Rider Decade Versi 0.3 ]]>
<![CDATA[Prasetiyo, Budi]]>;
<![CDATA[Hidayah, Maulidia Rahmah]]>
<![CDATA[ Scientific Journal of Informatics Vol 1, No 2 (2014): November 2014 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
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DOI: 10.15294/sji.v1i2.4022
<![CDATA[Pada permainan Game Kamen Rider Decade ini sangat membutuhkan strategi yang tepat jika ingin memenangkan dengan mudah permainan ini. Penelitian ini bertujuan untuk mengimplementasikan metode Dept First Search (DFS) dan Breadth First Search (BFS) pada Game Kamen Rider Decade, yang merupakan permainan dengan strategi penyelesaiannya menggunakan metode pencarian buta (blind search). Pengumpulan data dilakukan dengan pendekatan kualitatif dengan metode deskriptif, dimana pengujian dilakukan dengan memainkan 3 kali masing-masing dengan metode selalu BFS dan selalu DFS. Hasil menunjukan peluang lebih besar memenangkan permainan ini adalah dengan strategi selalu BFS. Dimana kemampuan BFS pada permainan ini dapat berguna untuk pertahanan terhadap musuh. ]]>
<![CDATA[A Comparison of Non Blind Image Watermarking Using Transformation Domain ]]>
<![CDATA[Kartikadarma, Etika]]>;
<![CDATA[Udayanti, Erika Devi]]>;
<![CDATA[Sari, Christy Atika]]>;
<![CDATA[Doheir, Mohamed]]>
<![CDATA[ Scientific Journal of Informatics Vol 8, No 1 (2021): May 2021 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
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DOI: 10.15294/sji.v8i1.28334
<![CDATA[Purpose: This study aims to know which of the algorithms had the better results for image processing by comparing these two algorithms for blind watermarking as the prevention of image plagiarism. Methods: The DCT and HWT algorithms used to get better results. Result: The results of this study indicate that HWT has better results for image processing, especially blind watermarking because the results with MSE, PSNR, and NC show that HWT has advantages in every aspect. using 512x512 pixels grayscale image as cover image, the MSE result from HWT is 0.0004156 with PSNR 81.9440 better than MSE from DCT 0.003 with PSNR 73.2949. Novelty: Robustness aspect has been tested using NC. DCT has good NC than HWT only in JPEG compression attack with value is 1, while another attack has better NC in HWT that yield close to 1.]]>
<![CDATA[A Hybrid Security Algorithm AES and Blowfish for Authentication in Mobile Applications ]]>
<![CDATA[Purwinarko, Aji]]>;
<![CDATA[Hardyanto, Wahyu]]>
<![CDATA[ Scientific Journal of Informatics Vol 5, No 1 (2018): May 2018 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
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DOI: 10.15294/sji.v5i1.8151
<![CDATA[Nowadays, everything is within our grasp and with the mobile phones become easier. Its use is not limited to calls and SMS but has become a tool that can be used to serve business transactions, banking, academic of data through mobile applications. Tus, the security of authentication in the mobile application needs to be improved to avoid a hacker attack. This article presents an authentication in the mobile application to the server using a hybrid of cryptographic algorithm Advanced Encryption Standard (AES) and Blowfish. AES and Blowfish is a symmetric key algorithm is very fast and powerful. With the utilization of a large block size of AES and Blowfish to encrypt keys, AES security will be much more robust and complicated to attacked. So, it will be difficult for hackers to perform Man in the Middle (MitM) attacks.]]>
<![CDATA[The Analysis of Implementation Business Model Canvas At The E-Marketplace Dipeta Company ]]>
<![CDATA[Purnawati, Ni Wayan]]>;
<![CDATA[Setyohadi, Djoko Budiyanto]]>
<![CDATA[ Scientific Journal of Informatics Vol 4, No 2 (2017): November 2017 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
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DOI: 10.15294/sji.v4i2.9945
<![CDATA[In the internet Era as now everything is easily accessible, obtaining good information, education, services even trade. E-Marketplace as a new innovation for interaction between buyer and seller can also encourage micro medium to promote his business. www.pesansaja.com released by dipeta in the field of E-Marketplace of local culinary, which still require a lot of innovation to be able to attract customers and keep them. Innovation is also needed to be able to compete with other competitors on the E-Marketplace that engaged in the same. Hence the need for the implementation of the business model in this business model Canvas to get new business models to suit the wishes of the customer and an evaluation based on the strong and weak points of this business. The results of the implementation are expected to make the company's E-Marketplace is getting big and compete at a national level as an E-Marketplace of successful culinary attract customers]]>
