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This paper introduces PureFed, an innovative Federated Learning (FL) framework designed for efficiency, collaboration, and trustworthiness. In the background of FL research, it was observed that previous frameworks often neglected participant privacy, a critical aspect not aligned with the core FL concept. Additionally, there was room for improving the efficiency of existing frameworks. PureFed addresses these shortcomings by offering participants the flexibility to initiate FL tasks or join existing ones without sharing any private data and removing unnecessary actions that led to an inefficient system. Leveraging blockchain technology, it employs smart contracts to ensure traceability and immutability, enhancing the security of the framework. Additionally, PureFed employs symmetric key encryption and dual digital signature mechanisms using ECDSA to guarantee the confidentiality and integrity of shared models. To expedite model convergence, PureFed incorporates a dynamic aggregation scheme, selecting the most suitable model from three distinct techniques: FedAvg, accuracy-based, and loss-based. Furthermore, the framework introduces a dynamic incentive and punishment mechanism to incentivize collaboration and maintain trust. Extensive performance evaluations reveal PureFed’s significant advantages. It outperforms its counterparts by 63.39% and 67.72% in terms of smart contract deployment and interaction gas costs, respectively. Lastly, scalability analyses indicate PureFed’s ability to adapt efficiently, achieving target accuracy in fewer rounds.

Abstract: EVOLUSI Program (English Vocabulary Submission) is the innovation of English program applied for improving vocabulary skill to all the school members as a form of achieving bilingual school. This research used mixed-method research. The data was collected by questionnaire, interview, and documentations. The research participants were 26 teachers and 313 students the seventh and eighth graders of SMP Islam Al-Fahd Jakabaring. The result showed that there were three main benefits in this innovation program: (1) Teachers and students’ confidence in vocabulary skill for all the school members was improved so that bilingual school could be achieved; (2) The literacy in reading interest for teachers and students was raised effectively and productively; (3) Establish the competent students in realizing Pancasila Student Profile. Abstrak: Program EVOLUSI (English Vocabulary Submission) adalah program inovasi Bahasa Inggris yang dilaksanakan untuk meningkatkan kemampuan perbendaharaan kata pada warga sekolah sebagai wujud menuju bilingual school. Penelitian ini menggunakan mixed-method research. Data dikumpulkan melalui kuesioner, wawancara dan dokumentasi. Subjek dari penelitian ini adalah 26 guru dan 313 siswa tingkat kelas tujuh dan delapan di SMP Islam Al-Fahd Jakabaring. Hasil menunjukkan bahwa program inovasi ini ada tiga manfaat utama: (1) Meningkatnya kepercayaan diri guru dan siswa dalam vocabulary skill bagi warga sekolah dapat terwujud sehingga bilingual school yang diharapkan terealisasi; (2) Menumbuhkan literasi minat baca guru dan siswa dapat terwujud secara efektif dan produktif; (3) Pembentukan karakter siswa yang kompeten dalam mewujudkan Profil Pelajar Pancasila.

The development of critical thinking is closely related to the questions asked by teachers as the teachers higher-order questions are cognitively demanding to promote students critical thinking. The purposes of this study are to investigate how critical thinking was implemented in EFL teachers questions in the classroom and the challenges faced by EFL teachers in integrating critical thinking questions. In addition, this study also investigated students reasons for non-response to particular questions asked by teachers. Applying mixed-method research design, the data were collected from classroom observation, interview, questionnaire and documentations. The research participants were two English teachers and 229 number of students of year 8. The results showed that the most dominant questions asked by the two English teachers were in Lower-order questions (78,8%), while the Higher-order questions were only (21,2%) questions. Second, the challenges faced by teachers were students intelligence has yet to reach the level of higher-order thinking, unconducive-classroom environment, teachers creativity itself, parental involvement and students lack of vocabulary. Third, dealing with the reason for students non-response in particular questions asked by teachers, there were some reasons, such as students are afraid of making mistakes, they could not put ideas into words, and lack of vocabularies. In conclusion, the teachers faced various challenges in implementing critical thinking questions in the classroom.

