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In this work, polysulfone (PSf)/hydroxyapatite (HAp) ultrafiltration mixed matrix membranes (MMMs) were prepared for wastewater treatment by using phase inversion method. The effect of hydroxyapatite (HAp) dispersion on the PSf/PVP membrane surface were investigated. Characterizations were done to observe the distribution of HAp on the membrane surface by using X-ray diffractometer (XRD) and scanning electron microscope (SEM). The XRD analysis showed the crystallinity of the HAp derived from cow bone. The dispersion of HAp in polymer matrix is a promising materials that can change the structure of the PSf membrane.

A modern application of composite hollow fibre membrane derived from hydroxyapatite cow bone and kaolin has been developed in wastewater treatment. The common fabrication method, a process that combined both phase inversion and sintering technique was used to fabricate the membranes. The hollow fibers membrane were developed using the spinning process by using a dope that have ratio of 20:20 (kaolin:cow bone hydroxyapatite). The sintering temperature that used in this study are 1000 °C, 1100 °C, 1200 °C and 1300 °C. The effect of sintering temperature on hollow fiber membranes were characterized by scanning electron microscopy (SEM), 3-point bending and pure water flux. The results showed that the hollow fibre membrane sintered at 1200 °C showed a unique membrane’s morphology, the highest mechanical strength (13.33 Mpa) and a stable pure water flux (140.6 L/m2h).

Pathfinding is the method for determining the shortest path. Pathfinding is widely used in various fields of Computer Science. One of them is game development. This research will design and analyze the pathfinding using the A-Star algorithm and implement it on a tree planting game. The Artificial Intelligence in the game will find its own shortest path from the start node to the goal node. The heuristic of A-Star is the Manhattan Distance that allows movement in four different directions. The result shows that the number of visited nodes will increase if the grid has many obstacle nodes, and the average time of the A-Star pathfinding process is 0.0732 seconds.

The RSA public key cryptosystem was among the first algorithms to implement the Diffie-Hellman key exchange protocol. At the core of RSA’s security is the problem of factoring its modulus, a very large integer, into its prime factors. In this study, we show a step-by-step tutorial on how to factor the RSA modulus using Euler’s factorization algorithm, an algorithm that belongs to the class of exact algorithms. The Euler’s factorization algorithm is implemented in Python programming language. In this experiment, we also record the relation between the length of the RSA moduli and its factorization time. As a result, this study shows that the Euler’s factorization algorithm can be used to factor small modulus of RSA, the correlation between the factoring time and the size of RSA modulus is directly proportional, and better selection of some Euler’s parameters may lead to lower factoring time.

The Rivest-Shamir-Adleman (RSA) public key cryptosystem has been extensively used to secure digital communication since more than forty years. The security of RSA relies on the hardness of factoring a big integer into its two big prime factors: the bigger the integer, the securer the cryptosystem. However, the RSA cryptosystem is proven to be not semantically secure. Some variants of Dependent RSA encryption schemes have been introduced by Pointcheval to overcome this problem. This study shows how the first variant of Dependent RSA (DRSA-1) encryption scheme is used to secure text. All algorithms have been implemented in the Python programming language version 2.7.15.

Image is a visual representation of an object The process of sending information, especially images, can be done anywhere and with any intermediary, but not all information is public. Sometimes someone needs privacy or security from data or information that will be sent or received. One way to secure image files is to use cryptography. Cryptography is the study of how to keep data or messages safe when sent, from the sender to the recipient, without experiencing interference from third parties. In this study cryptography used is Rail Fence Cipher that was combined with steganography, so that the secret message could not be seen in plain view. Steganography serves to hide secret messages in other messages, so the secret is a very hidden existence. There are several methods in Steganography, one of which is Least Significant Bit. The concept of Least Significant Bit works by replacing the last bit of RGB image, where the message is converted first into bits. Based on experiments conducted on the Rail Fence Cipher algorithm, the time of encryption and decryption needed when the resolution of the image gets larger is linearly proportional to the value. The image does not show significant changes before and after inserting a secret message.

Transferring an image is one of the common processes. The image transferring, the sender wants to send a picture by maintaining the security and integrity and even the confidentiality of an image. One of the techniques to manage that aspect is cryptography – hybrid cryptosystem and Rivest-Shamir-Adleman algorithm. Hybrid cryptosystem uses RSA-OTP algorithm for its combination. Hybrid cryptosystem has the strength to secure an image because of its combination of the algorithm. A hybrid use symmetric algorithm to encrypt the image and asymmetric algorithm to encrypt the key from a symmetric algorithm. Rivest-Shamir-Adleman algorithm is an asymmetric algorithm which is hard to guess because of its different key. Rivest-Shamir Adleman Algorithm has a public key to encrypt and private key to decrypt; also prime test was implemented using the Agrawal-Kayal-Saxena algorithm. One-Time-Pad algorithm is a symmetric algorithm that is too hard to guess because this algorithm must have a key which length must be similar to plain’s length, the more length of the plain, the harder key to guess.

