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The development of sending messages from one place to another can be done regardless of distance and time. However, the delivery of these messages is hampered by problems of confidentiality and message security. Especially if the data contains important and confidential information that not just anyone is allowed to read and find out about it. In overcoming this problem, steganography techniques can be used with the Modified Least Significant Bit algorithm, where the determination of the embedding index is based on random numbers generated by the Pseudo-Random Number Generator with the Multiply with Carry algorithm. In addition to security, data size is also an important factor in data transmission. The larger the size the more time it will take to transmit the data. Therefore, the Run Length Encoding algorithm is needed to compress the data size, which will shorten the time to transmit the data. In the message extraction process, a stego key is needed to generate random numbers. Based on the testing of the extraction process with an arbitrary key, it is obtained that the message tested is not the original message that has been embedded previously. In the results of the embedding and extraction process, it is obtained that the average value of PSNR is 63.61498 dB, which means the quality of the stego object produced is quite good. Whereas the measurement of file compression performance results with an average value of Compression Ratio at 1.00113, Space Savings at 0.1133%, and Bitrate at 584025.33 bits/sample. These results indicate that RLE algorithm compression is not efficient to compress file sizes.

Penerapan grafika komputer dalam kehidupan sehari-hari sudah sering kita temukan. Salah satu contoh penerapan dari grafika komputer ini adalah penerapan teknik morphing. Morphing adalah proses transisi dari suatu bentuk objek ke bentuk objek yang lainnya. Salah satu algoritma yang dapat digunakan untuk membuat teknik morphing adalah dengan metode interpolasi linear. Tujuan kami melakukan penelitian ini adalah untuk melihat bagaimana penerapan algoritma morphing metode interpolasi linear dalam pembuatan animasi integral. Metode yang digunakan pada penelitian kali ini adalah dengan mengimplementasikan algoritma morphing metode interpolasi linear pada OpenGL dan melakukan simulasi dalam bahasa pemrograman C++ yang nantinya akan menghasilkan animasi integral.

Data exchange is a very important thing in today’s technological development. Two important factors must be considered in the process of data exchange, namely speed and security. Rapid technological development can result in insecure data because it can be stolen or manipulated by people who are not privileged. Thus, we need a way or method to be able to overcome these problems, such as cryptography and steganography. The Rivest-Shamir-Adleman or RSA algorithm is an asymmetric cryptographic algorithm that uses 2 prime numbers to generate a public key and a private key that is used in the encryption process for the data. The ECC concept is used to determine the seed or initial value in the generation of prime numbers in the RSA Algorithm by using point addition and multiplication in an elliptic curve. The Least Significant Bit Algorithm is a Steganography Algorithm that inserts bits from the message at the last bit in a cover, replacing the last bit. The parameter used is Running Time in steganography. The results of the research show that image files can be hidden in another image file and returned to normal with a combination of cryptography and steganography with an average Running Time for the insertion process of 3090.167 ms and the extraction process of 2917.167 ms.

Data compression was born as a solution to human needs for digital data. This research compares two compression algorithms, namely the Start-Step-Stop code algorithm and Gopala-Hemachandra codes 2 (GH-2 (n)) algorithm in the case of text file compression. compression ratio (CR), space savings (SS), bit rate and running time are calculated in the test as consideration to compare the advantages of both algorithms. Tests carried out using homogeneous strings, heterogeneous strings and artificial corpus. In homogeneous string compression, both algorithms have the same advantages because the value of CR, SS and bit rate are the same for each number of strings used. From the time of compression, Start-Step-Stop algorithm faster than the Gopala-Hemachandra algorithm. Testing of heterogeneous strings found that the Start-Step-Stop algorithm is superior to the Gopala-Hemachandra algorithm because it can save more storage space.

We present a client-server based smartphone application that act as a music input device with several outputs. The application allows user to interact with one phone as the input and the server and hear the sound from several connected smartphones that act as clients. Since transmitting data may require some time, we need to deal with transmission delay. Hence, we developed an algorithm to detect the delay and synchronize these values between all connected devices. By agreeing to a single delay value, we were able to minimize the difference in playtime between server and connected clients. We performed the test by building an Android-based smartphone application, installing it to multiple devices, and connecting them to a WiFi-based local area network. The test shows that our proposed system has successfully reduce the difference between devices and the connected devices were able to produce sounds with insignificant delay.

North Sumatera Province in Indonesia has many amazing tourism spots to visit. Unfortunately, information about these places is not organized well yet. Not all of these tourism spots have official websites and that made information with specific parameters according to user needs cannot be fulfilled if only depend on a search engine on the internet. The limitation of ordinary search engines cannot generate complex queries that involving relevant background knowledge of these places such as tourist locations, facilities offered, culinary and so on. Therefore in this paper, we offer North Sumatera Tourist sports searching system based on the semantic web. We utilized ontology as a source of knowledge that describes tourism in the province of North Sumatera. We observed and scrapped information about tourism spots in North Sumatera from trusted traveling websites. The next stage is the design of the Resource Description Framework (RDF) and ontology to describe relations between parameters. The result of this study produces a system that can help and understand the desires of tourists to get information about tourism objects in North Sumatera. Test results with various relevant semantic keywords parameter show the success of this system is 85%.

In the cultivation of Oyster Mushrooms need special treatment because oyster mushrooms are susceptible to disease. Mushroom growth will be inhibited if the temperature and humidity are not well controlled because temperature and inertia can affect mold growth. Oyster mushroom growth usually will be optimal at temperatures around 22-28°C and humidity around 70-90%. This problem is often encountered in the cultivation of oyster mushrooms. Therefore it is very important to control the temperature and humidity of the room of oyster mushroom cultivation. In this paper, we developed an automatic temperature monitoring tool in the cultivation of oyster mushroom-based Arduino Uno microcontroller. We have designed a tool that will control the temperature and humidity automatically by Android Smartphone. If the temperature increased more than 28°C in the room of mushroom plants, then this tool will turn on the pump automatically to run water in order to lower the room temperature. And if the room temperature of mushroom plants below of 22°C, then the light will be turned on in order to heat the room. Thus the temperature in the room oyster mushrooms will remain stable so that the growth of oyster mushrooms can grow with good quality.