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Anggur merupakan salah satu tanaman yang dibudidayakan oleh Greenhouse Duren Tiga. Untuk menanam anggur dibutuhkan tanah yang tidak terlalu basah, suhu yang tidak terlalu panas, dan pH yang sesuai. Sehingga diperlukan Smart Greenhouse untuk membantu melakukan monitoring dan proses penyiraman pada tanaman anggur. Sistem ini menggunakan sensor suhu DHT11, sensor soil moisture sebagai lembap tanah, sensor pH tanah dan sensor intensitas cahaya BH1750. Untuk mentransmisikan data memerlukan modul LoRa dengan frekuensi 922 Mhz dan selain itu digunakan NodeMCU ESP32 sebagai mikrokontroler baik pada sisi transmitter maupun receiver. Pengujian pada sensor suhu dengan nilai eror 1.40 dan 1.49 pada kedua node yang memiliki akurasi sangat baik, pada sensor lembap tanah menghasilkan nilai eror 1.97 dan 2.36 pada kedua node memiliki akurasi sangat baik dan pada sensor pH tanah menghasilkan nilai eror 1.34 dan 1.72 pada kedua node memiliki akurasi sangat baik. Sensor BH1750 memiliki nilai eror 4.13 dan 5.08 memiliki akurasi baik. Pengujian LoRa dapat menjangkau 1.4 Km dengan nilai RSSI -109 dBm dan SNR -9.5 dB serta data yang dapat diterima sebanyak 10 paket data dengan throughput sebesar 42.67 bps termasuk kategori cukup.

The value of π is one of the famous mathematical constant, not only to mathematicians, but also to physicists and to engineers. Numerous algorithm is used to compute what is the value of π, but most of programmer do not use lambda function and neglect the aesthetic of their script. This study aims to compute the value π by write it first as infinite series using Riemann sum, and then the computing of it is conducted in R programming language. We involved the role of anonymous function or known as lambda function to make the R code is more beautiful, artistic, and elegant.

Superhydrophobic membranes have great potential towards various application, especially for thermal-based membrane system such as membrane distillation. In this study, bioceramic hollow fibre membranes derived from cow bone waste were prepared by phase inversion/sintering method, followed by surface modification via immersion grafting with fluoroalkylsilane (FAS) agent. Interestingly, the grafting process led to the formation of hydroxyapatite nanorods, mimicking the unique structure of electrospun nanofiber membranes. The hydrophobicity of the modified membranes was assessed by measuring the water contact angle and showed excellent improvement from hydrophilic property to superhydrophobic with the highest value of 174° After the modification, the water entry pressure also improved from 0 to 1 bar. In addition, the presence of FAS agent on the membrane surface was observed using X-ray photoelectron spectroscopy (XPS). A correlation between pore size, porosity, and mechanical strength of the modified membrane was discussed; the increment of membrane pore size after grafting process is synonym to the dental erosion mechanism. The result indicates that the superhydrophobic bioceramic hollow fibre membranes derived from cow bone waste have significant potential to be developed for membrane distillation application in treating water and wastewater.

Vigenère cipher is a classical cryptography algorithm and similar to other classical algorithms, it produces smaller but less secure ciphertexts than a public key cryptography algorithm. Meanwhile, Rabin-p is a public key cryptography algorithm with a stronger encryption than Vigenère cipher. Nevertheless, as a public key algorithm, Rabin-p is inefficient to encrypt vast amounts of messages such as BMP image files, since the size of the cipherimages will increase manyfold and this would lead to a problem in storing and sending the cipherimages. To overcome these problems, in this study, we combined the Vigenère cipher and the Rabin-p algorithm in a hybrid cryptosystem scheme. In the experiment, the Vigenère cipher was used to encrypt the BMP files and the Rabin-p algorithm was used to encrypt the Vigenère keys. The result showed that the size of the cipherimages did not increase and the decryption procedure could recover the original BMP files while maintaining their integrity.

