Acta Polytechnica最新文献

Application of the Source-Jerk method using a neutron generator in a subcritical reactor 在亚临界反应堆中应用使用中子发生器的源-杰克法

IF 0.8

Acta Polytechnica Pub Date : 2023-11-07 DOI: 10.14311/ap.2023.63.0356

Jan Rataj, Jakub Mátl, Pavel Suk

引用次数: 0

Stator current signal crossing for fault diagnosis of self-excited induction generators 用于自励磁感应发电机故障诊断的定子电流信号交叉

IF 0.8

Acta Polytechnica Pub Date : 2023-11-07 DOI: 10.14311/ap.2023.63.0293

Fares Belynda, R. Abdelli, A. Bouzida

{"title":"Stator current signal crossing for fault diagnosis of self-excited induction generators","authors":"Fares Belynda, R. Abdelli, A. Bouzida","doi":"10.14311/ap.2023.63.0293","DOIUrl":"https://doi.org/10.14311/ap.2023.63.0293","url":null,"abstract":"This paper presents a novel method for modelling and diagnosis of electrical and mechanical faults in fixed-Speed Self-Excited Induction Generators (SEIGs) operating in autonomous mode in a small-scale wind energy system. The proposed method is validated using the finite element method. After the selection of the magnetising capacitors, the self-excitation process is performed under no-load conditions. Once the stator voltage is established, a symmetrical three-phase load is connected. The fault detection method introduced here is called Stator Current Signal Crossing (SCSC). The SCSC extracts a new signal from the stator currents, that enables the detection of stator inter turn shortcircuits, broken rotor bars, and dynamic eccentricity faults in SEIGs. A spectral analysis of SCSC using the Fast Fourier Transform (FFT) algorithm is used to precisely locate the induced fault components. What sets this fault-tracking method apart from its predecessors is its exceptional ability to detect faults of any magnitude by analysing the modulation of the SCSC signal. These faults are directly identified by the presence of distinct harmonics, each indicative of a specific type of fault. This study also focuses on the SEIG in a wind energy system, whereas previous works have mainly addressed the induction machine in motor mode. In contrast, previous methods involved analysing a single current signal and isolating specific harmonics from a wide frequency range. The effectiveness of the proposed fault detection method and the self-excitation process are illustrated by simulation results and spectral analysis.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":"127 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139285283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improving QoS in mobile multimedia streaming with SCTP-PQ 利用 SCTP-PQ 改善移动多媒体流的 QoS

IF 0.8

Acta Polytechnica Pub Date : 2023-11-07 DOI: 10.14311/ap.2023.63.0347

Alisettar Hüseynli, Mehmet Şimşek, M. Akcayol

{"title":"Improving QoS in mobile multimedia streaming with SCTP-PQ","authors":"Alisettar Hüseynli, Mehmet Şimşek, M. Akcayol","doi":"10.14311/ap.2023.63.0347","DOIUrl":"https://doi.org/10.14311/ap.2023.63.0347","url":null,"abstract":"The Stream Control Transmission Protocol (SCTP) is often the preferred transport layer protocol in streaming applications. This protocol combines the best aspects of Transmission Control Protocol (TCP) and User Datagram Protocol (UDP), but also offers additional features. SCTP supports multihoming and multi-streaming applications and has a congestion mechanism like TCP. Media streaming consists of different types of frames with different levels of importance. For example, I-frames carry more information than B-frames in Moving Picture Experts Group (MPEG). Usually, MPEG frames are processed using the First-In-First-Out (FIFO) algorithm. In this paper, a four-level priority queue integrated protocol named SCTP Priority Queue (SCTP-PQ) has been developed to reduce jitter and delay in real-time multimedia streaming for mobile devices. As part of the development, priority and retransmitted packets are determined on the sending side and these packets are processed faster by using the priority queue on the receiving side. In this way, the average queue delay of priority packets on the receiving side is reduced by 90 % and the throughput values are increased by an average of 10 times. The developed protocol has been extensively tested and compared with SCTP. The results show that the SCTP-PQ outperforms the standard SCTP in terms of jitter and delay.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":"82 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139283521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The effect of ambient temperature on the delay time of perimeter protection 环境温度对周界保护延迟时间的影响

IF 0.8

Acta Polytechnica Pub Date : 2023-11-07 DOI: 10.14311/ap.2023.63.0320

Jakub Durica, R. Sovják, Martin Boroš, Radoslav Kuffa

引用次数: 0

PAPR reduction in CP-OFDM (5G) using hybrid technique 利用混合技术降低 CP-OFDM （5G）中的 PAPR

IF 0.8

Acta Polytechnica Pub Date : 2023-11-07 DOI: 10.14311/ap.2023.63.0364

Azlan Yusof, A. Idris, Ezmin Abdullah

引用次数: 0

Fake face detection based on a multi discriminator deep CNN architecture (MDD-CNN) 基于多判别器深度 CNN 架构（MDD-CNN）的假脸检测