<![CDATA[Data-Driven E-commerce Techniques and Challenges in the Era of the Fourth Industrial Revolution ]]>
<![CDATA[Norian, Joma H.]]>;
<![CDATA[Jama, Abdelazez M.]]>;
<![CDATA[Eltaieb, Mohammed H.]]>;
<![CDATA[Adam, Ali A.]]>
<![CDATA[ Scientific Journal of Informatics Vol 7, No 2 (2020): November 2020 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
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DOI: 10.15294/sji.v7i2.25760
<![CDATA[The E-commerce industry has a significant role in the national and international economy. E-commerce is vital in the implementation of the fourth industrial revolution, where information and communication technologies are tools in creating digital channels of trade. Understanding e-commerce is essential for it is development. The objective of this paper is to explore the popular techniques and data sources of e-commerce in addition to the current challenges that face e-commerce in the last five years. We used a literature review as a method for this research. According to the literature, sales records are the most popular data source used in the research community for e-commerce analytics, then followed by big data and social media. Besides, detecting and predicting customer behavior is the most used technique in e-commerce research followed by personalized recommendations. Also, we reported the main three challenges that face researchers in the field of e-commerce currently: First, e-commerce Security and privacy is a major concern for consumers and industries. Second, understanding the collected data from e-commerce systems and how to create business value from it efficiently. Third, providing personalized offers with the most appropriate items, still a difficult task.]]>
<![CDATA[Analisa dan Perancangan Sistem Informasi Penjualan Online (E-Commerce) pada CV Selaras Batik Menggunakan Analisis Deskriptif ]]>
<![CDATA[Himawan, Himawan]]>;
<![CDATA[Saefullah, Asep]]>;
<![CDATA[Santoso, Sugeng]]>
<![CDATA[ Scientific Journal of Informatics Vol 1, No 1 (2014): May 2014 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
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DOI: 10.15294/sji.v1i1.3641
<![CDATA[Batik merupakan salah satu pakaian tradisional yang menjadi ciri khas dan kebanggaan bagi bangsa Indonesia, dimana batik juga telah dikenal secara luas baik dalam skala nasional dan internasional. Peluang dalam kegiatan bisnis penjualan batik yang meningkat beberapa waktu ini dilihat oleh banyak pihak sebagai prospek yang menjanjikan. Penjualan batik secara umum di beberapa wilayah di Indonesia masih dilakukan dengan cara yang sederhana dan klasik. Untuk dapat menjangkau lebih banyak pelanggan serta memperluas area pemasaran sekaligus promosi batik, maka diperlukan media yang dapat menunjang kegiatan promosi, transaksi penjualan dan informasi batik dengan optimal. Salah satu media yang menjadi perhatian masyarakat sekarang ini adalah dengan menggunakan media website online. E-Commerce merupakan salah satu kegiatan transaksi bisnis baik barang dan jasa yang dilakukan secara elektronik dengan menggunakan jaringan internet CV Selaras Batik menyadari bahwa peranan media website dapat digunakan untuk meningkatkan omset penjualan dan juga sebagai media sarana dalam memasarkan produk batik yang mereka miliki untuk menjangkau pasar yang lebih luas lagi serta dapat meminimalkan biaya-biaya operasional seperti biaya iklan dan juga biaya sewa toko secara fisik. Penulisan paper ini bertujuan untuk menganalisa pengaruh dari penggunaan media website online dalam hal ini adalah e-commerce dengan menggunakan pendekatan B2C (Business-to- Customer) dalam upaya meningkatkan transaksi penjualan batik pada CV Selaras Batik dan juga media penyampaian informasi baik pada para pelanggan dan masyarakat umum dalam memperoleh informasi mengenai produk-produk batik yang dipasarkan oleh CV Selaras Batik. ]]>
<![CDATA[Determination of The Shortest Route Based on BFS Algorithm for Purpose to Disaster Evacuation Shelter ]]>
<![CDATA[Sularno, Sularno]]>;
<![CDATA[Mulya, Dio Prima]]>;
<![CDATA[Astri, Renitra]]>;
<![CDATA[mulya, Dwiki]]>
<![CDATA[ Scientific Journal of Informatics Vol 8, No 1 (2021): May 2021 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
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DOI: 10.15294/sji.v8i1.27863