Durin Tonggal is one of the villages in Pancur Batu sub-district, Deli Serdang Regency, North Sumatra province, Indonesia. 60% of the people in Durin Tonggal Village work as entrepreneurs, especially small business entrepreneurs such as souvenir businesses, snack & catering businesses, and so on. The activities of Pengabdian Kepada Masyarakat that have been carried out have focused on increasing understanding of the use of online media as a promotional tool for small business entrepreneurs in the Village of Durin Tonggal. With increasing public understanding, it can expand the buyers of products so that it will increase the sales of products and services. Increased sales transactions will result in high economic turnover so that this PKM activity is expected to improve the lives of Durin Tonggal villagers.

As one form of the greedy algorithm, Dijkstra's can handle the shortest path search with optimum result in longer search time. Dijkstra's is contrary to A-Star, a best-first search algorithm, which can handle the shortest path search with a faster time but not always optimum. By looking at the advantages and disadvantages of Dijkstra's and A-Star, this tutorial discusses the implementation of the two algorithms in finding the shortest path in routes selection between 24 SPBU (gas stations). The routes are located in Medan City and represented in a directed graph. Moreover, the authors compare Dijkstra's and A-star based on the complexity of Big-Theta (Θ) and running time. The results show that the shortest path search between SPBU can be solved with Dijkstra's and A-Star, where in some cases, the routes produced by the two algorithms are different so that the total distance generated is also different. In this case, the running time of A-Star is proven to be faster than Dijkstra's, and it is following A-Star principle which selects the location point based on the best heuristic value while Dijkstra's does not. For the complexity, Dijkstra's is $\Theta(\mathrm{n}^{2})$ and A-Star is $\Theta(\mathrm{m}\ast \mathrm{n})$ , where $0\leq \mathrm{m}\leq \mathrm{n}$ .

The security of the RSA cryptosystem is directly proportional to the size of its modulus, n. The modulus n is a multiplication of two very large prime numbers, notated as p and q. Since modulus n is public, a cryptanalyst can use factorization algorithms such as Euler’s and Pollard’s algorithms to derive the private keys, p and q. Brute force is an algorithm that searches a solution to a problem by generating all the possible candidate solutions and testing those candidates one by one in order to get the most relevant solution. Random search is a numerical optimization algorithm that starts its search by generating one candidate solution randomly and iteratively compares it with other random candidate solution in order to get the most suitable solution. This work aims to compare the performance of brute force algorithm and random search in factoring the RSA modulus into its two prime factors by experimental means in Python programming language. The primality test is done by Fermat algorithm and the sieve of Eratosthenes.

The adverse effects of ammonia found in wastewater streams lead to the development of advanced water treatment technology, i.e. membrane contactor (MC). In this study, single layer hollow fibre membrane (SLZK) and dual layer hollow fibre membrane (DLZK) were prepared from zirconia and kaolin and modified into hydrophobic membrane through simple grafting process via fluoroalkylsilane (FAS) agent. The properties of membranes such as morphology, surface roughness, mechanical strength, wettability and liquid entry pressure were analysed through scanning electron microscopy (SEM), atomic force microscopy (AFM), 3-point bending strength, contact angle and LEPw setup. Finally, the performance of the membranes was also investigated towards ammonia removal via membrane contactor system. Our findings showed that hydrophobicity properties significantly improved for both SLZK and DLZK membranes after grafting modification process as indicated by the increase of contact angle value from 5° and 1° to 132.7° and ~180.0° respectively. Based on the morphological analysis, the surface of DLZK showed more porous structure as compared to the SLZK. In addition, DLZK also displayed the highest mechanical strength and contact angle reading of 125 MPa and ~180° respectively. This suggests that the DLZK showed an excellent membrane contactor performance with highest value of mass transfer coefficient (3.77 x 10-5 ms-1) and almost complete removal of ammonia removal (91%). Overall, these results implied that dual layer ceramic membrane developed from kaolin and zirconia could provide the basis for the development of alternative ceramic membrane with excellent properties for membrane contactor system.

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).

