Robust Beamforming for Two-Way Relay Systems

In wireless communication systems, relays are widely used to extend coverage. Over the past years, relays have evolved from simple repeaters to more sophisticated units that perform signal processing to improve signal to interference plus noise ratio (SINR) or throughput (or both) at the destination receiver. There are various types of relays such as amplify and forward (AF), decode and forward (DF), and compress and forward (CF) (or estimate and forward (EF)) relays. In addition, recently there has been a growing interest in two-way relays (TWR). By utilizing the concept of analog network coding (ANC), TWRs can improve the throughput of a wireless sys- tem by reducing the number of time slots needed to complete a bi-directional message exchange between two destination nodes. It’s well known that the performance of a TWR system greatly depends on its ability to apply signal processing techniques to effectively mitigate the self-interference and noise accumulation, thereby improving the SINR. We study a TWR system that is equipped with multiple antennas at the relay node and a single antenna at the two destination nodes. Different from traditional work on TWR, we focus on the case with imperfect knowledge of channel state information (CSI). For such a TWR, we formulate a robust optimization problem that takes into ac- count norm-bounded estimation errors in CSI and designs an optimal beamforming matrix. Realizing the fact that this problem is extremely hard to solve globally, we derive two different methods to obtain either optimal or efficient suboptimal beam- forming matrix solutions. The first method involves solving the robust optimization problem using the S-procedure and semidefinite programming (SDP) with rank-one relaxation. This method provides an optimal solution when the rank-one relaxation condition for the SDP is satisfied. In cases where the rank-one condition cannot be satisfied, it’s necessary to resort to sub-optimal techniques. The second approach presented here reformulates the robust non-convex quadratically constrained quadratic programming (QCQP) into a robust linear programming (LP) problem by using first-order perturbation of the optimal non-robust beamforming solution (which assumes no channel estimation error). Finally, we view the TWR robust beamforming problem from a practical standpoint and develop a set of iterative algorithms based on Newton’s method or the steepest descent method that are practical for hardware implementation

Implementasi Metode Single Moving Average dan Double Moving Average untuk Memprediksi Populasi Sapi Potong di Jawa Timur

Berdasarkan data Dinas Peternakan yang terpublis di Badan Pusat Statistik Jawa Timur ( BPS ) menunjukkan jumlah populasi Sapi Potong di Kota / Kabupaten di Jawa Timur mengalami peningkatan dan penurunan dari tahun ke tahun. Tujuan dari penelitian ini adalah mengetahui tingkat akurasi populasi sapi potong menggunakan metode Single Moving Average (SMA) dan Double Moving Average (DMA) karena dari jurnal yang telah diperoleh peneliti menunjukkan bahwa metode Single Moving Average dan Double Moving Average memiliki nilai akurasi MAPE dibawah 10%. Metode untuk mengetahui tingkat akurasi dalam penelitian ini diuji akurasi error menggunakan Mean Absolut Deviation (MAD) dan Mean Absolut Percentage Error (MAPE). Metode Single Moving Average dan Double Moving Average dalam penelitian ini juga diimplementasikan untuk memprediksi populasi sapi potong menggunakan Python dengan hasil yang sama dengan perhitungan manual. Kualitas prediksi yang dihasilkan dalam pengujian oleh peneliti dengan data aktual pada tahun 2022 menggunakan metode SMA (Single Moving Average) dan DMA (Double Moving Average) dengan periode 3 tahun atau interval 3 berjumlah 5.018.296,00, MAD 1.876,22, dan MAPE 4,99% untuk periode 4 tahun atau interval 4 berjumlah 5.036.615,04, MAD 1.728,85, MAPE 5,97%. Berdasarkan hasil yang diperoleh dapat disimpulkan bahwa metode  Single Moving Average dan Double Moving Average  interval 4 atau periode 4 tahun bisa dikategorikan prediksi sangat baik dikarenakan jumlah prediksi mendekati data aktual dan nilai MAPE kurang dari 10%

OPTIMASI ALGORITMA C4.5 BERBASIS PARTICLE SWARM OPTIMIZATION (PSO) UNTUK MENENTUKAN WHOLESALES PENJUALAN

Algorithm C4.5 is an algorithm used to form a Decision Tree. The C4.5 Algorithm definitely has advantages and disadvantages. The features of the C4.5 algorithm can create decision trees that are easy to version, dominate the level of acceptable accuracy, efficient in managing effective category attributes and can set attributes of discrete and numeric types, and in an advantage there are definitely drawbacks. The weakness of the C4.5 algorithm is the instability in determining accuracy. The amount of data used is 1000 with 7 attributes. Data were analyzed using Particle Swarm optimization in C4.5. Because the accuracy produced by C4.5 is still low, it is optimized with Particle Swarm optimization. Accuracy on C4.5 is 81% after using optimization the accuracy increases by 86%. Data processing uses Python programming and accuracy testing uses the Confusion Matrix to compare accuracy results

IMPLEMENTASI MEDIA ONLINE (WEBSITE) SEBAGAI PUBLIKASI POTENSI DESA SIDODADI MELALUI PEMBERDAYAAN KARANG TARUNA

Sidodadi Village is one of the villages located in southern Malang area located in Gedangan sub-district. The village is one of the villages that has the most extraordinary natural potentials such as Ungapan Beach, Bajulmati Beach, Parangdowo Beach, Jolangkung Beach, Bengkung Beach, Ngudel Beach, and Ngantep Beach, which is a beach located in the southern cross of Malang Regency. Rows of mountains are sturdy and beautiful to make the tourists interested to travel there.Sidodadi village area bounded with Sumbermanjing wetan district in the east, village elephant rejo in the west. On the other hand, not only the potential of nature is extraordinary, but the results of the abundant earth. Rice, corn, coconut, banana, rice, cassava, mangosteen, durian, and palm are natural products that can be processed there. The potential possessed and remarkable until now has not been published or promoted through websites and social media, to hog the visitors who more aplagi most visitors see the first reference before coming directly.The abundant natural resources with the stammered human resources of technology will make the potential of nature unknown to the wider community. Coral cadets and devices in the village of Sidodadi maximal educated High School (SMA) and only two people who can take the bench lecture. This is where the turmoil experienced by villagers Sidodadi where they can not publish the area. Only limited to the beaches that have been published, but for other natural potentials can not be published because of lack of knowledge about the use of the internet (Online Media). Keywords:Sidodadi, Karangtaruna, Publikasi, Online