<![CDATA[Purpose: This study aims to determine the shortest route that can be taken by the user (community) during a disaster to reduce the risk of a greater number of victims by using the Breadth-first search algorithm, which is integrated into a web-based GIS application. By determining the starting point, which is the user's position when the disaster occurs, and then determining the endpoint, which is the location of the closest shelter, it will be possible to calculate the shortest distance that can be reached by the user at that time. Methods: The method chosen in this study is a waterfall because each step of the research carried out must be sequential and structured to avoid the risk of errors in each sequence of processes carried out. Result: The results of this study can be proven by doing manual calculations to determine the shortest distance, which will later be compared with the results of applications that have been designed using the BFS algorithm. Novelty: The novelty of this research is the development of GIS as a disaster mitigation education. The function of this research can help the community in finding an evacuation route in the event of a tsunami disaster.]]>
<![CDATA[K-Nearest Neighbor and Naive Bayes Classifier Algorithm in Determining The Classification of Healthy Card Indonesia Giving to The Poor ]]>
<![CDATA[Safri, Yofi Firdan]]>;
<![CDATA[Arifudin, Riza]]>;
<![CDATA[Muslim, Much Aziz]]>
<![CDATA[ Scientific Journal of Informatics Vol 5, No 1 (2018): May 2018 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
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DOI: 10.15294/sji.v5i1.12057
<![CDATA[Health is a human right and one of the elements of welfare that must be realized in the form of giving various health efforts to all the people of Indonesia. Poverty in Indonesia has become a national problem and even the government seeks efforts to alleviate poverty. For example, poor families have relatively low levels of livelihood and health. One of the new policies of the Sakti Government Card Program issued by the government includes three cards, namely Indonesia Smart Card (KIP), Healthy Indonesia Card (KIS) and Prosperous Family Card (KKS). In this study to determine the feasibility of a healthy Indonesian card (KIS) required a method of optimal accuracy. The data used in this study is KIS data which amounts to 200 data records with 15 determinants of feasibility in 2017 taken at the Social Service of Pekalongan Regency. The data were processed using the K-Nearest Neighbor algorithm and the combination of K-Nearest Neighbor-Naive Bayes Classifier algorithm. This can be seen from the accuracy of determining the feasibility of K-Nearest Neighbor algorithm of 64%, while the combination of K-Nearest Neighbor-Naive Bayes Classifier algorithm is 96%, so the combination of K-Nearest Neighbor-Naive Bayes Classifier algorithm is the optimal algorithm in determining the feasibility of healthy Indonesian card recipients with an increase of 32% accuracy. This study shows that the accuracy of the results of determining feasibility using a combination of K-Nearest Neighbor-Naive Bayes Classifier algorithms is better than the K-Nearest Neighbor algorithm.]]>
<![CDATA[Expert System Diagnosis Dental Disease Using Certainty Factor Method ]]>
<![CDATA[Setiabudi, Whisnu Ulinnuha]]>;
<![CDATA[Sugiharti, Endang]]>;
<![CDATA[Arini, Florentina Yuni]]>
<![CDATA[ Scientific Journal of Informatics Vol 4, No 1 (2017): May 2017 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
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DOI: 10.15294/sji.v4i1.8463
<![CDATA[Technological development is growing rapidly among with the increasing of human needs especially in mobile technology where the technology that often be used is android. The existence of this android facilitates the user in access of information. This android can be used for healthy needs, for example is detecting dental disease. One of the branches of computer science that can help society in detecting dental disease is expert system. In this research, making expert system to diagnosis dental disease by using certainty factor method. Dental disease diagnosis application can diagnose the patient based on griping of the patient about dental disease so it can be obtained diseases possibility of the patient itself. This application is an expert system application that operates on android platform. Furthermore, in the measurement accuracy of the system test performed by 20 patients, there were 19 cases of corresponding and 1 cases that do not fit. So, from system testing performed by 20 patients resulted in a 95% accuracy rate. ]]>