Wireless sensor networks consisting of sensor nodes can be used as an effective tool for collecting data in various situations. Nodes are usually placed randomly in an area to perform sensing and monitor various parameters related to environmental conditions in various locations. One of the major problems in wireless sensor networks is developing energy-efficient routing protocols that have a significant impact on the overall life of sensor networks so it is important to make energy savings in these limited energy sources to extend network life. This paper proposes a hardware design and Low-Energy Adaptive Clustering Hierarchy (LEACH) routing protocol configuration for power saving by utilizing cluster head selection mechanism. The cluster head selection process is performed periodically based on LEACH algorithm enables the node to have the best lifetime responsible for communication between the nodes and the server as well as the effort to save energy consumption of limited energy sources to extend network life. So that makes the process of sending information more effective and optimal. The system has been able to display data information along with the position of nodes in the web server with an average of 42 seconds of computing time in a rotation of the system so that it can be done 85 times in 1 hour. The system is able to provide real-time information with a throughput of more than 1.052 Kbps and packet loss of no more than 6.7%. In addition, energy savings can up to 6.5% of the existing energy in a lithium battery.

Wireless Sensor Network (WSN) is a network consisting of several sensor nodes that communicate with each other and work together to collect data from the surrounding environment. One of the WSN problems is the limited available power. Therefore, nodes on WSN need to communicate by using a cluster-based routing protocol. To solve this, the researchers propose a node grouping based on distance by using k-means clustering with a hardware implementation. Cluster formation and member node selection are performed based on the nearest device of the sensor node to the cluster head. The k-means algorithm utilizes Euclidean distance as the main grouping nodes parameter obtained from the conversion of the Received Signal Strength Indication (RSSI) into the distance estimation between nodes. RSSI as the parameter of nearest neighbor nodes uses lognormal shadowing channel modeling method that can be used to get the path loss exponent in an observation area. The estimated distance in the observation area has 27.9% error. The average time required for grouping is 58.54 s. Meanwhile, the average time used to retrieve coordinate data on each cluster to the database is 45.54 s. In the system, the most time-consuming process is the PAN ID change process with an average time of 14.20 s for each change of PAN ID. The grouping nodes in WSN using k-means clustering algorithm can improve the power efficiency by 6.5%.

Nowadays, wireless communication technology is developing rapidly. However, this technology still has some weaknesses, e.g. large bandwidth requirement and multipath fading. To overcome these weaknesses, MIMO OFDM technique is needed. This paper implements MIMO OFDM 2x2 communication system in Universal Software Radio Peripheral (USRP). The performance of MIMO OFDM 2x2 is shown by the throughput value. This value is compared to the throughput value of single carrier and SISO OFDM. The modulations used are BPSK, 4-QAM, and 16-QAM. In 4-QAM modulation, the throughput value of MIMO OFDM is significantly larger than throughput value of single carrier and SISO OFDM. The throughput value of single carrier communication system is 27.71 Mbit/s, while the throughput value of the SISO OFDM communication system is 60.27 Mbit/s, and the throughput value of the MIMO OFDM 2x2 communication system is 123.03 Mbit/s.

A DTN architecture consists of several nodes that are connected with high dynamic topology. The routing protocol is an important part which determine the DTN performance system. Although DTN is addressed to be tolerant of delay, a routing protocol with better performance will maximizing packet delivery rate and minimizing the delivery latency. This paper evaluate a level signal priority epidemic routing protocol for delay tolerant network architecture. Our system adopts DTN2 framework using classic epidemic and priority epidemic dynamic routing protocols. The performance of both dynamic routing is observed and compared based on throughput and delay of transmitted data. The measurement results show that the classic epidemic use more bandwith due to sending the same messages many times. The delay transmission using a level signal priority epidemic routing is smaller than classic epidemic routing protocol in all hops of the test-bed. Epidemic based on signal level routing could make traffic of network more efficient than classic Epidemic routing because of filtering system in node before sending bundle to neighbor node. Keywords: DTN, dynamic routing, level signal priority

We present an implementation of Zero Forcing (ZF) equalizer in OFDM scheme using Software Defined Radio platform whereas NI USRP-2920 as the Radio Frequency (RF) front-end. ZF equalizer is employed to achieve reliable system at the receiver. Center frequency used for data transmission is 915 MHz. The reliability transmission and the performance of ZF equalizer are measured in term of different symbol mapping (i.e., M-PSK and M-QAM). The IQ rate determines the bandwidth available, whereas good performance is achieved with IQ rate less than 1 MHz.ZF equalizer achieves good performance when using BPSK, QPSK and 16-QAM modulation techniques. By applying ZF equalizer, bit error on BPSK and QPSK modulations can be reduced from 29,16% and 39,06% into 0%. This advantage of ZF equalizer also is able to press the bit error on 16- QAM and 64-QAM modulations into 3,125% and 8,85%, respectively. Keywords: OFDM,SDR, USRP,Zero Forcing Equalizer