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.
Articles
14 Documents
Search results for
, issue
" Vol 6, No 1 (2019): Mei 2019"
:
14 Documents
clear
<![CDATA[Digital Evidence Identification on Google Drive in Android Device Using NIST Mobile Forensic Method ]]>
<![CDATA[Yudhana, Anton]]>;
<![CDATA[Umar, Rusydi]]>;
<![CDATA[Ahmadi, Ahwan]]>
<![CDATA[ Scientific Journal of Informatics Vol 6, No 1 (2019): Mei 2019 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.15294/sji.v6i1.17767
<![CDATA[The use of cloud storage media is very popular nowadays, especially with the Google Drive cloud storage media on smartphones. The increasing number of users of google drive storage media does not rule out the possibility of being used as a medium for storing illegal data, such as places to store negative content and so on. On a smartphone with an Android operating system that has a Google Drive application installed, digital evidence can be extracted by acquiring and analyzing the system files. This study implemented a mobile forensic method based on guidelines issued by the National Institute of Standards of Technology (NIST). The results of this study are presented in the form of data recovery in the deleted Google Drive storage media, which results in the form of headers of the data type in the form of deleting account names, deleted file types, and timestamp of deleted files. Digital evidence obtained with 59 Axiom Magnet software found in the Entry227 file, with 46 files, if the percentage is a success rate of 77%.]]>
<![CDATA[Decision Support System for Household Labor Services Selection “Best Helper” Using AHP and TOPSIS Methods ]]>
<![CDATA[Pirnanda, I Kadek Aditya]]>;
<![CDATA[Pradnyana, I Made Ardwi]]>;
<![CDATA[Wirawan, I Made Agus]]>
<![CDATA[ Scientific Journal of Informatics Vol 6, No 1 (2019): Mei 2019 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.15294/sji.v6i1.18050
<![CDATA[Selection of household labor services was an important aspect in families who have a lot of activity. The existence of helpful household labour services would avoid the occurrence of problems that should be caused. Types of household labour services which were often used were maids, baby sitters, elderly nurses, gardeners, and drivers. The main problem arose in the difficulty of service seekers in choosing the desired service and how to minimize the time spent. To overcome this, a decision support system was used using the Analytical Hierarchy Process (AHP) method which was used to find the criteria for each alternative weight, and ranking calculations using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method. This research was implemented using PHP language with CodeIgniter framework. The result shows that the usability test obtains the average value with the system usability scale (SUS) method of 71.09%. It shows that the level of system usability is classified as good and can be accepted and used easily by the users. Meanwhile, the result of the user response test shows a percentage of 87.5%, so it can be concluded that the system belongs to good category and feasible to use.]]>
<![CDATA[Comparative Analysis of Dempster-Shafer Method and Certainty Factor Method On Personality Disorders Expert Systems ]]>
<![CDATA[Yuwono, Doddy Teguh]]>;
<![CDATA[Fadlil, Abdul]]>;
<![CDATA[Sunardi, Sunardi]]>
<![CDATA[ Scientific Journal of Informatics Vol 6, No 1 (2019): Mei 2019 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.15294/sji.v6i1.17216
<![CDATA[Kepribadian adalah sifat dan kebiasaan seseorang yang membedakannya dari orang lain. Identifikasi gangguan kepribadian penting untuk semua orang. Kondisi kepribadian yang mencerminkan kondisi mental yang sehat. Namun, tidak bagi manusia untuk tidak bisa menerima tekanan pada diri sendiri. Dalam beberapa kasus, banyak orang ingin melakukan pengujian dengan sumber daya yang cukup dan verifikasi yang sesuai. Untuk mengatasinya, diperlukan tes validasi untuk metode deteksi cacat. Metode yang mendukung validasi adalah Metode Dempster-Shafer dengan Metode Faktor Kepastian.Analisis validasi dilakukan pada metode Dempster-Shafer dengan metode Certainty Factor karena menimbang nilai kerusakan kedua metode ini diperlukan dari data hipotesis atau perubahan dalam bentuk data simptom. Analisis validasi dilakukan pada nilai bobot yang dihasilkan untuk setiap metode yang diterapkan. Dari hasil analisis validasi, nilai bobot yang diperoleh dengan metode Demp-ster-Shafer dapat menghasilkan nilai bobot yang lebih akurat.]]>
<![CDATA[Comparison of PCA and 2DPCA Accuracy with K-Nearest Neighbor Classification in Face Image Recognition ]]>
<![CDATA[Sutarti, Sri]]>;
<![CDATA[Putra, Anggyi Trisnawan]]>;
<![CDATA[Sugiharti, Endang]]>
<![CDATA[ Scientific Journal of Informatics Vol 6, No 1 (2019): Mei 2019 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.15294/sji.v6i1.18553