Indonesia has a variety of local languages, which is the Batak Toba language. This time, there are still some Batak Toba people who do not know speak Batak Toba language fluently. Nowadays, desktop based dictionary is one of reference that very efficiently used to learn a language and also to increase vocabulary. In making the dictionary application, string matching can be implemented for word-searching process. String matching have some algorithm, which is Berry – Ravindran algorithm and Zhu-Takaoka algorithm and will be implemented on the dictionary application. Zhu-Takaoka algorithm and Berry – Ravindran algorithm have two phases, which are the preprocessing phase and the searching phase. Preprocessing phase is a process to make the shifting values according to in pattern that input by user. To know the shifting value with Zhu-Takaoka algorithm, it’s need Zhu-Takaoka Bad Character (Ztbc) and Boyer-Moore Good Suffix (Bmgs). Then, Ztbc will be compared to Bmgs to get the maximum value of them that will be set as shifting value. While Berry-Ravindran algorithm, to know the shifting value is needed Berry-Ravindran Bad Character, which the two characters right of the text at the position m + 1 and m+ 2, is needed to determine the shifting value, where m is length of the pattern.

It is intuitively clear that the security of RSA cryptosystem depends on the hardness of factoring a very large integer into its two prime factors. Numerous studies about integer factorization in the field of number theory have been carried out, and as a result, lots of exact factorization algorithms, such as Fermat’s factorization algorithm, quadratic sieve method, and Pollard’s rho algorithm have been found. The factorization problem is in the class of NP (non-deterministic polynomial time). Tabu search is a metaheuristic in the field of artificial intelligence which is often used to solve NP and NP-hard problems; the result of this method is expected to be close-to-optimal (suboptimal). This study aims to factorize the RSA modulus into its two prime factors using tabu search by conducting experiments in Python programming language and to compare its time performance with an exact factorization algorithm, i.e. Pollard’s algorithm. The primality test is done with Lehmann’s algorithm.

Mohammad Arief Budiman. Evaluasi Implementasi Program Sekolah Menengah Kejuruan 4 Tahun Dalam Meningkatkan Employability Lulusan. Penelitian ini bertujuan untuk mengetahui evaluasi implementasi program SMK 4 tahun dengan mengetahui tingkat employabality dengan berfokus pada melihat hasil keterserapan tamatan siswa yang telah lulus mendapatkan pekerjaan sehingga dapat diketahui tingkat ketercapaian program. Jenis penelitian adalah penelitian kualitatif. Penelitian ini melibatkan berbagai pihak seperti wakil kepala sekolah bidang kurikulum, wakil kepala sekolah bidang sarana prasarana dan wakil humas&kemitraan serta siswa. Evaluasi ini menggunakan metode CIPP (Context, Input, Process, Product). Teknik pengumpulan data menggunakan kuisioner, observasi, wawancara, dan analisis dokumen. Hasil penelitian menunjukkan bahwa implementasi program SMK 4 Tahun di SMK N 26 Jakarta dari aspek context yang meliputi latar belakang dan tujuan memiliki persentase ketercapaian 100%. Aspek input yang meliputi kurikulum, kualifikasi guru, sarana prasarana dan pembiayaan persentase ketercapaian 86,5%. Aspek process yang meliputi proses pembelajaran menurut persepsi siswa dengan melihat bagaimana cara guru memberikan materi dan pembelajaran praktik disekolah memiliki presentase ketercapaian 90,77%. Aspek terakhir pada penelitian ini adalah product memiliki ketercapaian sebesar 92%. Berdasarkan rata-rata persentase ketercapaian tersebut maka implementasi program SMK 4 Tahun yang dilaksanakan dapat dinyatakan “sangat baik” namun masih perlu ada sedikit perbaikan dan ditingkatkan pada beberapa aspek dan agar lebih baik lagi kedepannya.

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.

Cryptography used to send digital images to keep them safe from unauthorized parties who want to see or change the digital image. In cryptography, there is Hybrid Cryptosystem method, which is a method by combining the advantages in 2 types of cryptographic algorithms, symmetrical and asymmetrical. Hill Cipher 4x4, with a 4x4 square matrix, is used as a symmetrical algorithm, which has a relatively fast processing time. ElGamal Elliptic Curve is used as an asymmetric algorithm, where the key used for the encryption and decryption process is a different key, so no key distribution is needed. The Algorithms implemented in an Android-based system using the Java programming language. The conclusion obtained from system testing is that the elliptic curve parameter generation time process is directly proportional to the magnitude of the prime number, the time process of image encryption-decryption is directly proportional to the image pixel size, and the time process of key matrix encryption-decryption is directly proportional to the value of the private key.