In this age, there are many types of information. An image is a form of information that can be sent from anyone to anyone in various ways. But in the shipping process, there is often a hijacking or theft by an unwanted party. So that information must be secured by cryptography to avoid this. To add a sense of security between the sender and recipient, cryptography will be combined with steganography. In this study, the Blowfish Algorithm was combined with First Of File and End Of File steganography methods. Information that has been encrypted will be inserted into other media. Likewise for the recipient, can extract information then decrypt information. Based on experiments conducted on the Blowfish algorithm, the time of encryption and decryption needed when the resolution of the image gets larger is linearly proportional to the value. MSE gets smaller, and the PSNR value gets higher, it shows better image quality. Cover image will increase in size after the embedding process so that it becomes a stego image.

Today’s data transactions using the android device is commonly done anytime. Cryptography is needed to secure data to be transmitted to ensure data security from the manipulation of others. To secure the data, one of cryptography scheme is Three-Pass Protocol, this scheme allows data transmission without key exchange, so this scheme is more secure and efficient. A Massey-Omura algorithm is an asymmetric key cryptography system that will be used in this research. For primality testing in key and prime number generator, the Agrawal-Biswas algorithm will be used. The strength of Massey-Omura is the difficulty of calculating enormous discrete logarithmic and Three-Pass Protocol with his no key exchange capabilities make this method more secure. In this research, the Mean Squared Error value obtained is 0 and the value of Peak Signal to Noise Ratio obtained is infinite. The complexity of the Massey-Omura algorithm and the Agrawal-Biswas algorithm is Θ (n). Graph of file extension against processing time shows a stable graph that means file extension is not affecting processing time. Graph of file size against processing time shows a linear graph that means a processing time would increase along with file size.

A singer doesn't just recite the lyrics of a song, but also with the use of particular sound techniques to make it more beautiful. In the singing technique, more female have a diverse sound registers than male. There are so many registers of the human voice, but the voice registers used while singing, among others, Chest Voice, Head Voice, Falsetto, and Vocal fry. Research of speech recognition based on the female's voice registers in singing technique is built using Borland Delphi 7.0. Speech recognition process performed by the input recorded voice samples and also in real time. Voice input will result in weight energy values based on calculations using Hankel Transformation method and Macdonald Functions. The results showed that the accuracy of the system depends on the accuracy of sound engineering that trained and tested, and obtained an average percentage of the successful introduction of the voice registers record reached 48.75 percent, while the average percentage of the successful introduction of the voice registers in real time to reach 57 percent.

Rapidly increasing number of web pages or documents leads to topic specific filtering in order to find web pages or documents efficiently. This is a preliminary research that uses cosine similarity to implement text relevance in order to find topic specific document. This research is divided into three parts. The first part is text-preprocessing. In this part, the punctuation in a document will be removed, then convert the document to lower case, implement stop word removal and then extracting the root word by using Porter Stemming algorithm. The second part is keywords weighting. Keyword weighting will be used by the next part, the text relevance calculation. Text relevance calculation will result the value between 0 and 1. The closer value to 1, then both documents are more related, vice versa.

This study aims to combine the trithemus algorithm and double transposition cipher in file security that will be implemented to be an Android-based application. The parameters being examined are the real running time, and the complexity value. The type of file to be used is a file in PDF format. The overall result shows that the complexity of the two algorithms with duper encryption method is reported as Θ (n 2). However, the processing time required in the encryption process uses the Trithemius algorithm much faster than using the Double Transposition Cipher. With the length of plaintext and password linearly proportional to the processing time.

Confidentiality, integrity, and efficiency are the crucial aspects of data security. Among the other digital data, image data is too prone to abuse of operation like duplication, modification, etc. There are some data security techniques, one of them is cryptography. The security of Vernam Cipher cryptography algorithm is very dependent on the key exchange process. If the key is leaked, security of this algorithm will collapse. Therefore, a method that minimizes key leakage during the exchange of messages is required. The method which is used, is known as Three-Pass Protocol. This protocol enables message delivery process without the key exchange. Therefore, the sending messages process can reach the receiver safely without fear of key leakage. The system is built by using Java programming language. The materials which are used for system testing are image in size 200×200 pixel, 300×300 pixel, 500×500 pixel, 800×800 pixel and 1000×1000 pixel. The result of experiments showed that Vernam Cipher algorithm in Three-Pass Protocol scheme could restore the original image.

Security becomes a very important issue in data transmission and there are so many methods to make files more secure. One of that method is cryptography. Cryptography is a method to secure file by writing the hidden code to cover the original file. Therefore, if the people do not involve in cryptography, they cannot decrypt the hidden code to read the original file. There are many methods are used in cryptography, one of that method is hybrid cryptosystem. A hybrid cryptosystem is a method that uses a symmetric algorithm to secure the file and use an asymmetric algorithm to secure the symmetric algorithm key. In this research, TEA algorithm is used as symmetric algorithm and LUC algorithm is used as an asymmetric algorithm. The system is tested by encrypting and decrypting the file by using TEA algorithm and using LUC algorithm to encrypt and decrypt the TEA key. The result of this research is by using TEA Algorithm to encrypt the file, the cipher text form is the character from ASCII (American Standard for Information Interchange) table in the form of hexadecimal numbers and the cipher text size increase by sixteen bytes as the plaintext length is increased by eight characters.