<![CDATA[Face recognition is a special pattern recognition for faces that compare input image with data in database. The image has a variety and has large dimensions, so that dimension reduction is needed, one of them is Principal Component Analysis (PCA) method. Dimensional transformation on image causes vector space dimension of image become large. At present, a feature extraction technique called Two-Dimensional Principal Component Analysis (2DPCA) is proposed to overcome weakness of PCA. Classification process in 2DPCA using K-Nearest Neighbor (KNN) method by counting euclidean distance. In PCA method, face matrix is changed into one-dimensional matrix to get covariance matrix. While in 2DPCA, covariance matrix is directly obtained from face image matrix. In this research, we conducted 4 trials with different amount of training data and testing data, where data is taken from AT&T database. In 4 time testing, accuracy of 2DPCA+KNN method is higher than PCA+KNN method. Highest accuracy of 2DPCA+KNN method was obtained in 4th test with 96.88%. while the highest accuracy of PCA+KNN method was obtained in 4th test with 89.38%. More images used as training data compared to testing data, then the accuracy value tends to be greater.]]>
<![CDATA[Bayes Theorem and Forward Chaining Method On Expert System for Determine Hypercholesterolemia Drugs ]]>
<![CDATA[Perbawawati, Anna Adi]]>;
<![CDATA[Sugiharti, Endang]]>;
<![CDATA[Muslim, Much Aziz]]>
<![CDATA[ Scientific Journal of Informatics Vol 6, No 1 (2019): Mei 2019 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.15294/sji.v6i1.14149
<![CDATA[The development of technology capable to imitating the process of human thinking and led to a new branch of computer science named the expert system. One of the problem that can be solved by an expert system is selecting hypercholesterolemia drugs. Drug selection starts from find the symptoms and then determine the best drug for the patient. This is consist with the mechanism of forward chaining which starts from searching for information about the symptoms, and then try to illustrate the conclusions. To accommodate the missing fact, expert systems can be complemented with the Bayes theorem that provides a simple rule for calculating the conditional probability so the accuracy of the method approaches the accuracy of the experts. This reseacrh uses 30 training data and 76 testing data of medical record that use hypercholesterolemia drugs from Tugurejo Hospital of Semarang. The variable are common symptoms and some hypercholesterolemia drugs. This research obtained a selection of hypercholesterolemia drugs system with 96.05% accuracy]]>
<![CDATA[Dataset Characteristics Identification for Federated SPARQL Query ]]>
<![CDATA[Rakhmawati, Nur Aini]]>;
<![CDATA[Fadzilah, Lutfi Nur]]>
<![CDATA[ Scientific Journal of Informatics Vol 6, No 1 (2019): Mei 2019 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.15294/sji.v6i1.17258
<![CDATA[Nowadays, the amount of data published in the RDF format is increasing. Federated SPARQL query engines that can query from multiple distributed SPARQL endpoints have been developed recently. A federated query engine usually has different performance compared to the others. One of the factors that affect the performance of the query engine is the characteristic of the accessed RDF dataset, such as the number of triples, the number of classes, the number of properties, the number of subjects, the number of entities, the number of objects, and the spreading factor of a dataset. The aim of this work is to identify the characteristic of RDF dataset and create a query set for evaluating a federated engine. The study was conducted by identifying 16 datasets that used by ten research papers in Linked Data area.]]>
<![CDATA[Compression and Decompression of Audio Files Using the Arithmetic Coding Method ]]>
<![CDATA[Silitonga, Parasian D. P]]>;
<![CDATA[Morina, Irene Sri]]>
<![CDATA[ Scientific Journal of Informatics Vol 6, No 1 (2019): Mei 2019 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.15294/sji.v6i1.17839
<![CDATA[Audio file size is relatively larger when compared to files with text format. Large files can cause various obstacles in the form of large space requirements for storage and a long enough time in the shipping process. File compression is one solution that can be done to overcome the problem of large file sizes. Arithmetic coding is one algorithm that can be used to compress audio files. The arithmetic coding algorithm encodes the audio file and changes one row of input symbols with a floating point number and obtains the output of the encoding in the form of a number of values greater than 0 and smaller than 1. The process of compression and decompression of audio files in this study is done against several wave files. Wave files are standard audio file formats developed by Microsoft and IBM that are stored using PCM (Pulse Code Modulation) coding. The wave file compression ratio obtained in this study was 16.12 percent with an average compression process time of 45.89 seconds, while the average decompression time was 0.32 seconds.]]>
<![CDATA[Digital Evidence Acquisition System on IAAS Cloud Computing Model using Live Forensic Method ]]>
<![CDATA[Sudyana, Didik]]>;