IF 0.8

Acta Polytechnica Pub Date : 2023-11-07 DOI: 10.14311/ap.2023.63.0305

Chemesse ennehar Bencheriet, Hiba Abdelmoumène, A. Sebbagh, Abdennour Yahiyaoui, Zahra Taba

{"title":"Fake face detection based on a multi discriminator deep CNN architecture (MDD-CNN)","authors":"Chemesse ennehar Bencheriet, Hiba Abdelmoumène, A. Sebbagh, Abdennour Yahiyaoui, Zahra Taba","doi":"10.14311/ap.2023.63.0305","DOIUrl":"https://doi.org/10.14311/ap.2023.63.0305","url":null,"abstract":"Due to the robustness of the deep learning tools used to design these applications, fakes are becoming increasingly common as these applications become more widely available and accessible to the general public. These fakes are typically fake faces or even fake people, which are difficult to distinguish from real individuals. Therefore, we need more efficient applications for fraud detection. In this work, we propose a new multi-discriminator architecture to distinguish fake faces from real ones. The architecture consists of three deep networks (discriminators) competing with each other, each trained differently. The final decision is made by voting based on the decisions of the three discriminators. The core element of our architecture is the proposed new adversarial deep network discriminator (NDGAN), which is trained in three different ways, resulting in three distinct discriminators. Discriminator 1 undergoes adversarial training, discriminator 2 is trained using transfer learning, and the third discriminator undergoes supervised training with a standard CNN using examples and counterexamples. Training and testing were performed on 70 000 real faces from the Flickr-Face-HQ (FFHQ) dataset, while 70 000 fake faces were generated using Nvidia’s StyleGAN. The tests conducted on the three networks produced significant results, with accuracy ranging from 79 % to 98 % for fake faces, and from 80 % to 98 % for real faces. The reliability of the discriminators contributes significantly to the overall performance of the multi-discriminator system, achieving an accuracy of 96 % for fake faces and 98 % for real faces.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":"13 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139286876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Geometric approach to solving inverse kinematics of six DOF robot with spherical joints 用几何方法解决带球形关节的六 DOF 机器人的逆运动学问题

IF 0.8

Acta Polytechnica Pub Date : 2023-11-07 DOI: 10.14311/ap.2023.63.0326

Nacer Hadidi, Mohamed Bouaziz, Chawki Mahfoudi, Mohamed Zaharuddin

{"title":"Geometric approach to solving inverse kinematics of six DOF robot with spherical joints","authors":"Nacer Hadidi, Mohamed Bouaziz, Chawki Mahfoudi, Mohamed Zaharuddin","doi":"10.14311/ap.2023.63.0326","DOIUrl":"https://doi.org/10.14311/ap.2023.63.0326","url":null,"abstract":"Inverse kinematics is a fundamental concept in robotics that plays a crucial role in a robot’s ability to perform tasks. In this contribution, we propose a novel geometric approach based on vector calculus to solve the inverse kinematics problem. The primary advantage of this approach originates from the solutions, which exhibit a linear form and uncoupled equations. To validate the effectiveness and correctness of our proposed method, we constructed a six-degrees-of-freedom robot. This robot is controlled by an Arduino Mega 2650 on which we have implemented the inverse kinematics algorithm. The validation process involved considering various desired trajectories of the end-effector, which were simulated in Matlab and then performed by the physical robot. Importantly, our findings confirm that the end-effector successfully tracks the predefined trajectories. Furthermore, we conducted a comparative analysis between Paul’s method and the results obtained from joint angles using our proposed approach. Interestingly, our study reveals a significant similarity between the two sets of results, reaffirming the accuracy and validity of the approach presented in this study.","PeriodicalId":45804,"journal":{"name":"Acta Polytechnica","volume":"904 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139285080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Construction of angular-dependent potentials from trigonometric Pöschl-Teller systems within the Dunkl formalism 在Dunkl形式体系中三角Pöschl-Teller系统的角相关势的构造

Acta Polytechnica Pub Date : 2023-09-05 DOI: 10.14311/ap.2023.63.0273

Axel Schulze-Halberg

引用次数: 0

The effects of potassium permanganate on the geotechnical properties of soils 高锰酸钾对土壤岩土力学性质的影响

Acta Polytechnica Pub Date : 2023-09-05 DOI: 10.14311/ap.2023.63.0260

Samuel Akinlabi Ola, Osemudiamen Ayoposi Usifoh, Emeka Segun Nnochiri

引用次数: 0

Shock wave configuration in a transonic flow through a mid-section of a last stage turbine blade cascade equipped with a part-span connector 采用部分跨接头的末级涡轮叶片叶栅中部跨声速流动中的激波结构

Acta Polytechnica Pub Date : 2023-09-05 DOI: 10.14311/ap.2023.63.0268

Tomáš Radnic, Pavel Šafařík, Martin Luxa, David Šimurda

引用次数: 0