<![CDATA[Lizarti, Nora]]>
<![CDATA[ Scientific Journal of Informatics Vol 6, No 1 (2019): Mei 2019 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.15294/sji.v6i1.18424
<![CDATA[Cloud Computing is a technological development that has been warmly discussed in recent years and has seen significant increases in usage, especially on the IAAS Cloud Computing model. The high rate of development of IAAS Cloud Computing model is in line with the high number of crimes involving IAAS Cloud Computing model on server virtualization. When a computer crime occurs and a digital forensic investigation will be carried out to uncover the case, it raises issues related to the acquisition of digital evidence. Because the acquisition model in general, it is done only to one operating system, while in virtualization there is more than one operating system, so the acquisition technique in general cannot be used because it takes only one operating system involved crime, and cannot acquire the whole data server related privacy data in other virtual operating systems. Therefore, research to make the acquisition system of server virtualization is needed. The focus in this research is to make system acquisition in server virtualization Proxmox using the live forensic method to produce a system that can acquire virtualization without disrupting the overall data server and in accordance with the principle of digital forensics. The resulting acquisition system can be a reference for investigators to investigate the IAAS Cloud Computing model on Proxmox virtualization and facilitate the investigator's work in the use of the system because the investigator simply chooses which virtual operating system to acquire, after which the system will work on its own the acquisition.]]>
<![CDATA[Security Login System on Mobile Application with Implementation of Advanced Encryption Standard (AES) using 3 Keys Variation 128-bit, 192-bit, and 256-bit ]]>
<![CDATA[Utami, Hamdan Dian Jaya Rozi Hyang]]>;
<![CDATA[Arifudin, Riza]]>;
<![CDATA[Alamsyah, Alamsyah]]>
<![CDATA[ Scientific Journal of Informatics Vol 6, No 1 (2019): Mei 2019 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.15294/sji.v6i1.17589
<![CDATA[The development of mobile applications is unbalanced with the level of its security which is vulnerable to hacker attacks. Some important things that need to be considered in the security of mobile applications are login and database system. A login system that used the database as user authentication and passwords are very vulnerable to be hacking. In securing data, various ways had been developed including cryptography. Cryptographic algorithms used in securing passwords usually used MD5 encryption. However, MD5 as a broader encryption technique is very risky. Therefore, the level of login system security in an android application is needed to embed the Advanced Encryption Standard (AES) algorithm in its process. The AES algorithm was applied using variations of 3 keys 128-bit, 192-bit, and 256-bit. Security level testing was also conducted by using 40 SQL Injection samples which the system logins without security obtained 27.5% that be able to enter the system compared to the result of login systems that use AES algorithm 128-bit, 192-bit or 256-bit was obtained 100% that cannot enter into the system. The estimation of the average encryption process of AES 128, 192 and 256 bits are 5.8 seconds, 7.74 seconds, and 9.46 seconds.]]>
<![CDATA[INTESTINE DISEASE DIAGNOSIS SYSTEM USING CERTAINTY FACTOR METHOD ]]>
<![CDATA[Kirana, Chandra -]]>;
<![CDATA[Pradana, Harrizki Arie]]>;
<![CDATA[Sulaiman, Rahmat -]]>
<![CDATA[ Scientific Journal of Informatics Vol 6, No 1 (2019): Mei 2019 ]]>
Publisher : <![CDATA[Universitas Negeri Semarang ]]>
Show Abstract
|
Download Original
|
Original Source
|
Check in Google Scholar
|
DOI: 10.15294/sji.v6i1.17908
<![CDATA[Inside the human body there are many important organs, one of which is the intestine. Intestinal disease / digestive disease is a disease that most often attacks the digestive tract in humans. There are several intestinal diseases that are dangerous and there are also harmless intestinal diseases. In this research, researchers created an android-based expert system application that can provide information to the users about diseases that are being suffered through the symptoms experienced by the user. The process of making expert system applications using the certainty factor algorithm. The certainty factor algorithm is used to accommodate the uncertainty of an expert's. The mechanism that be used in the certainty factor algorithm on each symptom uses a measure of increased belief (MB) and measure of increased disbelief (MD). Expert system applications that have been built to detect intestinal diseases based on Android have been successfully implemented with a presentation of accuracy of 99.7265625%. by that percentage, it show us that the diagnosis of symptoms of the selected disease is in suitable by the experienced of user, and has the accuracy determined by the system]]>
